PB94-963701
EPA/ROD/R01-94/086
July 1994
EPA Superfund
Record of Decision:
Loring Air Force Base
(O.U. 6) Site, ME
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FINAL
()
OPERABLE UNIT 6 (OU 6)
RECORD OF DECISION
u
March 1994
The
Air force
Rebuilding Our
Environment
'",
Installation Restoration Program
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FINAL
Loring Air Force Base
OU 6 RECORD OF DECISION
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[,
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~on
OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
TABLE OF CONTENTS
Title
Page No.
DEClARATION FOR THE RECORD OF DECISION. . . . . . . . . . . . . . . . . I
DECISION SUMMARY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
,PART A
Al
A.2
A.3
A.4
AS
A6
A7
A8
'v
W0099319.080
RAILROAD MAINTENANCE SITE ............. A-I
SITE NAME, LOCATION, AND DESCRIPTIO~ .., A-I
SITE HISTORY AND ENFORCEMENT
AcnvrI1ES .......... '. . . . . . . . . . . . . . . . . . . . . A-3
A.2.1 LuID USE AND REsPONSE HISTORY. . . . . . A-3
A.2.2 ENFORCEMENT HISTORY. . . . . . . . . . . . . . . A-3
COMMUNITY P.ARTICIP ATION ............... A-5
SCOPE AND ROLE OF RESPONSE ACTION. . . . . A-6
SUMMARY OF SITE CHARACl'ERISTICS ... . . . . A-7
AS.! SURFACE Son..' . . . " . " . . . . . . . . . . . . . . . . . A:"7
AS.2 SUBSURFACE SOn. . . . . . . . . . . . . . . . . . .. A-lO
AS.3 GROUNDWATER. . . . . . . . . . . . . . . . . . . . A-lO
AS.4 M,IGRATION PATHWAYS. . . . . . . . . . . . . ., A-lO
SUMMARY OF SITE RISKS. . . . : . . . . . . . . . . . . . A-13
A6.1 HUMAN HEALTH RISK AssESSMENT.. . . . A-l3
A6.2 ECOLOGICAL RISK AsSESSMENT. . . . . . . . A-22
DEVELOPMENT AND SCREENING OF
ALTEFUNATTVES ..,. ...... ........ ........ A-27
A 7.1 STATUTORY REQUIREMENTS/RESPONSE
OBJECI1VES . . . . . . . . . . : . . . . . . . . . . . .. A-27
A.7.2 TECHNOLOGY AND ALTERNATIVE
DEVELOPMENT AND SCREENING. . . . . . . . A-27
DESCRIPTION OF ALTEFUNATIVES . . . . . . . . . . . ' A-32
ALTERNATIVE 1: No ACTION. . . . . . . . . . . . . . . . . A-32
ALTERNATIVE 2: EXCAVATION AND OFF-SITE
, DISPOSAL/TREATMENT. .. . . . . . . . . . . .. A-32
ALTERNATIVE 3: EXCAVATION AND USE AS
SUBGRADE MATERIAL FOR ON-BASE
LuIDFll.L COVER SYSTEM CONSTRUCTION A-33
1626-08
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Section
WOO99319.080
A9
AlO
All
OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
TABLE OF CONTENTS
( continued)
;~
Title
Page No.
SUMMARY OF 1HE COMPARATIVE ANALYSIS
OF ALTERNATIVES. . . . . . . . . . . . . . . . . . . . . .. A-34
A9.1 OVERALL PROTECI10N OF HUMAN HEALm
AND THE ENVIRONMENT. . . . . . . . . . . . " A-36
COMPLIANCE WITH APPLICABLE OR
RELEVANT AND ApPROPRIATE
REQUIREMENTS. . . . . . . . . . . . . . . . . . . .. A-36
LONG-TERM EFFECTIVENESS AND
PE~NCE ..... ..... ..... ....... A-36
REDUcnON OF MOBILITY, TOXICITY, OR
VOLUME THROUGH TREATMENT. . . . . . " A-37
A9.5 SHORT-TERM EFFECI'IVENESS .......... A-37
A9.6 IMPLEMENT ABILITY . . . . . . . . . . . . . . . . .. A-37
A9.7 COST. . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-37
A9.8 STATE ACCEPTANCE. . . . . . . . . . . . . . . . . A-38
A9.9 COMMUNITY ACCEPTANCE. . . . . . . . . . " A-38
TIiE SELECTED REMEDY. . . . . . . . . . . . . . . . . . A-39
AIO.I SOIL Cl.EANuP LEVELS. . . . . . . . . . . . . . . A-39
STATUTORY DETERMINATIONS............ A-40
AI1.1 THE SELEerED REMEDy IS PROTECI1VE OF
HUMAN HEALTH AND THE ENVIRONMENT A-40
A1l2 THE SELECTED REMEDY ATTAINS'
ARARs . . . . . . . . . . . . . . . . . . . . . . . . . . . A-40
A 11.3 THE SELECTED REMEDIAL ACTION IS
COST-EFFECTIVE. . . . . . . . . . . . . . . . . . .. A-42
AHA THE SELECTED REMEDY UTILIZES
PERMANENT SOLUTIONS AND ALTERNATIVE
TREATMENT OR RESOURCE RECOVERY
TECHNOLOGIES TO THE MAxIMuM ExTENT
PRACTICABLE. . . . . . . . . . . . . . . . . . . . .. A-42
AI1.S THE SELECTED REMEDY AND THE
PREFERENCE FOR TREATMENT WHICH
PERMANENTL Y AND SIGNIFICANTLY
A9.2
A9.3
A9.4
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SITE NAME, LOCATION, AND DESCRIPTION... B-1
SITE HISTORY AND ENFORCEMENT
ACTIVITIES. . . . . . . . . . . . . . . . . . 0 0 . . 0 0 0 0 .' 0 0 0 0 B-2,
Bo2.1 lAND USE AND REsPONSE HISTORY 0 . 0 0 0 0 B-2
B.2.2 ENFORCEMENT HISTORY. . . . . . 0 0 0 . 0 0 . .. B-3
COMMUNITY PARTICIPATION............... B-5
SCOPE AND ROLE OF NO ACTION REMEDY. .. B-6
SUMMARY OF SITE CHARACfERISTICS '0"'" B-7
B.5.1 EAST GATE WASTE STORAGE TANK SITE .. B-7
B.502 FuEL DROP SITES ................... B-ll
B.5.3 MIGRATION PATHWAYS. . . . . . . . . . . . . .. B-17
B.6 ' SUMMARY OF SITE RISKS. . . . . . . . . . . . . . . . .. B-20 ,
B.6.1 EAsT GATE WASTE STORAGE TANK ...0. B-20
B.6.2 FuEL DROP SITES ..... 0 . . . . . . . 0 . . . .. B-29
DESCRIPTION OF NO AcrION ALTERNATIVE
FOR EGWST AND FDS SITES. . . . 0 . . . . . . . . 0 .. B-47
DOCUMENTATION OF NO S'IGNIFICANT
CHANGES. . . . . . . 0 . . . . . . . . . . . . . . . . 0 . . . . . o. B-48
STATE ROLE. . . . . . . 0 . . . . . . . . . . 0 . . . . . . . . .. B-49
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Section
A12'
A13
PART B
B.l
B.2
B.3
B.4
B.5
B.7
B.8
B.9
OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
TABLE OF CONTENTS
( continued)
Title
Page No.
REDUCES THE TOXICITY, MOBILITY OR
VOLUME OF THE HAzARDoUS SUBSTANCES
AS A PRINCIPAL ELEMENT. . . . . 0 . . . . . .. A-43
DOCUMENTATION OF NO SIGNIFICANT
CHANGES' . 0 , . . . . . . . . . . . . . . . . . . . . . . . . . . . .. A-44
STATE ROLE. . . . . . . 0 . . . . . . . ..0' . . . . . . . . .. A-45
EAST GATE WASIE STORAGE TANK AND FUEL
DROP SITES. . . . 0 0 . . . . . . . . . . . . . 0 . . . . . . . . . .. B-1
GLOSSARY OF ACRONYMS AND ABBREVIATIONS
REFERENCES
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Section .
APPENDICES
APPENDIX A
APPENDIX B
APPENDIX C
WOO99319.080
OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
TABLE OF CONTENTS
( continued)
h)
Title
Page No.
TRANSCRIPT OF PUBUC MEETING (AUGUST 23, 1993)
AND COMMENT LETIERS FOR OU6 PROPOSED PLAN
RESPONSIVENESS SUMMARY .
LETTERS OF CONCURRENCE/NON-CONCURRENCE
IV
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OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
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LIST OF FIGURES
(,
.figure
Title
Page No.
A 1-1 Location of Sites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-2
AS-1 Distribution of Contaminants in Surface Soil at the RRMS . . . . . . . . . A-8
A5-2 Distribution of Contaminants in Subsurface Soils at the RRMS .... A-ll
B.5-1 Distribution of Contaminants in Sudace Soil - EGWST ........... B-9
B.5-2 Distribution of Cont:;lminants in Intermediate Soil (2'-15' BGS) -
EGWST ............................................. B-IO
B.5-3 Distribution of Cont~minaJ1ts in Soil at the FDS-S (Former) . . . . . .. B-13
B-5-4 Distribution of Contaminants in Soil at the FDS-S (Active) ....... B-14
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Table
A6-I
A6-2
A6-3
A7-I
All-l
B.6-I
B.6-2
B.6-3
B.6-4
B.6-5
B.6-6
B.6-7
B.6-8
B.6-9
W0099319.080
OU 6 RECORD OF DECISION
LORING AIR FORCE BASE
LIST OF TABU;S
w
Title
Page No.
Contaminants of Concern to Human Health - RRMS . . . . . .. A-l4
Risk Summaries - RRMS . . . . . . . . . . . . . . . . . . . . . . . . . . " A-IS
Contaminants of Concern to Ecological Receptors -
RRMS ............'............................. A-23
General Response and Potential Remedial
Technologies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. A-29
ARARs, Criteria, Advisories, and Guidance. . . . . . . . . . . . .. A-4l
Compounds of Potential Concern - EGWST ............. B-21
Risk Summaries - EGWST .......................... B-24
Contaminants of Concern to Human Health - FDS-Nl . . . . .. B-30
Contaminants of Concern to Human Health - FDS-N2 . . . . " B-31
Contaminants of Concern to Human Health -
FDS-South ...................................... B-32
Risk Summaries - FDS-Nl . . . . . . . . . . . . . . . . . . . . . . . . . " B-36
Risk Summaries - FDS-N2 . . . . . . . . . . . . . . . . . . . . . . . . . .. B-37
Risk Summaries - FDS-SA . . . . . . . . . . . . . . . . . . . . . . . . . " B-38
Risk Summaries - FDS-SF . . . . . . . . . . . . . . . . . . . . . . . . . .. B-39
"
7626-{)S
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DECLARATION FOR THE RECORD OF DECISION
{,1
SITE NAME AND LOCATION
..
Loring AFB (LAFB) Operable Unit (OU) 6. consists of the Railroad Maintenance
Site (RRMS), East Gate Waste Storage Tanks Site (EGWST), and Fuel Drop Sites
(FDS) North 1 and 2 (FDS-Nl and FDS-N2, respectively), South-Active (FDS-SA)
and South-Former (FDS-SF).
STATEMENT OF BAsIS AND PURPOSE
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,
and to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP); 40 CFR Part 300 et seq (1990). It is based on the
aclmini"trative record 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 Robert A Frost Memorial Library, 238 Main Street,
Limestone, Maine and the Office of Public Affairs at 42 CES/CEvR, 7300
Pennsylvania Road, Loring AFB, Maine. It presents the selected remedial action for
the RRMS at LAFB OU 6 that will provide excavation and off-base disposal or
treatment of contaminated soiL Through the remedial action at the RRMS, the U.S.
Air Force (USAF) plans to remedy the threat to human health and the environment
posed by cont~min3ted soil at the RRMS. This decision document also ?resents the
selected No Action decision for the EGWST,FDS-N1, FDS-N2, FDS-SA, and
FDS-SF. .
. .
The State of Maine Department of Environmental Protection (MEDEP) concurs with
the selected remedy for the R&.\1S and with the No Action remedy under CERCLA
for FDS-N1, FDS-N2, and FDS-SA In separate actions which are not part of this
Record of Decision (ROD), the Air Force is taking non-CERCLA remedial actions
at EGWST and FDS-SF pursuant to state requirements under an Air Force/State
Two-Party Supplement to the Federal Facility Agreement (FF A) being signed
simultaneously with this ROD.
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ASSESSMENT OF RRMS
Actual or threatened releases of hazardous substances from the RRMS, if not
addressed by implementing the response action selected in this ROD, may pose an
imminent and substantial endangerment to the environment.
r\
DESCRIPTION OF TIlE SELECI'ED REMEDY
For the RRMS, the key comp(:ments of the selected remedial action alternative are:
1)
2)
3)
mobilization and site preparation;
excavation of contaminated surface and/or subsurface soil;
disposal of excavated material in an off-base licensed landfill or
treatment facility;
4)
5)
restoration of the site; and
site review including confirmation sampling.
This remedy addresses the principle threats posed by the contamination found at the
RRMS.
For the EGWST, FDS-N1, FDS-N2, FDS-SA, and FDS-SF sites, the Air Force has
. determined that No Action under CERClA is necessary. The No Action alternatives
involve only monitoring of the sites to verify that no unacceptable exposures will
occur in the future. Under the No Action alternatives, no treament or cont~inment
of the sites will occur under CERCLA and no institutional controls will be required
pursuant to CERClA to restrict access to these sites.
STATUTORY DETERMINATIONS
The selected remedy for the RRMS is protective of human health and the
environment, complies with federal and state Applicable or Relevant and
Appropriate Requirements (ARARs) for this action, and is cost-effective. This
remedy utilizes permanent solutions and alternative treatment or resource recovery
technologies to the maximum extent practicable, and may satisfy the statutory
preference for rem~dies that employ treatment that reduces toxicity, mobility, or
volume as a principal element, depending on the method of treatment and/or
disposal chosen during the design phase.
InstalliIion Restoration Program
W0099319.080
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7:-:~ =:=cd :Jr cis'oosal or ====:::t or ct:: ~":c:::.va::d ~oils "Niil :e c=~:==:d cfu.--CT
.:..,., -,.,-o,.;;..i dec::~~ ...;..~<".:a ~-.. C'.a""-;r."";OIl ,uoi;~ -...;:.a- .;'0 -"'''''~-,.,-o..'''' O-ro
-- .. ....--.............. -...-. .J&....~'-'. .-- ---. ~ ...~ .."'----- ........ .._------~
r"'=-= r; ~ '-"('0)('-) -L.:'t "-A""Q,.;:~i ~C::~IlS :.., .N"'~"'''' -o~-g,"'- ...;..;".;" .....a;"'--~..."'.' --c:,o
---'....- \0 -- ."''''''''' .---......... ~ -'"'" .... L...- .....------ "'1....~ :,w"--"--"." .......
:~~:':':~$ :b.~ vciu..::=:. :O:C.C:~/, or =cbi.li.:-/ ::
-",",--""!-~--~.': ~c: -:- -"--co_-r ~.~.a....:.-- ~.,._.. ._~ ~~-
-\J'- "!._-- - ~ ~........ ~..u -..----- ~ t"J-
:::"'~"''''=ot:.S !~=s~~c~s.
. - "
Si:---:='::':'::I
=~i~::-:d
c.,.:e:- :,,::::~~31
;:Ol..:.:..;,:.:.:::.s :Jr
=Ot :.=./clving st.:.c=
-~",,!""-Q". .,
..-----...
:L.:~ :=::.::..:~s
rJ
3=~e -:..;~ ::==~: 'Niil ::ct :=-"'c:ul: :n ~~'7"''''cic~ su.=st:.=.c:s
:-=..sk-:::::sec. :~".'ei.s, :.:.~ 5.ve-~.e~ ::wrie..v tNill .:lot :;:ppi:, := .-.~
:=...~tT'._;
Cr:-:l~
above
~OI1.
..~ :=~ c::::-=.sicn fer )70 ...l...c=::::. ::::=~.:- C2~c-_~ :'::lS :~~:::. ==ac~ ::: :=.~ Ef~""''''S 1. ~
SS-~:~. SS-~:' P'DS-S.~ a=.d SS-SF £l!:s :;.: CL- 5. :::~ 5~..l:C:-/ :~~~~=e:::s
.~~ r-=-::; r~ j. ,-,....;,...- ~-:'~ :....... -.............;.,1 a.c:::or:s ..,.:a -ot ..,-,..;:c::=;a be"=",.::.a - ~~~_:''''<:''''';
JJ.. "'---"'---- - -\0.0.--,,",,- -.. .\-'... .------- - -- - -:"'~.... 60W --- --... 'J~-"'"
:=..'~:": l!"= =Ct ~:{c:~~ed at :t.~e sit::.s ~d :10 ="te-:.e=.: ::..r:~..fw. .,;,i1! :e ::::::~=-~,,~::..
DEC=-~~TION
T.c~ :=r:zoi~C' =-::;r:se::IS th~ sel:c::on of the :e:=-ii~ t ~-On ~ c::E:tc:..A :OI" ~~
RR~;(S by ct1~ USAF and tl::e U.s. E..-viromne:ttai P:'ot:c::cn Age~c::: (USEP_~)~
R...;-... .
~~c... 1.
It also :~:::rese~tS cl:e dete; ,:: ,.,~riOll by USAF :u:d U~..c..:' A :hat no re::-....;y::w r a.c::icn
is ae:::ssarl under CERC....~ at d1e EGWST~ FDS-:.'.fl. FDS~'l2. FDS-S~ and.
FDS-5r sit~- . .
By:
Conc-..:: aI:d ~c=e:1d. fer immediate imDle=:::::u:on:
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(ci,.l( QL' -
Alazl K. OIse:J.
Dir~c:cr
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Date: 1~ W~-
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Air F orc: B~e Conversion Age:lC"f
By:
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:oc=. P. DeVillars
~~~oI:cl Ari-;T'!i~~:or
CSC:PA Re~c!l r
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DECISION SUMMARY
This decision summary for the Operable Unit (OU) 6 sites at Loring AFB is
organized in the following manner to facilitate understanding the rationale for the
decisions made relative to each of the six sites which comprise OU 6. Part A
addresses the Railroad Maintenance Site (RRMS), and is further subdivided into 13
sections: Section AI, Site Name, Location, and Description; Section A2, Site History
and Enforcement Activities; Section A3, Community Participation; Section A4,
Scope and Role of Response Action; Section AS, Summary of Site Characteristics;
Section A6, Summary of Site Risks; Section A 7, Development and Screening of
Alternatives; Section A8, Description of Alternatives; Section A9, Summary of the
Comparative Analysis of Alternatives; Section AID, The Selected Remedy; Section
All, Statutory Determinations; Section A12, Documentation of No Significant
Changes; and Section A 13, State Role. .
r.>
\.~-:
Part B addresses the East Gate Waste Storage Tanks Site (EGWST) and the Fuel
Drop Sites (FDSs), and is subdivided into nine sections: Section B.I, Site Name,
Location, and Description; Section B.2, Site History and Enforcement Activities;
Section B.3, Community Participation; Section BA, Scope and Role of No Action
Remedy; Section B5, Sllmm~ry of Site Characteristics; Section B.6, Snmm~ry of Site
Risks; Section B.7, Description of No Action Alternative; Section B.B,
Doc1.imentation of No Significant Changes; and Section B.9, State Role. .
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PART A
{/.
PART A
RAILROAD MAINTENANCE SITE
'"'
A.l SITE NAME, .LOCATION, AND DESCRIPTION
Loring Air Force Base (lAFB) is a National Priorities List (NPL) site. There are
currently several areas of concern within LAFB that are under investigation. The
areas of concern at LAFB have been organized into 21 operable units (OUs) for
remediation purposes. This ROD relates to the Source Control Remedial Action for
OU 6, which js comprised of the following sites: the RRMS; the EGWST; and IDSs
North 1 and 2 (IDS-Nl and FDS-N2, respectively), South-Active (FDS-SA) and
South-Former (FDS-SF) (Figure AI-I). .
LAFB, in nonheastern 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 base is approximately three miles west of the United
States/Canadian border and cover.; approximately 9,000 acres. Base operations are
expected to gradually ded~ase until base closure in September 1994.
Because of its primary mission, l.AFB personnel are engaged in various operations,
a nQD1ber 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), LAFB has initiated
activities to identify, evaluate, and remediate former disposal or spill sites containinf
hazardous materials. .
Since initiation of the IRP, the base has been placed on the U. S. Environmental
Protection Agency's (USEP A) NPL of sites and will be remediated according to the
Federal Facility Agreement (FF A) entered into among USAF, the USEP A. and the
state of Maine Department of Environmental Protection (MEDEP).
Part A of the ROD relates to the RRMS. The RRMS is located in the southeastern
. comer of LAFB about 800 feet from th.e eastern bas~ boundary.
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-----------~------
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(i)
Caswell
0,'
Connor
LORING AIR FORCE BASE
Fuel Drop Site North 1
----
Fuel Drop Site South
Limestone
~Railroad
Maintenance
Site
Former
East Gate Waste Storage Tanks Site~ .
Caribou
-----
TOWN UNE
LORING AIR
FORCE BASE
FIGURE 1
LOCA TJON OF SITES
I
o
SCALE IN FEET
°
4000
I
8000
OU 6 ROD
LORING AIR FORCE BASE
UMESTONE. MAINE.
t306007D
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PART A
()
o SITE HISTORY AND ENFORCEMENT ACTIVITIES
"
lbis section summarizes the uses, response history, and enforcement activities at the
RRMS.
0.1 LAND USE AND RESPONSE HISTORY
A more detailed description of the RRMS history can be found in the Remedial
Investigation Report/Focused Feasibility Study (RI/FFS).
The RRMS area was used as a maintenance yard for railroad equipment. In 1984,
investigators conducting the preliminary assessment (P A) observed 19 drums stored
at the site. Some drums were empty, while others contained heavy oil and antifreeze
formerly used in maintenance operations at the site. According to verbal reports
from base personnel, the drums were placed on-site sometime during the early 1980s.
The drum contents were analyzed and properly disposed of by LAFB Civil
Engineering. Analytical results from the drum sampling could not be located (~M
Hill, 1984). Investigators also observed three areas of stained soil adjacent to a
shack in a small clearing. It appeared that these stained areas we're the result of
surface spills associated with railroad maintenance activities. Based on these
observations and the proximity to the base boundary, the site was identified as a
potential location where practices may have impacted the environment. The RRMS
was added to the IRP for funher investigation. In 1989, oil-stained soil was removed
from two areas as part of a removal action. Confirmation sample results indicated
that all the contaminated soil was not removed (ABB-ES, 1990).
0.2 ENFORCEMENT HISTORY
The enforcement history of au 6 is summarize as follows:
.
In 1984, a Preliminary Assessment (PA) was completed by CH2M Hill
detailing historical hazardous material usage and waste disposal
practices at LAFB.
.
Initial Site Investigation .(51) field work to determine if contaminants
were present at the au 6 sites was conducted in 1985 by RF. Weston,
Inc.
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PART A
r.:,
.
A Remedial Investigation (RI) process by ABB-ES commenced in 1988
and continued into 1993.
Q
.
LAFB was added to the NPL in February of 1990.
.
The Air Force entered into an FFA in 1991 with the USEPA and
MEDEP regarding the cleanup of environmental contamination at
LAFB.
.
A Focused Feasibility Study (FFS) was conducted in 1993 for the
RRMS, EGWST, and the FDS-SF to determine alternatives for
remediation of contamination based on information presented in the
RI.
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PART A
,",
~3 COMMUNITY PARTICIPATION
c
Throughout L~'s history, the community has been active and involved to a high
level in base activities. The Air Force and USEPA 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 bouses~ and Technical
Review Committee (TRC) meetings. Membership of the TRC is comprised of Air
Force, USEP A., MEDEP, and local officials 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.
On June 24, 1992, Air Force made the administrative record available for public
review at the Robert A Frost Memorial Library, 238 Main Street. Limestone, Maine
and at the Office of Public Affairs, 42 CES/CEVR, 7300 Pennsylvania Road, Loring
AFB, Maine. The Air Force published a notice and brief analysis of the Proposed
Plan in the Bangor Daily News and the Aroostook Republican on July 28, 1993, and'
made the plan available to the public at the Robert A Frost Memorial library.
LAFB held informational meetings on February 23, 1993 in Limestone, ~arch 24,'
1993, in Caribou, and April 28, 1993 in Fort Fairfield, Maine to discuss the results
of the RI and the clean-up alternatives presented in the FFS, and to present the Air
Force's Proposed Plan. Also during this meeting, the Air Force ansWered questions
from the public. From July 28 through August 27, 1993, the Air Force held a 3O-day
public comment period to accept public input on the alternatives presented in the
RI/FFS and the Proposed Plan and on any other documents previously released to
the public. On August 23, 1993, LAFB personnel and regulatory representatives held
a public meeting to discuss the Proposed Plan and to accept any oral comments. A
transcript of this meeting is included in Appendix A, and the commentS received
during the comment period and the Air Force's respo~e to these comments are
included in the Responsiveness Summary in Appendix B.
\)
Installation Restoration Program
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PART A
A.4 SCOPE AND ROLE OF RESPONSE ACTION
.'0,
The seleCted remedy for the RRMS is a source control action which provides for
excavation of contaminated soil and its disposal off-base at a licensed landfill or
treatment facility.
<;>
For the RRMS, the key components of the seleCted remedial action alternative are:
1)
2)
mobilization and site preparation;.
excavation of contaminated surface and/or subsurface soil;
3)
disposal of excavated material in an off-base licensed landfill or
treatment facility;
4)
5)
restoration of the site; and
site review including confirmation sampling.
The nature and distrIbution of contaminants in groundwater will be evaluated as part
of OU 12 investigations. The groundwater characterizations are incomplete at the
time of this ROD. Additional action will be taken if the groundwater investigation
indicates that action is required. :
This remedial action will rninirni7.e the environmental risks associated with exposure
to contaminated surface and subsurface soils at the site.
"
Installation Restoration Program
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PART A
A.5 SUMMARY OF SITE CHARAcrERISTICS
<>
Sections 6.0 of the RI/FFS contains an overview of the RI and field activities at au
6 through 1991, and Section 11.0 presents the results of a supplemental soil boring
and sampling program conducted in 1993 to address data gaps (ABB-ES, 1993b).
The significant findings of these investigation are summarized below.
The nature and distribution of contaminants in both surface and subsurface soils at
the RRM:S are described in the following subsections. Groundwater sampling results
are discussed briefly because they provide possible indicators of the impact that
contaminants detected in soil may have on groundwater quality. However, the nature
and distribution of contaminants in groundwater will be evaluated as part of OU 12
investigations. Surface water is not addressed because no surface water exists at the
site. Air cont~mination is not addressed because there is no evidence indicating that
air contamination exists at the site.
A.S.l SURFACE Son.
Investigations were conducted between 1985 and 1993 to characterize the nature and
extent of contamination at the site. These investigations included power auger
borings, excavation of test pits, installation of shallow overburden and bedrock
~onitoring wells, and field and laboratory analysis of soil and groundwater ~a.mples.
Laboratory samples were analyzed for Target Compound List (TCL) volatile organic
compounds (VOCs), semivolatile organic compounds (SVOCs), pesticides and
polychlorinated biphenyls (PCBs), and Target Analyte List (TAL) inorganic
compounds using Contract Laboratory Program (CLP) methodology. Some of these.
samples were also analyzed for total petroleum hydrocarbons (PHC).
Data gathered in 1988 indicated the presence of PHCs including polynuclear
aromatic hydrocarbons (PAHs) in soil. To address the soil contamination, a removal
action was implemented by the Air Force in 1989. During the removal action, soil
was excavated from two oil-stained areas. Approximately 375 cubic yards were
excavated from one area and 200 cubic yards were excavated from the other. The
detection of PHCs in confirmation samples indicated that not all contamination had
been removed.
Figure A.5-1 shows the distribution of contaminants in surface soil at the RRMS.
The primary contaminants identified in surface soil at RRMS are PHCs and
Installation Restoration Program
W0099319.080
7~
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G
~ .ITS.tOlO
\IOC NO
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-------
PART A
,)
carcinogenic and non-carcinogenic P AHs. PHC analyses detected the highest
concentrations in the area where the shack was located, in the area where
investigators had observed stained soil during the PA, and in the northern portion
of the site. The off-site laboratory detected PHCs in seven surface soil samples at
concentrations ranging from 28.5 mgjkg (J55-1063) to 10,000 mg/kg (ITB-1044).
P AHs were detected in. samples from across the site with the high~st detections
within 40 feet of the southern edge of the large 1989 excavation. The concentration
of P AHs in the majority of samples could not be quantified, since only one CLP
sample, J55-1041, had detections of PAHs that were above the Contract Required
Quantitation Limits (CRQLs) (non-carcinogenic PARs at 14.47 mg/kg and
carcinogenic P AHs at 82 mgjkg). These detections may represent contaminated soil
from the stained area that was not removed in 1989 and was spread over this area
by the track clearing operations that occurred after the removal action. Carcinogenic
and non-<:arcinogenic P AHs were detected in six other samples at concentrations that
were below the CRQI..s or that were estimated because of failure to meet all U5EP A
quality control guidelines.
Other organic compounds that were detected by off-site analyses include
pentachlorophenol, Endosulfan ll, and Aroc1or-1260: The pesticide Endosulfan n
'was qualitatively detected in one sample at an estimated concentration of
0.21 mgjkg. No LAFB background concentration has been established fot this
compound; however, the infrequent detection and low estimated concentration
indicate that it may be from pesticide applications. The PCB Aroclor-1260 was
qualitatively detected in two samples at estimated concentrations of 0.250 and
0260 mgjkg; the potential source of this compound is unknown. Pentachlorophenol
was qualitatively detected in one sample at an estimated concentration of
0.081 mgjkg, which is below the sample quantitation limit (5QL). Pentachlorophenol,
is a wood preservative and may have leached out of railroad ties~
The only inorganic compound detected above lAFB background was zinc. Zinc was
detected at 79 mgjkg which is very close to the maximum background concentration
of 74 mgjkg. If the zinc detected is related to past site activities, its low
concentration indicates that it could have come from a galvanized metal object that
was set on the grouqd and rusted (Le., a metal pail).
"
Installation Restoration Program
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PART A
A.S.2 SUBSURFACE SOIL
"
Figure AS-2 shows the distribution of contaminSll'1ts in subsurface soil at the RRMS.
The primary contaminants detected in off-site laboratory analyses in RRMS
subsurface soil are low concentrations of PHCs in the 4- to 6-foot sample from
JTB-1042 (25 mg/kg) at the former shack location and in the 2- to 4-foot sample
from rrB-1044 (66 mg/kg) southwest of the large area of soil removal, and a
detection in 1993 of fluoranthene, a non-carcinogenic PAH, in the 8- to 10-foot
sample from JTB-1080 (0.53 mg/kg) in the northern part of the site. These low
concentrations may represent limited downward migration of surface spills.
a.2 analyses also detected P AHs in two samples from the pre-1993 investigation at
concentrations below the CRQLs. In addition, two samples from 1993 at JTB-1080
also showed carbazole, an incomplete combustion by-product, and some other
previously undetected P AHs. No inorganics were detected at concentrations above
LAFB background ranges.
A.S.3 GROUNDWATER
One round of groundwater sampling was collected at the RRMS each year from 1988
through 1991. Contaminants were only detected sporadically and at low
concentrations. Fuel-related compounds (i.e., xylene) were detected in soil at the
site. The PHCs, 2-methylnaphthalene, and oil and grease detected in groundwater
may indicate that soil contaminSltion is impacting groundwater. The potential sources
of vinyl chloride and phenol, each detected in one sample, are unknown.
Groundwater will be evaluated in au 12.
A.S.4 MIGRATION PATHWAYS
The media into which chemicals migrate can affect the types of exposures that could
occur. Potential migration pathways at the RRMS are by wind (advection of
volatiles, or wind erosion of soil particles with adhering contaminants), leSlchine
through soils by water infiltration, and groundwater. Based on topographic relief at
the ~ite and the interpreted distribution of contaminants, minimal overland flow of
contamin~l1ts is anticipated. The detection concentrations of VOCs and !PHs in the
groundwater at the site, indicates that contaminants may have migrated from the
surface through the unsaturated zone and locally to the saturated zone.
~
Installation Restoration Program
W0099319.080
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"
" JT80'-
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-------
PART A
Contaminant migration in the vadose zone is limited by the. physical properties of the
bulk contaminants and the pore size available for migration. Further migration of
contaminants may occur as leaching and degradation of contaminants continues in
the dissolved phase. Rainfall and snowmelt will continue to infiltrate and percolate
through the soil at the site and provide the mechanism for the leaching of soluble
contaminants. .
A discussion of site characteristics can be found in the RI/FFS in Sections 6.0
and 11.0. .
Installation Restoration program
WOO99319.080
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PART A
A.6 SUMMARY OF SITE RISKS
<)
A Risk Assessment was performed to estimate the potential risks to human health
and the environment from exposure to contaminants associated with the RR..\1S. The
human health risk assessment followed a four step process: 1) contaminant.
identification, which identified those hazardous substances that, given the specifics
of the 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 magriitude 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 site are discussed below
followed by a discussion of the ecological risk assessment. As discussed below, the
human health risk assessment under all scenarios did not exceed USEP A's acceptable
risk of lxl~. However, the ecological risk assessment demonstr~ted that there was
an unacceptable risk. . '.
A.6.1 HUMAN HEALTH RISK AsSESSMENT
The contaminants of concern to human health identified for the RRMS, listed in
Table A6-1, were selected for evaluation in the risk assessment and include 33
surface soil and 11 subsurface soil contaminants of concern. These contaminants
constitute a representative subset of the contamimmts identified at the site during the
RI. The contamin,ants of concern 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
contamimmts of concern can be found in Subsection 82.3, Tables 8-6 and 8-7, of the
RI/FFS (ABB-ES, 1993b).
Human health risks associated with exposure to the contaminants of concern were
quantitatively evaluated under both current (groundskeeper and child trespasser) and
future (residential and consttuction worker) land-use scenarios. Several hypothetical
exposure pathways were developed to reflect the potential for exposure to 'surface
and subsurface soils. The following is a brief summary of the exposure pathways
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TABLE A.6-1
CONTAMINANTS OF CONCERN TO HUMAN HEALTII
RAILROAD MAINTENANCE SITE
; COMPOUND
I Surface Soil
I .
I
june
!4.4'-DDD
.4.4'-DDE
i 4.4'-DDT
I
I Aroclor-l260
I Endosulfan II
12-McthyiDlpbtbalenc
, Al:cUpbtbcae
AccDaphtbylale
Anthracene
Beazo( a)aDtIuaceBe
8cDm(a)pyleDe
IJeazio(b )OUOI8IIthefte
BcIIza(8Ja.i)peryIcac
I Beam(It)Ouonuliheue
'leDZDic: acid
utylbeuzyiphchalale
. I OIryseae
i Di-n-butylpbtbalalc
i Di-n-octyIpbtbalare
I Dj~ a.h )anthracene
I Dibcnzo(uran
I Dietbylphtbalate
I Auoranthenc
j Auorcne
IIDdeno(l.2.3-c.d)pyrene
I Napbthalenc
Pentachlorophenol
; Phenanthrenc
i Pyrcnc
: Bis(2-ethylhayl)pbthala1e
I Tow Carcinogenic PAHs
Totals P AHs without RIDs
22-Oc:t-93 \TabA.6-1
au 6 ROD
LORING AIR FORCE BASE
I
i . RANGE OF
I 801.888 '
I
I
I
I
,
..
i Q.OO44 - 0.022
! 0.0044 - 0.022 I
i 0.0074 - 0.022 I
! 0.004 - 0.22 I
I 0.0044 - 0.022 i
; Q.38 - 1.941
I 038 - 1.941
I Q.38 - 1.941
038 - 1.941
I Q.38 - 1.941
Q.38 - 1.941
i 038 - 1.941
! 038 - 1.941
I o.J8 - 1.941
i 2.1 - 9.412
. Q.J8 - 0.51
I 038 - 1.941
! 038 - 0.51
; Q.J8 - 0.51
! 0.38 - 1.941
. Q.38 - 1,941
i Q.J8 - 0.51
0.38 - 1.868
0.38 - 1.941
038 - 1.941
0.38 - 1.941
2 - 9.412
0.38 - 1.941
0.38 - 1.941
, 0.38 - 0.51
:
FREQUENCY
OF
DET£cnON
515
1/11
1/U
4111
7/11
1/11
1/16
1/16
2116
7/16
3/16
2116
6(16
1/16
2113
3/11
2/16
4116
4116
7/16
1/16
1/16
3/16
7/16
1/16
2/16
1/16
1/16
3/16
5/16
3/16
MAXIMUM.
DE"JEC'JED .
CONCENTRAi10N
i
i
I
I
I'
I
i
I
79
0.022
9.038
0.062
0.26
0.021
0.15
~
0.15
G.26
1.1
1.1
3.1
0.72
0.11
Q.29
Q.94
22
0.63
0.77
0.15
0.27
D.82
4.3
0.4
0.82
Q.23
0.081
4
3.8
4.5
8.58
13.83
.,
I
A-14
MINIMUM i
, DETECTED i
CONCEN"DtAi10N i
!
i BACKGROUND ;
MEAN j RANGE
I'
!
19.3
0.022
0.038
0.019
0.2S
0.021
0.15
G.23
0.14
0.16
0.079
Q.9
0.086
Q.68
Q.06
Q.069
Q.88
o.m7
0.062
0.7
0.15
Q.27
0.17
0.11
0.4
0.75
Q.23
0.081
0.084
0.1
0.083
62.9 ' 45-74
0.00822 . <0.0076 - 0.47
0.00922: <0.0076 - 0.14
0.0171 ,<0.0076 - 0.94
0.107 ' NA
0.00817. NA
0.16 ; NA
0.165 i NA
0.131 i NA
0.139 ! NA
G.236 i NA
Q.238! NA
0.464 , NA
0.2011 NA
0.1041 . NA
.! NA
=1 ~~
0.247 : NA
0.3 ; NA
0.16 i NA
0.168 NA
Q.29 ! NA
0.537 ; NA
0.176; NA
0.211 : NA
0.165 : NA
NA
NA
NA
NA
NA
NA
0.389 .
0.484
0.737
1.76 :
-------
continued
TABLE A.6-1
CONTAMINANTS OF CONCERN TO HUMAN HEALTH
RAn.ROAD MAINTENANCE SITE
()
OU 6 ROD
LORING AIR FORCE BASE
, MAXIMUM. MINIMUM
i RANGEOF FREQUENCY. DE1ECIED DE"IECIED BACKGROUND
I SOLa... .'OF CONCENlRA110N. CONCENTltA110N MEAN RANGE
r
COMPOUND i DETECI10N
! Subsvf_.Soil I
I
I BUl)'lbenzylphtliala1c I
0.363 - Q.388 2/6 0.22 0.21 0.1961 . NA
iCuyscDe I Q.363 - Q.388 ]/6 0.084 0.084 0_04531 NA
i Di-D-butyiphthaJaac 0.363 - Q.388 2/6 0.11 0.1 0.159, NA
I Di-n-oc:tyIphthaiate 0.363 - Q.388 2/6 0.25 0.23 0.204 ' NA
,
I Dietbylphthalate 0.363 - Q.388 2/6 0.13 0.11 0.164/ NA
F1uorantheoe Q.363 - Q.388 2/6 0.14 0.06 0.0333 NA
Pheoanthreoe Q.363 - Q.388 1/6 0.044 0.044 0.0386 NA
Pyreoe 0.363 - Q.388 2/6 0.1 0.053 0.0255 NA
Bis(2 -ethyUay1)phthalale 0.363 - Q.371 4/6 1.2 0.076 0.474 NA
Total Can:ioogeoic P AHs 0.a!4 0.0453 NA
Totals PAIls without RIDs 0.368 0.1427 NA
NOTES: .
See Scctioo 27.1 of IUIFFS for discussion.
Raoge of Sample Quantiwion Limi&s for parame&eIS reponed as .nOt detected. io a sample.
NA = No backgrouod daIa av.Wa:;1e.
22-Oct-93 \TabA6-1
-------
PART A
evaluated. A more thorougb description can be found in Subsection 8.2 of the
RI/FFS (ABB-ES, 1993b).
Current exposure scenarios include occupational land use (adult-grounds keeper) and
recreational land use (child-trespasser). Future scenarios include adult and child
resident and occupational adult (i.e., construction worker for subsurface soils). Soil
exposure includes incidental ingestion, dermal absorption, and inhalation of
particulates for both current and future land use scenarios. Exposure to groundwater
was not considered as an exposure pathway, because groundwater will be considered
in a separate operable unit. The pOtential future land use by a farm family (referred
to as tbe resident farmer scenario) was considered and eliminated from further
evaluation based on soil limitations not due to contamination that make soils
generally unsuitable for cultivated crops, pasture, or hayland (e.g., surface stornness)
(USDA-SCS, 1986).
Different exposure levels were evaluated for the exposure pathways in the risk
assessment. The parameters and assumptions used to determine the exposure levels
for each pathway are described in Tables A through J in Appendix J of the RIfFFS.
(ABB-ES, 1993b). For dermal contact and ingestion of soils in the residential
scenario, a child was evaluated based on the assumed exposure of 182 days per year
(it is assumed that the soil is frozen or snow-covered 26 weeks of the year) for six
years, with 24 years for an adult (USEPA, 1991a). For the current grounds keeper
scenario, dermal contact and ingestion of soils was based on an assumed exposure
of 26 days per year (1 day per week for 26 weeks) for 25 years (USEPA, 1991a). For
tbe future construction worker, dermal contact and ingestion exposure \v,as assumed
to be for 130 days per year for 1 year. For the residential inhalation pathway, an
exposure time of 16.' hours per day waS assumed for a period of 70 years for both the
child and adult (USEPA, 1991a). This exposure time was utilized in all au 6 RI
calculations for residential scenarios. For the groundskeeper, the inhalation exposure
was assumed to be 8 hours per day, 26 days per year, and for the construction
worker, the inhalation exposure was assumed to be 8 hours per day, 130 days per
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 concentra~ion detected in that particular medium.
Excess lifetime cancer risks were determined for each exposure pathway by
multiplying the exposure level with the chemical-specific cancer potency factor.
Cancer potency factors have been, developed by USEP A from epidemiological or
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PART A
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., 1 x 10-6 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 USEP A 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 (HQ) is calculated
by dividing the exposure level by the reference dose (RID) or other suitable
benchmark 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 anima J studies and incorporate uncertainty factors to help ensure
that adverse health effects will not occur. The HQ is often expressed as a single.
value (e.g., 0.3) indicating the ratio of the stated exposure 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 and
the sum is referred to as the hazard index (In). The. target risk level for
noncarcinogenic effects is an In of 1.0 (USEP A, 1989b). If the ratio is less than 1.0,
no adverse health e,ffect is anticipated. If t~e ratio exceeds 1.0, there may be a
concern for potential noncancer effects. (For example: the hazard quotient for a
compound known to produce liver damage should not be added to a second whose
toxic endpoint is kidney damage). .
Table A6-2 depicts the risk sUIIUi:Iary for the contaminants of concern to human
health in surface soil evaluated to reflect present and potential future incidental
ingestion, dermal contact, and inhalation exposure pathways corresponding to the
aveJ:age and the RME scenarios.
Quantitative estimates of both carcinogenic and non-carcinogenic risks were
calculated for each contaminant of concern identified and each complete exposure
scenario selected for evaluation in the exposure assessment. The equations for
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TABLE A.6-2
RISK SUMMARIES
RAILROAD MAINTENANCE SITE
.,)
OU 6 ROD
LORING AIR FORCE BASE
u
I
i
I
i
I CURRENr.USE
i
lacideDlallagestioD of Surface Soil: GroWlClskeeper
Dermal CoalaCt wilh Swfac:c Soil: GroUDdsk.ccpcr
Ittltalation &p05W'C to PaniculatC$: Grolllldskeeper
TOTAL: GroUDdsk.ccpcr
lacidcnlal Ingestion of Soufacc Soil: Older Child EzpIorinS
Dcrmal Coatact With Souface Soil: Older Child EzpIoriDg
TOTAL: Older Child
i
I
I PUItJRE.US£
I
IDCidCDIaI IDption of Surface Soil: Residential Adult
Dermal CoDtact with Surlace Soil: ResidcDtial Adult
Inhalation l2posurc 10 Paniculates: Residential Adult
TOTAL: RcsidcDtial Adult
lIII:ideallllllSCSIioD or Surface Soil: Residealial CbiId
Dermal Contact with Sunac:e Soil: RcsideAtial Child
IDltalation Exposure to Particulates: ResiI;Icntial Child
TOTAL: Residential Child
I
I'
lacidCDlalingeslion of Soufacc Soil Construction W orter
I>crtml CoDlaCtwith Surface Soil: CoIISuuction Worker I
Inhalation EzposW'C to Poniculates: CoIIStructioa Worker I
TOTAL: CoDSU1lClion Worker
I
IDption of Grouttdwatcr. Residential Adult (Summers Model) - Nonh Area
Dermal contact with groUDdwatcr. Residential Adult
TOTAL: RcsidcDtialAduit
IDption of GroUDdwater. Residential Adult (Summers Modcl) - South Area
Dermal contact with groUDdwatcr. Residential Adull
TOTAL: RcsidcDtial Adull
3E-06 0.0004 2E-05
SE-06 0.0004 2E-05
~ NA 9E-08
SE-06 o.oooa 4E-05
7E-06 0.D04 4E-05
IE-OS 0.D04 5E-05
3E-08 NA lE-07
1£-GS 0.Dtr1 9E-05
IE-OS O.()()OO) 2E-08
4E-09 O.ooom 7E-09
6E-ll NA I lE-10
1£-08 0.0001 3E-08
i 9E-06
I lE-05
I ZE-GS
I 3E-05
4E-05
I 7E-GS
I AVERAGE
Total Cancer Total Hazard
FUsk Index
I
j
:!E -07
8E-07
~
lE-06
3E-07
~
1£-G6
0.00003 I
O.()()()OO
NA I
OJlOOO9 - j
I
i
I
I
O.()()OO)
0,0003
O.DOOf
I' Total C~al Hazard
! RJsk . Index
lE-06
4E-06
2E-08
SE-06
0.00007
0.0002
:-:A
0.0003
lE-06
7E-06
8E-06
0.0002
'G.CO!
0.001
0.001
0.002
SA :
0.003 :
0.01
0.01
NA I
0..112
0.000:
o.oooos ;
~'
0.0003
0.006
0.0014
G.OO8
0.02
0.007
0.03
NOTES:
SA - Taacity dala nOI available to evahDtC risks
22-OcI-93 \TabA.6-2
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PART A
calculating chemical-specific and pathway-specific cancer risks and hazard quotients
are presented in Appendix J, Section 2.0, of the RI/FFS (ABB-ES, 1993b). The
quantitative risk estimate tables for the R&\1S are presented in Tables 1 through 20
in Appendix J of the RI Report.
"
Surface Soils
The highest cancer risk associated with exposure to surface soils under current land
use is for the recreational (older child/trespassing) exposure with a cancer risk =
2xlcrs for the average exposure scenario and a cancer risk = 8xlO-
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PART A
"
The concentrations of contaminants potentially leached from the soil were derived
using the Summers Model (Appendix L of the RI/FFS). These concentrations were
used to evaluate potential risks from chemicals that do not have a groundwater
standard. Evaluation of the future groundwater ingestion scenario using the modeled
concentrations yields an excess cancer risk of 7xlO-5 in the southern area of the site.
This value exceeds the MEDEP target cancer risk level and is below the USEPA's
limit. The compounds detected in surface soils (primarily P AHs) evaluated in the '
Summers Model were not detecte,d in the groundwater at this site. P AHs tend to
sorb to soil particles and are not readily leached to groundwater, thus, the risk
associated with the modeled values may be overestiinated. The existing groundwater
quality'data is not conclusive because groundwater investigations are ongoing as part
of au 12 If data gathered during that investigation change the interpretation of the
site conditions, the need for additional work at the site will be evaluated and work
performed if necessary.
The non-carcinogenic HIs associated with exposure under all scenarios ~ere well
below 1.0. The greatest systemic hazards calculated for the site were predicted for
the future residential child (Ill = 0.02) using maximum soil concentrations and the
hazard associated with adult residential ingestion of groundwater based on Summers
, modeled potential groundwater concentrations (Ill = 0.03). These HIs indicate
minimal non-carcinogenic hazards to human health from site soils. '
Subsurface Soils
The risks associated with exposure to subsurface soils for a potential future resident
were not quantitatively evaluated based on the assumption that the majority of '
residential exposure to soils would occur in the interval from. 0 to 2 feet bgs.,
However, a qualitative evaluation was performed by comparing risk estimates
calculated for surface soils with conditions in subsurface soils. A data review
indicates that fewer chemicals were detected in subsurface soils (31 cont::lminants of
concern in surface soils; nine cont::lmimmts of concern in subsurface soils), and those
chemicals that were detected in the subsurface soils were at lower concentrations
than in surface soils (all the maximum detects were less than or equal to 33 percent
of the surface concentrations and some were as much as two orders of magnitude less
than surface concentrations).
The estimated adult residential cancer risk for the average exposure scenario
(average being more representative of actual risks) from dermal exposure, incidental
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ingestion, and inhalation of particulates from surface soils was 8xl~, and the
estimated child residential cancer risk for the average exposure scenario was 2x1D-5.
Bas~d on the fact that exposures to subsurface soils would be expected to be less
than exposures to surface soils and risks from exposure to surface soils are below
MEDEP's target risk level of 1xIO.5 for adults (and slightly greater than MEDEP's
target risk level for children), it is unlikely that adverse health effeCts would be
expected from potential future residential exposures to subsurface soils.
'"
The risk to a potential future consttuction worker was evaluated using an excavation
scenario. The total cancer risks associated with dermal, ingestion, and inhalation
exposure to subsmface soils were 2xIo-& for an average exposure scenario and 3xlO-8
for the RME scenario. These cancer risks are below both USEP A and MEDEP
target risk levels.
The non-carcinogenic HIs associated with consttuction worker exposure to subsurface
soils are well below 1.0, indicating minimal non-carcinogenic hazards to human
health.
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). 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 uncertainties inherent in the risk assessment methodology
that might lead to an underestimation of true risks, most assumptions will bias an
evaluation in the direction of overestimation of risk.
The possibility for underestimation of true risks is caused by the exclusion from
quantitative evaluation of several pathways (Le., residential exposures to potentially
excavated subsurface soils spread aboveground . and ingestion of homegrown produce
from backyard garden plots). Under cenain circumstances, these pathways may be
significant and, therefore, may be quantitatively evaluated in those cases. As
mentioned, the subsurface soils at the RRMS are less contaminated than surface
soils, and therefore quantitative evaluation of residential risks from exposure. to
subsUrface soils would be less than that evaluated for exposure to surface soils. The
possibility for a backyard garden plot is considered slight at sites that are less than
I acre. The RRMS is less than one-half acre.
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As stated, the RI Report does not evaluate the risks associated with exposures to
groundwater at the RRMS other than the evaluation of the leaching potential for
contaminants in soils using the Summers Model. Groundwater at the site will be
evaluated as a separate operable unit. 'This could cause underestimation of tOtal risk
from the site if the risk from groundwater proves significant. Should this occur.
reevaluation of total site risks would be warranted.
Because benzo( a)pyrene and naphthalene are the most toxic representatives of
carcinogenic and non-carcinogenic PAHs. respectively, the use of their toxicity values
to estimate the adverse effects of eXposure toPAHs lacking specific 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 only the "hot spots"); the estimation of exposure concentrations by the use
of maximum detections (while assnming no degradation, dilution, and so forth); the
use of the 95 percent (or upper-bound 90 percent) exposure parameter values such
as contact rate and exposure frequency and duration; and 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 USEP A Risk Assessment Guidance states that the
carcinogenic risk estimate will generally be an upper-bound estimate, and that
USEP A is reasonably confident that the 'true risk' will not exceed the risk estimate
derived through use of this model and is likely to be less than predicted (USEP A,
1989b). Therefore, the true risk is likely not much more than the estimated risk, but
it could very well be considerably lower, even approaching zero.
A.6.2 ECOLOGICAL RISK AsSESSMENT
, .
The cont~mimmts of concern to ecological receptors identified for the RRMS, listed
in Table A6-3, were selected for evaluation in the risk assessment and include 29
surface soil contamin~nts ofconcem. These contaminants constitute a representative
subset of the contaminants identified at the site during the RI. The contaminants of
concern were selected to represent potential site-related hazards based on toxicity,
concentration, frequency of detection, and mobility and persistence in the
environment. A snmmary of the health effects of each of the cont.aminants of concern
. can .be found in the Final RI/FFS (ABB-ES, 1993b).' .
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TABLE A6-3
CONTAMINANTS OF CONCERN TO ECOLOGICAL RECEPTORS
RAILROAD MAINTENANCE SITE
ou 6 ROD
LORING AIR FORCE BASE
! MAXIMUM.
I FREQUENCY OETECTED. BACKGROUND
I AVERAGE OF CONCENTRATION MAXIMUM
: COMPOUND lmgltg) OETEC'I10N (mgltg) (mgltg)
i !
:2 - Methylnaph thaJene 0.150 [a) 1/15 0.150 NA !
I' !
Acenaphthene 0.165 1/15 0.230 I NA
Ace naphthylene 0.131 2/15 0.150 i NA
I
Anthracene 0.139 2/15 0.260 I NA :
Benzo(a)anthraccne 0.236 4/15 1.100 NA i
Benzo( a )pyrcne 0.238 3/15 1.100 NA I
Benzo(b )f1uorantbenc 0.464 7/15 3.100 [b] I NA '
Benzo(g,bJ)pcrylene 0.201 3/15 0.720 I NA
Benzo(k)fluorantbene 0.104 6/15 3.100 [bJ NA ;
, ,
Benzoic acid ! 0.290 [a] 3/10 0.290 NA i
Cbrysene 0.353 5/15 2.200 ' NA !
i
Di - n - butylphthaJatc I 0.247 4/15 0.630 NA
Di - n - octylphtbaJatc 0.300 2/15 0.770 NA ;
i
Dibenz( a.b )antbracene I 0.150 [a] 1/15 0.150 NA I
Dibenzofuran I 0.168 1/15 0.270 NA i
DiethylphtbaJatc I 0.290 3/15 0.820 NA
I
Fluoranthene I 0~37 8/15 4.300 .NA
Fluorene ! 0.176 1/15 0.400 NA
I ndeno( 1.2.3-c.d)pyrcne 0.211 3/15 0.820 NA
Naphthalene I 0.165 3/15 0.230 NA I
Pentacbloropbenol i 0.081 [a] 1/15 0.081 NA
Phenantbrene f 0.389 4/15 4.000 NA I
Pyrene : 0.484 6/15 3.800 NA
4.4'-000 0.008 1/11 0.022 NA
4.4'-DOE 0.009 1/11 0.038 NA
4.4'-DDT 0.017 4/11 I 0.062 NA
Endosulfan II 0.008 1/11 0.021 NA I
ArocJor-1260 0.107 2/11 0.260 NA I
Zinc 63 5/5 I 79 74
NOlES:
[a] When calculated average exceeded maximum value, maximum was used.
[b) Benzo(b)fluoranthene and benzo(ld1uoranthene values were not speciated by the lab. Repooned as. summed lotal.
NA = no background data available. .
22-0ct-93 \Table 8-10
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PART A
"
The ecological risk assessment selected five terrestrial wildlife indicator species to
represent exposure for terrestrial organisms through ingestion of food and soil:
.
short-tailed shrew (Blarina brevicauda), small mammal, carnivore
American woodcock (Scolopax minor), small bird, omnivore
garter snake (Thamnophis s. sirta/is), reptile, carnivore
fisher (Manes pennanti) predatory mammal, carnivore
broad-winged hawk (Buteo plalypterus), predatory bird, carnivore
.
.
.
.
Use of these species in estimating risk is conseIVative because the species are
predominantly carnivorous, and therefore prone to exposure. to chemicals through the
food chain. Organisms with small home ranges, such as the shrew and garter snake,
and/ or that ingest a high proportion of earthworms and other. terrestrial
invenebrates, are particularly susceptible to food chain exposures.
These indicator species were chosen for the following reasons: (1) the species are all
potential ecological receptors at the RRMS; (2) the various feeding habits (e.g.,
omnivore, carnivore) are representative of those typical of the terrestrial ecological
community; and (3) these species were recommended for a conservative evaluation
of ecological risk by USEPA and U.S. Fish and Wildlife SeIVice (USFWS) (USEPA,
1991c). The fisher, a wide-ranging and wary animal, may occur at the RRMS
because the site is relatively undisturbed and isolated from human activity. It is
ass:wned that each of the indicator species chosen is the most sensitive representative
of other species at a similar trophic position occurring at the RRMS. Modeling of
chemical exposures for rare, threatened or endangered species was not performed
as no such species have been identified at LAFB (see Subsection 8.3.2 of the RI
Report [ABB-ES, 1993b]). .. ,
The HIs for the RRMS range from a low of 0.00081 (chronic exposure for the fisher)
to a high of 99 (chronic exposure for shrews). Based on the HIs, indicator species
may be adversely affected by chemicals in surface soils at the RRMS. Adverse
effects related to short-term exposures to the surface soils are predicted for all
indicator species at.the RRMS. Adverse effects related to'long-term exposures are
po~sible for small mammals, small birds, and reptiles.
Benzo(a)pyrene is the greatest contributor to potential risks associated with acute
exposures at the RRMS, based on the results of food-web modeling. Benzo{a)pyrene
is also the major contributor to risks associated with chronic exposures at the RRMS.
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This is due in pan to the conservativism used in selecting the lowest Reference
Toxicity Value (RlV) identified in the literature for benzo(a)pyrene. The chronic
R1V for benzo(a)pyrene (0.002 mg/kgBW-day) was chosen because it results in the
most conservative estimation of risk. The HQs for indicator species for
benzo( a)pyrene in the chronic scenario are therefore higher than for any other
chemical of potential concern (e.g., chronic HQ = 80 for shrew for RRMS, while the
next elosest HQ is that for dibenz(a,h)anthracene, HQ = 17). In the chronic
exposure scenario, only two contaminants of concern have a HQ higher than 1 for
any of the five indicator species. The benzo( a)pyrene HQ exceeds 1 only for the
shrew (HQ = 80) and the woodcock (HQ = 12)~ The dibenz(a,h)anthracene
chronic scenario HQ exceeds 1 only for the shrew (HQ = 17). .
The acute RlVs for benzo(a)pyrene and dibenz(a,h)anthracene were derived by
multiplying the very conservative chronic R1V by a factor of 10 because there are
no data available for effects related to acute exposures. The acute R1V should not
be interpreted as a lethal dose, but as a possible (although unlikely) sublethal effects
dose level.
Adverse effects associated with acute exposure are probable for the shrew and the
woodcock, and possible for the snake, the fisher, and the hawk. Three CODtamin~nts
of concern have an HQ higher than 1.0 for any of the five indicator species. The
benzo(a)pyrene HQ exceeds 1.0 for the shrew (HQ = 87), the woodcock (HQ = 50),
the snake (HQ = 4.3), the fisher (HQ = 1.1), and the hawk (HQ = 2.3). The
dibenz(a,h)anthracene acute scenario HQ exceeds 1.0 only for the shrew (HQ = 4.0),
and the woodcock (HQ = 2.3). Aroelor-I260 contributes to risk associated with
acute exposures predicted for the fisher (HQ = 2.9) at the RRMS.
Using the relative ranking scheme described above, HIs indicate that effects to
individuals are probable although they do not necessarily provide an indication of
population effects. In cenain cases, acute and chronic effects to individuals may
occur with little effect on population growth, stability or structure.
Despite the conservative nature of the benzo(a)pyrene RlV, adverse effects are
predicted with significant hazard indices for short-term exposures to all indicator
species, and an ~acceptable risk is predicted for some species from other
contaminants of concern. Unacceptable risk is also predicted through long-term
exposures to a number of the indicator species. Because little is known about the
additive effects of the contaminants on the indicator species, the multiple
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PART A
contaminants producing Ins greater than 1.0, the prediction of adverse effects on
many of the indicator species through either exposure scenario, and the habitat
present at the site creating an exposure pathway, actual or threatened releases of
hazardous substances at this site, if not addressed by implementing the response
action in this ROD, may present an imminent and substantial endangerment to the
environmenL
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PART A
A. 7 DEVELOPMENT AND SCREENING OF ALTERNATIVES
A.7.1 STATUTORY REQUIREMENTS/REsPONSE OBJECl'lVES
Under its legal authority, the Air Force's primary responsibility at this NPL site is to
undenake remedial actions that are protective of human health and the environment.
Section 121 of CERCLA establishes several other statutory requirements and
preferences, including: a requirement that the Air Force's remedial action, when
complete, must comply with all federal and more stringent state environmental
standards, require~ents, criteria or limitations, unless a waiver is invoked;' a
requirement that the Air Force 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 pennanently 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. These remedial
action objectives were developed to mitigate existing and future potential threats to
public health and the environment. For the RRMS, these response objectives were:
.
Reduce human health risk associated with carcinogenic P AH-contam;nated
surface soil.
.
Reduce the ecological risk associated with the contaminated surface soil.
Based on these objectives and the results of the Rl, the estimated volume of soil
requiring remedial action at this site is 200 cubic yards (cy).
A. 7.2 TECHNOLOGY AND ALTERNATIVE DEVEWPMENT AND SCREENING
CERClA and the NCP set forth the pro~ by which remedial actions are evaluated
and selected. In accordance with these requirements, a range of alternatives were
developed for the site.
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PART A
With respect to source control, the RI/FFS 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
minimizing 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.
The RI/FFS screened technologies based on implementability, effectiveness, and
cost~ These technologies were combined into remedial action alternatives.
Subsection 13.4 of the RI/FFS presents the remedial alternatives developed by
combining the technologies identified in the previous. screening process in the
categories identified in Section 300.430(e) (3) of the NCP. The purpose of the initial
screening was to narrow the number of potential remedial actions for further detailed
analysis while preserving a range of options. Each alternative was then, evaluated, '
and screened according to its implementability, effectiveness, and cost.
In snmmary, two of the remedial alternatives screened in Subsection 132 of.. the
RIjFFS were retained for detailed analysis. Table A7-1 identifies the seven general
response alternatives that were retained through the screening process, including
those that were eliminated from further consideration. 'In addition, a true No Action
Alternative (Le., involves no remedial actions and includes no costs) was developed
and included as part of the d~tailed evaluation.
In-situ bioremediation' and land treatment technologies will not be effective in
remediating the soil to sufficient levels to meet risk requirements, and therefore,
were eliminated. Administrative actions, monitoring, and passive remediation were
also eliminated because they would not meet objectives for remediation. The
containment option was eliminated because it would not' reduce the toxicity or
volume of the contaminants. Soil flushing was eliminated, during screening because
of the risk of spreading contamination to clean soils. High and low temperature
thermal treatment ,were eliminated because of the higher cost associated with the
same benefit. "
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TABLE A.7-1
GENERAL RESPONSE ACTIONS AND POTENTIAL REMEDIAL TECHNOLOGIES
RAI~OAD MAINTENANCE SITE
au 6 ROD
loRING AIR FORCE BASE
.
: . GENERAL:RESPONSE
. AcnON:. .. .PROCESS/TECHNOLOGY DESCRIPTION
No Action None No action
Prevent Exposl:.lre Deed restrictions . Prevent physical access to contaminated
Fencing/signs soil and use of groundwater.
Monitoring Sampling, analysis. and Monitor concentrations of soil
evaluation contaminants.
Monitor groundwater wells downgradient
of the area.
Containment Cover System Construct a cover system (consisting of
low permeability layers and drainage
layers) over the site.
Passive Remediation Relies on natural degradation Monitor concentrations of soil
process. contaminants.
Monitor groundwater wells downgradient
of the area.
In situ Remediation In situ Bioremediation Inject nutrients' into soil to encourage
development of a microbial population
that degrades the contaminants.
Soil Flushing (Leaching) Flush a water/surfactant mixture through
the soil to collect or react with the
contaminant. and remove the leachate at
or near the water table using recovery
wells.
Removal and Low Temperature Thermal Excavate soil and place in a low
Treatment Treatment temperature stripper which volatilizes the
contaminants. but does not combust the
soil matrix. May use off-site facility or a
mobile unit.
High Temperature Thermal Excavate soil and place in a high
Treatment (Incineration) temperature incinerator, such as an
asphalt plant, rotating kiln. or fluidized
bed incinerator, which causes the soil
and contaminants to combust.
October 22. 1993\TabA.7-1
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continu~
TABLE A.7-1
GENERAL RESPONSE ACTIONS AND POTENTIAL REMEDIAL TECHNOLOGIES
RAILROAD MAINTENANCE SITE
OU 6 ROD
loRING AIR FORCE BASE
GENERAL ~ESPONSE:
. AcnON.,. PROCESS/TECHNOUOGY DESCRIPTION
Removal and Land Treatment - Ex situ Excavate soil. place it on a prepared pad
Treatment Bioremediation to prevent contaminant migration. then
(continued) till, water and fertilize it to promote
biodegradation, and volatilization.
Use as Sub-Grade Material in Excavate so~ and place it in a prepared
Landfill area of an existing landfill to be used as
sub-grade material beneath the landfill
cap.
Off-site DisposaljTreatment Excavate so~ and transport it by truck to
an existing off-site licensed landfill or
treatment facility.
October 22, 1993\TabA.7-1
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PART A
The two alternatives, plus the no action alternative,. which were retained for detailed
analysis were soil excavation and off-site disposal/treatment, and soil excavation and
use as subgrade material in landfill cover system. Both of these alternatives are
readily implementable, are effective (meet the remedial objectives) and are cost-
effective. .
"
"
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A.8 DESCRIPTION OF ALTERNATIVES
This section provides a narrative summary of each alternative evaluated. A detailed
tabular assessment of each alternative can be found in Tables 13-4 through 13-9 of
the RI/FFS (ABB-ES, 1993b).
ALTERNATIVE 1: No ACTION
Evaluation of the No Action Alternative is required by the NCP, and provides a
baseline against which other alternatives can be compared. The No Action
Alternative for the RRMS would involve leaving the contaminated soil in place.
Under CERClA Section 121(c), at least one 5-year site review would be required.
It was assumed one sampling event would occur five years after the ROD is signed.
Estimated Tune for Design and Construciion: Not Applicable
Estimated Time of Operation: 5 years until the first site reyiew
Estimated Capital Cost: $0
,Estimated Operation and MaintenllnCe Costs (net present worth): $8,800
Estimated Total Cost (net present wonh): $8,800 .
ALTERNATIVE 2: EXCAVATION AND OFF-SITE DISPOSALj'rREATMENT
This alternative for the RRMS would consist of excavating the contaminated soil and
transporting it to a privately operated special waste landfill or treatment facility
licensed by the State of Maine, located outside the base. Sampling would be
performed to determine the extent of excavation. The excavated area would be
backfilled with clean fill and seeded to promote groWth of vegetation.
This alternative would consist of the following components:
. Mobilization
. Site Preparation
. Excavation
. Off-site Pisposal
. Site Restoration
.' Site Review
<)
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Estimated Time for Design and Construction: 3 months (following agency
-: approval)
Estimated Time of Operation: Not Applicable
Estimated Capital Cost: $183,000
Estimated Operation and Maintenance Costs (net present worth): $0
Estimated Total Cost (net present worth): $183,000
--;
ALTERNATIVE 3:
EXCAVATION AND USE AS SUBGRADE MATERIAL FOR ON-BASE
LANDFILL COVER SYSTEM CONSTRUCTION
This alternative would involve excavating PAR-contaminated soil exceeding soil
target remediation levels from the site and disposing of it at LAFB Landfill No.2.
Landfill No.2 is currently being evaluated as a site under the FFA and will be the
subject of a separate Proposed Plan and ROD at a later date. Should a landfill
cover system be implemented as part of the final remedial action for the landfill, the
soil would be used as subgrade material. The soil would be placed and compacted
according to design specifications for landfill covers. Ecological risks would be
eliminated at the RRMS once the contaminated soil exceeding target remediation
levels were excavated and the cover system installed. After excavation of the
contaminated soil, the site would be backfilled with clean fill, graded, and seeded.
Estimated Time for Design and Construction: 3 months (following agency
approval)
Estimated Time of Operation: Not Applicable
Estimated Capital Cost: $137,000
Estimated Operation and Maintenance Costs (net present worth): $0
Estimated Total Cost (net present worth): $137,000
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PART A
A.9 SUMl\1ARY OF TIlE COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 121(b)(1) of CERCLA presents several factors that, at a minimum, the Air
Force is required to consider in itS assessment of alternatives. Building upon these
specific statUtory mandates, the NCP articulates nine evaluation criteria to be used
in assessing the individual remedial alternatives.
"
A detailed analysis was performed on the alternatives using the nine evaluation
criteria in order to select a site remedy. The following is a summary of. the
comparison of each alternative's strength and weakness with respect to the nine.
evaluation criteria. These criteria are summarized as follows:
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.
1.
Overall protection of human health and the environment addresses.
whe~er or not a remedy provides adequate protection and describes
how risks posed through each pathway are eliminated, 0 reduced or
controlled through treatment, engineering controls, or institutional
controls.
2.
Compliance with ARARS describes how the alternative complies with
action-specific ARMs, criteria, advisories, and guidance.
Prima" Balancinl! Criteria.
The following five criteria are used to compare and evaluate the elements of one
alternative to another that meet the threshold criteria.
"
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Long-term effectiveness and permanence addresses the criteria that 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.
4.
Reduction of toxicity, mobility, or volume through treatment addresses
the degree to which alternatives employ recycling or treatment that
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reduces toxicity, mobility, or volume, including how treatment is used
to address the principal threats posed by the site.
5.
Short-term e1fectiveness 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 remedial action objectives are achieved.
6.
Implementability addresses the technical and admini~trative feasibility
of a remedy, including the availability of materials and services needed.
to implement a particular option.
7.
Cost evaluates the capital and operation and maintenance costs of
each alternative, and provides an estimate of the total present-wonh
cost of each alternative. .
Modifvinl! Criteria
The modifying criteria are used on the final evaluation of remedial alternatives,
generally after the Air Force has received public comment on the RI/FFS and
Proposed Plan.
8.
9.
State acceptance addresses the State's p.;sition and key concerns
related to the preferred alternative and other alternatives, and the
State's comments on ARARs or the proposed use of waivers.
The State of Maine has provided comments on the Proposed Plan and
has documented its concurrence with the remedial action in a letter of
concurrence in Appendix C of this ROD.
Community acceptance addresses whether the public concurs with the
Air Force's Proposed Plan. Community acceptance of the Proposed
Plan was evaluated based on oral and written comments received at
the public hearings 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 the ROD.
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A detailed tabular assessment of each alternative according to seven of the nine
criteria can be found in Tables 13-4, 13-6, and 13-8 of the RI/FFS (ABB-ES. 1993b).
o
The section below presents the nine criteria and a brief narrative summary of the
alternatives and the strengths and weaknesses according to the comparative analysis.
A.9.1 OVERALL PROTEcrION OF HUMAN HEALTH AND THE ENVIRONMENT
Alternatives 2 and 3 both involve excavating and disposing/treating of the
contaminated surface soil and would eliminate" the pOtential risk to ecological
receptors at the site. Under Alternative 2, the soil would be disposed of at an
appropriately designed and regulated special waste landfill or treatment facility
located off-base. Under Alternative 3, the soil would be placed at an on-base landfil1
to be used as subgrade material placed under an appropriately designed landfill cover
system. The No Action Alternative for the RRMS would not reduce risks to
ecological receptors at the site.
A.9.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND ApPROPRIATE
REQUIREMENTS
No chemical-specific ARARs have been promulgated for soil contamination.
Alternatives 2 and 3 would be designed and implemented so that location- and
action-specific ARARs would be satisfied. Remedial activities conducted under
Alternatives 2 and 3 would be required to preserve the scenic character of the site.
Site restoration activities are included in each of tbese alternatives. Remedial
activities performed under Alternatives 2 and 3 would need to comply with OSHA
regulations and employ safe working practices. Air emissions would be monitored
during excavation activities under Alternatives 2 and 3 to comply with action-specific
ARARs. "
A.9.3 LoNG-TERM EFFEcrIVENESS AND PERMANENCE
Alternatives 2 and 3 would excavate the contaminated surface soil from the site and
would e1iminate the site risks associated with the surface soil. Alternative 3 involves
lan~g of the soil, whicb does not treat the soil but reduces the risk associated
with the soil by restricting exposure. The landfill/treatment facility utilized in
Alternative 2 should be designed, regulated, and operated to minimize the risk
associated with the disposed/treated material. Placement of soil from the RRMS at
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Landfill No.2 could leave the soil exposed and would require controls until such
time that the Landfill' No.2 cover were constructed. The No Action Alternative for
the RRMS would not address the risk associated with surface soil.
A.9.4 REDUCTION OF MOBILI1Y, TOXlCI'IY, OR VOLUME THROUGH TREATMENT
Alternative 2 would effectively eliminate the mobility of the cont::lminants in the soil
either by treatment or by placing the soil in a facility that would be covered in a
manner that would limit infiltration of precipitation. Alternative 3 would also
eliminate the mobility of the cont~minaTlts in the soil when the Landfill No.2 cover,
system were constructed but not through treatment. The No Action Alternative for
the RRMS would not reduce the mobility, toxicity, or volume of the contaminated
soil.
A.9.S SHORT-TERM EFFECI1VENESS .
Alternatives 2 and 3 would involve excavation and transportation of contaminated
soil. Potential shon-term impacts would be minimi7ed by uri1i7iT\g safe working and '
transportation procedures. The generation of dust during excavation would be
minimi7,ed by wetting the soil prior to excavation, should airborne particulate levels
exceed applicable standards. The No Action Alternative for the RRMS would have
no shon-term impacts because no remedial action would occur.
A.9.6 IMPLEMENTABll.11Y
Excavation and disposal/treatment of the soil under Alternatives 2 and 3 are not'
anticipated to pose any problems, but will require coordination with LAFB to
minimi7'e the impact to base operations. Placement of the soil at Landfill No.2 as
described in Alternative 3 would be contingent upon and would need to be
coordinated with any Landfill No.2 remedial investigation or construction activities.
A.9.7 COST
Among the alternatives that satisfy the remedial response objectives, Alternative 3
,is the least expensive, with a net present worth (NPW) of $137,000. Alternative 2 has
an NPW of $183,000 for disposal/treatment of the soil at a licensed treatment facility
or a special waste landfill facility.
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PART A
A.9.8 STATE ACCEPTANCE
J
As party to the FF A. the State of Maine has provided commentS on the RI/FFS and
the Propo~ed Plan and has documented itS concurrence with the remedial action as
stated in Section A13 of this ROD. A copy of the State's letter of concurrence is
presented in Appendix C of this ROD.
A.9.9 COMMUN11Y ACCEPTANCE
. . . .
CommUnity acceptance of the Proposed Plan was evaluated based on oral and
written comments received at public meetings and during the public comment period.
This is documented in the Transcript of the Public Meeting in Appendix ~ and in
the Responsiveness Summary in Appendix B of this ROD.
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PART A
A.IO THE SELEcrED REMEDY
The selected remedial alternative is a source control remedy. This remedy for the
RRMS consists of excavating the contaminated soil and transporting it to an off-base,
privately operated, special waste landfill or treatment facility licensed by the State
of Maine. Sampling would be .perfonned to determine the extent of excavation. The
excavated area would be backfilled with clean fill and seeded to promote growth of
vegetation.
A.IO.I Son. CLEANUP LEvELS
The Table below summarizes the clean-up levels for contaminants of concern in soils.
The basis for this determination is set forth in Section 13.0 of the RI/FFS.
Contaminant Cleanup Level. (mg/kg) Basis
. Benzo(a)pyrcne 0.33 Risk
Dibenz( a,h)antbracene 0.33 Risk
Total Carcinogenic PAHs 1.3 Risk
. Cleanup level is based on detection limit for analytical method.
These clean-up levels must be met at the completion of the remedial action at the
points of compliance. The preliminary area of excavation is approximately 36 feet
by. 70 feet, down to a depth of 2 feet bgs. ConfinDation sampling will be conducted
to ensure soil requiring remediation has been excavated. These clean-up levels attain
USEPA's risk management goal for remedial actions and have been determined to
be protective.
The site will be reviewed at the conclusion of the groundwater study for au 12 to
assure that the residual risk from the soil, when combined with the groundwater risks,
is protective of human health and the environment.
.,
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A.ll STATUTORY DETERMINATIONS.
o
The remedial action selected for implementation at the RRMS is consistent with
CERClA and, to the extent practicable, the NCP. The selected remedy is protective
of human health and the environment, attains state and federal ARARs and is cost-
effective. The selected remedy also may satisfy the statutory preference for
treatment which permanently and significantly reduces the mobility, toxicity or
volume of hazardous substances as a principal element, depending on the method of
treatment and/or disposal chosen during the design phase. Additionally, the selected
remedy utilizes alternate treatment technologies or resource recovery technologies
to the maximum extent practicable.
A.l1.1 THE SELECI'ED REMEDY IS PROTECTIVE OF HUMAN HEALTH AND THE
ENVIRONMENT
The remedy at the RRMS will permanently reduce the risks posed to human health
and the environment by eJimina.ting, reducing or controlling exposures to human and
environmental receptors through excavation and disposal of soil at a licensed facility.
Removal of the contaminated soil will eliminate any exposures to human and
environmental receptors on-site, and disposal at a licensed disposal/treatment facility
will eliminate any exposures to the soil through its existing institutional controls or
through treatment.
A.l1.2 THE SELECTED REMEDY AtTAINS ARARs
This remedy will attain all federal and state ARARs that apply to the RRMS.
Environmental laws fto~ which ARARs for the selected remedial action are derived,
and the specific ARARs are presented in Table All-I. The selected remedy will
attain all substantive, non-procedural requirements of federal and state ARARs for
the selected remedial action at RRMS as set forth in Table All-! which includes
chemical-, location-, and action-specific requirements. The tables include the
regulatory citation, a brief summary of the requirement, and .the action to be taken
to attain the requirement. In addition, policies, criteria, and guidelines which will
also be considered during the implementation of the remedial action are set forth in
the table. It is note~ that although the requirements, standards. and regulations of
the Occupational Safety and Health Act of 1970, United States Codes, Title 29, et
~ are not ARARs, they will be complied with and connected with the RRMS
remedial activities' where applicable (USEP A, 1990).
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TABLEA.11-1
ARAR8. CRmRIA. ADVISORIES, AND GUIDANCE
RAILROAD MAINTENANCE Sne
au 6 RECORD OF DECISION
LORINO AIR FORCE BASE
MEDIA
REQUIR~EffT
8TATUS
. ~EQ~~$rff.i:I~ .
CHEMICAL.SPECIFIC REQUIREMENTS
WASTE MATERIAL
~
RCRA Identification and
Ustlng of Hazardous
Wastes (40 CFR 261)
LOCATION-SPECIFIC REQUIREMENTS
).
.J.
.....
State
Maine Site Location
Development Law and
Regulations (38 MRSA,
Section 481-490; MEDEP
Regulations, Chapter 375)
ACTION-SPECIFIC REQUIREMENTS
Federal CERCLA Off-Site Disposal
"tIiiTCIiii"ce and Policy (OSWER Directive
Criteria to be 9834.11; November 13,
Considered 1987)
State Maine Ambient Air Quality .
- Standards (38 MRSA,
Section 584; MEDEP
Regulations, Chapter 110)
Notel:
ARAA
CFR
MEDEP
MRSA
OSWER
RCRA
Relevant and
Appropriate
Applicable
To Be
Considered
Applicable
= Applicable or Relevant and Appropriate Requirement
= Code of Federal Regulations
. Maine Department of Environmental Protection
. Maine Revised Statues Annotated
= Office of Solid Waste and Emergency Response
= Resource Conservation and Recovery Act
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3
Defines those wastes that are subject to regulations as
hazardous wastes under RCRA.
This act and regulations govern development and include
hazardous activities that consume, generate, or handle.
hazardous wastes and oil. 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 specified Items Including air quality
and runoff/Infiltration relationships, no unreasonable
alteration of climate or natural dralnageways, and
provisions for erosion, sedimentation, and noise control. .
This policy requires the off-site receiving facility to be in
compliance with all permits and applicable state federal
and requirements..
Tills Chapter establishes ambient air quality standards
that are maximum levels of a particular pollutant
permlUed In the ambient air.
ACTION TO BE TAKEN TO ATTAIN ARAR
Analytical results were evaluated against the
criteria and definitions of hazardous waste. No
hazardous waste was Identified at the site. These
regulations may be referred to and utilized when
developing remedial alternatives and during
remedial actions.
Remedial action will meet these regulations. A
permit will not be required if the activity is on-
site.
The off-site receiving facility will need to be
licensed and in compliance with permits and
applicable state and federal requirements before
the waste is taken to the facility.
The standard for particulate matter Is 150 J.I9/mJ,
24-hour average concentration. Air monitoring
will be conducted during remedial actions.
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PART A
A.ll.3 THE SELECI'ED REMEDIAL ACTION IS COST-EFFECTIVE
o
In the Air Force's judgment, the selected remedy is cost effective, Le., the remedy
affords overall effectiveness proportional to its costs. In selecting this remedy, once
the Air Force identified alternatives that are protective of human health and the
environment and that attain, or, as appropriate, waive ARARs, the Air Force
evaluated the overall effectiveness of each alternative by assessing the relevant three
criteria: long term effectiveness and permanence; reduction in toxicity, mobility, and
volume througn treatment; and short term effectiveness, in combination. The
relationship of the overall effectiveness of this remedial alternative was determined
to be proponional to its costs. The costs of this remedial alternative are:
Estimated Capital Cost: $183,000
Estimated Operation and .\fainIenance Costs (net present worth): $0
Estimated Total Cost (net present worth): $183,000
The No Action Alternative is clearly the least expensive alternative, estimated to cost
nothing because. it would not require any additional controls or monitoring.
Alternative 3 is expected to cost approximately $137,000. The selected remedy is
also relatively inexpensive at $183,000.
A.1l.4 THE SELECI'ED REMEDY UTII.I7.FS PERMANENT SOLunONS AND A:Ln:RNA11VE
TREATMENT OR RESOURCE RECOVERY TECHNOLOGIES TO THE :\-IAXIMUM
EXTENT PRACTICABLE
Once the Air Force identified those alternatives that attain ARARs and that are
protective of human health and the environment, the Air Force identified which
alternative utilizes permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable. This
determination was made by deciding which one of the identified alternatives provides
the best balance Qf trade-offs among alternatives in terms of: 1) long-term
effectiveness and permanence; 2) reduction of toxicity, mobility or volume through
treatment; 3) short-term effectiveness; 4) implementability; and 5) cost. The
balancing test emphasized long-term effectiveness and permanence and the reduction
of toxicity, mobility and volume through treatment, and considered the preference
for treatment as a principal ele~ent, the bias against off~site land disposal of
untreated waste. and community and state acceptance. The selected remedy provides
the best balance of trade-offs among the alternatives.
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A.ll.S THE SELECTED REMEDY AND THE PREFERENCE FOR TREATMENT WHICH
PERMANEN11..Y AND SIGNIFICANTLY REDUCES THE ToXIC nY, MOHlLnY OR
VOLUME OF THE HAzARDous SUBSTANCES AS A PRINCIPAL ELEMENT
"
The principal element of the selected remedy is the source control of contaminated
soils. This element addresses the primary threat at the site which is contamination
of surface and subsurface soils at the RRMS. The selected remedy may satisfy the
statutory preference for treatment as a principal element by excavating and disposing
of contaminated soil, depending on the method of treatment or disposal chosen
during the design phase.
The method of disposal or treatment of the excavated soils will be determined during
the remedial design phase. The determination will reflect the requirements of
CERCLA 121(b)(1) that states remedial actions in which treatment which
permanently and significantly reduces the volume, toxicity, or mobility of hazardous
substances, pollutants or contaminants as a principal element, are to be preferred
i)ver remedial alternatives not involving such treatment.
'"
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A.12 DOCUMENTATION OF.NO SIGNIFICANT CHANGES
')
The Air Force presented a Proposed Plan (preferred alternative) for remediation of
the RRMS on July 28, 1993. The preferred alternative for the RRMS consists of
excavating the contaminated soil and transporting it to an off-base, privately
operated, special waste landfill or treatment facility licensed by the State of Maine.
Sampling would be performed to determine the extent of excavation. The excavated
area would be backfilled with clean fill and seeded to promote growth of vegetation.
1bis alternative would consist of the Jallowing components:
.
Mobilization
Site Preparation
Excavation
Off-site Disposal or Treatment
Site Restoration
Site Review
.
.
.
.
.
There have been no significant changes made to the aiternative as stated in the
Proposed Plan.
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A.13 STATE ROLE
The Maine Department of Environmental Protection has reviewed the various
alternatives and has indicated its suppon for the selected remedy. The State has also
reviewed the Rl, Risk Assessment and FFS 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 the Loring AFB
Railroad Maintenance Site. A copy of the declaration of concurrence is attached as
Appendix C.
('
. "
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PART B
PART B EAST GATE WASTE STORAGE TANK AND FUEL DROP SITES
'..)
B.l SITE NAME, LOCATION, AND DESCRIPTION
LAFB is an NPL site. There are currently several areas of concern within LAFB
that are under investigation. The areas of concern at LAFB have been organized
into 21 ODs for remediation purposes. This ROD relates to the Source Control
Remedial Action, for au 6, which is comprised of the following sites: the RR.'A:S; the
EGWST; and mss North 1 and 2 (FDS-NI and FDS-N2, respectively), South-Active
(FDS-SA) and South-Former (FDS-SF) (Figure AI-I). .
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 base is approximately three 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.
Part B of this ROD relates to EGWST, FDS-Nl, FDS-N2, FDS-SA, and FDS-SF.
,The EGWST is located in the southeast portion of the base along Maine Road
approximately 300 feet north of the -:~t Gate entrance. Of the four fuel drop sites,
tWo are located on the northern end of the runway (i.e., FDS-NI and FDS-N2) and
tWo are located on the southern end of the runway (FDS-S [active] and [former]).
o
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B.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES
This section summarizes the uses, response history and enforcement activities at the
EGWST and the FDS.
B.2.1 LAND USE AND RESPONSE HISTORY
A more detailed description of the site history can be found in the RI/FFS.
Until 1968, the EGWST site was a motor gasoline (MOGAS) pumping station for
base personnel. Two 5,OOO-gallon underground storage tanks (USTs) were used for
gasoline storage. After closure of the facility as a gasoline pumping station, the
USTs were used as holding tanks for liquid hazardous waste. Wastes, including waste
fuels, crankcase oils, gear oils, brake fluid, hydraulic fluids, solvents, and paint
strippers, were stored in the USTs awaiting periodic off-base disposal by a private
contractor. Use of the tanks was discontinued in 1980.
Because no evidence suggested the tanks were leaking, the site was not
recommended for inclusion in the IRP in the 1984 PA Howev~r, the PA
recommended evaluating the status of the UST5 with regard to UST regulations
requiring contents removal, and securing the tanks.
A magnetometer survey, test pitting, and soil and tank sampling were performed in
1985. Based on analytical results, a removal action was planned and ~he site was
added to the IRP. The interim removal action implemented in 1989 included
removal of the two USTs, their contents, and soil adjacent to the tank pit. The
materials were properly disposed of off-base. Although no signs of leakage from the
tanks were observed during excavation, soil samples from the excavation side walls
indicated that soil around the tank was contaminated and that additional
characterization was recommended.
The excavations were lined with polyethylene sheeting and backfilled with clean fill.
The purpose of the lining was to ~gregate the clean fill from the contaminated soil.
If additional contaniinated soil needed to be removed, the clean fill could be easily
identified, removed, and r.eused.
"
The FDSs are located at the north and south ends of the runway. Because of the
large payloads that B-52s carry, fully-laden aircraft must take off into the wind.
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"
However, in the event of a "strip alert", aircraft must be launched immediately
regardless of wind conditions. If optimum wind conditions do not exist during a strip
alert, aircraft may have to dump some fuel to lighten their payload and enable them
to takeoff.
If fuel were dumped, it would spill onto the paved area and the fire department
would flush the fuel into the adjacent grassy area. Interviews indicated that FD5-N1
may have been used on old FDS-N2 three times, both areas are located on the north
ends of the runway. Information indicated that both the former and active FSD
located south of the runway, were not used. . .
Surface drainage from both nonhem areas eventually discharges to East Loring lake
through a series of storm drains. Surface drainage from the southern areas goes to
separate locations. The former dr9P location has subdrains that empty into an
unnamed tributary of the east branch of Greenlaw Brook The active drop area has
subdrains that conVerge into the Bomber Alert area. Visual observatio~ during the
RI site visit did not indicate that discharge had drained into the Bomber Alert area.
B.2.2 ENFORCEMENT HISTORY
The enforcement history of au 6 is summarized as follows:
.
In 1984, a P A was completed by CH2M Hill detailing historical
hazardous material usage and waste disposal practices at LAFB.
.
;
Initial'SI field work to determine if contaminants were present at the .
au 6 sites was conducted in 1985 by R.F. Weston, Inc. .
.
An RI process by ABB-ES commenced in 1988 and continued into
1993.
.
LAFB was added to the NPL in February of 1990.
.
The Air Force entered into an FFA in 1991 with the USEPA and
MEDEP regarding the ~leanup of environmental contamination at
LAFB. .
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"
.
An FFS was conducted in 1993 for the RRMS, EGWST, and the
FDS-SF to determine alternatives for remediation of contamination
based on information presented in the RI.
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PART B
B.3 COMMUNI1Y PARTICIPATION
Throughout LAFB's history, the community has been active and involved to a high
level in base activities. The Air Force 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 'IRC
meetings. Membership of the TRC is comprised of Air Force, MEDEP, and local
officials and community representatives.
I
. During August of 1991, the LAFB community relations plan (CRP) was released.
The CRP outlined a program to address community concerns and keep citizens
infqrmed about and involved during remedial aCtivities.
On June 24, 1993, the Air Force made the administtative record available for public
review at the Robert A Frost Memorial Library, 238 Main Street,.Limestone, Maine
and at the Office of Public Affairs, 42 CES/CEVR, 7300 Pennsylvania Road, Loring
~, Maine. USEP A published a notice and brief analysis of the Proposed Plan in
Bangor Daily News and the Aroostook Republican on July 28, 1993 and made the
plan available to the public at the Robert A Frost Memorial Library.
LAFB held informational meetings on February 23, 1993 in Limestone, March 24,
1993 in Caribou, and April 29, :993 in Fort Fairfield, Maine to discuss the results of
the RI and the clean-up alternatives presented in the FFS, and to present the Air
Force's Proposed Plan. Also during this meeting, the Air Fqrce answered questions
from the public. From July 28 through August 27, 1993, the Agency held a 3O-day
public comment period to accept public input on the alternatives presented in the
RI/FFS and the Proposed Plan and on any other documents previously released to
the public. On August 23, 1993, lAFB personnel and regulatory representatives held
a public meeting to discuss the Proposed Plan and to accept. any oral comments. A
transcript of this meeting is included in Appendix A, and the comments received
during the comment period and the Air Force's response to these comments are
included in the Responsiveness Summary in Appendix B.
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PART B
B.4 SCOPE AND ROLE OF NO ACTION REMEDY
The Air Force has determined that no further CERCLA action is required at the
EGWST, FDS-~l, FDS-N2, FDS-SA, and FDS-SF sites. The levels of organic and
inorganic compounds in the soils at these sites do not pose an unacceptable risk to
human health or the environment under CERCLA.
No five year review will be undertaken, but the Air Force and USEP A will continue
to monitor the soil and sediments to assess that no unacceptable exposures occur in
the future.
The decision by the Air Force not to pursue further CERCIA action at these sites
is not a determin~tion that no action is warranted under other regulations or statutes.
The State of Maine has requirements that apply to these sites even though CERClA
action is not warranted.
In separate actions which are not part of this ROD, the Air Force is taking non-
CERClA remedial actions at EGWST and FDS-SF pursuant to state requirements
under an Air Force/State Two-Party Supplement to the FF A being signed
simultaneously with this ROD.
The USAF and the USEPA have the authority to revisit this No Action decision
under CERCLA if future conditions indicate an unacceptable risk to human health
or the environment would result from exposure to contaminants at the sites. .
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PART B
8.S SUMMARY OF SITE CHARACTERISTICS.
J
Sections 6.0 of the RI/FFS contains an overview of the RI field activities at OU 6
through 1991, and Section 11.0 presents the results of a supplemental soil boring and
sampling program conducted in 1993 to address data gaps (ABB-ES, 1993b). The
significant findings of these investigation are summarized below.
The nature and distribution of contaminants in both surface and subsurface soils at
the EGWsr and FDS sites are described in the following subsections. Groundwater
sampling results are discussed briefly because they provide possible indicators of the
impact that contaminants detected in soil may have on groundwater quality.
However, the nature and distribution of contaminants in groundwater will evaluated
as part of OU 12 investigations. .
8.5.1 EAsT GATE WASTE STORAGE TANK SITE
Surface Soil
The initial investiga~on to confirm the presence of contamination was conducted in .
1985, and included' a geophysical survey, test pits, analysis of soil samples, and
Resource Conservation and Recovery Act (RCRA) hazardous waste characteristic
. analysis of one tank's contents (the other tank was empty). Subsequent investigations
conducted betWeen 1988 and 1991 included test pits, subsurface soil sampling,
overburdenjbedrock monitoring well pairs, and field and laboratory analysis of soil
and groundwater samples.
Laboratory samples were analyzed for TCL VOCs, SVOCs, pesticides and PCBs, and
TAL inorganics. ExPlorations were located both within and outside the suspected
area of contamination to confirm the presence of contaminants. Explorations were
also completed throughout the paved area of the site to evaluate if contaminants may
have been released from underground piping associated with the former pump island.
Samples of the tank contents were also collected and analyzed.
The only organic contaminants detected by CI..P analyses were carcinogenic and ~on-
carcinogenic PAHs, and were detected in tWo surface soil samples, JSS-1461 from the
1991 investigation (1.1711 mg/kg and 1.32 mg/kg respectively), and JSS-1482 from
1993. The concentrations of all the carcinogenic compounds were estimated because
they were below CRQu. Phenol was also detected below CRQL in JSS-1482 at 0.06
Installation Restoration Program
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PART B
mgjkg, but had not been detected during previous investigations at the site. No
inorganic compounds were detected at concentrations above background
(Figure B.5-l). .
"
Analytical results indicate that there is no wide-spread distribution of contaminants
in surface soil (Le., 0 to 2 feet bgs) at the EGWST site.
Subsurface Soil
'Ethylbenzene (ranging from O.OOlJ mgjkg to 0.24' mgjkg), Xylenes (0.072 mgjkg to
590 mgjkg), and PECs (70 mgjkg to 8,700 mgjkg), were detected above CRQLs in
several samples. Toluene, 2-methyInaphthalene, and naphthalene were each detected
once at concentrations above the CROI., with naph~alene and 2-methylnaphthalene
detected in the 8- to 10-foot sample from JTB-1443 at concentrations of 1.3 mgjkg
and 2.6 mgjkg respectively. Chlorobenzene was detected below the CROL in 1993,
but had not been detected previously. The presence of these fuel-related
contaminants is consistent with the history of this site (Figure B5-2)..
Me~ylene chloride was detected at a concentration above the CROL in one sample,
collected when the south storage tank was removed Although this compound is a
common laboratory contaminant, the detected concentration (19 mgjkg) and the use
of the tanks to store solvents indicate that it is a site-related contaminant. No
inorganic compounds were detected at concentrations above background.
CLP analyses detected the highest concentrations of fuel-related contaminants in
subsurface soil (i.e., greater than 2 feet bgs) samples collected from within the
southern portion of the footprint. of the former storage tanks (Figure B5-2).
Methylene chloride was only detected in samples from southern portion of the tank
footprint. These 'detections indicate that the southern storage tank, and possibly the
northern tank, leaked.
This site was a gasoline station and likely sOurces of contMninants include: gasoline
spilled while filling vehicles; lubricant that leaked from vehicles or was spilled; and
spills that may have occurred while filling storage tanks. Because the former pump
area is located at the highest part of the site, storm runoff would have washed
, contaminants that accumulated on the paved surface towards the northeast and
southeast, or to the west.
Installation Restoration Program
W0099319.080
B-8
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&'
.
I'
-"!i
~.
-.,
LEGEND
...
.
.
NOT1!S:
SOl\. BORING (JTB)
~
-$-
OVERBURDEN
MONITORING WELL (JMW)
BEDROCK MONITORING WELL (JMW)
MU\.T101'ORT BEDROCK
MONITORING WELL (JMW)
TEST PIT'(JTP)
.
.
SURFACE SOIL (JSS)
1993 SURFACE SOIL SAMPLE
t. CONTOUR INT1!RVAL IS 2 FEET. DATUM IS MEAN SEA
LEVEL 1929. LA F B COORDINATE SYSTEM. NORTH IS
BASED ON L A F B GRID COORDINATE SYSTEM.
2. COMPILED AND CONTROLLED USING STANDARD
MAPPING PROCEDURES.
_II
J. CHEMICAL CONCENTRATIONS IN mlllkg UNLESS
OTHERWISE NOTED.
-.,
\,.
~~"
I
..... ,
SCALI! ..' FUr
I I
«I ...
7IZf002/t2CII051CD/tZOI0870
,
10
FIGURE 8.5-1
DISTRIBUTION OF CONTAMINANTS IN
SURFACE SOIL
EAST GATE WASTE STORAGE TANKS
OU 8 ROD
LORING AIR FORCE BASE
UMESTONE; MAINE
-------
NOTES: I
1. CONTOUR INTeRVAL IS 2 FEET. OATUMIS MEAN SEA
LEVEL 1929. LA.F.B. COORDINATE SYSTEM. NORTH IS
BASED ON LA.F.B'NTIIGRID CLOEODRUDSINI ATE TSAYNSTDEAMR'D /.
2. COMPILED AND CO OL NG S
MAPPING PROCE;)URES.
I
t
I
,
nD~~
EOS!02
~ 'JOe
NO ......,....... CItIQndl "
NO TOIII X~.... 59
~IO .. ~ST. :
INORGANICS NO
PI«: .030
_II.
" EG"TOO
I'
.~
05T01
1.2: ---..!
i
~
-~u11
voc
1%'" TGluM'1 18
TOUI X-,.en.. S90"
SVClC NO
PCIllPEST. "0
INORQANICS ND
PHC .700
1118111-
~ T .,uo
............... VCC
SVOC
PCIliPEST.
1.580
NO
NO
1.9.
~
voc
SVOC
PCIllPEST.
"
.a::u:
T .,...
JT!Iolca.
voc
EfrJIMn-
Tcarl X,....
0.0lI&l
..0112./
JJ::J.a:
...7OJJ
NO
NO
'JOe
EfrJIMn-
TOOl X,,-
0.1M
0.l1li
it
'JOe
EIh.,.,.,.:r8ft8
To<8IX,,-
svoc;
rn)pAM
PHC
510.
NO .
~~
NO
-
,
T"
-.
_II
0.2.
0."
S. CHEMICAL CONCENTIIATIONS IN mlJlkg UNLESS
OTHERWISE NOTED.
voc
PC8IPEST.
VOC
PCIIII'EST.
i ,
I~ 'JOe
-~t
'\ \_Sf.
2::t:
NO
"0 VOC
NO SVOC
~ PHC
NO ,
VOC
E"'yIboII""
T..,."
To..fX~-
VOC
Chlcwab8nr-
E"'yIboII....
T08u8M
T_X-
O.Ot.o.OOtJ
o.COSJ.tIO
0.'JO.D01J
JJ::J.a:
t::5:
110
NO
NO
voc
a ~~ST.
NO
:~
=
~
NO
NO
NO
=
NO
NO
NO -
'JOe
svoc
PCQ.1>t;ST.
'JOe
SVCIC
PCQ.1>t;ST.
'JOe
svoc
PCIIIPEST.
INOROANM:S'
voc
....,...OIlondi 0.138
SVOC NO
PHC NO
0.":1.1
...
0..00&.1
2
11
NO
"+
~
o..OCJoW
NO
NO
720~'1
I
-en.
SCAle .. F1!I!T
".
o
7UI.oZ19Z0105ICD
.
10.
LEGEND
...
~
.Q.
-$-
SOIL BORING
OVERBURDEN MONITORING WELL
SECROC!( MONIT'JRING wEn
~
.
~
MULTI.PORT BEDROCK'
MONITORING WELL
TEST PIT
GRAB SOIL SAMPLE
1993 SOIL BORING
FIGURE 8.5-2
DISTRIBUTION OF CONTAMINANTS IN
INTERMEDIATE SOIL (2'.15' BGS)
EAST GATE WASTE STORAGE TANKS
au 8 ROD
LORING AIR FORCE BASE
UMESTONE. MAINE
-------
PART 8
Groundwater
c,
Other than laboratory contaminantS, no compounds were deteCted in groundwater
samples colleCted b~fore 1991. However, benzene, xylenes, and PARs detected in
1991 samples indicate that fuel-related contamination in soil may be impacting
groundwater quality. I .
8.5.2 FuEL DROP SITES
Investigations initiated.in 198.5 at FDS-Nl. and in 1991 at FDS-N2, FDS-SA, and
FDS-SF have included test pits, installation of overburden and bedrock monitoring
wells, sampling and laboratory analyses of soil. sediment, groundwater, and surface
water samples for TCL VOCS, SVOCs, pesticides and PCBs, TAL inorganics, PHCs,
and/ or total organic carbon.
The site history for the FDSs indicates that these sites were designated areas for
discharging fuel in the event of a strip alert. It is believed that FDS-N1 was used
once for this purpose, and FDS-N2 three times. It is believed that the FDS-S
. locations were never used. The potential source of contamination would primarily
be jet fuel (ie., JP4). In addition to organic compounds, JP4 may contain inorganic
elements. Although many metals have been deteCted in petroleum, the most
common are nickel and vanadium. However, the inorganic content of fuel varies
from one source of petroleum to another (Anhur D. Uttle, Inc., 1985).
Surface Soil
The only site-related. cont~minants detected in FDS-N1 surface soil (0 to 2 feet bgs) .
were PHCs. Off-site analyses detected PHCs in only one sample, JSS-2760, at a
concentration of 19.1 mg/kg. This sample is located in the drainage ditch
approximately 50 feet west of' a catch basin. There are no indications that large
quantities of jet fuel have been spilled at FDS-Nl.
o
The only site-related contaminants detected in FDS-N2. surface soil were PHCs.
Although PHCs were detected in five samples from FDS-N2, the concentrations in
three samples were equal to or less than 50 mg/kg. The two highest concentrations,
115 and 118 mg/kg, were detected in samples from J5S-2865 and JTB-2864,
respectively. JSS-2865 is in the drainage ditch and JTB-2864 is next to the runway.
These two PHC concentrations may be from fuel and oil that was washed off the
"
Installation Restoration program
WOO99319.080
7626-08
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PART B
runway by stOrm runoff or may be interference from ubiquitous PHCs. There are
no indications that large quantities of jet fuel have been spilled at FD$-N2.
PHCs were detected by off-site analyses in four samples from FD$-5F (Figure B.5-3).
Two of these samples had concentrations less than 26 mg/kg. PHCs were detected
in the other two samples, J5$-2960 and J55-2961, at concentrations of 417 and
447 mgjkg, respe~ively. J5$-2960 is within 40 feet of the aircraft warmup area.
J5S-2961 is in the drainage ditch and is approximately 75 feet from the aircraft
warmup area. The most like sources. of the PHCs deteCted in these two samples are
motor vehicle and aircraft exhaust, and fuel and oil that were washed off the Wa.miup
area by storm water runoff. CLP analyses detected P AHs in J$$-2962 at
concentrations below the CRQL. JSS-2962 is located approximately 150 feet north
of the aircraft warmup area and on the far side of the drainage ditch. Given the
location of tbe sample, it is not likely that these compounds are the result of a jet
fuel spill. They may be attributed to aircraft exhaust. There are no indications that
large quantities of jet fuel have been spilled at FD5-SF.
I
Off-site analyses detected PHCs in one sample from FDS~SA (JSS-296S) at
80.3 mg/kg (Figure B5-4). JSS-2965 is next to the taxiway. There are no indications .
that large quantities of fuel were spilled at FDS-SA
Inorganics were detected above background concentrations in surface and subsurface
samples at these four fuel drop sites. Based on the nature and distribution of the
contaminantS at the FDSs, there are no indications that large quantities of jet fuel
have been spilled.
Four inorganics, .cyanide, cobalt, mercury, and sodium, were detected above
background concentrations inFDS-N2 soil in 1993. Cobalt was detected in JTB-2821
at a concentration of 12.6 mg/kg. Mercury was detected above background ranges
in surface soil at concentrations 0.12 and 0.14 mg/kg from JTB-2821 and JTB-2820,
respectively. Sodium was detected above background ranges in surface soil samples
at estimated concentrations ~ngine from 120 to 134 mg/kg. Sodium concentrations
were estimated because of blank contamination. Although concentrations for cobalt,
mercury and sodium are greater than LAFB soil background concentrations, they are
within the range identified in literature (5hacklette ~d Boemgen, 1984). .
o
Installation Restoration Program
W0099319.080
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~0 1
~
JTWMO
~g
g;z
ND
ND
ND
ND
25.9
Z:£
ND
YOA
SYOA
PCBIPEST.
INORGANICS
PHC
VOA
SYOA
(n)PAH
(c)PAH
PCBIPEST.
INORGANICS
PHC
mgikg
2:£
YOA NO
SVOA NO
PCBlPEST. NO
INORGANICS ND
PHC NO
YOA
SVOA
PC8IPEST.
INORGANICS
Cadmium
BeryUlum
Nickel
ZInc
PHC
LEGEND
. SURFACE SOil SAMPLE
I
~
..
III
. SOIL BORING
.. BEDROCK MONITORING WELL
~ 1993 SOIL BORING
III
CATCH BASIN
-c>
TAXIWAY UGHTS
I
o
SCALE IN FEET
I
100
I
200
9303046D (b)
~
~
I
I
JTB.2961
JSS-2962 mgikg
a:z YOA
VOA NO SVOA
SVOA (n)PAH 90.12
(n)PAH O.53JJ (C)PAH 68.3
(c)PAH O.205JJ Carbazole 3.7 N12500
PCBIPEST. NO PCB/PEST. ND
INORGANICS ND INORGANICS ND
PHC 22.6 Barium 354
Lead 72.9
ZInc 112J
. J5S-2962 PHC 822
a::a:
YOA ND
SVOA
(n)PAH
(c)PAH
PCB/PEST.
INORGANICS
PHC
.. JT8.2961
740-
.. JTB-2962
~g JTB-2920
~
ND
ND
ND
ND
NO
.lZ:l.4:
ND
ND
ND
1.4
1.6
112
87.3J
13.7
VOA
SYCA
(n)PAH
(C)PAH
INORGANICS
MERCURY
SODIUM
'lOA
SVOA
INORGANICS
MERCURY
SODIUM
YOA
SVOA
(n)PAM
(c)PAH
INORGANICS
MERCURY
SODIUM
0.25
155J
Ja::1Z
ND
O.4J
0.31J
B-13
mgikg
a::z:
ND
0.2J
O.1J
0.19
14&1
z
en
::D
c:
z
:E
~
<
mglkg
a:z
YOA
4-MetnyI1,2-PenlanOne
SVOA
PCBlPEST.
INORGANICS
Cadmium
PHC
0.008JJ
NO
NO
1.3
417
N12OQO
III
"
FIGURE 8.5-3
DISTRIBUT10N OF CONTAMINANTS
IN SOIL AT THE FDs.s (Fonner)
OU 6 ROD
LORING AIR FORCE BASE
-------
w
VOA
SVOA
PCB/PEST.
INORGANICS
PHC
VOA
SVOA
PCB/PEST.
Aroclor.l260 0.019.1
INORGANICS NO
PHC NO
N 12000
~
~
~
(:)
w
OJ
I
-
,J::o.
JTB.Z968
£i[ mglkg
VOA NO Z:£
SVOA NO
PCB/PEST. NO NO
INORGANICS NO NO
. NO
PHC NO NO
1£:1Z NO
VOA NO 1D::..1Z
SVOA NO VOA NO
JSS-Z963 mgikg PCB/PEST. NO SVOA NO
a:.z: INORGANICS NO PCBIPEST. NO
VOA NO PHC NO INORGANICS
SVOA NO Zinc -'., 79.9
PCB/PEST. NO PIIC NO
INORGANICS NO
P~fC NO
. JSS-Z963
011
N 12000
VOA
SVOA
PCB/PEST.
INORGANICS
PHC
.lTB.Z964
LEGEND
. SURFACE SOIL
SAMPLE (JSS)
. SOIL BORING (JTB)
.. BEDROCK MONITORING
WELL (JMW)
UI CATCH BASIN
~ TAXIWAYUGHTS
FIGURE B.5-4
DISTRIBUTION OF CONTAMINANTS IN
SOIL AT THE FD5-S (ACTIVE)
~
OU 6 ROD
I
o
93030460 (8)
SCALE IN FEET
I
100
I
200
LORING AIR FORCE BASE
-------
PART B
Cyanide was deteCted in one surface sample soil from FDS-SA at an estimated
concenttation of 0.64 mgjkg, which is below the CRQL; cyanide was not detected in
the associated duplicate sample.
Cadmium was detected in one surface soil sample from FDS-SF at a concentration
of 1.3 mgjkg. Cadmium is a common additive in the formulation of tire rubber
compounds, therefore, the cadmium detected in 1SS-2960 may be from tire particles
that were washed off the paved areas by storm runoff. Mercury and sodium were
detected at concentrations above LAFB background ranges in surface soils in 1993
at FDS-SF (Figure B.5-3). .AJthough the mercury concentration is greater than the
LAFB soil background concentration, it is within the range identified in literature
(Shacklette and Boerngen, 1984). Sodium concentrations were estimated because of
blank contamination. These inorganics were not detected above background ranges
during previous investigations.
Subsurface Soil
The only potentially site-related contamin~nts detected at FDS-Nl were PHCs, which .
were detected in two samples at low concentrations. There are no indications that
large quantities of jet fuel were spilled at the site.
The only potentially site-related contaminants detected at FDS-N2 were PHCs.
Laboratory results were all less than 18 mgjkg. These PHC concentrations may be
from fuel and oil that collected on the runways and taxiways and was washed off the
runway by storm runoff, or may be interference from ubiquitous PHCs. There are
no indications that large quantities of jet fuel have been spilled at FDS-N2.
The primary site contaminants detected at FDS-SF were PHCs; carcinogenic and
non-carcinogenic P AHs, and carbazole, which were detected in samples from
ITB-2960 and JTB-2961 (see Figure B.5-3). The highest concentrations of PAHs and
the only detection of carbazole were found in the 2- to 4-£oot sample from ITB-2961.
This sample also had the highest PHC concentration detected by the laboratory,
822 mgjkg. P AHs were detected below the CRQLs in the sample collected from the
6-to-8 foot depth interval in this boring. Additionally, the laboratory detected low
concentrations of P AHs and PHCs in the 2- to 4-foot and 4- to 6-foot depth interval
. samples collected from JTB-2960. The contaminants detected in JTB-2960 may be
attributed to normal operations; however, the source of the relatively high
concentrations of contaminants detected in JTB-2961 are unknown. Analytical
D
Installation Restoration Program
W0099319.080
B-15
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PART B
results for subsurface soil samples from FDS-SF (with the exception of ITB-2961) do
not indicate that large quantities of jet fuel have been spilled at the site.
The only potentially site-related contaminants detected at FDS-SA were PHCs, which
were detected in sample JSS-2965 at 80.3 mg/kg (see Figure B.5-4). There are no
indications that 13.!ge quantities of jet fuel have been spilled at the site.
No inorganics were detected at concentrations above background in samples from
FDS-Nl. Inorganics were detected, in subsurface soil samples from FDS-N2 and
, FDS-SF at concentrations above LAFB background ranges.
Beryllium was detected in four subsurface soil samples from FDS-N2 at
concentrations above background soil concentratiQns. Calcium was also detected
above background. Calcium, cadmium, barium, beryllium, lead, nickel and zinc were
detected in FDS-SF subsurface soil samples at concentrations above background.
Barium (354 mg/kg), lead (72.9 mg/kg) and zinc were (127 J mg/kg) were detected
above background in the sample collected from 2- to 4-feet bgs in JTB-2961.
Cadmium (1.4 mg/kg), beryllium (1.6 mg/kg), nickel (112 mg/kg), and zinc (873
J mg/kg) were detected above background ranges in a sample collected from 12-
to 14-feet bgs in JTB-2962. The inductively coupled plasma (ICP) serial dilution
analysis result for zinc had a percent difference between the sample result and serial
dilution of greater than 15 percent and associated samples were qualified as
estimated with a "J".
I
At FDS-SA, zinc was detected above background in a sample collected from 10- to
12-feet bgs in JTB-2967.
The sources of the inorganics detected at FDS-N2, FDS-SF, andFDS-SA are
unknown. The presence of these compounds is not consistent with the FDSs' history.
Groundwater
No contaminants were detected in groundwater samples collected from the FDSs.
Sediments/Surface Water
Only the northern FDSs have an associated surface drainage system. Four sediment
samples collected from this system were analyzed in an off-site laboratory by CLP
Installation Restoration Program
W0099319.080
7~
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PART B
methodologies for TCL VOCs, SVOCs, Pesticides/PCBs, and TAL inorganics. In
addition to the CLP analyses, sediment samples were also analyzed for PHCs, and
TOe. The inductively coupled plasma (ICP) serial dilution analysis results for zinc
has a percent difference between the sample result and serial dilution of greater than
15 percent and associated samples were qualified as estimated with a "J". The
laboratory also analyzed two surface water samples for TCL VOCs, SVOCs,
pesticides/PCBs, TAL inorganics, total suspended solids, and hardness.
. 4,4'-DDT was reported in one sediment sample (JSD;.2761) at a concentration of
0:028 J mg/kg; this is below the 0.94 mg/kg background concentration established
for LAFB soil. The compound was not detected in any of the other samples
analyzed. The presence of 4,4'-DDT may be attributed to pesticide application.
Arsenic was detected in a surface water sample (JSW-2862) at 4.2 ""g/L, which is
below the CRQL Arsenic was not identified above background concentrations in
the soils at the site. The detection of arsenic is inconsistent with reported possible
fuel releases at the site.
Lead was detected in one of two surface water samples at an estimated cOncentration
of 2.4 ,.,.g/L, a concentration that is below the CRQL Although lead was not
identified above background in the soils at the site, lead was reported in one
sediment sample (JSD-2862) at 163 mg/kg. This is above the background soil
concentrations of 70 mg/kg estimated for LAFB soils. Zinc was detected at
139 mg/kg and 198 mg/kg in two sediment samples (JSD-2861 and JSD-2862,
respectively). This is above the estimated background concentration for LAFB soil.
Zinc has been identified as a site contaminant in sediment at the site.
Sediment sample JSD-2861 contained five fuel-related P AH compounds, with a total
P AH concentration of 0.899 mg/kg.
PHCs were detected in all four sediment samples. Samples collected at FDS-N1 had
concentrations of 56.0 mg/kg (JSD-2760) and 55.9 mg/kg (JSD-2761). FDS-N2
concentrations were 1,080 mg/kg (JSD-2861) and 311 mg/kg (JSD-2862).
Installation Restoration Program
W0099319.080
B-17
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PART 8
8.5.3 MIGRATION PATHWAYS
The media into which chemicals migrate can affect the types of exposures that could
occur. Mechanisms of chemical migration are discussed below to help identify
potential exposure pathways.
East Gate Waste Storage Tanks
Pot~ntial contaminant migration pathways at EGWST are by wind (advection of
volatiles or erosion of contaminated particles), groundwater movement, and the
leaching of contaminants through soils by water percolation. The disttibution of the
fuel-related VOCS, chlorinated VOCS, and P AHs indicates that most contaminants
were released to the environment in the subsurface through leaks from the USTs or
associated piping. Once in the subsurface soils, coDt~minants appear to be migrating
horizontally through the movement of perched water observed in the overburden at
the site. This is evidenced by the presence of contaminants in soil west of the tank
locations. VOCs and light SVOCs move in water after being solubilized; heavier
SVOCs, such as phenanthrene, possibly move with soil colloids through water
movement. The data obtained to date indicates that there has been minim3-l
migration of the contaminants.
. The perched water at the EGWST site is the result of a ''bathtub effect" created
when tight soils around the tank were excavated during installation of the
underground storage tanks. The soil that was backfilled in the excavation was
disturbed and, as a result, less dense and likely more permeable. During'
precipitation events, the rain infiltrates more readily through the disturbed soil than .
the undisturbed till. Ponding occurs when the infiltrating rainwater encounters the
native till. The perched water is likely a temporary condition that only occurs during
prolonged rain events. The extent of ponding is probably limited to the area of the
excavation. The presence of perched water facilitates the lateral dispersion of fuel-
related contaminants. As the ponded (contaminated) water spreads within the
excavation, vertical infiltration begins to occur through unconsolidated materials at
the site. At this point, the infiltrating rainwater would likely migrate downslope to
the west along the less permeable bedrock surface until it gradually infiltrated into
the bedrock and groundwater. Upon contact with the. water table, potential
cont~mincmts that migrated with the infiltrating rain water would flow northeast with
groundwater.
Installation Restoration Program
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7~
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PART B
A complete discussion of site char~cteristics can be found in the RI/FFS in Sections
6.0 and 11.0 (ABB-ES, 199b).
Fuel Drop Sites
There are no indications that repeated large quantities of fuel were discharged at
these sites. It is believed that FDS-N1 was used once for fuel discharge and FDS-N2
was used three times. No site-related analytes have been identified in the soils at
FDS-N1 or FDS-N2.
The SVOCs detected in soils at FDS-S may be attributed to aircraft exhaust or fuel
and oil that accumulated on pav~ment and was washed off by the storm runoff.
Further migration of site contamimmts appears not to have occurred. The available
data does not indicate the presence of fuel-related compounds in groundwater at the
site, however, a comprehensive groundwater study has n~t been completed. This
groundwater study will be completed under OU 12 H the data gathered during that
investigation changes the interpretation of site conditions, the need for additional
work at the site will be evaluated and work performed if necessary.
Metals in the surface soils and sediments are expected to undergo migration by
surface water. Downward migration in the soil column is not expected to be a major
migration pathway; still, this may occur in the near-surface soils with rainwater
infiltration. Some metals are present in groundwater, but cadmium, which has been
detected in soil, is not one of them.
The groundwater data indicate that SVOCs and metals detected in soil have not
impacted groundwater quality. However, groundwater will be evaluated further as
a separate operable Unit~ . .
A complete disaISSion of site characteristics can be found in the RI/FFS in Sections
6.0 and 11.0 (ABB-ES, 1993b).
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PART B
B.6 SUMMARY OF SITE RISKS
B.6.1 EAST GATE WASTE STORAGE TANK
A risk assessment was performed to estimate the potential risks to human health and
the environment from exposure to contaminants associated with the EGWST. The
human health risk assessment followed a four step process: (1) contaminant
identification. which. identified those hazardous substances that, given the specifics
of the 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 and ecological risk assessment for the EGWST site are
dis~ed below. Since the cumulative carcinogenic healtb risk is less than lxlO" and
the hazard index (HI) is less than 1.0, remedial acton due to human health risks is
not necessary at the EGWST site under CERCLA. .
Human Health Risk Assessment
The contaminants of concern identified for the EGWST, listed in Table B.6-1, were
selected for evaluation in the risk assessment and include 12 for surface soil, 10 for
subsurface soil, and 10 for the area below the removed tank. These contaminants
constitUte a representative subset of all the contaminants identified at the site during
the RI. The compounds were selected to represent potential site- related hazards
based on toxicity, concentration, frequen~ of detection, and mobility and persistence
in the environment. A summaxy of the health effects of each of the contaminants of
concern can be found in Subsection 9.23 of the RI/FFS (ABB-ES, 1993b).
Human health risks associated with exposure to the contaminants of concern were
quantitatively evaluated under both current (groundskeeper and child trespasser) and
future (residential and construction worker) land-use scenarios. Several hypothetical
C)
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TABLE B.6-1
CONTAMINANTS OF CONCERN TO HUMAN HEALTH
EAST GATE WASTE STORAGE TANK slm
OU 6 ROD
LORING AIR FORCE BASB
WAXDaJy,. MlHt1IItJW I BACKGROUND !
'RANGE OJ>. 'PREQUBNCY. .. Dl!1.'Bcrm DI!TECl'BD,
, SQu- OJ> . COHCl!NTaATIOH. CONCENTRATION YEAH. . RANGE ;
COMPOUND. . (.aJb1 , DBTEcnON. . (.8Jb\ (.8/b). (.a/b) , (.aJb) I
Sulacc Sol I I
I
BellZiO(a)aalilneeae 0.37 - 0.4 1/6 0.27 0.27 0.045 I NA '
BeaZO(a )pyreae 0.37 - 0.4 1/6 0.22 0.22 0.0367 NA ,
BeallD(b)Buonallleoeoo 0.37 - 0.4 1/6 0.23 0.23 I 0.0383/ NA
BeallD(k)Buonatbeoeoo 0.37 - 0.4 1/6 0.23 0.23 I 0.0383 NA
Chryseae 0.37 - 0.4 1/6 0.3 0.3 I 0.05 NA
Fltaonameae 0.37 - 0.4 1/6 0.s5 0.s5 I 0.0917/ NA I
racleao(l.2.3-c.d)pyreae 0.37 - 0.4 1/6 0.15 U5 O.OZS NA :
Pbe..alilreoe 0.37 - 0.4 1/6 0.37 0.37 I 0.0617/ NA
Pyreae 0.37 - 0.4 1/6 0.4 0.4 0.0667/ NA
Dis(2 -elbylbayl)pbtbalare 0.36 - 0.4 1/6 U5 0.45 I 0.233 NA
TolD! Careiaopaie PAHs 1.4 0.:3 NA
TOI8I PAHs witbOtlI RIDs 1.77 0.295 NA
"'""sol'(;;;hz,.::..}:::
2 - Medlyl-piatbaJe- 0.36 - 0.42 1/12 2.6 2.6 0.217 NA
8IIlylbeuyI"""'te 0.36 - G.42 1/12 o.os 0.05 0.176 NA
Di-o -ocayIplatUJ8re 0.36 - G.42 7/12 0.31 US 0.203 NA
NapiatbalDo. 0.36 - 0.42 1/12 1.3 1.3 U08 NA
Dis(2 -etbylbayl)pblllalare 0.36 - 0.37 S/12 0.28 0.05 0.177 NA
Beucoe G.OO6 - 1.4 1/18 0.004 OJlO4. I O.OCI1 NA i
Blilylbeaza:a. OJlO6 - 1.4 I
1/18 0.24 0.24 I 0.0136 NA ,
Mctbyleae CWoride OJlO6 - 1.4 :J118 0.14 0.014 0.0532 NA
TolD! Xyteaa 0.006 - 1.4 1/18 U8 0.18 0.0103 NA
Total PAHI witboul RIDs 3.9 I 0.325 NA
Soil ~ Ile~T~(>i2 ft~)
I
I
A81im08Y 3.7 - 6.3 1/8 6.7 6.7 2.73/ <1.0 ;
2 - Melbyl_pb thale... 0.37 - 21 317 12 0.17 I 1.873 NA i
I
Napblbaleae 0.37 - 21 2/7 8.7 0.62 1.359 NA
3.3.S41 i
Dis(2-etbyllaezyl)pbtbalare 0.37 - 24 117 0.2 0.2 NA I
Beucaae 0.011 - 31 1/8 0.01 0.01 3.0114 NA !
Elilylbeazeo. 0.028 - 31 418 U 0.012 3.154 NA ,
Mctbyleae CIIIoricie 0.011-4.3 318 21 0.56 5.343 NA I
I
Tolucoe 0.011 - 14 318 98 0.008 13.397 NA i
TOIaI Xyleaa 0.028 718 S90 0.072. az.so7 NA i
TOIaI PAMs witboDI RIDs I
20.7 I 3.232 NA
NOTES:
°Ra.p' of Sa.pI. Qaori.lieo Uaails for pa"'..len reported AI 'DOI cleleClcd° ia . ".ple.
.°BeaZO(b)Ouonatbeae a04 belUll(k)Oaon8tbeo. _111..- 1IOI1peci81ed: reporred al co.biaed wlue.
NA . No backpu04 data a¥Dibbie. .
22-0Cl-93 \TabB.6-1
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PART B
exposure pathways were developed to reflect the potential for exposure to surface
and subsurface soils. The following is a brief summary of the exposure pathways
evaluated. A more thorough description can be found in Subsection 9.2 of the
RI/FFS (ABB-ES, 1993b).
Current exposure scenarios include occupational (adult-groundskeeper) and
recreational (child-trespasser). Furore scenarios include adult and child resident and
occupational adult (Le., construction worker for subsurface soils). Soil exposure
includes incidental ingestion, dermal absorption, and inhalation of particulates for
both current and future land use scenarios. Exposure to groundwater was not
considered as an exposure pathway, because groundwater will be considered in a
separate operable unit. The potential future land use by a farm family (referred to
as the resident farmer scenario) was considered and eliminated from further
evaluation based on soil limitations that make soils generally unsuitable for cultivated
crops, pasture, or hayland (e.g., surface stoniness) (USDA-SCS, 1986).
Different exposure levels were evaluated for the exposure pathways in the risk
assessment The parameters and assumptions used to determine the exposure levels
for each pathway are described in Tables A through J in Appendix J of the RIfFFS
'(ABB-ES, 1993b). For dermal contact and ingestion of soils in the residential
scenario, a child was evaluated based on the assumed exposure of 182 days per year
(it is assumed that the soil is frozen or snow-covered 26 weeks of the year) for six
years, with 24 years for an adult (USEPA, 1991a). For the current groundskeeper
scenario, dermal contact and ingestion was of soils was based on an assumed
exposure of 26 days per year (1 day per week for 26 weeks) for 25 years (USEP A,
1991a). For the future construction worker, dermal contact and ingestion exposure
was assumed to be for 130 days per year for 1 year. For the residential inhalation,
pathway, an exposure time of 16 hours 'per day was assumed for a period of 70 years
for both the child and adult (USEP A, 1991a). This exposure time was utilized in all
au 6 RI calculations for residential scenarios. For the groundskeeper, the inhalation
exposure was assUmed to be 8 hours per day, 26 days per year, and for the
construction worker, the inhalation exposure was assumed to be 8 hours per day, 130
days per year. For each pathway evaluated, an average and an RME estimate was
generated corresponding to exposure to the average and the maximum concentration
detected in that particular medium.
Excess lifetime cancer risks were determined for each exposure pathway by
multiplying the exposure level with the chemical-specific cancer factor. Cancer
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PART B
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., 1 x 1Q-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 USEP A 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 RID or other suitable benchmark 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., 0.3>" indicating
the ratio of the stated exposure 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 and the sum is' referred to
as the ID. The target risk level for noncarcinogenic effects is an III of 1.0 (USEPA,
1989b). If the ratio is less than 1.0, no adverse health effect is anticipated. IT the
ratio. exceeds 1.0, there may be a concern for noncancer effects. (For example: the
hazard quotient for a compound known to produce liver damage should not be added
to a second whose toxic endpoint is kidney damage).
Table B.6-2 depicts the risk snmT11ary for the contaminants of concern in surface soil
and subsurface soil, evaluated to reflect present and potential future incidental
ingestion, dermal contact, and inhalation exposure pathways corresponding to the
average and the RME scenarios.
Quantitative estimates of both carcinogenic and non-carcinogenic risks were
calculated for each contaminant of concern identified and each complete exposure
scenario selected for evaluation in the exposure assessment. The equations for
I
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TABLE B.6-2
RISK SUMMARIES
EAST GATE WASTE STORAGE TANK SITE
OU 6 ROD
LORING AIR FORCE BASE
AVERAGE
. Total Cancer Total Hazard,
Risk Indcx
MAXIMUM l
I
Total Cancer Total Hazard;
Risk Index i
I
I
I
I CURRENT USB
!
j
lacideatallagcstioa or Surrace Soil: Grauadskeeper
Dermal Coaiaci with Surface Soil: Grouadskeeper
lahalatiol1 EJqIosure 10 Particulales: Graul1dsk.eeper
TOTAL:GROVSDSKEEPER
I
I
I
3E-08 0.000001 I 2E-07 0.000005
9E-08 0.000004 I 6E-07 0.0000 I
4E-I0 NA I 2E-09 ~A
1£-07 0.000005 i 8E-07 0.00002
4E-08 0.000004 2£-'07 0.0000:
~ 0.00002 lE-06 9.:!!QQQ1
2E -07 0.00002 lE-06 0.00008
lacidealallagcslioo or Surface Soil: Older Child ExplOring
Dermal Coolael with Surface Soil: Older Child Exploring
TOTAL: OLDER CHILD
FUTURE USE
TOTAL: CONSTRUCTION WORKER
4E-07 O.OOOOZ ZE-06 0.0002
6E-07 0.00003 4E-06 0.0002
3E-09 NA 2E-08 NA:
IE -06 0.00004 6E-06 0.0004
lE-06 O.OOIIZ 6E-06 0.0006
lE-06 0.0002 8E-06 0.0008
~ ~ ~ NA'
-I
2£-06 0.0004 IE-OS 0.001
lE-10 0.00007 2E-I0 0.0003
7E-11 0.00003 2E-I0 0.0001
3E-14 0.000000002 8E-14 0.00000002
2£-10 0.0001 3E-I0 0.0004
2£-09 0.02 6£-09 0.04
4£-09 0.001 2E-08 0.005
~ 0.000002 8E-IZ 0.0000 1
6£-09 0.02 3E-08 0.05
2E-02 101.20
Incideotal [agestioo or Surface Soil: Resideatial Adult
Dermal CoOlKt with Surface Soil: Resideotiai Adult
Iohalatioo EJqIosure to Particulates: Resideatial AduJt
TOTAL: RESIDENTIALADUL T
IDcideDtaliDgestioo oC Surface Soil: Resideatial Child
Dermal Contact with sarCace Soil: Residential Child
IahalatioD EJqIosure to Particulates: Resideatial Child
TOTAL: RESIDENTIAL CHILD
IDcideDlallagestioD or Subsurface Soil: CODstruClioD Worker
Dermal Cootael with Subsurface Soil: CoDStructioa Worker
labalalioD Exposure 10 Paniculates: CCDStructioa Worker
TOTAL: CONSTRUCTION WORKER
[acideatal [Oleslioo or Taak Area SubsurC,ce Soil: cOuuudioa Worker
Dermal Cootlel with TaDkAreI Subsurface Soil: CoutructioD Worker
lahalatioD Exposure 10 Paniculates: Coastructioo Worker
IOlestioo or Grouadwater: ResideDtial Adult (Summers Model)
(due 10 tbe ~resease or VOCs. tbe mgestioa mllk.e wu multiplied by 2.3
[MED£P.l99Z])
NOTES:
SA - ToKicity iaCormltioo Dot available to evaluate risk.
2:-0cl-93 \TabB.6-Z
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PART B
calculating chemical-specific and pathway-specific cancer risks and HOs are
presented in Appendix J, Section 2.0 of the RI/FFS (ABB-ES, 1993b).
Surface Soils
The highest cancer risk associated with exposure to surface soils under current land
use is the recreational (older child/trespassing) exposure with a cancer risk = 2x1O-7
for the average exposure scenario and a cancer risk = lxlO-6 for the RME scenario
(see Table B.6-2). These values are below regulatory risk criteria. Carcinogenic
P AHs are responsible for most of the risk associated with exposure to surface soils
(carcinogenic risk from PAHs = lxlO-6 for the RME scenario).
The potential future residential land-use scenario presents the greatest potential risk
to human health (see Table B.6-2) because of the potential for long-term, repetitive
exposure to soil CODt~minants and the conservative assumptions involving soil
ingestion rates. The highest carcinogenic risks are associated with future residential
exposure to children (2xl0-6 for the average exposure scenario and lxlQ-s for the
RME scenario) and, adults (lxlQ-6 for the average exposure scenario and 6x1Q-6 for
the RME scenario). The total 30-year residential risk is 2xlO-s (for the RME
scenario) and 3xl0-6 (for the average exposure scenario). These risks represent the
sum of ingestion, dermal, and inhalation pathways. The cancer risk for a child in the
RME scenario is equal to the MEDEP's target cancer risk level of lxlO-s. The
. average exposure risk scenario to residential children and both the average and RME
risks to adults are below ~DEP's target risk level. The total 3D-year residential
cancer risk associated with the RME scenario slightly exceeds MEDEP's target
criteria. Average total residential risks are within MEDEP's criteria. No risk
estimates exceed the USEPA's risk limit of lxl~. Exposure to carcinogenic PARs
accounts for the majority of the risk involving contaminated surface soils (i.e., future
residential exposure to children: lxlO"s for the RME scenario; future residential
exposure to adults: 6xlQ-6 for the RME scenario).
The non-carcinogenic HIs associated with exposure under all scenarios were well
below 1.0. Non-carcinogenic health risks are not of concern.
Subsurface Soils
The carcinogenic risks to the theoretical futUre construction worker are well below
all target risk criteria in the range of 10-10 to 10-& for the RME scenario in both
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PART B
'"
subsurface and "hot spot" subsurface soils. The. non-carcinogenic HIs associated with
all subsurface soil pathways are well below 1.0. The greatest systertric hazards
calculated for the site are to the future construction worker using the RlvfE scenario
(tank area) soils (In = 0.05). This indicates minimal non-carcinogenic effe.cts are
expected from site soils.
The concentrations of contaminants potentially leached from the soil were derived
using the Summers Model (Appendix L of the RIjFFS). Modeled concentrations of
. VOCs (Le., methylene chloride, toluene, and xylene) exceeded state and federal
standards. Because many of the modeled compounds (e.g., PARs) do not bav"e
groundwater standar-ds, the modeled concentrations were used to evaluate potential
future risk from domestic use of groundwater. Following MEDEP guidance for
evaluating VOCS in groundwater, the ingestion intake was multiplied by 2.3 to
provide estimates of inhalation and dermal absorption for the residential adult
groundwater-use scenario (ABB-ES, 1992a). Maximum contaminatlt concentrations
(Le., "hot spots") were used in the 'Summers. Model. The potential risks associated
with the contaminants leached to groundwater are high (cancer risk = 2xlO-2, In =
101.2) because of the use of analytical data collected from the "hot spot" area. Both
values exceed appropriate regulatory criteria. The calculated risks from the modeled
concentrations in groundwater are primarily due to methylene chloride (cancer risk
= 1.8x1()"2, In = 94.7). .
Uncertainty Evaluation
Quantitative estimates of risk are based on numerous assumptions, most of which are
intended to be protective of human health (Le., conservative). 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 uncertainties inherent in the risk assessment methodology
that might lead to an underestimation of true risks, most assumptions will bias an
evaluation in the direction of overestimation of risk.
The possibility for underestimation of true risks is caused by the exclusion from
quantitative evaluation of several pathways (i.e., residential exposures to potentially
excavated subsurface soils spread aboveground and ingestion of homegrown produce
from backyard garden plots). Under certain circumstances these pathways may be
significant and therefore may be quantitatively evaluated in those cases. As
mentioned before, "hot spot" soils at the EGWST were below 15 feet bgs and
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therefore not appropriate for a residential evaluation. The possibility of a backyard
garden plot is considered slight at sites that are less than 1 acre. Tbe EGWST site
is less than one-half acre.
As stated, risks associated with exposures to groundwater at the EGWST were not
assessed other than the evaluation of the leaching potential for contamimmts in soils
using the Summers Model. These, results are inconclusive because a comprehensive
groundwater study has not been' completed. Groundwater at the site will be
evaluated as a separate operable unit (OU 12). ,If data gathered during that
investigation changes the interpretation of site conditions, the need for additional
work at the site will be evaluated and work performed if necessary.
I
Because benzo(a)pyrene and naphthalene are the most toxic representatives of
carcinogenic and non-carcinogenic P AHs, respectively, the use of their toxicity values
to estimate the adverse effects of exposure to P AHs lacking specific toxicity values
will likely result in an overestimation of risks. Other sources of uncertainty that
could cause overestimation of risks include: the use of purposive (biased) sampling
(targeting only the "hot spots"); the estimation of exposure concentrations by the use '
of maximum detections (while assuming no degradation, dilution, and so forth); the
use of the 95 percent (or upper bound 90 percent) exposure parameter values such
as contact rate and exposure frequency and duration; and the use of conservatively
derived toxicity values such as RIDs (incorporating multiple safety factors) and CSFs,
which are based on experimental animal data used in a multistage model. The
USEP A Risk Assessment Guidance states that the carcinogenic risk estimate will
generally be an upper-bound estimate. and that USEP A is reasonably confident that
the, 'nue risk' will not exceed the risk estimate derived through use of this model and
is likely to be less' than predicted (USEP A, 1989b). Therefore, the true risk is likely
not much more than the estimated risk, but it could very well be considerably lower,
even approaching zero.
ECOLOGICAL RISK ASSESSMENT
The ecological risk assessment chose five terrestrial wildlife indicator species were
selected to represent exposures for terrestrial organisms through ingestion of food
, and, soil. The five indicator species are,:
.
short-tailed shrew (Blarina brevicauda), small mammal, carnivore
American woodcock (Scolopax minor), small bird, omnivore
.
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PART B
.
ganer snake (Thamnophis s. sirtalis), reptile, carnivore
fisher (Manes pennanti) predatory mammal, carnivore
broad-winged hawk (Buteo plarypterus), predatory bird, carnivore
.
.
Use' of these species in estimating risk is conservative because the species. are
predominantly carnivorous, and therefore highly prone to exposure to chemicals
through the food chain. Organisms with small home ranges, such as the shrew and
garter snake, and/or that ingest a high proportion of earthworms and other terrestrial
invertebrates, are panicularly susceptible to food .chain exposures.
These organisms were chosen for the following reasons: (1) these species are all
potential ecological receptors at the EG'WST; (2) the various feeding habits (e.g.,
omnivore, carnivore) are representative of those typical of an ecological community;
and (3) these species were recommended for a conservative evaluation of ecological
risk by USEPA and USFWS (USEPA, 1991c). It is assumed that each species
chosen is the most sensitive representative of other species at a similar trophic
position occurring at the EGWST. Modeling of exposures to rare species was not
performed because no rare, threatened, or endangered species have been identified
at LAFB (see Subsection 9.32 of the RI/FFS) (ABB~ES, 1993b).
Adverse effects related to short-term exposures to contaminants of concern in surface
soils are predicted for the short-tailed shrew and the American woodcock. HIs
exceed 1.0 for the shr~w (HI = 17), and the woodcock (Ill = 9.9), and are solely
attributable to benzo(a)pyrene (HQ = 17 for the shrew, and '9.9 for the woodcock).
Adverse effects related to acute exposures are not predicted for the snake, fisher, or
hawk.
Adverse effects related to long-term exposures are probable for small mammals, and
possible for small birds, and herptiles; HI = 80 for the shrew, In = 1.2 for the
woodcock, and III = 1.0 for the snake. Benzo(a)pyrene is the greatest contributor
to risks related to acute exposures at the EGWST. The benzo( a)pyrene HQs equal
79 for the shrew, 1.2 for the woodcock, and 1.0 for the snake.
Benzo(a}pyrene is also the major contributor to risks at the EGWST because of the
conservativism used in seleCting the lowest R TV identified in the literature for
. benzo(a)pyrene. The chronic RTY for benzo(a)pyrene (0.002 mg/kgbw-day) was
chosen because it results in the most conservative estimation of risk. The HQs for
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indicator species for benzo(a)pyrene in the chrome scenario are therefore .bigher than
for any other chemical of potential concern.
Using the relative ranking scheme described above, Ins indicate that effects to
individuals are probable although they do not necessarily provide an indication of
population effects. In certain cases, acute and chronic effects to individuals may
occur with little effect on population growth, stability or structure.
Because of the infrequent detection of contaminants in surface soils, and because the
single contaminant of concern (Le., benzo(a)pyreIie) contributed virtually the entire
m values outside the risk range, it is unnecessary to perform a CERClA remedial
action at the EGWST to protect the environment.
B.6.2 FuEL DROP SITES
A risk assessment was performed to estimate. the potential risks to human health and
the environment from exposure to contaminants associated with the FDSs. The
human health risk assessment followed a four step process: (1) contaminant
identification, which identified those .hazardous substances that, given the specifics
of the 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 magoitude 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 and ecological risk assessment for the fuel drop sites are
discussed below. Since the cumulative carcinogenic health risk is less than 1x1~ and
the HI is less than 1, remedial action due to human health risks is not necessary
under CERCLA at the fuel drop sites.
Human Health Risk Assessment
The contaminants of concern identified for the FDS, listed in Tables B.6-3, B.6-4,
B.6-5, w~re selected for evaluation in the risk assessment. For FDS-N1, (Table
B.6-3) these include two for surface soil and one for subsurface soil. For FDS-N2
(Table B.6-4), these include one for surface soil and two for subsurface soil for
subsurface soil. For FDS-SA and FDS-SF (Table B.6-5), these include 11 for surface
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TABLE B.6-3
CONTAMINANrS OF CONCERN TO HUMAN HEALTH
FUEL DROP SITE - NORTH 1
OU 6 ROD
WRING AIR FORCE BASE
COMPOUND
'I RANGE OP
. SQu.
PREQUENCY
OP
. DE:I'ECI'ION
YAXDlUN
DETECl"ED
CONCEHTRA110N
.
Surface Soil
Bis(2 -elby\besyl)phtbalale
Cyaaide
035 - 036
I 0.53 - 0.54 I
I
I 035 - 0.4
::!I4
V4
0.52
0.54
0.31
0.54
0.296
0.336
SA
NA
Sub-surface Soil
BD(Z -elhylhayl)pbthalate
418
03
0.14
0.196
SA
NOTES: .
-Ra. 01 Sample OuaDtiwioD Umiu for ,-lamelelS reponed 8S "DOl delCl:led- in 8 sample.
NA = No b8cqroaDd uta available..
22-OcI-93 \TabB.6-3
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TABLE B.6-4
CONTAMINANTS OF CONCERN TO HUMAN HEALTH
FUEL DROP SITE - NORm 2
OU 6 ROD
"
LORING AIR FORCE BASI:.
MAXIMUM . MINIMUM I
; RANGB OP PREQUENCY DETECTED DE'l'BCTED BACKGROUND I
. SOu-. OP. CONCENl"RATION CONCBNJ"RATJON . MEAN RANGE i
:
COMPOUND . DETECTION .
Sarface Soil I
Bis(:!-eillylhexyl)phlbalale I 0.34 - 0.36 lIS 0.27 0.27 0.194 NA
I
Sub-sudace Soil I
i
Bis( 2 - elbylhexyl )phtbala Ie 0.35 - O.36 :!1ll 0.46 0.26 0.205 NA
Beryllium 0.43 7/11 :! 0.47 0.935 < 1.0-1.5
NOTES:
. Raase of Sampie QuaDtitatioD Limits for parameters reported .Dot detected. in a sample.
NA = No bac:kpou;Dd data available.
22-Qct-93 \TabB.6~4
-------
I COMPOUND
: Surrace Soil
I
I
14-Methyl-2-pcnlanone
, Bis(2-ethylhexyl)phthalate
I Benzo(b)Ouoranthene
I
'I Benzo(k)Ouoranthene
Fluoramhene
! Phenanthrene
; Pyrene
: Cadmium
! Cyanide"
I, Total Carcinogenic PAHs
Total PAHs without RIDs
I Sub-IurCacc Soil
2 - Methylnapbthalene
Accnaphtbene
Benzo( a )antlu'8ccne
BcnzO( a )pyrene
Benzo(b )t1uoranthene
Benzo(g.hj)pcrylene
Benzo(k)fluorantbene
Bis(2 -ethylhexyl)pbthaJa1e
: Carbazole
I Chrysene
Dibenzoruran
I Fluoranthene
I Fluorene
! Indeno(l.2.;J-c,d)pyrene
: Phenanthrene
I Pvrene
Barium
i Beryllium
! Cadmium
Lead .
Nickel
Zinc
4,4'-DDT'"
Aroclor-1260u
Total Carcinogenic PAHs
TOIaI PAHs wilhoul RIDs
TABLE B.6-5
CONTAMINANTS OF CONCERN TO HUMAN HEAL TIt
FUEL DROP SITE SOUTH
OU 6 ROD
LORING AIR FORCE BASE
I MAXIMUM I MINIMUM,
RANGB OF I FRBQUENCY DETECTED. I DETECTED I
SOLa- I OF CONCENTRATION i CONCENTRATION I
m DETECTION m : m '
i
, I
I 0.011 - 0.012 i
0.35 - 0.47 :
I 0.35 - 0.47 :
i 0.35 - 0.47 i
, 0.35 - 0.47 .
I 0.35 - 047 I
! 0.35 - 0.47 :
: 1.1-1.2 I
I 0.57 - 0.48 !
i
i
0.36 - 0.47
0.36 - 0.47
0.36 - 0.47
0.36 - 0.47
0.36 - 0.47
0.36 - 0.47 I
0.36 - 0.47
0.36 - 0.43 I'
0.36 - 0.47
0.36 - 0.47 I
0.36 - 0.47
0.36 - 0.47 i
I 0.36 - 0.47 I
I 0.36 - 0.47
! 0.36 - 0.47
I 0.36 - 0.47 I
!I' 0.41 ~ 0.52 I
1 - 1.3
I .: J
I 0.0072 - O.~
i 0.072 - 0.086 I
MEAN
i BACKGROUND i
I RANGE
I
,
:
119
119
119
119
119
119
119
119
119
0.008
0.26
0.095
0.11
0.19
16
0.18
1.3
0.64
0.205
0.365
0.008
0.::6
0.095
0.11
0.19
016
0.18
1.3
0.64
I
1/16
1/16
2116
1/16
5/16
1/16
5/16
5/16
1/16
2/16
1/16
4/16
In6
1/16
4/16
~/16
16/16
7/16
1/16
16/16
16/16
16/16
1/15
1/15
0.32
2.3
13
12
14
2.6
10
0.71
3.7
14
1.5
31
2.6
5.3
27
24
354
1.6
1.4
72.9
112
127
0.012
0.079
68.3
101.12
0.32
2.3
.17
12
0.047
1.4
0.042
0.13
3.7
0.18
1.5
0.18
2.6
5.3
0.16
0.15
34.7
0.5
1.4
7.1
42.2
46.5
0.012
0.079
N01CS:
""These compounds were only detected at FDS- S (active)
"Range or Sample Quantitation umilS ror parameters reported "nol detected" in a sample.
NA = No background da&a available
B-32
0.00589 I
0.198 i
0.0106 I
0.01221
0.0211 .
00178 i
,
i
I
!
0~6~11
0.307
0.0228
0.0406 i
I
0.06531
0.1891
0.857
0.795
0.899 I
0.1331
0.647,
om
0.409
0.92
0.139
1.9941
0.208
0.377
1.7371
1.55
65.11
0.445
. 0.61
16.31
53.2
66.2
0.00433
0.0405
4.844
6.:'8
NA
NA
NA
NA
NA
NA
NA
< 1.{)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
10-300
.< 1.0 - 1.5
<1.0
11.5-70
29.5-70
45-74
<0.0076 - 0.94
NA
NA
-------
PART B
soil and 26 for subsurlace soil. These contamin:'lQts constitute a representative subset
of the contaminants identified at the Site during the RI. The compounds 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 eff~CtS of each of the contaminants of concern can be found in
Subsection 10.23 of the RI/FFS (ABB-ES, 1993b).
",..,
Human heaJth risks associated with exposure to the contaminants of concern were
estimated quantitatively evaluated under both current (groundskeeper) and futUre
(residential and construction worker) land-use scenarios. Several hypothetical
exposure pathways were developed to refleCt the potential for exposure to surface
and subsurface soils. The following is a brief summary of the exposure pathways
evaluated. A more thorough description can be found in Subsection 102 of the Final
RI/FFS (ABB-ES, 1993b).
Current exposure scenarios include occupational (adult-groundskeeper). Future
scenarios include adult and child resident and occupational adult (i.e., construction
worker for subsurface soils). Soil exposure includes incidental ingestion, dermal
absorption, and inhalation of particulates for both current and future land-use
scenarios. Exposure to groundwater was not considered as an exposure pathway,
because groundwater will be considered in a separate operable unit. The potential
future land use by a farm family (referred to as the resident farmer scenario) was
conSidered a..""lG elhtiinated from further evaluation based on soil limitations that
make soils generally ~uitable for cultivated crops, pasture, or hayland (e.g., surlace
stoniness) (USDA-SCS, 1986).
Different exposure levels were evaluated for the exposure pathways in the risk
assessment. The parameters and assumptions used to determine the exposure levels
for each pathway are described in Tables A through J in Appendix J of the RI/FFS
(ABB-ES, 1993b). For dermal contact and ingestion of soils in the residential
scenario, a child was evaluated based on the assumed exposure of 182 days per year
(it is assumed that the soil is frozen or snow-covered 26 weeks of the year) for six
years, with 24 years for an adult (USEPA, 1991a). For the current groundskeeper
scenario, dermal contact and ingestion was of soils was based on an assumed
exposure of 26 days per year (1 day per week for 26 weeks) for 25 years (USEPA,
1991a). For the futlire construction worker, dermal contact and ingestion exposure.
was assumed to be for 130 days per year for 1 year. For the residential inhalation
pathway, an exposure time of 16 hours per day was assumed for a period of 70 years
Installation Restoration Program
W0099319.080
B-33
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PART B
for both the child and adult (USEPA. 1991a). This exposure time was utilized in all
au 6 RI calculations for residential scenarios. For the groundskeeper, the inhalation
exposure was assumed to be 8 hours per day, 26 days per year, and for the
construction worker, the inhalation exposure was assumed to be 8 hours per day, 130
days per year. For each pathway evaluated, an average and a reasonable maximum
exposure estimate was generated corresponding to exposure to the a,:,erage and the
RME detected in that particular zhedium.
Excess lifetime cancer risks were determined for each exposure pathway by
multiplying tbe exposure level with the chemical.;specific cancer potency 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., 1 x 10~ 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 USEP A praCtice considers
carcinogenic risks to be additive when assessing exposure to a mixture of hazardous
. substances. .
The HI was also calculated for each pathway as USEPA's measure of the potential
for non-carcinogenic health effects. A hazard quotient (HQ) is calculated by dividing
the exposure level by the RID or other suitable benchmark 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., 0.3) indicating
the ratio of the stated exposure 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 HQ is only considered additive for compounds that
have the same or similar toxic endpoint and the sum is referred to as the HI. (For
example: the bazard quotient for a compound known to produce liver damage should
not be added to a second whose toxic endpoint is kidney damage).
Installation Restoration Program
W0099319.080
7626-08
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PART B
Tables B.6-6 through B.6-9 depict the risk summaries for the contamin~nts of concern
in surface soil and subsurface soil at FDS-NI, FDS-N2, FDS-SA, and FDS-SF
respectively. They were evaluated to reflect present and potential future incidental
ingestion, dermal contact, and inhalation exposure pathways corresponding to the
average and the RME scenarios. The equations for calculating chemical-specific and
pathway-specific cancer risks and HQs are presented in Appendix J, Section 2.0 of
the RIjFFS (ABB-ES, I993b). The quantitative risk estimate tables for the FDSs
are presented in Appendix J of the RIjFFS.
I
Risk Characterization (or FDS-Nl
Surface Soils
The potential cancer risk associated with exposure to surface soils under current land
use for the groundskeeper is 5xlo-10 for the RME scenario (see Table B.6-6).
The highest carcinogenic risks are associated with theoretical future residential
exposure to children (1xIo-&) and adults (4xl0"9) using the ,RME scenario for surface
soil. Therefore, the total 30-year residential cancer risks associated with the RME
scenario are equal to the sum, or lxlO"s. These cancer risk estimates represent the
sum of the ingestion, dermal, and inhalation pathways. In calculating future
residential exposure, the use of the RME scenario yields a cancer risk level well
below both the MEDEP cancer risk target level of 1xlO-' and USEP A's risk limit of
1xlQ4.
Subsurface Soils
The carcinogenic risk associated with the theoretical future construction worker's
RME to subsurface soils is 2xlO"10.
The non-carcinogenic HIs associated with exposure under all scenarios (for both
subsurface and surface soils) are well below 1.0. These HIs indicate minimal non-
carcinogenic hazards to human health. Based on the results of the baseline risk
assessment, remedial action objectives are not considered necessary to protect against
dermal contact, incidental, ingestion, and inhalation of particulates exposure to soil
contaminants at the FDS-Nl. .
. "
Installation Restoration Program
W0099319.080
B-35
-------
TABLE B.6-6
RISK SUMMARIES
FUEL DROP SITB NORm I
OU 6 ROD
LORING AIR FORCE BASE
AVERAGE
Total CaDccr Total Huard
Rilt IDdex
MAXIMUM
Total caDCCr: Total Huard
Rilt..' Indcx
! CURReNT USB
IDcicleDllllDsCllioD of Surface Soil: GrouDd8ecper
Dermal CoDlact with Suriacc Soil: GrouDcblu:c~r
IDUJatioD Expoal&rc tD ParticuialCl: Grouadslr.ecper
TOTAL: GROlJNDSKEEP£R
aE-ll
%E-I0
NA
'B-I0
. PtTIURB USB
IDcicleDtallDsCllioD of Surf8ce Soil: ResideDtill Adult
Dermal CoDlaa with Surf8cc Soil: ResideDIiai Adalt
lobalatioD Expoaurc to PanieuJalCl: Resideatial Adult
TOTAL: RESIDe-.-rIALADULT
lE-09
2E-09
~
'B-at
lacide8t8lla&CllioD of Starf80e Soil: Resideatial Old
DeI88l eo.laet with S.1face Soil: Reside.1iaI Oid
labIatioa ezp..re tD PanieuialCl: Resideatial ODd
TOTAL: RESIDEN'T1AL CHILD
2£-09
3E-09
!!!A
'B-at
lacideatallasCllioa of S.IIIwf8cc Soil: CoutnaioD WOlter
De"" eo.l8ct wi~ S...rfacc Soil: Coutr8C1iD8 WOlter
lobalatioD Expoa.rc tD Panieulata: CoaanctiD8 Worter
TOTAL: CONSTRUcnON WORXER
lE-10
3£-11
~
18-10
IDlealioa of Gnnaadw8tc:r: ResideDtial Ad8l' (S..lDCn Modd)
DeI88l eo.l8ct witll Gro.Ddlnter: Residcati81 A41111
TOTAL: llESIDEN'T1ALADULT
0.00000%
O.ooooos I
~I
0.l1IIOOO7 .
;
O.~ I
O.~ I
NA
CUIOCIIM
0.0001
0.0001
!!!A
IUID83
O.~
O.oooooa
!!!A
JI.IIOOOJ .
lE-10
4E-I0
NA
SE-I0
2E-09
3E-09
~
4B-09
4E-09
6£-09
&.
m-oa
1£-10
SE-ll
t!A
28-10
9B-07
5E-0&
9B-G7
I
.0.000003 I
0.000008
NA
0.00001 I
I
i
0.00004
0.00003
. . NA
CUIOOO7
0.0006
0.000%
&
0.G006
0.00004
0.00001
~
OJlOOO5
0.D07
0.00044
O.ooa
NOTES:
NA - ToDciIy values Dot available tD evall&8l0 risks
:!:!-Oc:l-93 ITable B.6-6
-------
TABLE B.6-7
RISE: SUMMARIES
FUEL DROP SITH NORTH 2
OU6ROD
LORING AIR FORCE BASE
A VBRAGB
Total Cancer To&a. Hazard
Rilk Index
i MAXIMUM I
ITo&aJ Cancer To&al Hazard I
Rilk lad" I
CuRaENrUSE
1Dcideal81lDsealioa of Surface Soil: Gl'OUDdsbeper
Denaal CooIKI willi Surface Soil: Gl'OUDdslceepcr
ltIbaialiOil &po.ure to PanicuJara: Gl'OUDdskeeper
TOTAL: GROUNDSKEEPER
I PU'JURE USE
I 1Dcidea18llDsalioa of Surface Soil: Rcsidearial Adull
Denaa! CooIK' with Surface Soil: Resideurial Adull
1tIbaialioa &pc.ure 10 PanicuJara: Rcsidealial Adult
TOTAL: RESlDENI1AL ADULT
IDcideal81lDpoAioa of Surface Soil: RcsideatiaJ OIiId
Denaa! Coo- Vtith Surface Soil: Rcsideulial OIiId
Iahalalioa &pc.ure 10 PaniaUara: Rcsiclealial OIiId
TOTAL: RESIDENI1AL am.D
IDcideal81lDpstioa of Subsurface Soil: Coastruclioa Worker
Denaal Coa- with Sublurface Soil: Coosauclioa Worker
ltIbaJalioa &pc.ure 10 PanicWara: Coosll1lClioa Worker
TOTAL: CONSmUcnON WORKER
IDpalioa ofGnluadwacer. Raidealial Adult (Summers Model)
Dermal Coo- with Groundwacer. Rcsidealial Adull
TOTAL: RESIDENI1ALADULT
N011'S:
NA- TClllicityvallleSDoUv.ailabie 10 evaluate risla
Z;!-Oct-93 \Table 1U-7
B-37
SE-ll
2£-10
NA
ZE-I0
o.oooooos
0.000002
NA
o.CIOOCICD
7E-ll
2£-10
SA
3E-I0
0.0000007
0.000002
NA
o.CIOOCICD '
7E-I0 0.QX)()07 9E-I0 0.00001
lE-()I} 0.00001 lE-()I} 0.00001
NA NA SA NA
ZE-Q9 o.OOOOZ ZE-09 o.OOOOZ
2£-()I} ~ 2E-()I} O.lJOOO9
2E-()I} 0JXI009 3E-()I} 0.0001
NA, ~ ~ NA
4B-09 o.oooz .58-. o.oooz
lE-07 o.oooS 3E-07 0.001
9E-I0 0.00001 2E-()I} O.QO()()Z
~ ~ ~ ~
1B-07 0.0005 3B-07 0.001 I
I
I
8E-07 0.006 I
~ ~
-------
TABlE B.6-8
RISK SUMMARIES
FUEL DROP SITE SOUIH (ACTIVE)
OU 6 ROD
LORING AIR FORCE BASE
'"
r A VERAGE~. . MAXIMUM;
I Total Cancer Total Hazard Total Cancer Total Hazard \
Risk Index Risk Index
I
I CURREHrUSE:
Incidallallllpilioa of Surface Soil: Gl'OWIciskeepel' --- O.oooooos --- O.OOOOO:!
, Dermal ConlKlwilh Surface Soil: Gl'OWIcisaeper --- O.ooooooos --- 0.0000001
lIIhaialicm &poIUrc 10 PaniculalCS: Gl'OWIcIskeepeI' --- NA --- NA '
- -
TOTAL: GROUNDSKEEPER --- 0.000D009 --- 0.D0000211
I PUJURE USB i
lDcidallallllllcslioa or Surface Soil: Residealial Ad1l!! --- 0.00001 --- 0.0000: !
Dermal ConIKI wilb Surface Soil: Rcsidealial Adul! --- 0.0000003 --- 0.00000071
lIIhaialioa &posure 10 Paniculales: Reside/Ilia! Adul! --- NA --- NA I
- -
TOTAL: RESIDENnAL ADULT --- O.JlOOO1 --- o.ooooz i
I
lDciclealallllpltioa of Surface Soil: Resiclealia! Chilcl --- O.DOO1 --- O.GOOZI
Dermal ConlKlwilh Surface Soil: Residealia! Child --- 0.000003 --- 0.000006 .
lIIhaIalioD Exposure 10 PaniculalCS: Residealia! Chilcl --- NA --- NA i
- -
TOTAL: RESIDENnAL CHn.D --- 0JI001 --- o.oooz I
lDcidealallllSCSlioa or Sublllrface Soil: CoasU1ll:Ii11a Worker .3E-09 O.oocm3 7E-09 0.0001 i
Dermal ConlXlwilh Subsurface Soil: Coasauclioa Worker 4E-09 0.000015 1£-09 0.0000471
lDhaIalioG Ezposure 10 PanicllDles: CoastructioG Wortu &!1 NA 9E-13 NA I
,
TOTAL: CONSTRUcnONWORKER 7E-G9 0.l1OOO5 1E~ 0.00011
IIISCSlioa ofGl'OWIdwaleF: Rcsideolial Adult (Summas Model) 5E-07 O.0G4Si
Dermal ConlKlwilh Growcctncer: Residealial Adull ~ a,OOO:7 I
TOTAL: RESIDEI'TT1A1.ADULT 6E-07 0.005 I
u
N01CS:
- - - No carciDogCIIS delec:led
NA - Taxicicy values DOl awilable 10 evaluale risb
22-0CI-93\Tab B.6-8
-------
TABlE B.6-9
RISK SUMMARIES
FUEL DROP SITE SCum: (FORMER)
OU6ROD
LORING AIR FORCE BASE
AVERAGE MAXIMUM !
Total Caocer Total Hazard Total Cancer Total Hazard i
Risk Index Risk Index
CURRENT USE !
i
IlICicieDla1 IDsestioD or Surface Soil: Groundskeeper i 3E-09 0.00003 3E-08 0.0000; .
Dermal CoDlaCt witb Surface Soil: Groundskeeper i 9E-09 O.I)()()()(N 8E-08 0.00009 ,
JDbalatioD EzpBure to Panjculates: GroWldskeeper I ~ 0.OOOOOOOO5 ~ 0.OOOOOOOO7
TOTAL: GROUNDSKEEPER i 1£-0& 0.00003 1£-07 O.ooooa ,
Pt1I'URE USE i
IlICicieD1a1 IDsaaioD or Surface Soil: Residential Adult I 4E-08 0.0005 4£-07 0.001
Den.1 CoDtact witb Surface Soil: ResicieDlia1 Adult 6E-08 O.ooooJ 6E-07 0.00007 .
IDbalatioD &po5ure to Paniculalcs: ResicleD1ia1 Adult 3E-I0 0.D0000003 ~ 0.()()()()0004 I
TOTAL: RESIDEN'I1ALADULT 1£-0'7 o.ooos 9£-0'7 OJIOl;
IlICicieDtallDsestioD of Surface Soil: Raiclential Child lE-07 o.oos 9E-07 0.01 i
Den.1 Contacl wilb Surface Soil: ResideD1ia1 CbiId lE-07 0.00D3 lE-06 0.0005 ;
IDbalatioD &po5ure to Paniculale8: RaicieDlia1 Child ~ ~ 4E-09 ~i
TOTAL: RESIDENnAL CHD.D ZE-0'7 0.005 2E-G6 0.01:
IDCicleDtailDsesiioD or SubArface Soil: CoDSlnlCtioD Worker lE-06 0.01 ZE-05 O~;
Den.1 CoalaCl witb Subsurface Soil: CoDSUIIClioD Worker 4E-07 0.00D2 6E-06 O.oo:! '
IDbalatioD &po5ure to Paniculala: CoDSUIICtioD Worker 7E-09 0.0005 ~ 0.003:
TOTAL: CONsrRUcnONWORKER ZE-G6 0.01 m-05 O.os
IDsatioDofGl'OIIIIdwater: RaidealialAduit (SIIIDIIIeI'S Model) I 3£-04 v.:N
Den.1 Coatacl witb Gl'Ouactwaler. ResideD1ia1 Adult I &Q! O~O.;-;.~ :
TOTAL: RESIDEN'I1AL ADULT 8£-cM ~.l2'
I
..-
U-Oct-93 \Ta!>!e 6,6-9
B-39
-------
PART B
"
<>
Only one organic chemical, bis(2-ethylhexyl)phthalate (BEHP), was reported in the
soils at FDS-Nl; it is believed to be a sampling artifact. A groundwater
concentration value of 5.29 p.g/L for BEHP, which is less than the MEDEP
maximum exposure guideline (25 p.g/L), was predicted using the Summers Model
(Appendix"L of the RI/FFS). No VOCs, SVOCs, or pesticides/PCBs were detected
in groundwater samples collected from monitoring wells associated with FDS-Nl.
These results are inconclusive because a comprehensive groundwater study has not
been completed. This groundwater study will be completed under OU 12. If data
gathered during that investigation changes the interpretation of site. conditions, the
. need for' additional work at the site will be evaluated and work performed if
necessary.
Risk Characterization for FDS-N2
Surface Soils
The potential cancer risk associated with. exposure to surface soils under current land
use. for the groundskeeper is 3xlO-lo for the RME scenario (see Table B.6-7).
The highest carcinogenic risks are associated with. theoretical future residential
exposure to children (5xHt9) and adults (2x10"9) using the RME scenario for
contaminants in soil. Therefore, the total 30-year residential cancer risk associated
with the RME scenario is equal to the sum, or 7x10.9. These cancer risk estimates
represent the sum of the ingestion, dermal, and inhalation pathways. In calculating
future residential exposure, the use of the RME scenario yields a cancer risk level
well below the MEDEP's and USEP A's target risk criteria.
. .
Subsurface Soils
The carcinogenic risk associated with a future construction worker RME to
subsurface soils is 3x10.7.
The non-carcinogenic HIs associated with exposure under all scenarios (for both
subsurface and surface soils) are well below 1.0. These HIs indicate minimal non-
carcinogenic hazards to human health. Based on the results of the baseline risk
. assessment, remedial action objectives are not cOnsidered necessazy to protect against
dermal contact, incidental ingestion, or inhalation of particulates exposure to soil
contaminants at FDS-N2.
Installation Restoration Program
W0099319.080
7626-08
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PART B
Only one organic chemical, BEHP, was reported in the soils at FDS-N2, and it is
believed to be an artifact of the sample collection process. A groundwater
concentration of 4.7 ",g/L for BEHP, which is below the MEDEP maximum exposure
guideline (25 ",g/L), was predicted using the Summers Model (Appendix L of the
RI/FFS). No VOCs, SVOCs, or pesticides/PCBs were detected in groundwater
samples collected from wells associated with the site. These results are inconclusive
because a comprehensive groundwater stUdy has not been completed. This
groundwater study will be completed under OU 12 H the data gathered during that
. investigation changes the interpretation of site conditions, the need for additional
work at the site will be evaluated and work performed if necessary. "
Risk Characterization for FDS-SA
Surface Soils
No carcinogens were detected in surface soils. The non-carcinogenic HIs were well
below 1.0 (see Table B.6-8).
Subsurface Soils. The carcinogenic risk associated with a future construction worker
RME to subsurface soils is lxlo-a.
The non-carcinogenic IDs associated with exposure under all scenarios (for both
subsurface and stiIface soils, are well below 1.0. These HIs indicate minimal non-
carcinogenic hazards to human health. Based on the results of the baseline risk
assessment, remedial action objectives are not considered necessary to protect against
dermal contact, incidental ingestion, or inhalation of particulates exposure to soil
contaminants at FDS-SA " .
Only one organic chemical, BEHP, was evaluated in the Summers Model for
FDS-SA, and it is believed to be an artifact of the sample collection process. A
groundwater concentration of 4.17 ",g/L for BEHP, which is below the MEDEP
maximum exposure guideline (25 ",g/L), was predicted using the Summers Model
(Appendix L of the" RIjFFS). No VOCs, SVOCs, or pesticides/pCBs were detected
in groundwater samples collected from wells associated with the site. These results
are inco~clusive because a comprehensive groundwater study has not been
completed. This groundwater study will be completed under OU 12. IT data
gathered during that investigation changes the interpretation of site conditions, the
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PART B
u
need for additional work at the site will be evaluated and work performed if
necessary.
Risk Characterization for FDS-SF
Surface Soils
The potential cancer risk associated with exposure to surface soils under current land
use for the groundskeeper is lxlO-7 for the RME scenario (Table B.6-9).
The carcinogenic risks associated with theoretical future residential exposure to
children and adults using the RME scenario are 2xl
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PART B
Using the groundwater concentrations derived from the Summers Model for the
chemicals that do not have a groundwater standard in the risk assessment in a future
groundwater ingestion scenario, yields a cancer risk of 8x104 (Appendix J of the
RIjFFS). This risk is associated with subsurface soils in the FDS-:SF area. Thus, it
is possible that the soils in this area could act as a contaminant source, although
none of the contamin~nts detected in the soils were detected in groundwater samples
from the site. These results are inconclusive because a comprehensive groundwater
study has not been completed; this study will be completed under au 12. H data
. gathered during that investigation changes the interpretation of site conditions, the
need for. additional work at the site will be evaluated and work performed if
necessary.
Based on the slight exceedance of the screening criteria by subsurface soils, an
imminent threat from dermal toxicity of PAH-contaminated soils may exist if
subsurface soils are transferred to the surface (no benzo( a)pyrene was detected in
surface soils; total carcinogenic PARs in ~urface soils = 0.21 mgjkg). Additionally,
the exceedance of the screening criteria indicates possible acute dermal risks to
workers if remediation occurs at the site. This suggests that appropriate skin
covering should b~ worn during any subsurface soil excavation. .
Uncertaintv Evaluation
Quantitative estimates of risk are based on numerous assumptions, most of which are
intended to be protective of human health (Le., conservative). As such, risk
estimates are not truly probabilistic estimates of risk, but are conditional estimates
given a series of conservative assumptions a~out exposure and toxicity. While it is
true there are some uncertainties inherent in the risk assessment methodology that
might lead to an underestimation of true risks, most assumptions will bias an
evaluation in the direction of overestimation of risk. .
The possibility for underestimation of true risks is caused by the exclusion from
quantitative evaluation of several pathways (Le., residential exposures to potentially
excavated subsurface soils spread aboveground, and ingestion of homegrown produce
. from backyard garden plots). Under certain circumstances, these pathways may be
. significant and therefore. may be quantitatively evaluated in those cases. The
potential residential exposure to subsurface soils was not evaluated at the FDSs.
There was no contamination found in subsurface soils at FDS-N1, FDS-N2, or
FDS-SA Although subsurface contamination was detected at FDS-SF, quantitative
~
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PART B
evaluation of residential risks from these soils was not completed. Additionally, the
FDSs are approximately three acres each, portions of which are covered by asphalt.
Because the sites, are larger than one acre, the potential contribution to residential
risks from a backyard garden plot could be imponant. Therefore, in the absence of
remediation, risk to residents from subsurface soils and risks from surface soils (from
ingestion of produce grown in backyard gardens) will need to be reevaluated if
residential land use is considered likely. However, the FDSs have been classified for
an industrial future land use because of the extensive asphalt paving (runway and taxi
areas) and the plan to utilize the base flightline area in an aircra..ft-related industry.
. .
As stated, the RI/FFS does no~ evaluate the risks associated with exposure to
groundwater at the FDSs, other than the evaluation of the leaching potential for
contaminants in soil using the Summers Model. Groundwater at the site will be
evaluated as a separate operable unit. This could cause underestimation of total
risks from the site if the risk from groundwater proves significant. Should this occur,
reevaluation of total site risks would be warranted.
Because benzo(a)pyrene and naphthalene are the most toxic representatives of
carcinogenic and non-carcinogenic P AHs. respectively, the use of their toxicity values
to estimate the adverse effects of exposure to P AHs lacking specific 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 only the "hot spots"); the estimation of exposure concentrations by the use
of maximum detections (while assuming no degradation, dilution, and so forth); the
use of the 95 percent (or upper-bound 90 percent) exposure parameter values such'
as contact rate and exposure frequency and duration; and the use of conservatively
derived toxicity values such as RIDs (incorporating multiple safety factors) and CSFs,
which are based on experimental animal data used in a multistage model. The
USEP A Risk Assessment Guidance states that the carcinogenic risk estimate will
generally be an uwer-bound estimate. and that USEP A is reasonably confident that
the 'true risk' will not exceed the risk estimate derived through use of this model and
is likely to be less than predicted (USEP A, 1989b). Therefore, the true risk is likely
not much more than the estimated risk, but it could very well be considerably lower,
even approaching zero.
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PART B
Ecological Risk Assessment
The ecological risk assessment selected five indicator species to represent exposure
for terrestrial organisms throughl ingestion of food and soil:
.
short-tailed shrew (Blarina brevicauda), smaIl mammal, carnivore
American woodcock (Scolopax minor), small bird, omnivore
garter snake (Thamnophir s. sirtalir), reptile, carnivore
marten (j"Jartes americana), predatory mammal, carnivore
broad-winged hawk (Buteo plazypterus), predatory bird, carnivore
.
.
.
.
Use of these species in estimating risk is conservative because the species are
predominantly carnivorous, and therefore highly prone to exposure to chemicals
through the food chain. Organisms with small home ranges, such as the shrew and
garter snake, and/or that ingest a high proportion of earthworms and other terrestrial
invertebrates, are particularly susceptible to food chain exposures.
These five indicator species were chosen for the following reasons: (1) these species
may be potential ecological receptors at the FDSs; (2) the various feeding habits
(e.g., omnivore, carnivore) are representative of those typical of a terresnial
ecological community; and (3) these species were recommended for a conservative
evaluation of ecological risk by USEPA and USFWS (USEPA, 1991c). It is assumed
that each indicator species chosen is the most sensitive representative of other
species at a similar trophic position occurring at the FDSs. Modeling of exposures
to rare species was not performed because no rare, threatened, or endangered
species have been identified at LAFB (see Subsection 103.2 of the RI/FFS)
(ABB-ES, 1993b).
Lethal effects related to short-term exposures to cyanide in surface soils at FDS-N1
are not anticipated. Lethal effects related to acute exposures at the FDS-Ss surface
soils may be possible for small mammals (shrew In = 2.0) and smaIl birds
(woodcock m = 1.1). Cadmium is the greatest contributor to risk for both species
(cadmium HQ for shrew = 13, cadmium HQ for woodcock = 0.76) at the FDS-SF.
No adverse effects related to acute exposures at the FDSs are expected for the snake,
the marten, or the hawk.
"
Adverse effects related to long-term effects at FDS-N1 are possible for small
mammals (shrew III = 5.6). Cyanide is the sole contributor to risk at the FDS-Nl.
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PARTB
"
Effects related to' chronic exposures are not expected for the woodcock, snake,
marten, or hawk at FDS-Nl. Adverse effects related to long-term effects at the
FDS-SA are possible for small mammals (shrew HI = 6.6). Cya.nide is the major
contributor to chronic exposure risk at the FDS-Nl. Adverse effects related to
chronic exposures at the FDSs are not anticipated for the woodcock, the snake, the
marten, or the hawk.
Ovimium is the greatest contributor to risks from acute exposures to small J11amm3.1~
at the FDS-SF. This risk estimate is, however, based on only one detection of
cadmium out of seven samples analyzed. It is possible that the detected ~nmium
concentration of 1.3 mg/kg represents a statistically insignificant outlier for naturally
occurring background levels.
These total HIs are within the risk management range of 1 to 10. HIs slightly greater
than 1 are predicted for short-term exposures for none of the species at FDS-N1 and
only two of the indicator species at FDS-SA and FDS-SF. A similar scenario exists
for long-term exposures. In view of the occurrences of HIs within the risk range, the
few indicator species likely to be affected, and the poor ,habitat at the sites making
an eXposure pathway unlikely, the need for remediation of surface soils under
CERCLA for the protection of the environment is unnecessary. '
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PART B
B.7 DESCRIPTION OF NO ACTION ALTERNATIVE FOR EGWST AND FDS
SITES
I
There are no construction activities associated with the No Action decisions under
CERCLA at EGWST and the FDSs. However, residual soil contamination at the
EGWST and FDS-SF, which will be present after the non-CERCIA actions being
taken by the Air Force pursuant to state requirements, will be monitored and the
results incorporated, if appropriate, into the remedial action for the separate
operable unit which deals with groundwater and the management of migration for
this portion of the base. .
. ()
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PART B
'"
B.8 DOCUMENTATION OF NO SIGNIFICANT CHANGES
The USAF presented a Proposed Plan for EGWST and FDS Sites on July 28, 1993,
which described USAF's decision to pursue no further action under CERCLA at
these sites. No significant changes have been made to the No Action decision under
CERCLA described in the Proposed Plan.
~
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PART B
B.9STATE ROLE
The Maine Department of Environmental Protection concurs with the Air Force's
No Action decision under CERCIA for FSD-Nl, FDS-N2, and FDS-SA A copy of
the declaration of concurrence is attached as Appendix C. In separate actions which
are not part of this ROD, the Air Force is taking non-CERClA remedial actions at
EGWST and FDS-SF pursuant to state requirements under an Air Force/State Two-
Party Supplement to the FF A being signed simultaneously with this ROD.
. "
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GLOSSARY OF ACRONYMS AND ABBREVIATIONS
o
ABB-ES
ARARs
BEHP
CERCIA
CLP
CRP
DOD
DOE
EGWST
FDS-Nl
FDS-N2
FDS-SA
FDS-SF
FFA
FFS
HAZWRAP
In
HQ
IRP
LAFB
MEDEP
p.g/L
MOGAS
MMES
NCP
NOEL
NFL
ABB Environmental SerVices, Inc.
Applicable or Relevant and Appropriate Requirements
bis-2-ethylhexylphthalate
Comprehensive Environmental Restoration, Compensation, and
Liability Act
Contract Laboratory Program
Community Relations Plan
U.S. Department of Defense
u.S. Department of Energy
East Gate Waste Storage Tanks
Fuel Drop Site - North No.1
Fuel Drop Site - North No.2
Fuel Drop Site - South (Active)
Fuel Drop Site South (Former)
Federal Facility Agreement
Focused Feasibility Study
Hazardous Waste Remedial Actions Program
Hazard Index
Hazard Quotient
. .
Installation Restoration Program
Loring Air Force Base
Maine Department of Environmental Protection
micrograms per liter
Motor Vehide Gasoline
Martin Marietta Energy Systems, Inc.
National Contingency Plan
No Observed Effect Level
National Priorities List
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GLOSSARY OF ACRONYMS AND ABBREVIATIONS
NPW
Net Present Wonh
OU
Operable Units
PA
PAH
PCB
PHC
RCRA
RI
RME
RRMS
RTV
Preliminary Assessment
polynuclear aromatic hydrocarbon
polychlorinated biphenyl
petroleum hydrocarbon
Resource Conservation and Recovery Act
Remedial Investigation.
reasonable maximum exposure
Railroad Maintenance Site
Reference Toxicity Value
SARA
SI
SOL
SVOC
Superfund Amendment and Reauthorization Act
Site Inspection
Sample Ouantitation Limit
semivolatile organic compound
TAL
TCL
TPH
'IRC
Target Analyte List
Target Compound List
total petroleum hydrocarbon
Technical Review Committee
USAF
USEP A
UST
u.s. Air Force
U.S. Environmental Protection Agency
underground storage tank
VOC
volatile organic compound
~
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REFERENCES
ABB Environmental Services, Inc. (ABB-ES), 1990. "Remedial Investigation/
Feasibility Study at Loring Air Force Base; Status Report"; Installation
Restoration Program; prepared for HAZWRAP; Ponland, Maine; August 1990. .
. .
ABB Environmental Services, Inc. (ABB-ES), 1991a. Applicable or Relevant and
Appropriate Requirements (ARARs) Handbook. Draft. Portland, Maine.
ABB Environmental Services, Inc. (ABB-ES), 1991b. "Final Project Work Plan";
Insta~lation Restoration Program; Loring. Air Force Base; prepared for
HAZWRAP; Portland, Maine; July 1991. . .
ABB Environmental Services, Inc. (ABB-ES), 1991c. "Sampling and Analysis Plan";
Final; Installation Restoration Program; Loring Air Force Base; prepared for
HAZWRAP; Portland, Maine; July 1991.
ABB Environmental Services, Inc. (ABB-ES), 1992a. "MEDEP 1992 Risk
Assessment Comments/RI Report No.1: Minutes from Review Meeting for
. . Loring Air Force Base"; April 23, 1993.
ABB Environmental Services, Inc. (ABB-ES), 1993a. "RRMS, EGWST, and FDS
Operable Unit (OU 6) Project Work Plan Addendum"; Installation Restoration
Program; Loring Air Force Base; prepared for HAZWRAP; Portland, Maine;
March, 1993.
ABB Environmental Services, Inc. (ABB-ES), 1993b. "Operable Unit (OU 6)
Remedial Investigation Report/Focused Feasibility Study"; Installation
Restoration. Program; Loring Air Force Base; prepared for HAZWRAP;
Portland, Maine; July, 1993.
ABB Environmental Services, Inc. (ABB-ES), 1993c. "OU 6 Proposed Plan; Railroad
Maintenance Site, East Gate Waste Storage Tanks Site, and the Fuel Drop
Sites"; Installation Restoration Program; Loring Air Force Base; prepared for
HAZWRAP; Portland, Maine; July, 1993. .
. Arthur D. little Inc., 1985. 'The Installation Restoration Program Toxicology
Guide"; Cambridge, Massachusetts; October, 1985. .
Installation Restoration program
W0099319.080
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REFERENCES
CH2M Hill, 1984. ''IRP Records Search"; Loring Air Force Base; Limestone, Maine;
January 1984.
E.C. Jordan Co., 1989. "Remedial Investigation/Feasibility Study At Loring Air
Force Base, Maine: Remedial Investigation Status Report"; Installation
Restoration Program; prepared for HAZWRAP; Portland, Maine; May 1989.
Maine Department of Environmental Protection (MEDEP), 1989. "Solid Waste
Management Regulations; Chapters 400406, 408 &.409"; Bureau of Solid Waste
Management; Augusta, Maine; May 23, 1989.' .
Martin Marietta Energy Systems, Inc., 1988. "Hazardous Waste Remedial Actions
Program. Requirements for Quality Control of Analytical Data"; DOE/HWP-6S;
prepared for U.S. Department of Energy; Contract No. DE-ACOS-840R21400;
Oak Ridge, Tennessee; August 1988.
Martin Marietta Energy Systems, Inc., 1989. "Hazardous Waste Remedial Actions
Program. Quality Control Requirements for Field Methods"; DOE/HWP-69;
prepared for U.S. Department of Energy; Contract No. DE-ACOS-840R21400;
Oak Ridge, Tennessee; February 1989.
R.F. Weston, Inc., 1988. "IRP Phase n Confirmation/Quantification"; Loring Air
Force Base, Limestone, Maine; January 1988. .
Shacklette, Hansford T., and Josephine G. Boerngen, 1984. "Element Concentrations
in Soils and Other Surficial Materials of the Conterminous United States"; U.S.
Geological Survey Professional Paper 1270; U.S. GovemmentPrinting Offic;e;
Washington, DC .. .
U.S. Department of Agriculture (USDA) Soil Conservation Service (SCS), 1986.
"Soil Swvey and Interpretations of Selected Lands in Maine for Loring Air Force
Base;" Orono; Maine.
U.s. Environmental Protection Agency (USEP A), 1988. "Guidance for Conducting
Remedial Investigations and Feasibility Studies Under CERCIA"; USEP A Office
of Solid Waste and Emergency Resj)QDse; Washington, DC; October 1988.
"
~onReno~uonprog~m
WOO99319.080
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REFERENCES
'-.0
u.s. Environmental Protection Agency (USEPA), 1989b. "Risk Assessment
Guidance for Superfund, Volume I: Human Health Evaluation Man~ Part A,
"Interim Final"; EPA/540/1-89/002; December 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; Final Rule; Federal Register,
Vol. 55, No. 46; pp. 8666 et seq.; March 8, 1990.
u.S. Environmental Protection Agency (USEP A), 1991a. "Risk Assessment
Guidance for Superfund, Volume I: Human Health Evaluation Man~ Part A,
Supplemental Guidance, Standard Default Exposure Factors," Interim Final;
Office of Solid Waste and Elnergency Response 9285.6-03; March 25, 1991-
U.S. Environmental Protection Agency (USEPA), 1991b "Solid Waste Disposal
Facility Criteria"; Federal Register, Vol 56, No. 196; October 9, 1991-
. ,
u.s. Environmental Protection Agency (USEPA), 1991c. Loring RI Report/Risk.
Assessment Approach Meeting between representatives of EP A Region I, Maine
Department of Environmental Protection, u.S. Fish and Wildlife SeIVice, Loring
AFB, HAZWRAP, ABB Environmental Services; December 6, 1991.
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APPENDIX A .
~
TRANSCRIPT OF THE PUBLIC MEETING (AUGUST 23, 1993) AND
COMMENT LETTERS ON OU 6 PROPOSED PLAN
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1
STATE OF MAINE
AROOSTOOK, SSe
LORING AIR FORCE
PUBLIC HEARING
ENVIRONMENTAL CLEANUP OF OPERABLE UNIT (OU) 6
HEARD BEFORE:
DANA E. COLEMAN,. CHAIRPERSON,
LORING COMMUNITY RELATIONS AND PUBLIC
AFFAIRS OFFICER FOR THE 42ND BOMB WING
INSTALLATION RESTORATION PROGRAM
PETER FORBES, LORING REMEDIAL PROJECT
CARIBOU CENTER FOR THE PERFORMING ARTS
410 SWEDEN STREET
CARIBOU, MAINE
AUGUST 23, 1993
7:15 P.M.
Philip R. Bennett, Jr.
Court Reporter
13 Vaughn Street
Caribou, Maine 04736
207-498-2729
I
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BASE
MANAGE'
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"
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12 EXHIBITS
13 EXHIBIT ONE
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2
TAB L E
o F
CONTENTS
DANA COLEMAN 3
BEEJ' STOECKELER 4, 10
MARY. SANDERSON 6
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2
ENVIRONMENTAL CLEANUP OF OU6
"
3
4
August 23, 1993
5
6
CHAIRPERSON COLEMAN:
Good
7
8
evening.
This is the OU6 Public Hearing to receive
comments on the OU6 Proposed Plan.
Today's date is 23 .
9
August, 1993.
The time is 7: 15 p.m..
I
My name is Dana I
10
Coleman.
I am the Loring Community Relations and Publ.c
11
Affairs Officer for the base's Installation Restoratio
12
Program.
This is Mr. Peter Forbes, Loring Remedial Project
13
14
Manager and he will assist me in taking commentary fro
the public. I
The public is asked to comment on the OU6 Proposed
15
16
17
Plan, which is comprised of six sites on Loring Air
18
Base." These sites are the Railroad Maintenance Site,
19
I
Drop Sites. These sites were grouped into an operable I
unit, or what we call OU, based on the fact that each I
was found to have soil contamination resulting from thJ
the East Gate Waste Storage Tanks Site and four Fuel
20
21 "
22
23
.release of petroleum based compound.
24
EverYthing that is said from this moment on will
e
25
a matter of public record.
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4
ENVIRONMENTAL C:'EANUP OF OU6
2
3
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6
7
8
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10
"
12
13 I
14
15 I
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18
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20
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23
24
25
Aroostook Legal Reporters recording all statements and
testimony.
Those individuals who would like to make a I
comment, will you please raise your hand.
Lieutenant
Wolfe is going to give you an address 'reply card.
Please fill out your name and the organization that
you are representing and the Air Force will formally
respond to your comment.
Is there anyone else that
intends to make a formal comment?
OAt a public hearing, only testimony is
acceptable.
If you have questions, our technical
advisers or technical representatives will be
available to answer those later on or in another part
of the auditorium but not as part of the formal
hearing.
Ma'am, would you like to make a formal comment?
Wou~d you like to make --?
BEEJ STOECKELER: I just
wanted to ask when is this all going to be starting?
CHAIRPERSON COLEMAN:
The
formal portion has started.
BEEJ STOECKELER:
No, no,
when is all the remediation going to start on the --
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2
ENVIRONMENTAL CLEANUP OF OU6
5
3
CHAIRPERSON COLEMAN:
Okay.
4
We're asking that any questions that you have about
5
OU6, if you could hold them until after we've made
6
our comments or taken our testimony, because this is
7
a part of the record and we are interested in simply
. .
8
getting the citizens' statements, opinions on the
9
proposed plan; but we do have technical representatives
here that will answer that question for you after the
10
11
hearing or in another part of the auditorium.
For those who are interest~ in making a comment, I
would they please come to the--one moment, please, we'r$.
12
. 13
14
not ready to take comments but I'm giving instructions
15
right now.
I apologize.
Would they please come to
16
the mike, state your name and your organization.
Please do not give us your address, tha~'s a personal
17
18
matter that we won't actually put on the record
19
right here; and state your testimony.
Mr. Bennett
20
will record it as close to possible as you make the
21
statement.
~
Before we proceed on to the formal hearing, are
23
. n
there any questions on the procedures?
Yes, ma'am.
24
BEEJ STOECKELER:
The
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ENVIRONMENTAL CLEANUP OF OU?
CHAIRPERSON ~OLEMAN: Yes.
BEEJ STOECK~R:
--this,
doesn't count?
CHAIRPERSON ~OLEMAN: That
does not count. as part of the formal p~lic record.
That was an informal meeting.
. BEEJ STOECKE- LR:
So then
when everybody ~tated off the record that they agreed
that .they would diminish(sic)their perscnal statements,
whether it be from the Air Force or the Maine DEP or.
whatever, that's all off the record?
CHAIRPERSON ~LEMAN: That
will not be part of this record, no, ma' am.
I
I
BEEJ STOEC~R: Well, then~
\
I
I
CHAIRPERSON COLEMAN: Because i
testimony--the formal hearing is not to ask--or answer
can we re-ask it?
EPA.
questions. You may make a comment to t~t effect but--,
I
MARY SANDERSON: I'm with I
I
I
format we have here and the size of the group and there I
I'd like to. suggest o~e thing, be~ause of the
might have been some misunderstanding.
I would propose
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1
7
2
ENVIRONMENTAL CLEANUP OF OU6
3
record. We will not be formally responding to them--t,
you here now, you will get written responses in the I
Responsiveness Summary as a part of the record
4
5
6
selection and then once everyone has a cnance to give
7
a comment or a question, we're then
willing to stay th~s
I
8
evening and to reiterate--you know, give any answers
9
that we can.
Does that sound okay?
Because I think
10
we have the questions and I think the questions could
be in the form of testimony, if you will,--
11
12
CHAIRPERSON COLEMAN:
They
13
can.
14
MARY SANDERSON:--and. you ca
still formally get your responses to those. I under- I
I
stand they're important ones in terms of the future land
use for these sites and such and that we can certainly I
make ~hat a part of the record.
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10
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UNKNOWN PERSON: Ma' am,
20
could you tell who you are for the record?
MARY SANDERSON: I'm sorry.
21
22
And for the record, I am Mary Sanderson with the
23
. Environmental Protection Agency.
And if that's okay--
24
25
I don't mean to -- let's call those questions testimon1"
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ENVIRONMENTAL CLEANUP OF OU6
2
3
the record, I'm Dana Coleman.
Community Relations and
4
Public Affairs for IRP at Loring.
Ma'am, would you llkl
5
to make a comment?
6
BEEJ STOECKELER:
You
7
want(sic)--?
8
CHAIRPERSON COLEMAN:
Well,
9
we have a --Lieutenant Wo~fe will give you an --.
10
BEEJ STOECKELER:
Oh, boy.
11
I can't even remember how to phrase a question.
12
CHAIRPERSON COLEMAN:
Ma'am,
13
we're not opening the floor just yet.
Lieutenant., coul
14
you give her a card?
Okay.
Are there any other
15
questions on our procedures before we begin to accept
16
testimony?
17
UNKNOwN PERSON:
Dana, can
18
you move-the podium by this -mike?
19
CHAIRPERSON COLEMAN:
Yes.
20
One more time, are there any questions on the
21
procedures?
Are there any other people who would like
22
to make a comment and do not have an address reply
23
card?
Okay.
Mr. Robichaud, would you like to begin?
24
Please state your name and the organization you're
representing, for the record.
-------
2
ENVIRONMENTAL CLEANUP OF OU6
9
3
LEO ROBICHAUD:
My name is
4
Leo Robichaud.
I'm chairman of the Loring Readjustment
5
Committee's Environmental Subcommittee.
6
My comments on OU6 are mainly based on Craig
7
Gendron's--who's our technical assistant grant
8
consultant, on the letters that he sent to our
9
committee dated June 21st,- 1993 and August 17th, 1993.
10
. We feel "the ~roposed plan for OU6 as described is
11
on the right track for the most part.
The concern our
12
consultant has is that by using the ~xcavated material
13
from the East Gate waste storage tank site and the fuel
14
drop sites as part of the closing of landfill number
15
two, these materials with ~heir contaminants should
16
be included in" evaluating remedial action on landfill
" 17
two.
18
The groundwater and surface water ~ill be assessed
19
as separate operating unit, namely OU12 and OU13.
20
Along with my comments, I will provide you with
21
copies of Craig Gendron's letters of June 21st, 1993
22
and August 17th, 1993.
I would like to thank you for giving me the
23
24
opportunity to comment on your proposal. I am lookipg
25
-------
1
10
2
ENVIRONMENTAL CLEANUP OF OU6
3 I
4 I
,
proposals.
Thank you.
CHAIRPERSON COLEMAN:
Thank
5
you, Mr. Robichaud. Ma'am, would you like to address-l
present your comments? Please state your name and the i
organization you're representing. i
. I
BEEJ STOECKELER: My name ~s
I
6
7
8 I
9 I
10 I
Beej Stoeckeler, I'm with Uniterra Groups.
My --
essentially I don't have a problem with your proposed
11
plans if your people will go on record, in writing, to
12
say that they agree with this; whether it be the U. S.
13
Air Force that is submitting the proposal, the EPA
and the Maine DEP, that they agree with this in its
14
. 15
16 i
I
17 I
entirety and that if they have specific problems with
various areas of this, that they should be identified.
18
I'd like to know also when is this going to start, whel
is ~h~ actual schedule for each and every site--I have
. . . I
not so much problems with you picking it up, but where!
I
19
20
you're putting it.
You're putting it back.on the same -
21
either putting it--it!s more like a shell game and
essentially you're taking one thing and putting it
22
23
. to' another area on the site and so my concern is. that
24
I haven't got enough information to state my objection
25
-------
2
ENVIRONMENTAL CLEANUP OF OU6
11
3
However, my biggest concern is that if there is a
4
5
specific site on this base that is going to be used
as--whe~her it's a spreading site or a land fill or
6
whatever it is, that that--the recipient of all the
7
garbage from all the other areas is, number one,
documented so everybody knows what that new stuff is
8
9
and, number two, that -- t~at significant measures
are made to restrict or reduce migration from that
10
11
land .fill or that repository for all the other stuff.
That it doesn't continue spreading because you've got--
12
13
you've got little green hats(sic)and you've got 3ugared.
14
water; each of which are known entities but whe~ you
mix those together, you could have sulfuric acid,
15
16
you know what I mean?
17
50 my problem is that I think we're--we have a
significant problem in that there's very, very great
18
19
potential for redistribution of contamination through
20
other media; through the aquifers, through the ground
21
and surface water sources.
And that anybody reusing--
~.
or air, just evaporation. And so that people that are
very much concerned with reusing the site who have
23
24
real and valuable uses for this site and to the tune
25
-------
12
ENVIRONMENTAL CLEANUP OF OU6
2
3
4
5
6
7
8
9
10
11
12
13
14
:
"
15
16
17
'18
19
20
21
22
23
24
25
there.
Hundreds or thousands.
The bottom line is what
is this new mixture?
Is it going to hurt my people?
If so, when?
What can we expect?
How can we prevent
i~?
Real questions here.
It's one thing to say--it's
one thing to say I've got this plan for remediation.
It's a horse of a different shade to be the new
'recipient of this base and. to live and work and play
on this base as a turnkey function.
Every single
thinq on this base essentially being used as a turn-
key function, other than the planes and critical
computers and critical documents.
I don't want to
live with their contamination for the next thirty
or forty years and put my people in jeopardy.
My biggest problem is my own lawyers are having
a very big problem with this.
What is our corporate
liability? What is the EPA, Maine DEP, et cetera, going
to do to assure not just us but are they willing to
pick up the differential in tabs of liability because
of these unknowns that are being introduced?
What--and
just morally, how do you protect your people and
somebody's got to be responsible for saying what we've
got to live with for the next thirty or forty years.
I'm really concerned about that.
-------
2
ENVIRONMENTAL CLEANUP OF OU6
13
3
people be put on the record, you know what I mean?
4
Not a committee, not a blind man's bluff search. Real
5
people committing their word, their professional
6
integrity to the validity of what you're 90ing on all
7
levels.
So anyway that's, again, a primary concern,
8
where you're making a finite decision on those three
9
sites that you are calling. clean.
So if you could
10
kind of clarify those things for us.
11.
CHAIRPERSON COLEMAN:
Ms.
12
Stoeckeler, we have a point of clarification. Your
13
concerns are the three sites that are being declared
14
clean, is that what --?
15
BEEJ' STOECKLER:
Yeah, and i
16 '
you can, you're sending--you're bringing stuff to a
17
third--another place on the base as'a whole.
We're
18
interested in the base as a whole.
We see no reason to
19
even be here if it isn't a turnkey operation. Therefore
20
we are concerned about the whole base because
21
essentially our people are going to be allover the
place on that site.
22
23
CHAIRPERSON COLEMAN:
Ma'am,
24
you're also concerned about landfill two?
25
-------
14
ENVIRONMENTAL CLEANUP OF OU6
2
3
yeah.
4
CHAIRPERSON COLE.~:
The
5
receptor--.
6
BEEJ STOECKELER: Any
7
landfill, any recipient of these contaminan~s that
8
you're--when you say the word "Cap", my hea=t goes
9
pitter-patter because I know it's going to be there for
10
a period of time or forever.
And that isn't even
11
determined yet, do you see?
We're just pushing peas
12
under a shell.
13
CHAIRPERSON COL~~:
Does
14
that concluded your commentary?
15
BEEJ STOECKELER: Yeah, I
16
think so.
17
CHAIRPERSON COL~~: One mor
18
time, is there anyone else who 'would like to make a
19
statement, state a concern, pro or con, for the record?
20
We've
invited the public to comment on OU6 Proposed
21
Plan at this public hearing up u~til 8:30 and we will b
22
available to receive comments up until that time, but
24
seeing that there is no one else at this point in the
juncture that would like to make a comment, we do advis
23
25
-------
1
2
I
I
I
the Maine DEP or U.S. EPA. So unless there's someone I
else that comes in within the next hour or so, we
ENVIRONMENTAL CLEANUP OF OU6
15
3
representatives from ABB Environmental Services or
4
5
6
7
will take a slight break in the action and then I will
officially
close the hearing, which you do not need to I
for. You may leave at any point between now.
. . I
I
And any comments and the statements that
8
be present
9
and 8:30.
10
you make will not be part of the record.
Okay.
We'll
11
take a break.
12
RECESS
CHAIRPERSON COLEMAN: LadieJ
. I
and gentlemen, it is 8:25 p.m., and we're calling the ./
hearing back in to session. We're calling the hearing I
back in to session so that we may close. Is there
13
14
15
16
17
anyone else who has a formal comment that they would
18
l~ke .to present before we close the meeting?
close the hearing?
Before Wl
19
20
For the record, let it be shown that there are
21
no more comments.
Before we close, I'd like to enter
22
into evidence, four pieces of paper presented by Mr.
23
Leo Robichaud from the LRC Environmental Committee.
24
The first page is a letter dated August 23rd, 1993
signed by Mr. Robichaud and addressed to Mr. Peter
"
25
:1
-------
1
16
2
ENVIRONMENTAL CLEANUP OF OU6
3
I
I
I
Forbes; the second piece of paper is a memorandum to tHe
LRC Committee from Mr. Craig Gendron, P.G., P.E., dated
June 21st, 1993 regarding the review of Proposed Plan I
!
-- excuse I
i
,
i
I
I
i
And page four is also a memorandum and it's to the LRC i
I
I
I
I
I
for OU6 CH Project reference LRC-OS/609234
4
5
6
7
me.
354.
I will repeat that correction. The number
8
is LRC-OS/6092354.
And that's pages two and three.
9
10
Environmental Committee.
It is from Mr. Craig R.
11
Gendron, P.G., P.E.
It' is dated August 17th of 1993,
12
regarding public comment for final OU6 Proposed Plan.
I'd ~ike to also bring to the attention that Mr.
13
14
craig R. Gendron, P.G., P,.E., is associated,with
Caswell, Eichler & Hill, a firm out of Portsmouth, New i
1
i
I
Ladies and gentlemen, it, is 8:29 p.m., the 23rd o~
I'
I
I
I
I
I
hearing to discuss and receive comments for OU6
15
16
Hampshire.
17
18
August, 1993 and I officially declare the public
19
20
Proposed Plan officially closed.
21
.22
23
END OF HEARING
24
-------
I
17
2
3
C E R T I F I CAT ION
,4
5
I HEREBY CERTIFY THAT the foregoing is a true and
6
correct transcript of the record of proceedings held
7
on the afore-designated hearing date.
8
9
~ P2. ~I),'
Philip R. Bennett, Jr.,'
Court Reporter
10
11
12
13
14
15
16
17
18'
19
20
21
22
23
24
ENVIRONMENTAL CLEANUP OF OU6
CARIBOU CENTER FOR THE PERFORMING ARTS
CARIBOU, MAINE
AUGUST 23, 1993
-------
Leo J. Robichaud,
LRC Environmental
PO Box 779
Caribou, ME 04736
August 23, 1993
Chairman
Commit-:.ee
Peter Forbes
Remedial ?roject
42 CES/C~VR
Loring AFB, ME
Manager
04751-5000
Dear.Peter:
.My comments on OU6 are mainly based on Craig Gendron's (Technical
Assist.ant. Grant. consuit.*l:fV let.t.ers t.o our commit.tee dat.ed June
21, 1993 and .August. 17, 1993. . .
We. feel the proposed plan for OU6 as described is on the right
track for the most part. The concern our consul~ant has is that
by using tha excavated material from the East Gate Waste Storage
Tank Site and the Fuel Drop Sites as part of cl~sing Landfill 2,
these materials with their contaminants should be ~ncluded in
evaluating a remedial action on Landfill 2. The groundwater and
surface water will be assessed as separate operable units namely
OU12 and OU13.
. I .
Along with my comments, I will provide you with copies of Craig
Gendron's letters of June 21, 1993 and August 17, 1993. I would
like"to t.hank you for giving me the opportunity to comment on
your proposal, and I am looking forward to commenting on all of
your future cleanup proposals.
Sincerely,
.~tZA4
~~chaud, Chairman
LRt:Environmental Committee
Enclosure
-------
n
'--"
ONE HARBOUR PU.CE. SUITE 300
POST OFFICE BOX 4696
PORTSMOUTH. NEW HAMPSHIRE 03802-4696
TEL: 16031 431-4899 FAX: 16031 431-S982
CASWELL, BOiLER & HILL
MEl\10RANDUM
TO:
LRC - Environmental Committee
Craig R. Gendron, P. G., P .E. @..,f!f
FROM:
DATE:
August 17, 1993
RE:
Public Comment for Final OU 6 Proposed Plan
. . . .
. .
The June 21, 1993 memo we submitted to the LRC-EC outlined our findings with regard to the
Proposed Plan for OU 6. These findings are summarized below in a format that we hope you
will find useful for the August 23rd Public Meeting and H~,.;ng.
By wa.y of a brief s~, .the Propo,sed Plan for au 6 consists of the following components:
Excavation of contaminated soil;
Off-site treatment of contaminated soil at a
State of Maine Spec"~ Solid Waste Landfill or
treaanent facility; and
Bac1riit1iY\g, regrading, and seeding.
East Gate Waste Storage Tanks Site (EGWST) and Fuel Drop Site-South ~ormer (FDS-SF): .
Excavation of contaminated soil;
On-site disposal of contaminated soil in Land.fi11 2
(LF 2); and
Backfilling, regrading, and seeding.
We feel that the Proposed Plan for OU 6 as described herein is consistent with the identified soil
risks. Funher, we feel that the Proposed Plan is consistent with the intended future use of these
areas as developed in the May, 1993 Management Action Plan (MAP). We do, however, wish
to voice several. concerns. Management of the risks posed by these soils, including remedial
action scheduling, will require coordination with the closUre ofLF 2. In other words, the risks
posed by the OU 6 soils once deposited in LF 2 will have to be considered when evaluating and
selecting a remedial action for LF 2. LF 2 constitutes a portion of au 2. Additionally, these
actions are meant to mitiga.te the risks posed to human and environmental receptOrs by exposure
to the soils, not the groundwa.ter, at each site. Groundwater and sUIface water will be. assessed
as separate operable units, OU 12 and OU 13, respectively.
(5800)
Giving you Environmental So/u1ions that Work
GeoiogUlS. Engln~~rs. Hydrog~o'OglSlS & G~ophysicisis
"'u~usc~. ME t2071 622-0032
West TOP\n~m, VT 111021 439-52:0
-------
SENT.BY:ad
.'
; 6-21-93 ;11:15A:.1;
2074933108;;: 2
n
"'--'"
ON!: HARBOUR PIJ.Ct, SUITE 300
POST ernc:! sox 4696
PORTSMOUTH. NEW HAMPSHIRE: 0380204696
TEl.: 1603143104899 FAX: 16031431-5982
CASWELL, BaiLER &; HILL
:\m\1:0~'IDUM:
TO:
L..~C-Environmental Committee
DATE:
c."aig R. Gendron, P.G., F.E.
June 21, 1993
Q.~.A:
-r
FROM:
RE:
Review of Proposed Plan for au 6
CE.H Project Ref~enc:: LRC-OS/60923S4
.
.
.
.
.
The Air Farce prepared a Final Work Plan Addendum for au 6 (RRMS, EGWSTS, and FDS)
which presented the proposed FY93 field investigation programs for the operable unit (CU).
The work plan addressed the.Air Force's media (sail, groundwater, etc.) sampling needs. The
need for additional characterization was identified during regulatory review of the Draft RIlFFS
Report for au 6. The results of the additional sampling activities were incorporated into a Draft
Final RI/FFS Repon. The Draft Final RI!FFS Report was submitted in April, 1993.
OU6:
The Draft Final RIlFFS included an evaluation of several remedial aJ.t~mariv~ for each of the
three sites which comprise au 6: Railroad Maintenance Site (RRMS); East Gate Waste Sto!age
Tanks Site (EGWSTS); and Fuel Drop Sites (FDS). In general, :he remedial alternatives which
we:': found 10 address the remedial action objectives included the following componentS:
.
.
u .
Excava.~on of contamin~ferl soil;
On- or off-site disposal of contaminated soil; and
Backfilling, regrading, and seeding.
The preferred alternative outlined in the Proposed Plan includes the above-referenced
(5586)
Giving you Environmental SO/utiOIU tJuzt vt orlc
-------
S~NT. BY: ad
; 6-21-93 ;,,: 1 SAM;
2074933108:; 3
componentS and clarifies the question of on- versus off-site d.i.suosal of contaminated soil. The
preferred alternative identifies either Landfill 2 or 3 as the disposal site for the contaminated
soil. We have three primary con~ with this selection. Fir:;t .of all, the remedW action
schedules for Landfills 2 and 3 and au 6 will have to be coordinated. Second, the risk
assessment (RA), RI/FFS t and Proposed Plan for Landfills 2 and 3 should be modified to reflect
au 6 soils. And third, the placemem of au 6 soils on either Landfill 2 or 3 may impact the
configuration or an as yet unspecified capping system. .
Additionally, as we stated in the April 13, 1993 memorandum concerning the au 6 Draft
RL'FFS, it is clear that these actions are meant to mitigate the risks posed to human and
enVironmental. receptors by exposure to the soils (not the groundwate:') at each site. The
prefened alternative seems consistent with the identified soil risks~ As we suggested in our
April 13th merrio, if soil cleanup levels are to be established, in part, on groundwater leaching
models (Summers), it seems that the Air for~ should more clearly identify the mitigation of
risks to groundwater as a remedial action objective for the RRMS as they did for the remainder
of au 6. In the Draft Final RIIFFS, groundwater impacts due to leaching ~ used to evaluate
risks and to develop soil cleanup criteria. at the EGWSTS, the FDS, and the RRMS. Finally,
it is clearly Stated in both the Draft RIlPFS and the Draft Final RIlrFS Reports that groundwater
characterization at all three of ~e au 6 . is incomplete. Groundwater impacts and remedial
alternative evaluations,therefore, remain to be addressed as part of the Base-wide Grounciwater
Operable Unit (OU.12). Surface water will be addressed as part of the Base-wide Surface Water
Operable Unit (0'0 13).
(5586)
,,-......
:' \
-------
APPENDIX B
RESPONS~NESSS~Y.
Installation Restoration Program
WOO99319.080
-------
FINAL
OPERABLE UNIT (OU)" 6
RESPONSIVENESS
SUMMARY
March 1994
Installation Restoration Program
-------
FINAL
Loring Air Force Base
OU 6 RESPONSIVENESS SUMMARY
March 1994
Prepared for:
42nd Support Group
42nd Civil Engineering Squadron
Environmental Management Flight
Loring Air Force Base, Maine
DSN: 920-2257 Com: (207) 999-2257
Prepared by:
Service Center: Hazardous Waste Remedial Actions Program
Oak Ridge, Tennessee
Contractor: ABB Environmental Services, Inc.
Portland, Maine
-------
OU 6 RESPONSIVENESS SUMMARY
LORING AIR FORCE BASE
TABLE OF CONTENTS
Section
Title
Page No.
PREFACE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . " ii
LO OVERVIEW OF REMEDIAL AL1ERNATIVES CONSIDERED IN
THE PROPOSED PLAN INCLUDING THE SELECTED
RI;:MEDY . . . . . . . . . . . . . .". . . . . . . ~ . ~ ~ . . . . . ~ . . . . . . ." . . . . . . . .. 1
2.0 BACKGROUND ON COMMUNITY INVOLVEMENT AND
CONCERNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3.0 SUMMARY OF COMMENTS RECEIVED DURING THE PUBUC
COMMENT PERIOD AND USAF RESPONSES. . . . . . . . . . . . . . . . . 4
"
W0099312.080
1
-------
PREFACE
The C.S. Air Force (CSAf) held a 30-day comment period from July 28 to
August 27, 1993, to provide an opportunity for the public to comment on the
Proposed Plan and other documents developed for Operable Unit No.6 (OU 6)
source control at Loring Air Force Base Superfund Site in LimestOne, Maine. The
Proposed Plan is the document that identifies remedial aCtion objectives, evaluates
remedial alternatives, and recommends the alternative that best meetS the evaluation
criteria. The USAF made a preliminary recommendation of its preferred alternative
for remedial aCtion in Proposed Plan SeCtion 6.0, which was issued on July 28, 1993.
All documents on which the preferred alternative was based were placed in the
administrative record for review. The administrative record is a collection of the
documents considered by the USAF while choosing the remedial action for au 6
source areas. It is available to the public at the following locations:,
Robert A Frost Memorial Library
238 Main Street
Limestone, ME 04750
The purpose of this Responsiveness Summary is to document USAF responses to the
questions and comments raised during the public comment period regarding the
proposed OU 6 source control. USAF considered all comments in this document
before selecting a final removal alternative to address soil contamin3tion from au 6.
This Responsiveness Summary is organized into the following sections:
1.0
Overview of Remedial Alternatives Considered in Proposed Plan, including
the Selected Remedy. This section briefly outlines the remedial alternatives
evaluated in the Proposed Plan, including USAF's selected remedy.
~.o
. .
Background on Community Involvement and Concerns. This section provides
a brief history of community interest in OU 6 and concerns regarding these
areas.
3.0
Summary of Comments Received During the Public Comment Period and
USAF Responses. This section summarizes and provides USAF's responses
to all written and oral comments received from the public during the public
comment period. .
Installatior1 Restoration Program
W0099312.080
7626-08
-------
SECTION 1
1.0 OVERVIEW OF REMEDIAL ALTERNATIVES CONSIDERED IN THE
PROPOSED PlAN INCLUDING THE SELECTED REMEDY
1.
RRMS
Using information gathered during field investigations, USAF identified remedial and
response objectives for the source control actions at RRMS:
.
Reduce the ecological risk associated with the contaminated surface
soil.
.
Reduce human health risk associated with carcinogenic P AH-
contaminated surface soil. .
Target Clean-up Levels for soil are set at levels that the U.S. Environmental
Protection Agency (USEP A) and USAF considered to be protective of human health
and the enviromnent. After identifying the remedial action objectives, the USAF
developed and evaluated potential remedial alternatives. The Proposed Plan
describes the remedial alternatives considered to address the contaminants of
concern and the media in which they pose a threat. The Proposed Plan also
describes the criteria the USAF used to narrow the range of alternatives to one
,alternative. These criteria are the same nine criteria USEPA uses to evaluate clean-
up alternatives.
The remedial action selected by the USAF to address remedial objectives includes
excavation of contaminated soil, disposal of the excavated material in a landfill or
. tteatment facility, and restoration of RRMS. The remedial alternatives identified for
implementation for the RRMS source area are described in the Focused Feasibility
Study and the Proposed Plan.
n.
EGWST AND FDS
The Air Force has determined no action is necessary under CERCLA for the
EGWST, FDS-Nl, FDS-N2, FDS-SA, and FDS-SF sites. For two of the sites (Le.,
EGWST and FDS-SF), the Air Force proposed in Part II of the Proposed Plan to
take action pursuant to state requirements.
Installation Restoration Program
W0099312.080
1
-------
SECTION 2
2.0 BACKGROVl'D ON COMMUNI1Y INVOLVEMENT AL~D ; CONCERNS
Throughout LAFB's history, the community has been active and involved to a high
level in base activities. The Air Force and USEP A have kept the community and
other interested parries apprised of the LAFB activities through informational
meetings, fact sheets. press releases, public meetings, site tours and open houses, and
Technical Review Committee (TRC) meetings. Membership of the TRC is
comprised of LAFB Officials. USEPA, MEDEP, and local officials and community
representatives. . .
A Federal Facilities Agreement (FFA) between USEPA Region I, the Maine
Department of Environmental Protection (MEDEP), and the U.S. Air Force signed
on January 30, 1991, governs environmental activities being conducted at IAFB. The
FF A provides the framework for addressing environmental effects associated with the
past and present activities so that appropriate investigations and remedial actions are
implemented to protect human health, welfare, .and the environment. Since the
signing of this agreement, lAFB has been placed on. Congress' Base Qosure List and
. is scheduled to be closed in September 1994.
During August 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. In February and :March 1993, LAFB
held three public informational meetings in the towns of Limestone, Caribou, and
Fort Fairfield, respectively. The purpose of these meetings was to introduce the IRP
program to the public and respond to their questions.
On June 24, 1992, USAF made the administrative record available for public review
at the Robert A. Frost Memorial Library, Limestone, Maine. A TRC meeting was
held on June 2, 1993, to review and comment on the proposed remedy for OU 6.
USAF published a notice and brief analysis of the Proposed Plan on July 28, 1993,
and made the plan available to the public at the Robert A Frost Public Library.
The USAF mailed a fact sheet to approximately 300 citizens of central Aroostook
County during the public comment period.
.. FrOm July 28 through August 27, 1993, the Agency held a 3D-day public comment
period to accept public input on the alternatives presented in the FFS and the
Proposed Plan and on any other documents previously released to the public. On
Installation Restoration Program
WOO99312.0SO
7626-08
-------
SEcrION 2
August 23, 1993, LAFB held an informational meeting to discuss the results of the
au 6 RI and the cleanup alternatives presented in the FFS, and to present the Air
Force's Proposed Plan. Also during this meeting, the Air Force answered questions
from the public. Immediately following the public meeting, a pubijc hearing was held
to accept any oral comments.
Installation Restoration Program
W0099312.080
3
-------
SECTION 3
:.J
3.0 SUMMARY OF C01\-fMENTS RECEIVED DLlUNG THE PUBLIC
COMMENT PERIOD AND USAF RESPONSES
This. Responsiveness Summary addresses commentS received by the CSAF and
USEP A during the public comment period from July 28 to August '27, 1993.
. Comments include those received verbally during the public hearing and letters from
the Loring Readjustment Committee and Caswell, Eichler & Hill. The comments
and corresponding responses are included herein. It is nOted that the comments
which relate to the Air Force's proposed action for EGWST and FSD-SFas
discussed in Part II of the Proposed Plan, are for the proposed action under state
requirements and not under CERCLA
1.
Comment: One commenter requested that the excavated material and
conT~rnimmts from EGWST imd FDS-SF be included in the evaluation of the
remedial action at LF-2.
USAF Response: The excavated material and contaminants from the
EGWST and the FDS-SF will be included in the evaluation of the remedial
action at LF-2. Tbe objectives of the remedial alternatives for LF-2, (to
prevent exposure of the contaminants of concern to the soil. water. and air),
will remain unchanged after the addition of OU 6 soil. The technologies
identified for LF-2 will include one or a combination of the following; (1) no
actio~ (2) institutional controls, (3) groundwater monitoring, (4) containment,
(5) treatment, and (6) extraction. LF-2 is part of OU 2 under the Federal
Facility Agreement. The Air Force is currently preparing a Remedial
Investigation/Focused Feasibility Study under CERCLA on remedial
alternatives for LF-2. OU 2 will be the subject of a separate CERCLA
Proposed Plan and ROD. The Air Force's proposed action for EGWST and
FDS-SF is set forth in Part II of the OU 6 Proposed Plan. The material from
EGWST and FDS-SF will be handled pursuant to state requirementS and will
be included in the evaluation of the CERCLA remedial action decision at
LF-2. .
2.
Comment: One commenter asked when the remediation activities for OU 6
would start. .
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USAF Response: Remedial construction for au 6 is planned for summer
1994. The Air Force will complete the design documents which are subject to
EP A and MEDEPreview and approval. The schedule includes preparation
of construction documents and selection of a contractor in spring 1994, and
construction by summer 1994.
3.
Comment: One commenter was concerned with the on-base location for
disposal of the au 6 soils. The commenter stated that if an on-base site is
used as a spreading site or a landfill, that. the site be documented and
significant measures be made to restrict or reduce migration of contaminants.
USAF Response: The on-base disposal site for soils from EGWST and
FDS-SF is LF-2. Proposed remedial action for LF-2, a low permeable cap, will
include documentation of placement of EGWST and FDS-SF soil under the
cap and a post-closure plan. The post-closure plan for LF-2 will include
monitoring activities for a minimum of 30 years in accordance with USEP A
requirements for closing landfills. The plan will identify the location and
frequency of groundwater and air monitoring, and the compounds for which
samples will be analyzed:
As noted in the response to Comment #1, the concern for EGWST and
FDS-SF soils will be evaluated under state requirements and the CERCLA
remedial action decision at LF-2.
4.
Comment: One commenter didn't have enough information to state his
. opinion because he didn't know enough about the process.
USAF Response: Interested parties can consult the Administrative Record
and the Information Repository for information regarding a specific au or
the IRP Program. In addition, the public is welcome to contact the' Loring
IRP office at telephone 207-999-2257.
5.
Comment: One commenter expressed concern for potential redistribution of
contamination through various media, specifically groundwater, surface water
and air. .
USAF Response: The prevention of cross contamination of media is
recognized as an imponant issue. During construction the contractor will use
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SECTION 3
.;;
protective measures to prevent the migration of contaminants from wind
blown dust and leachate while performing the tasks of excavating, hauling, and
stockpiling. Construction activities will include water misting during excavation
to prevent dust, covering soil with tarpaulins while hauling and stockpiling,
and continuous monitoring for fugitive emissions and leachate.
6.
Comment: One commenter was concerned with reusing the disposal site and
the base after the remedial actions are complete.
USAF Response: The risk assessment took into account likely reuse scenarios
based on input from the Loring Readjustment Committee's (LRCs) initial
land use plans. All sites will be compatible with these use classifications. In
addition the property deed for the disposal site will have a restriction to notify
future landowners of its contents.
7.
Comment: One commenter asked about the consequence of mixing wastes
together, and specifically about the impact to future population in the area.
USAF Response: The soils from EGWST and IDS-SF are contaminated with
similar Petroleum Hydrocarbons (PHCs) and Polynuclear Aromatic
Hydrocarbons (P AHs). The excavated soil will be stockpiled and covered
together in one designated area at LF-2. Later, during proposed remediation
activities for LF-2, the stOckpile will be combined with clean common borrow
and used for the subgrade under the proposed low-permeability cap.
The impact to future population in the area of the EGWST and FDS-SF sites
will be negligible because the human health risk exposures under exis~ing
conditions are already within the USEPA's acceptable range. The excavated
RRMS soil will either be disposed of in an off-base landfill or treated.
8.
Comment: One commenter wanted clarification on the USEP A's and
MEDEP's liability, should additional remedial actions for OU 6 be necessary
in the furore. .
USAF Response: The Air Force. will be liable for any future remediation
necessary for au 6. USEPA and MEDEP are responsible for oversight of
the Air Force clean-up activities. The Air Force is required to include the
following CERCLA clause, Section 120(h)(3) , in property deed transfers:
..)
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"The United States warrants that- .
(i) all remedial action necessary to protect human health and the environment
with respect to any such substance remaining on the property has been taken
before the date of such transfer, and (ii) any additional remedial action found
to be necessary after the date of such transfer shall be conducted by the
United States."
9.
.Comment: The commenter stated that personal and professional
responsibility should be identified for the remedial actions, including the three
no action sites. ... .
USAF Response: A Record of Decision for the remedy selection of au 6
will be signed by Alan K. Olsen, Director of the Air Force Base Closure
Agency, and Paul Keough, Acting Regional Admini~trator, USEP A Region I
in their official capacities. The Air Force is responsible for design and
construction of the selected remedy. Confirmation sampling and analysis
during excavation will be conducted by qualified personnel and laboratories,
and will be used to demonstrate that clean-up goals are met.
10.
Comment: Another commenter stated the remedial action schedules for
au 6 and Landfills 2 and 3 needed to be coordinated.
USAF Response: The EGWST and FDS-SF remediation work will precede
the proposed landfill capping and the sequence will allow storage of the
EGWST and FDS-SF soils at the landfills.
11.
Comment:. One commenter stated that the risk assessment, remedial
investigation/focused. feasibility study (RI/FFS), and proposed plan for
Landfills 2 and 3 and au 6 should be modified to reflect disposal of au 6
soils. .
USAF Response: No change to the risk assessment for LF-2 is necessary
because the EGWST and FDS-SF soil does not present an unacceptable
human health or ecological risk under CERCIA The material from EGWST
and FDS-SF will be handled pursuant to state requirements and. will be
. included in the evaluation of the CERClA remedial action decision at LF-2
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..J
12.
Comment: A commenter noted the placement of au 6 soils on either
Landfills 2 or 3 may impact the configuration of a capping system.
u
USAF Response: The estimated volume of EGWST and FDS-SF soil, ~out
2.325 cubic yards, is much less than LF-2 subgrade volume which is estimated
at more than 200,000 cubic yards. The volume of EGWST and FDS-SF soil
will not significantly impact the proposed cap configuration; however, locating
the stockpile near the center of the proposed cover will minimi7.e the effort
of spreading the EG WST and FDS-SF soil into the. subgrade.
13.
Comment: One commenter requested that the Air Force more clearly
identify the mitigation of risks to groundwater as a remedial action objective
for the Railroad Maintenance site as they did for the remainder of OU 6.
USAF Response: Groundwater characterization at the six sites is incomplete
and will be addressed as part of ~e base-wide groundwater operable unit (Le.,
OU 12).
.j
,)
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APPENDIX C
STATE LE1TER OF CONCURRENCE
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\,,\1 11\ 0 N4f,."
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STATE OF MAINE
DEPARTMENT OF ENVIRONMENTAL PROTECTION
of. "-
'-I'f ~r ",..,\~
JOHN R. McKERNAN. JR.
GOVERNOR
DEAN C. MARRIOTT
COMMISSIONER
DEBAAH RICHARD
DEPUTY COMMISSIONE~
ij
Peter Forbes, Project Manager
42 CES/CEVR .
7300 Pennsylvania Road
Loring Air Force Base, ME 04751-5000
~ 28 1994
Re:
Loring Air Force Base, Limestone, Maine
Dear Sirs:
The Maine Department of Environmental Protection (MEDEP) has reviewed the
Final Record .of Decision (ROD) for Operable Unit 6 (OU 6) at the Loring Air Force Base
Superfund Site located in Limestone, Maine, which has been amended pursuant to the
comments of United States Environmental Protection Agency CCSEP A) and the State.
The au 6 ROD describes a CERCLA-driven remedial action ror the Railroad
~aintenance Site (RRL'vfS) and, finding that remedial action is not called for by CERCLA,
.il.e ac 6 ROD selects "no action" alternatives under CERCLA for the remaining five sites
which comprise OU 6. ~otwithstanding the ROD, the Air Force will be undertaking
remedial actions at two of the ac 6 sites, the East Gate Waste Storage Tank (EGvVST) site
and the Fuel Drop Site-South Former (FD5-SF) site, pursuant to Ytaine's Oil Discharge
Prevention and Pollution Control Act, 38 M.R.S.A. 9541, et ~ (1989). These non-
CERCLA remedial actions are described in the Two Party Supplement to the Loring Air
Fotce Base Federal Facility .:.Agreement entered between the United States Air Force and the
State of ),tfaine ("Two Party Supplement").
The MEDEP concurs in the II no action" alternatives selected in the au 6 ROD for
the following sites: Fuel Drop Site-North 1 (FDS-N1); Fuel Drop Site-North 2 (FDS-N2);
and Fuel Drop Site-South Active (FDS-SA).
The MEDEP concurs with the remedial action described in the au 6 ROD for the
RRJ.'vfS. This remedial action includes excavating approximately 200 cubic yards (cy) of the
.
v
GUSTA
:>TATe HOuSE STATION 17
AuGUSTA. MAtNE 00I333-0017
(207) 287.7888 FAX: (207) 2F.7826 .
C/FFICE ~OCAT£O AT: RAv BUILDING. I-tOSPrTAI. STREET
PORTlAND
312 CAHCO RCAD
POFmAHO. ME :)4103
(207) 879-0300 FAX: (207) 879-6303
BANGOR
106 JotOGAA RoAD
EIAHGOR. ME 04-401
(207) 941-4570 FAX. (207) 941-45IM
PRESQUE ISLE
1235 CENTRAL DRIIIE. SOCVWAY PAAK
PRESQUE ISLe. ME 04769
(207) 764-0477 FAX: (207) 764-1507
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rface soils at the RRMS site. Soil sampling will be conducted during excavation to
_.Jnfirm the limits of excavation. Samples will be collected and analyzed for Semi- Volatile
Organic Compounds (SVOCs). Analytical results will be compared to target cleanup levels
for SVOCs to determine whether additional soil should be excavated.
Following excavation, soil from the RRMS site will be transported to a landfill or
treatment facility which is licensed to accept such waste. Debris, stumps and other non-
soil materials from the RR.J.'vfS site will be disposed of at the landfill operated by the
remedial contractor for the Loring Air Force Base. The RRMS site will then be restored to
a similar topography as currently exists by placing clean fill into the areas affected by the
soil excavation called for in the remedial action. The disturbed area will be graded and
seeded with grass. The gravel roadbase placed over the railroad tracks to serve as an access
road will then be removed.
The MEDEP concurs with the non-CERCLA remedial actions described in the Two
Party Supplement for the EGWST site (Alternative 5 in the FFS), and for the FD5-SF
(Alternative 3 in the FFS) site. These remedial actions i11volve the same activities at each
site, consisting of: (1) excavating the contaminated soil from both the EGWST and FD5-SF
sites and (2) transporting this soil to the Loring Air Force Base Landfill 2 site. At both sites,
limits of excavation will be based on confirmation sampling. Soil samples will be collected
and analyzed for TCL VOCs and SVOCs and the results compared to target remediation
levels to determine if additional soil excavation is required. Areas where analytical results.
dicate the presence of compounds targeted or remediation at concentrations exceeding
...vil remediation levels will be excavated and disposed of. . After removal of contaminated
soil, the FD5-SF and EGWST sites will be backfilled with clean fill, graded, and seeded to
promote growth of vegetation.
The excavated soils for the EGWST and FDS-SF sites will be used as subgrade
materials for a landfill cover system at Loring Air Force Base Landfill 2 (OU 2 under the
FFA). Prior to construction of the cover system, the excavated soils will be temporarily
stockpiled at Landfill 2. At temporary cover (e.g., tarp, polyethylene sheeting, or similar
material) will be placed over the stockpile and secured to minimize leachate, odors, and
fugitive dust. Prior to constructing the landfill cover system, the stockpiled soils will be
uncovered and spread over a portion of the landfill as subgrade material. The landfill
cover system will then be constructed over these soils. The cover will further reduce
human and ecological exposU!e to the excavated soils. This spreading action will assist the
natural degradation process thus reducing contaminants of concern in the soils.
Each of the above-described remedial actions will include:
L
Development of a Health and Safety Plan.
A detailed Health and Safety Plan will be developed prior to any remedial actions at
au 6. This pl~n will comply with OSHA and other state and federal regulations, as
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A.
1I
B.
Site Preparation.
Access roads and small staging areas will be constructed at the EGWST and
FDS-SF sites outside the limits of the waste for storage of equipment during
excavation, decontamination of these areas, and as access for trucks to
remove soil and debris.
Erosion control measures will be employed during construction to minimize
soil/sediment from entering receiving waters adjacent to the EGWST or ros-
SF sites, in accordance with the Natural Resources Protection Act Permit by
Rule Standards, Chapter 305.
m
Excavation and Confirmation Sampling.
A.
B.
Excavation shall proceed pursuant to schedules contained in the remedial
action workplans for the above-referenced sites.
After excavation is completed, soil samples will be collected at the above-
referenced sites to confirm that no site-related contaminants are left in place.
A sampling and analysis plan will be developed by the remedial construction
contractor before work beg;..ns and submitted for regulatory and comment.
This concurrence is based upon the State's understanding that
c'
A. The MEDEP will continue to participate in the Loring Air
Force Base Federal Agreement dated January 30, 1991, as
amended, and in the review and approval of operational designs
and monitoring plans.
The MEDEP looks' forward to working with the Air Force and the USEP A to resolve
the environmental problemS posed by the au 6 site. If you need ~y additional
information, do not hesitate to contact II1:e or members of my staff.
c
J
D~tcb
Enclosure
Sincerely,
. /~AJ~e-zI}
Debrah J. Richard
Acting Commissioner
MAR 2 B 1994
Michael Nalipinski, EPA
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