Superfund Record of Decision Loring Air Force Base Operable Unit 13 Limestone ME


                                    EPA/ROD/R01-97/002
                                    1997
EPA Superfund
     Record of Decision:
     LORING AIR FORCE BASE
     EPA ID: ME9570024522
     OU13
     LIMESTONE, ME
     06/16/1997

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                                  FINAL

                          Loring Air Force Base

                         Operable Unit 13 (OU 13)
                            Record of Decision

                                 May 1997

                               Prepared for:

                      Air Force Base Conversion Agency
                        Loring Air Force Base, Maine
                               (207)  328-7109

                               Prepared by:

         Service Center:  Hazardous Waste Remedial Actions Program
                       Oak Ridge, Tennessee 37831-7606

              Contractor:  ABB Environmental Services, Inc.
                            Portland, Maine 04101

                               Job No. 9975-16

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                             TABLE OF CONTENTS

 Section                     Title                         Page  No.

 DECLARATION FOR THE RECORD OF DECISION  	   D-l

 1.0   SITE NAME, LOCATION, AND DESCRIPTION  	   1-1

 2 . 0   SITE HISTORY AND RESPONSE ACTIVITIES  	   2-1

       2 .1   LAND USE AND SITE HISTORY 	   2-1
       2 .2   RESPONSE ACTIVITIES 	 2-10

 3.0   COMMUNITY PARTICIPATION 	   3-1

 4 . 0   SCOPE AND ROLE OF RESPONSE ACTION  	   4-1

 5 . 0   SUMMARY OF SITE CHARACTERISTICS 	   5-1

       5.1   WOLVERTON BROOK/BRANDY BROOK STUDY AREA  	   5-2
       5 .2   GREENLAW BROOK STUDY AREA	   5-2
       5.3   BUTTERFIELD BROOK/LIMESTONE  STREAM STUDY AREA ..   5-6

 6. 0   SUMMARY OF SITE RISKS 	   6-1

       6.1   WOLVERTON BROOK/BRANDY BROOK STUDY AREA	   6-2
       6 . 2   GREENLAW BROOK STUDY AREA	   6-9
       6.3   BUTTERFIELD BROOK/LIMESTONE  STREAM STUDY AREA .. 6-56

 7.0   DEVELOPMENT AND SCREENING OF ALTERNATIVES  	   7-1

       7.1   STATUTORY REQUIREMENTS/RESPONSE OBJECTIVES  	   7-1
       7.2   TECHNOLOGY AND ALTERNATIVE DEVELOPMENT AND
             SCREENING 	   7-2

 8.0   DESCRIPTION OF ALTERNATIVES 	   8-1

       8.1   No ACTION 	   8-1
       8.2   LAND USE RESTRICTIONS 	   8-1
       8.3   SEDIMENT TRAPS - LAND USE RESTRICTIONS  	   8-2
       8 .4   CAPPING - LAND USE RESTRICTIONS 	   8-2
       8.5   REMOVAL - VOLUME REDUCTION - DISPOSAL  	   8-3
       8 . 6   REMOVAL - VOLUME REDUCTION - TREATMENT  	   8-4
       8.7   REMOVAL - DISPOSAL 	   8-5

9.0     SUMMARY OF THE COMPARATIVE ANALYSIS OF
       ALTERNATIVES 	   9-1

       9.1   EVALUATION CRITERIA USED FOR DETAILED ANALYSIS  .   9-1
             9.1.1   Threshold Criteria  	   9-1
             9.1.2   Primary Balancing Criteria 	   9-1
             9.1.3   Modifying Criteria  	   9-2
       9.2   SUMMARY OF COMPARATIVE ANALYSIS 	   9-3

10.0  THE SELECTED REMEDY 	 10-1

      10.1  REMEDIATION GOALS 	 10-1
      10.2  DESCRIPTION OF REMEDIAL COMPONENTS  	 10-2
            10.2.1  Removal - Disposal 	 10-2
            10.2.2  No Action 	10-20
            10.2.3  Future Action - Chapman Pit 	10-20

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11.0  STATUTORY DETERMINATIONS  	  11-1

      11.1  THE SELECTED REMEDY IS PROTECTIVE OF HUMAN
            HEALTH AND THE ENVIRONMENT  	  11-1
      11.2  THE SELECTED REMEDY ATTAINS ARARs 	  11-1
      11.3  THE SELECTED REMEDIAL ACTION IS COST-EFFECTIVE  ..  11-1
      11.4  THE SELECTED REMEDY UTILIZES PERMANENT  SOLUTIONS
            AND ALTERNATIVE TREATMENT OR RESOURCE RECOVERY
            TECHNOLOGIES TO THE MAXIMUM EXTENT  PRACTICABLE... 11-10
      11.5  THE SELECTED REMEDY DOES NOT SATISFY THE
            PREFERENCE FOR TREATMENT WHICH PERMANENTLY AND
            SIGNIFICANTLY REDUCES THE TOXICITY, MOBILITY, OR
            VOLUME OF THE HAZARDOUS SUBSTANCES  AS A PRINCIPAL
            ELEMENT  	11-12

12.0  DOCUMENTATION OF NO SIGNIFICANT CHANGES 	  12-1

13. 0  STATE ROLE 	  13-1

GLOSSARY OF ACRONYMS AND ABBREVIATIONS

REFERENCES

APPENDICES

APPENDIX A      TRANSCRIPT OF THE PUBLIC MEETING  (MAY 8,  1997)
APPENDIX B      RESPONSIVENESS SUMMARY
APPENDIX C      LETTER OF CONCURRENCE

                              LIST OF FIGURES

 Figure                      Title

 1-1   Location of OU 13 Study Areas 	    1-2
 2-1   Wolverton Brook/Brandy Brook 	    2-2
 2-2   Flightline Drainage Ditch 	    2-3
 2-3   FLDD Wetland  	    2-4
 2-4   East Branch Greenlaw Brook 	    2-6
 2-5   West Branch Greenlaw Brook (Northern Portion)  	    2-7
 2-6   West Branch Greenlaw Brook (Southern Portion)  	    2-8
 2-7   Butterfield Brook/Limestone Stream  	    2-9
 10-1  FLDD - Proposed Excavation Limits 	  10-12
 10-2  FLDD Wetland - Proposed Excavation Limits  	  10-13
 10-3  East Branch Greenlaw Brook - Proposed Excavation  Limits  ....  10-14
 10-4  Nose Dock Area Drainageways - Proposed Excavation Limits....  10-15
 10-5  Ditch G06 - Proposed Excavation Limits 	  10-16

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                             LIST OF TABLES

Table                            Title

6-1   Quantitative Risk Summary - little Madawaska River 	   6-4
6-2   Comparison of Surface Water and Sediment COG Concentrations
      with Aquatic RTVs - Little Madawaska River - Riverine Habitat 	  6-10
6-3   Comparison of Surface Water and Sediment Hot Spot COG
      Concentrations with Aquatic RTVs - Little Madawaska River -
      Riverine Habitat 	  6-11
6-4   Summary of Ecoloqical Risk Assessment for Sediment and Surface
      Water - Little Madawaska River - Riverine Habitat 	  6-12
6-5   Quantitative Risk Summary - FLDD and FLDD Wetland 	  6-14
6-6   Comparison of Surface Water and Sediment CPC Concentrations
      with Aquatic RTVs - Fliqhtline Drainaqe Ditch - Stream Habitat 	  6-16
6-7   Summary of Ecoloqical Risk Assessment for Sediment and Surface
      Water - Fliqhtline Drainaqe Ditch Study Area - Stream Habitat 	  6-18
6-8   Summary of Ecoloqical Risk Assessment for Sediment and Surface
      Soil - Fliqhtline Drainaqe Ditch Study Area - Floodplain Habitat 	  6-19
6-9   Comparison of Sediment COG Concentrations with Aquatic RTVs -
      Fliqhtline Drainaqe Ditch - Aquatic Ditch Habitat 	  6-20
6-10  Summary of Ecoloqical Risk Assessment for Sediment - Fliqhtline
      Drainaqe Ditch Study Area - Aquatic Ditch Habitat 	  6-21
6-11  Summary of Ecoloqical Risk Assessment for Surface Soil - Fliqhtline
      Drainaqe Ditch Study Area - Terrestrial Ditch Habitat 	  6-22
6-12  Quantitative Risk Summary - Greenlaw Brook (East Branch) Study
      Area 	  6-24
6-13  Comparison of Surface Water and Sediment COG Concentrations
      with Aquatic RTVs - Greenlaw Brook (East Branch) Study Area -
      Stream Habitat 	  6-30
6-14  Comparison of Sediment CPC Concentrations with Aquatic RTVs -
      Greenlaw Brook (East Branch) Study Area - Stream Habitat (PCB
      Hot Spot)  	  6-32
6-15  Summary of Estimated Risk to Semi-Aquatic Wildlife From
      Sediment and Surface Water - Greenlaw Brook (East Branch) Study
      Area - Stream Habitat 	  6-33
6-16  Comparison of Sediment CPC Concentrations with Aquatic RTVs -
      Greenlaw Brook (East Branch) Study Area - Palustrine Habitat 	  6-34
6-17  Summary of Estimated Risk to Semi-Aquatic Wildlife from
      Sediment Greenlaw Brook (East Branch) Study Area - Palustrine
      Habitat 	  6-35
6-18  Summary of Ecoloqical Risk Assessment for Sediment - Greenlaw
      Brook (East Branch) Study Area - Terrestrial Ditch Habitats 	  6-37
6-20  Comparison of Surface Water and Sediment CPC concentrations
      with Aquatic RTVs - Greenlaw Brook (West Branch) Study Area -
      Stream Habitat 	  6-46
6-21  Summary of Estimated Risk to Semi-Aquatic Wildlife from
      Sediment and Surface Water - Greenlaw Brook (West Branch)
      Study Area - Stream Habitat 	  6-47
6-22  Comparison of Surface Water and Sediment COG Concentrations
      with Aquatic RTVs - Greenlaw Brook (West Branch) Study Area -
      Palustrine Habitat 	  6-48
6-23  Summary of Estimated Risk to Semi-Aquatic Wildlife from
      Sediment and Surface Water - Greenlaw Brook (West Branch)
      Study Area - Palustrine Habitat 	  6-50
6-24  Comparison of Surface Water and Sediment CPC Concentrations
      with Aquatic RTVs - Greenlaw Brook (West Branch) Study Area -
      Lacustrine Habitat 	  6-51
6-25  Summary of Estimated Risk to Semi-Aquatic Wildlife from
      Sediment and Surface Water - Greenlaw Brook (West Branch)
      Study Area - Lacustrine Habitat 	  6-52
6-26  Comparison of Surface Water and Sediment CPC Concentrations
      with Aquatic RTVs - Greenlaw Brook (West Branch) Study Area -
      Aquatic Ditch Habitat 	  6-53
6-27  Summary of Estimated Risk to Terrestrial Wildlife from Soil and
      Surface Water - Greenlaw Brook (West Branch)  Study Area - Ditch
      Habitats 	  6-54

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6-28  Quantitative Risk Summary - Butterfield Brook/Limestone Stream
      Study Area 	   6-57
6-29  Comparison of Surface Water and Sediment CPC Concentrations
      With Aquatic RTVs - Butterfield Brook/Limestone Stream Study
      Area - Stream Habitat 	   6-63
6-30  Comparison of Sediment Hot Spot CPC Concentrations with
      Aquatic RTVs - Butterfield Brook/Limestone Stream Study Area-
      Stream Habitat 	   6-64
6-31  Summary of Estimated Risk to Semi-Aquatic Wildlife from
      Sediment and Surface Water Butterfield Brook/Limestone Stream
      Study Area -Stream Habitat 	   6-65
6-32  Comparison of Surface Water and Sediment CPC Concentrations
      with Aquatic RTVs Butterfield Brook/Limestone Stream Study
      Area - Palustrine Habitat 	   6-66
6-33  Comparison of Sediment Hot Spot CPC Concentrations with
      Aquatic RTVs - Butterfield Brook/Limestone Stream Study Area -
      Palustrine Habitat 	   6-67
6-34  Summary of Estimated Risk to Semi-Aquatic Wildlife From
      Sediment and Surface Water - Butterfield Brook/Limestone Stream
      Study Area -Palustrine Habitat 	   6-68
6-35  Comparison of Surface Water and Sediment CPC Concentrations
      with Aquatic RTVs - Butterfield Brook/Limestone Stream Study
      Area - Lacustrine Habitat 	   6-69
6-36  Summary of Estimated Risk to Semi Aquatic Wildlife From
      Sediment and Surface Water - Butterfield Brook/Limestone Stream
      Study Area-Lacustrine Habitat 	   6-70
6-37  Comparison of Sediment and Surface Soil CPC Concentrations with
      Aquatic RTVs - Butterfield Brook/Limestone Stream Study Area -
      Aquatic Ditch Habitat 	   6-71
6-38  Summary of Estimated Risk to Terrestrial Wildlife from Sediment
      and Surface Soil - Butterfield Brook/Limestone Stream Study Area
      - Ditch Habitat 	   6-72
9-1  Comparative Analysis of Alternatives - Fliqhtline Drainaqe Ditch 	   9-4
9-2  Comparative Analysis of Alternatives - Fliqhtline Drainaqe Ditch
     Wetland 	   9-5
9-3  Comparative Analysis of Alternatives - East Branch Greenlaw
     Brook 	   9-7
9-4  Comparative Analysis of Alternatives - West Branch Greenlaw
     Brook 	   9-8
9-5  Comparative Analysis of Alternatives - UTS Wetland 	  9-10
9-6  Comparative Analysis of Alternatives - Drainaqe Ditch GO6 	  9-12
10-1 Sediment Remediation Goals - FLDD 	  10-3
10-2 Sediment Remediation Goals - FLDD Wetland 	  10-4
10-3 Ditch Sediment and Surface Soil Remediation Goals - Ditch G06 	  10-5
10-4 Sediment Remediation Goals - East Branch Greenlaw Brook 	  10-6
10-5 Fish Tissue Remediation Goals - East Branch Greenlaw Brook,
     Chapman Pit, Green Pond,  and Little Madawaska River 	  10-7
10-6 Sediment and Surface Soil Remediation.  Goals - NDA Drainaqeways 	  10-8
10-7 Sediment and Surface Soil Remediation Goals - UTS Wetland  	  10-9
11-1 Chemical-Specific ARARs,  Criteria, Advisories, and Guidance 	  11-2
11-2 Location-Specific ARARs,  Criteria, Advisories, and Guidance 	  11-4
11-3 Action-Specific ARARs For Removal-Disposal Alternative 	  11-7

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                          DECLARATION FOR THE RECORD OF DECISION

SITE NAME AND LOCATION

This decision document addresses the findings of the basewide surface water and sediment study, referred
to as Operable Unit 13 (OU 13),  at the former Loring Air Force Base  (LAFB),  located in Aroostook County,
Maine.  Because of the size of the area, and the number of drainage systems involved, OU 13 was
subdivided into three primary study areas.  The study areas are the three major drainage systems that
comprise the terrain occupied by LAFB.  These are:

       •      Wolverton Brook/Brandy Brook Study Area
       •      Greenlaw Brook Study Area
       •      Butterfield Brook/Limestone Stream Study Area

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial action for OU 13.  The selected remedy includes
Removal and Disposal of contaminated surface soil and sediment that exceed remediation goals from six
locations within the OU 13 study areas and No Action at one location.  No further action is necessary for
the remaining areas in OU 13 because there is no unacceptable risk to human health or the environment.

Although the Remedial Investigation results indicate unacceptable risks associated with surface water in
some areas, a Feasibility Study was not recommended because remediating soil and sediment is expected to
adeguately reduce risks associated with surface water.

Removal and Disposal has been selected for areas that exceed remediation goals. These areas have been
identified to include:

         Greenlaw Brook Study Area
              Flightline Drainage Ditch  (FLDD)
              FLDD Wetland
              East Branch of Greenlaw Brook (EBGB) from Pennsylvania Road to
              the Ski Chalet
              Nose Dock Area  (NDA) Drainageways  (north and south drainageways only)
              Drainage Ditch GO6

         Butterfield Brook/Limestone Stream Study Area
              Underground Transformer Site (UTS) Wetland (northern portion only)

The State Fish Advisory,  currently in effect at designated on- and off-base areas, will remain in effect
until the fish are determined to be acceptable for consumption.

The No Action alternative has been selected for the little Madawaska River (LMR) because there is no
unacceptable risk associated with the LMR due to exposure to soil sediment and surface water.  The No
Action alternative will include a long-term environmental monitoring program and five-year site reviews
to assess whether human health and the environment continue to be adeguately protected.

No further action is recommended for the remaining areas within OU 13 because there is no unacceptable
risk to human health or the environment.

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 of 1986, and to the extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan.  This decision is based on the Administrative Record for OU 13, which was
developed in accordance with Section 113(k) of CERCLA and is available for public review at the Air Force
Base Conversion Agency Office, 5100 Texas Road, Limestone,  Maine.

The Maine Department of Environmental Protection  (MEDEP) concurs with the selected remedy for OU 13.

ASSESSMENT OF OU 13

Actual or potential releases of hazardous substances from the FLDD, FLDD Wetland, EBGB (from Pennsylvania
Road to the Ski Chalet),  north and south NDA Drainageways,  Ditch GO6, and UTS Wetland  (northern portion),
if not addressed, may pose a risk to human health and the environment.  This risk will be addressed by
implementing the Removal and Disposal remedy selected in this Record of Decision  (ROD).

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The United States Air Force  (USAF) has determined that no further action is necessary for the remaining
areas in OU 13 because of anticipated lack of future impacts and/or no unacceptable risks to human and
ecological receptors.

DESCRIPTION OF THE SEIiECTED REMEDY

This Decision Document presents the selected source control remedial action for OU 13, the basewide
surface water and sediment operable unit at LAFB.  The selected remedy addressed the principal threats
posed by contaminated soil and sediment in the drainageways in and around the former LAFB.

The selected remedy for surface soil and sediment that exceed remediation goals in the FLDD, FLDD
Wetland, EBGB (from Pennsylvania Road to the Ski Chalet) ,  north and south NDA Drainageways, Ditch G06,
and UTS Wetland  (northern portion) is Removal and Disposal.  The major components of the remedy include:

       •      pre-design studies to delineate the extent  of remediation for design purposes;

       •      pre-design wetland mitigation studies (i.e.,  wetland delineations and function-value
              assessments)  to evaluate the impacts resulting from remedial activities;

       •      site preparation and mobilization;

       •      cutting and clearing;

       •      stormwater management;

       •      sediment excavation;

       •      sediment disposal at LAFB Landfill  3 (LF-3);  some material may reguire disposal at off-base
              facilities;

       •      backfilling the excavations with material that closely matches the excavated material;

       •      compensatory wetlands mitigation and demobilization; long-term environmental and wetlands
              mitigation monitoring;

       •      continued fish advisory,  and

       •      five-year site reviews.

The State Fish Advisory, currently in effect at designated on- and off-base areas, will remain in effect
until the fish are determined to be acceptable for consumption. Areas covered by the advisory include
Chapman Pit, Green Pond, Greenlaw Brook, and the LMR and its tributaries from the Madawaska Dam Reservoir
south to the Aroostook River.

The No Action alternative has been selected for surface soil, sediment, and surface water for the LMR
because there is no unacceptable risk associated with these media.  The No Action alternative does not
include any remedial action components to reduce or control risks.  However, the No Action alternative
will include a long-term environmental monitoring program and five-year site reviews to evaluate the
long-term conditions of the site's ecology and to assess whether human health and the environment
continue to be adeguately protected.

The USAF has determined that no further action is necessary for the remaining areas within OU 13.

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STATUTORY DETERMINATIONS

The selected remedy is protective of human health and the environment, complies with applicable or
relevant and appropriate requirements for the action, and is cost-effective. The remedy uses permanent
solutions and alternative treatment technologies to the extent practicable. The selected remedy does
not, however, satisfy the statutory preference for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element. Mobility of contaminants is expected to be reduced through
the containment features of the landfill cover system to be constructed for LF-3, which will also reduce
rainwater infiltration, erosion, and direct contact with the contaminated soil and sediment.

This ROD represents the selection of a remedial action under CERCLA for areas within OU 13, that exceed
remediation goals. These areas include the FLDD, FLDD Wetland, EBGB (from Pennsylvania Road to the Ski
Chalet), north and south NBA Drainageways, Ditch G06, and UTS Wetland (northern portion). The State Fish
Advisory, currently in effect at designated on- and off-base areas, will remain in effect until the fish
are determined to be acceptable for consumption. No Action has been selected for the LMR. No further
action is necessary for the remaining areas within OU 13. The forgoing represents the selection of a
remedial action by the Department of the Air Force and the United States Environmental Protection Agency
Region I with the concurrence of the MEDEP.

Concur and recommend for immediate implementation:

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1.0 SITE NAME, LOCATION, AND DESCRIPTION

The former Loring Air Force Base (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.

LAFB is a National Priorities List (NPL) site. There are currently several areas of concern under
investigation within LAFB, which have been organized into Operable Units (OUs) for investigation and
remediation purposes. This Record of Decision (ROD) relates to OU 13, the basewide surface water and
sediment operable unit (Figure 1-1).

Because of its primary mission, LAFB personnel were engaged in various operations, a number of which
reguired 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 liguid 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 Installation Restoration Program (IRP), the Air Force initiated activities to identify,
evaluate, and remediate former disposal or spill sites containing hazardous substances.

Since initiation of the IRP, the base was placed on the United States Environmental Protection Agency's
(USEPA's) NPL of sites and is to be remediated according to the Federal Facility Agreement (FFA) , an
agreement under Section 120 of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) signed by the United States Air Force (USAF), the USEPA, and the Maine Department of
Environmental Protection (MEDEP) on January 30, 1991, as amended. Following the signing of the FFA LAFB
was placed on the U.S. Congress Base Closure List and was closed in September 1994.

2.0 SITE HISTORY AND RESPONSE ACTIVITIES

This section summarizes the land use, site history, and response activities for OU 13.

2.1 LAND USE AND SITE HISTORY

OU 13 is the basewide surface water and sediment operable unit. OU 13 includes brooks, streams, ditches,
lakes, ponds, and wetlands in approximately 30 sguare miles (19,250 acres) of watershed encompassing the
former LAFB. Because of the size of the area, and the number of drainage systems involved, OU 13 was
subdivided into three primary study areas (see Figure 1-1). The study areas are the three major
watersheds that comprise the terrain in and surrounding LAFB. These are:

Wolverton Brook/Brandy Brook Study Area (WB/BB)
• Greenlaw Brook Study Area
Butterfield Brook/Limestone Stream Study Area (BB/LS)

Wolverton Brook/Brandy Brook Study Area. These brooks receive runoff from the western edge of LAFB and
off-base areas west of the base, and flow southwesterly into the little Madawaska River (LMR) (Figure
2-1). The LMR flows south approximately 7 miles and merges with the Aroostook River.

The contamination detected in the WB/BB Study Area appears to be unrelated to base activities.
Pesticides and fuel-related contaminants have been detected in the WB/BB Study Area at off-site sampling
locations upstream of base influences. The most likely source of non-base-related pesticide
contamination is runoff from local agricultural fields. Runoff from roads and land where farm machinery
is used is a likely source of fuel-related contamination.

Greenlaw Brook Study Area. Greenlaw Brook, the principal on-base drainage, consists of the East Branch
and the West Branch, which merge and flow southwesterly into the LMR.

The Flightline Drainage Ditch (FLDD) and the FLDD Wetland (Figures 2-2 and 2-3) constitute a tributary to
the East Branch of Greenlaw Brook (EBGB) , which receives runoff and storm drain discharge from the
primary operations areas of the base. The primary contaminants include polynuclear aromatic hydrocarbons
(PAHs), polychlorinated biphenyls (PCBs), pesticides, total petroleum hydrocarbons (TPH), and lead.

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The EBGB (Figure 2-4) originates in a wetland south of the Fuels Tank Farm (FTF) , and flows westerly
approximately 2,500 feet before merging with the FLDD Wetland. The brook continues to flow west and
merges with the West Branch of Greenlaw Brook (WBGB). The primary contaminants in the EBGB include PAHs,
PCBs, pesticides, TPK and lead. PCBs have also been detected in fish tissue in the EBGB.

The WBGB (Figures 2-5 and 2-6) originates in a wetland north of the Flightline Area (FLA) west of the
base boundary. The WBGB flows southward onto base property, passing west of the Nose Dock Area (NBA) ,
and into Malabeam Lake, a distance of approximately 2 miles. The WBGB exits the southern end of Malabeam
Lake, continues southward into Chapman Pit, and then merges with the EBGB. Contaminants detected in the
WBGB are predominantly the result of base-related activities; however, some potential exists for
non-base-related contaminants to also enter the WBGB. The primary contaminants in the WBGB, specifically
in the NBA drainageways which originate on the western side of the NBA, include PAHs and inorganics.

Butterfield Brook/Limestone Stream Study Area. The headwaters of Butterfield Brook (Figure 2-7) are
north of the base boundary. Butterfield Brook drains roughly the eastern third of the base, flows
southeasterly into Burepo Reservoir, and becomes Limestone Stream below the reservoir dam. Limestone
Stream flows south approximately 11 miles and merges with the Aroostook River.

Contaminants detected within the study area are a result of a combination of base-and non-base-related
activities. Butterfield Brook and its northern tributaries are believed to be impacted by runoff from
agricultural field activity north of the base.

2.2 RESPONSE ACTIVITIES

The response activities for OU 13 are summarized as follows:

• In 1984, a Preliminary Assessment was completed detailing historical material usage and
waste disposal practices at LAFB (CH 2 M Hill, 1984).

• The Remedial Investigation (RI) process commenced in 1988 and continued into 1996 (ABB
Environmental Services, Inc. [ABB-ES], 1997c).

LAFB was added to the NPL in February 1990.

The USAF entered into a FFA in 1991 with the USEPA and MEBEP to address the cleanup of
environmental contamination at LAFB (FFA, 1991). The FFA was revised in Becember 1993 to
address base closure related issues, such as real estate property transfer, and to revise
the cleanup schedule. The FFA was further modified in January 1995 to allow the Remedial
Project Managers to make minor modifications, such as schedule adjustments and removal of
petroleum-contaminated sites from the agreement.

A Feasibility Study (FS) (ABB-ES, 1997a) was completed in 1997 for OU 13 to determine
remedial alternatives for remediation of contamination based on the information presented in
the RI report.

The OU 13 Proposed Plan (ABB-ES, 1997b) was submitted for public review in April 1997.

• A public comment period was held from April 14 to May 13, 1997.

Other key activities at LAFB relating to OU 13 are as follows:

• A Fish Advisory was issued by the Maine Bepartment of Human Services in May 1996 warning
against ingestion of fish from certain water bodies within and around the former LAFB.
These areas include Chapman Pit, Green Pond, Greenlaw Brook, and the LMR and its tributaries
from the Madawaska Bam Reservoir south to the Aroostook River.

• A time-critical removal action was completed in 1996 that included removal of contaminated
sediment from Bitch G12; removal of soil and sediment from Bitch Gil; and cleaning of storm
drains and catch basins from the Steam Plant to the head of Bitch G12.
• A removal action to address elevated levels of inorganic compounds in soil/sediment in the
vicinity of Chapman Pit is scheduled for the 1997 construction season.

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       •      Construction of Landfill 3 (LF-3)  cover system is scheduled for completion in 1998.

       •      Mitigation of basewide wetlands impacts related to environmental restoration activities is
              scheduled for 1998.

                                 3.0 COMMUNITY PARTICIPATION

Throughout LAFB's history, the community has been active and involved in base activities.  The USAF 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 houses, as well
as Restoration Advisory Board (RAB) meetings.  Membership of the RAB is composed of USAF, USEPA, MEDEP,
local officials, and community representatives.

The LAFB Community Relations Plan  (CRP) was released in August 1991 and revised in May 1995.  The CRP
outlined a program to address community concerns and keep citizens informed and involved during  remedial
activities.  The CRP can be found in the Administrative Record.

On June 24, 1992, the USAF made the LAFB Administrative Record available for public review.  The
Administrative Record is currently available for public review at the Air Force Base Conversion Agency
(AFBCA) Office, 5100 Texas Road, Limestone, Maine.

The AFBCA published a notice and brief analysis of the OU 13 Proposed Plan in the Bangor Daily News, the
Aroostook Republican, the Star Herald, and the Fort Fairfield Review on April 9, 1997, and made  the
Proposed Plan available to the public at the AFBCA Office.

From April 14, 1997 through May 13, 1997,  the USAF held a 30-day public comment period to accept public
input on the alternatives presented in the FS and the Proposed Plan, as well as other documents
previously released to the public.  On May 8, 1997, AFBCA 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 as Appendix A and a Responsiveness Summary is included as Appendix B.  Based on
public comments, the public is in agreement regarding the preferred remedial alternatives for OU 13 as
presented in the Proposed Plan.

                           4.0 SCOPE AND ROIiE OF RESPONSE ACTION

The selected remedy for OU 13 includes two remedial alternatives; 1) Removal and Disposal and 2) No
Action.  No further action is necessary for much of OU 13 because there is no unacceptable risk  to human
health or the environment.

The selected remedy for contaminated surface soil and sediment that exceed remediation goals for the
FLDD, FLDD Wetland, EBGB  (from Pennsylvania Road to the Ski Chalet), north and south NDA Drainageways,
Ditch G06, and the Underground Transformer Site (UTS) Wetland  (northern portion) is Removal and  Disposal.
The major components of the remedy include:

       •      pre-design studies to delineate the  extent of remediation for design purposes;  pre-design
              wetland mitigation studies (i.e.,  wetland delineations and function-value assessments)  to
              evaluate the impacts resulting from remedial activities;

       •      site preparation and mobilization;

       •      cutting and clearing;

       •      stormwater management;

       •      sediment excavation;

       •      sediment disposal  at LF-3,  some material may reguire disposal at off-base facilities;

       •      backfilling the excavations  with material that closely matches the excavated material;

       •      compensatory wetlands mitigation and demobilization;

       •      long-term environmental and  wetlands mitigation monitoring;

       •      continued fish advisory; and

-------
• five-year site reviews.

Although the RI results indicate unacceptable risks associated with surface water in some areas (i.e.,
FLDD and FLDD Wetland), an FS was not recommended for this medium because remediating soil and sediment
is expected to adeguately reduce risks associated with surface water.

The State Fish Advisory, currently in effect at designated on- and off-base areas, will remain in effect
until the fish are determined to be acceptable for consumption. Areas covered by the advisory include
Chapman Pit, Green Pond, Greenlaw Brook, and the LMR and its tributaries from the Madawaska Dam Reservoir
south to the Aroostook River.

The No Action alternative has been selected for surface soil sediment, and surface water for the LMR
because there is no unacceptable risk associated with these media. The No Action alternative does not
include any remedial action components to reduce or control risks. However, the No Action alternative
will include a long-term environmental monitoring program and five-year site reviews to evaluate the
long-term conditions of the site's ecology and to assess whether human health and the environment
continue to be adeguately protected.

No further action is necessary at the remaining areas within OU 13 because there is no unacceptable risk
to human health or the environment.

These actions will achieve the following remedial response objectives for OU 13:

• prevent or minimize ingestion of and dermal contact with contaminated soil/sediment by human
and ecological receptors;

• prevent human ingestion of contaminated fish;

• minimize migration of contaminated soil/sediment; and

• avoid destruction of existing ecological habitat where the risk associated with short-term
habitat loss outweighs the reduction in risk potentially realized by site remediation.

5.0 SUMMARY OF SITE CHARACTERISTICS

OU 13 assesses the surface water and sediment conditions at LAFB and the immediate areas surrounding the
former LAFB. Because of the size of the area, and the number of drainage systems involved, OU 13 was
subdivided into three primary study areas. The study areas consist of the three major watersheds that
comprise the terrain in and around the former LAFB. The three study areas consist of: (1) the WB/BB
Study Area; (2) the Greenlaw Brook Study Area; and (3) the BB/LS Study Area.

The following paragraphs provide a summary of the site characteristics for each of these study areas.
Additional information for these three study areas can be found in the OU 13 FS (ABB-ES, 1997a) and the
OU 13 RI Report (ABB-ES, 1997c). Section 2.0 of the OU 13 FS presents an overview of the Greenlaw Brook
and BB/LS Study Areas, including discussions on the hydrology and nature and distribution of
contaminants. Based on the sporadic nature of the contamination, and no unacceptable risk to human or
ecological receptors, the OU 13 RI recommended no further action for the soil and sediment in the WB/BB
Study Area. Conseguently, the OU 13 FS does not discuss this study area in detail. Section 6.0 of the OU
13 RI Report presents an overview of the WB/BB Study Area, including discussions on the hydrology and
nature and distribution of contaminants.

The database for OU 13 is very large including nine years of soil, surface water, and sediment data. The
data are presented in the OU 13 RI Report primarily in the individual study area contamination
assessments, human health risk assessments, and ecological risk assessments. Due to variation in human
health exposure scenarios, and the variety of 1AFB ecological habitats and receptors, individual samples
within each study area were combined as appropriate for specific receptors. As a result, contaminant
concentrations presented for different receptors within the same study area are based on different sample
groupings, and conseguently can have different maximum and mean contaminant concentrations in the human
health and ecological risk assessments. Other complexities are also present in the RI database and data
management. As an example, contamination assessments discuss total PAHs to provide an overview of SVOC
contamination in a pond or reach of stream, whereas the risk assessment tables present individual PAH
compound maximums based on samples in a given receptor-specific sample grouping. Also, due to the
transient nature of surface water, the most recent surface water data at a multi-sample location were
utilized in risk assessments, although higher analyte values could potentially have been detected in
earlier years. Further, at sites where multiple sediment samples were collected in 1993, 1994, and 1995,
the mean concentration used in the risk assessments was a "temporal" average of the detected values at

-------
that location over time. Additional information on the use of the OU 13 data is included in the human
health and ecological risk assessment methodology discussions in the RI Report.

5.1 WOLVERTON BROOK/BRANDY BROOK STUDY AREA

The WB/BB Study Area is located along the western side of LAFB and is approximately 4,600 acres in size
(see Figure 2-1). Base property within this study area covers approximately 700 acres. These brooks
receive runoff from the western edge of LAFB and areas west of the base, and flow southwesterly into the
LMR. The LMR is a relatively broad but shallow river located approximately 1.5 miles west of the base
boundary. The LMR flows south approximately 7 miles and merges with the Aroostook River.

The OU 13 RI recommended no further action for surface water and sediment in the WB/BB Study Area;
therefore, this study area was not evaluated in the OU 13 FS and is not discussed in this subsection.
Section 6.0 of the OU 13 RI Report presents the site characteristics of the WB/BB Study Area.

5.2 GREENLAW BROOK STUDY AREA

Greenlaw Brook, the principal on-base drainageway, consists of the East Branch and the West Branch, which
merge and flow southwesterly into the LMR. The EBGB and WBGB, and their respective drainage areas
together are approximately 7,500 acres in size. The FLDD and the FLDD Wetland constitute a tributary to
the EBGB and receive runoff and storm drain discharge from the primary operations areas in the central
portion of LAFB. A Spill Containment Facility (SCF), designed to remove and contain floating petroleum
products caused by spills or releases, is located next to the FLDD south of Weinman Road.

Flightline Drainage Ditch and Corresponding Wetland

The FLDD and FLDD Wetland are located in the south-central portion of LAFB, west of the FLA and
Pennsylvania Road (see Figures 2-2 and 2-3). The FLDD receives the majority of stormwater runoff from
the NDA, runways, and FLA via an extensive storm drainage system. Several culverts and drainage ditches
discharge stormwater into the FLDD. The FLDD is an unlined drainage channel, 20 to 25 feet wide and more
than 2,500 feet long. The FLDD extends from the outfall of three 4-foot diameter storm drain culverts
southward to the SCF diversion weir at Weinman Road. South of the SCF discharge, flow in the FLDD
drainage continues southward through the FLDD Wetland. This wetland is approximately 2,000 feet long,
with an average width of about 400 feet. Flow from the FLDD Wetland eventually enters the EBGB.

Surface water, sediment, and surface soil samples were collected from the FLDD and FLDD Wetland. VOCs,
including benzene, toluene, ethylbenzene, and xylenes (BTEX) and chlorinated solvents, were detected in
surface water with the highest freguency and concentrations near the FLDD headwall. Fuel-related VOCs
were
primarily detected in three distinct area: (1) just below the FLDD headwall, (2) just before diversion
into the SCF, and (3) just downstream of the SCF discharge confluence with the FLDD. VOCs were detected
in only two surface soil samples at low concentrations (close to the CRQL).

SVOCs were sporadically detected in most of the surface water samples but may have been associated with
suspended solids in unfiltered samples. Fuel-related SVOCs, including PAHs, were detected in many FLDD
and FLDD Wetland sediment and surface soil samples with the highest concentrations occurring in sediment
upstream of the SCF. The maximum reported concentration of total PAHs in sediment was 310 milligrams per
kilogram (mg/kg). PAH results from surface soils closely resemble the types and concentrations of PAHs
detected in sediment.

TPH was detected in the majority of the sediment samples. Detected concentrations of TPH are consistent
with overall elevated concentrations of SVOCs in each sediment sample. Surface soil and sediment TPH and
SVOC results indicate a modest trend in decreasing concentrations moving away from the main channel into
the floodplain.

Pesticide results from one surface water sample near the SCF indicated concentrations greater than
off-site concentrations. One PCB (Aroclor-1260) was detected in two surface water samples but is
believed to be the result of adsorption on suspended solids in the unfiltered samples. Pesticides in the
FLDD and FLDD Wetland sediments were typically at higher concentrations than in other LAFB study areas.
PCBs (primarily Aroclor-1260) were detected above off-site concentrations in most of the sediment samples
from the FLDD and FLDD Wetland at concentrations ranging from 0.21 to 140 mg/kg, and in only two of the
surface soil samples from the FLDD Wetland.

Numerous inorganics were detected above background in surface water, sediment and surface soil. Higher
concentrations and greater distribution of inorganics in surface water were generally encountered near
the FLDD headwall, approximately halfway down the FLDD, and downstream of the SCF. Detections in

-------
sediment and surface soil are distributed fairly uniformly throughout the FLDD and FLDD Wetland. Lead
was reported at a maximum concentration of 474 mg/kg in a sediment sample from the FLDD and 234 mg/kg in
a surface soil sample from the FLDD Wetland.

East Branch of Greenlaw Brook

The EBGB originates in the wetlands near the FTF and flows westerly for approximately 2,500 feet before
merging with the FLDD Wetland drainage (see Figure 2-4). After the confluence with the FLDD Wetland
area, the brook continues to flow westerly, and merges with the WBGB. The EBGB is generally a narrow,
shallow stream, except in wetland areas, where it broadens.

VOCs were detected in surface water and sediment samples collected from the EBGB. Detected compounds
were primarily BTEX and sporadic low concentrations of some chlorinated solvents. Most of the VOC
contaminants reported in surface water occurred in samples from the 1991 sampling event from locations
near the FTF. VOC contaminants in sediment were primarily detected in drainage areas from the Refueling
Maintenance Shop Area (RMSA), FTF, Vehicle Maintenance Building (VMB) , and near the confluence with the
FLDD Wetland.

SVOCs constitute a substantial portion of the contaminants reported in EBGB surface water and sediment.
The majority of SVOCs were detected in sediment throughout the EBGB. Detected compounds included PAHs
and other fuel-related compounds with total PAHs detected at a maximum concentration of 46 mg/kg. The
highest concentrations of PAHs were detected in the upper reaches of the EBGB and generally decrease in
freguency and concentrations downstream.

TPH was detected in most sediment samples throughout the EBGB but in only one surface water sample. The
highest concentrations were detected in drainage area sediments from the RMSA, FTF, and VMB. As with the
SVOCs, TPH concentrations in the EBGB generally decrease moving downstream.

In EBGB surface water, pesticides and PCBs were detected infreguently; when they occur, they may be
attributable principally to sorbed contaminants in unfiltered samples. Numerous pesticides were detected
in sediment throughout the EBGB, in some cases at concentrations an order of magnitude greater than
off-site
concentrations. With some exceptions, the highest concentrations were detected in drainage area
sediments from the RMSA, FTF, and VMB and generally decrease downstream. Where the exceptions occur,
detected concentrations may be partially associated with adjacent agricultural operations. PCBs were
detected in many sediment samples with the maximum reported concentration of 110 mg/kg. As with the
other contaminants, the greatest concentrations of pesticides and PCBs were detected in the upper reaches
of the EBGB.

Reported concentrations of inorganics are typically moderately low for both surface water and associated
sediment. Lead was detected above background in the drainage area sediments from the RMSA, FTF, and VMB
at concentrations as high as 110 mg/kg.

West Branch of Greenlaw Brook

The WBGB originates northwest of the FLA, west of the base boundary. The WBGB flows southward onto base
property, passing west of the Quarry and NDA, and into Malabeam Lake (see Figures 2-5 and 2-6). The WBGB
exits the southern end of Malabeam Lake and continues southward into Chapman Pit, and subseguently merges
with the EBGB. The total length of the WBGB is approximately 3.4 miles.

Surface water and sediment samples were collected from the WBGB. With few exceptions VOC detections in
surface water and sediment, not interpreted to be associated with laboratory contamination, were
infreguently detected and generally reported at concentrations below 10 parts per billion.

Fuel-related SVOCs were infreguently detected in surface water samples in the WBGB. The majority of
SVOCs detected in sediment were PAHs with the maximum total PAH concentration reported at 1,120 mg/kg.
This sample was collected from a drainageway originating from the western side of the NDA and was more
than 10 times higher in total PAH concentration than any other sediment sample associated with the WBGB.
SVOC results from the WBGB indicate the bulk PAH contamination remains in NDA drainageways with limited
transport to the WBGB.

With one exception, surface water TPH results were nondetect. Several positive results were reported for
TPH and fuel oil in sediment samples throughout the WBGB, with the highest concentration detected in
Chapman Pit sediments. Only four of the downstream sediment samples in the WBGB showed concentrations
greater than the upstream background location. TPH data were not available for the NDA drainageways.

-------
Pesticides detected in surface water in the WBGB were generally below observed off-site concentrations.
Various pesticides were detected in sediment throughout the WBGB. The majority of detections were less
than one order of magnitude above background. The highest concentrations were observed in samples from
the Quarry drainage ditch and the adjacent wetland area, and the southernmost NBA drainageway. The
number and concentrations of pesticides detected in the WBGB area are generally lower than observed in
the EBGB, and are interpreted to be consistent with routine application of pesticides at LAFB. PCBs were
detected above concentrations observed in off-site samples at two locations, the wetland area below the
Quarry drainage (0.56 mg/kg) and in Green Pond (0.6 and 0.8 mg/kg). One PCB was also detected in one of
the surface water samples from the WBGB.

Inorganics were reported above background in surface water and sediment throughout the WBGB. The
greatest number of individual metals detected above background concentrations in surface water was from a
turbid sample collected just below Chapman Pit. In sediment samples, cadmium was detected with the most
regularity at elevated levels (five times background) primarily in sample locations west of the NBA, and
manganese was detected at elevated levels in the vicinity of Chapman Pit.

A removal action to address elevated levels of inorganics in soil/sediment in the vicinity of Chapman Pit
is scheduled for the 1997 construction season.

5.3 BUTTERFIELD BROOK/LIMESTONE STREAM STUDY AREA

The BB/LS Study Area (see Figure 2-7) includes the northeastern and eastern portions of the base and is
approximately 7,150 acres in size. Base property within the study area covers approximately 5,100 acres.
The headwaters of Butterfield Brook are north of the base boundary. Principal drainage systems in the
study area include Willard and Butterfield Brooks in the north and Limestone Stream in the south.
Butterfield Brook drains roughly the eastern third of the Base, flows southeasterly into Burepo
Reservoir, and becomes Limestone Stream below the reservoir dam. Limestone Stream flows southerly
approximately 11 miles, and then merges with the Aroostook River. Contaminants detected within the study
area are likely the result of a combination of base- and non-base-related activities. Butterfield Brook
and its northern tributaries appear to be impacted by runoff from agricultural field activity north of
the base.

Surface water and sediment samples were collected from the BB/LS Study Area. Analytical results from both
Butterfield Brook and Limestone Stream are summarized together in the following paragraphs.

VOCs, including fuel-related compounds and trichloroethylene, were detected sporadically in surface water
samples from BB/LS. The only results that consistently indicate the presence of VOCs in surface water
and sediment is the wetland area south of the UTS. This wetland area receives stormwater runoff from the
UTS, as well as other buildings and former facilities on the north side of Oregon Trail.

SVOCs were detected in surface water sporadically throughout the BB/LS Study Area but were never detected
more than once at any location. SVOCs were detected in over 50 percent of the sediment samples. The
great majority of SVOCs detected were PAHs, with the maximum reported concentration (7.2 mg/kg) in a
sample collected from the wetland downstream of the UTS. SVOCs were detected in the background location
for Butterfield Brook upgradient of East Loring Lake but were not detected in background samples from
Masters Brook and Willard Brook. PAHs were detected in Burepo Brook where it enters the reservoir from
the east, indicating a potential off-base contribution to the reservoir. Upgradient sources along
Butterfield Brook and Burepo Brook include roadways and agricultural areas.

TPH was detected in surface water samples from the center of East Loring Lake and downstream of Burepo
Reservoir. TPH was detected in sediment throughout the BB/LS Study Area, with the highest concentration
detected in the drainage area between the Fire Training Area and East Loring Lake. As with SVOCs, TPH
was detected in the upstream background samples for Butterfield Brook and Burepo Brook. Neighboring
agricultural operation and road runoff presumably account for fuel-related contaminants entering these
areas.

Numerous pesticides were detected in both surface water and sediment throughout this drainage area. The
reported concentrations in both media are almost all less than or within an order of magnitude of
off-site concentrations for individual pesticides. One exception is the wetland area southeast of the
UTS, that also showed the presence of other organic and inorganic contaminants. One PCB (Aroclor-1260)
was detected above off-site concentrations in only two samples (1 J and 0.9 mg/kg), collected downstream
of the UTS storm drain outfall.

Inorganics above background concentrations in surface water and sediment are widespread and varied across
the study area but are generally characterized as low concentrations. With very few exceptions,
inorganics were detected at their highest levels in the wetland south of the UTS and in East Loring Lake.

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6.0 SUMMARY OF SITE RISKS

A baseline human health risk assessment (HHRA) and baseline ecological risk assessment (ERA) were
performed as part of the OU 13 RI. The assessments were performed in accordance with USEPA and MEDEP
risk assessment guidance documents and the LAFB Risk Assessment Methodology (Hazardous Waste Remedial
Actions Program [HAZWRAP], 1994). The purpose of the HHRA was to characterize the risks associated with
potential human exposure to contaminated media, define remediation goals and objectives, and provide
information to assist with remedial action decisions. The purpose of the ERA was to evaluate potential
risks to aguatic organisms and semi-aguatic wildlife that use aguatic habitat (i.e., stream and
palustrine areas) and to terrestrial receptors that may use habitat within the study areas. The baseline
FMRA and ERA consisted of a six step process:

1) Data evaluation was conducted to determine the usability of the data and to determine the data
sets that would be used for the HHRA and ERA.

2) Contaminant identification identified those hazardous substances that, given the specifics of
the site, were determined to be contaminants of potential concern.

3) Exposure assessment identified actual or potential exposure pathways, characterized the
potentially exposed populations, and determined the extent of the possible exposure.

4) Toxicity assessment considered the types and magnitude of adverse health effects associated with
exposure to hazardous substances.

5) Risk characterization integrated the four previous steps to summarize the potential and actual
risks posed by hazardous substances in the study areas, including carcinogenic and
non-carcinogenic risks.

6) Uncertainty evaluation considered possibilities that the above process may have over estimated
or under estimated the actual risk.

The following paragraphs summarize the results of the HHRA and ERA for each of the study areas. For more
detail on the data sets used, data evaluation, contaminant identification, exposure assessment, toxicity
assessment, risk characterization, and uncertainty evaluation, see the Final OU 13 RI Report (ABB-ES,
1997c) and the Final OU 13 FS (ABB-ES, 1997a).

The risk assessment process identified the primary risk contributors to both human and ecological
receptors. Remediation goals for the individual study areas were then developed for the primary risk
contributors. In a few instances, accumulated analytical data and site-specific knowledge about selected
inorganics (e.g., freguency of detection, randomness of detection, natural occurrence, lack of base
sources, and detections only slightly above background concentrations) indicated that remediation goal
development was not warranted. For example, in the FLDD/FLDD Wetland Study Area, selenium was detected
above background in less than 10 percent of the sediment samples, whereas lead was detected above
background in more than 95 percent of the samples. The widespread detection of lead, its co-location
with selenium, selenium detections only slightly above background, and the presence of other significant
risk-contributing compounds (i.e., Aroclor-1260 and 4,4-DDT) led to the elimination of selenium as a
cleanup indicator compound with a remediation goal. In some cases, manganese was eliminated from
remediation goal development primarily due to the fact that it is ubiguitous and naturally occurring in
soils and bedrock in the Loring area. Where similar circumstances were identified for aluminum, zinc,
and nickel, the decision was made to limit the number of cleanup indicator compounds and remediation
goals. This process enables the cleanup to focus on the primary contributors of risk.

6.1 WOLVERTON BROOK/BRANDY BROOK STUDY AREA

The OU 13 RI Report (ABB-ES, 1997c) recommended no further action for surface water and sediment in the
WB/BB Study Area. The site risks are not summarized in this subsection; however, the HHRA and ERA for
the WB/BB Study Area are presented in the OU 13 RI Report. The OU 13 RI Report recommended an FS to
address contamination in fish in the LMR. Therefore, the HHRA and ERA for the LMR are summarized below.

Little Madawaska River

The human health contaminants of concern (COCs) for the LMR are presented in the OU 13 FS (ABB-ES,
1997a). Quantitative estimates of carcinogenic and noncarcinogenic risks associated with exposure to
contaminated media, using both the average and RME scenarios, are summarized in Table 6-1.

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Total current and future receptor risks do not exceed the USEPA carcinogenic risk range or the MEDEP
cancer risk guidance value for the average and RME scenarios. Potential future and current carcinogenic
risks for all surface water and sediment data sets are within the USEPA carcinogenic risk range and at or
below the MEDEP cancer risk guidance value.

Noncarcinogenic risk for the total receptor does not exceed a Hazard Index (HI) of 1. Current and future
noncarcinogenic risks calculated for all surface water and sediment data sets, using both the average and
RME exposures for the wading and swimming scenarios, are significantly less than an HI of 1. In
addition, the combined surface water and sediment noncarcinogenic risks for the child and adult receptors
while wading and swimming are less than an HI of 1. Carcinogenic and noncarcinogenic risks associated
with ingestion of fish fillets from the LMR exceed regulatory guidelines. Aroclor-1260 is the primary
risk contributor for both carcinogenic and noncarcinogenic risks.

Qualitative evaluation of storm-event and snowmelt data indicate that episodic high-flow conditions do
not result in an increased human health risk associated with exposure to surface water and sediment.

Ecological COCs for the different habitats identified in the LMR are presented in the OU 13 FS (ABB-ES,
1997a). The primary risk contributors and the associated risks are summarized in Tables 6-2 through 6-4.

Impacts to aquatic receptors from exposure to COCs in surface water and sediment appear to be minimal.
For semi-aguatic receptors, acute and chronic exposure His were slightly above 1 for several indicator
species. Selenium and Aroclor-1260 are the primary risk contributors for these receptors. Risk
estimates for selenium in sediment are not apparently correlated with base-related contamination because
maximum sediment COG concentrations are generally comparable to background concentrations, and background
concentrations are generally greater than the RTVs. PCBs were detected at concentrations below those
observed off-site but greater than the RTV. Measured fish-tissue PCB residues in trout in the lower LMR
may be associated with reproductive and behavioral effects. Qualitative evaluation of data from the 1994
storm-event samples for the primary risk contributors did not indicate an unusual level of risks to
ecological receptors.

Acute and chronic risk estimates for semi-aguatic wildlife suggest that substantial risk would not occur
from potential exposures to average and maximum detected surface water and sediment concentrations.
Incremental risk to aguatic and semi-aguatic receptors associated with exposure to contaminants that may
migrate into the LMR in the future appears to be negligible.

6.2 GREENLAW BROOK STUDY AREA

The HHRA and ERA were evaluated separately for several waterways within the Greenlaw Brook Study Area:
the FLDD/FLDD Wetland and associated ditches, the EBGB, and the WBGB.

Flightline Drainage Ditch and Corresponding Wetland

The human health COCs for the FLDD/FLDD Wetland and associated ditches are presented in the OU 13 FS
(ABB-ES, 1997a). Quantitative estimates of carcinogenic and noncarcinogenic risks associated with
exposure to contaminated media, using both the average and RME scenarios, are summarized in Table 6-5.

Total current and future receptor risk exceeds the USEPA carcinogenic risk range and the MEDEP cancer
risk guidance value for both average and RME scenarios. Potential carcinogenic risks for a surface soil
and sediment data sets are within the USEPA carcinogenic risk range. Potential risk for surface water
exceeds the USEPA carcinogenic risk range. The surface water risk, and the RME surface soil and sediment
risk exceed the MEDEP cancer risk guidance value. Total noncarcinogenic risk exceeds an HI of 1 for
average and RME scenarios. Estimated noncarcinogenic risks exceed the HI of 1 for RME sediment and RME
and average surface water scenarios. The primary carcinogenic and noncarcinogenic risk contributor for
surface soil, sediment, and surface water, is Aroclor-1260. Qualitative evaluation of storm-event data
indicate that episodic high-flow conditions do not result in an increased human health risk associated
with exposure to surface water and sediment.

Ecological COCs for the different habitats identified in the FLDD/FLDD Wetland and associated ditches are
presented in the OU 13 FS (ABB-ES, 1997a). The primary risk contributors and the associated risks for
the different habitats are summarized in Tables 6-6 through 6-11.

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                                                       TABIiE 6-4
                            SUMMARY OF ECOLOGICAL RISK ASSESSMENT FOR SEDIMENT AND SURFACE WATER
                                       LITTLE MADAWASKA RIVER - RIVERINE HABITAT

                                          OPERABLE UNIT 13 RECORD OF DECISION
                                                 LORING AIR FORCE BASE
ECOLOGICAL RECEPTORS EVALUATED

        PRIMARY RISK
     CONTRIBUTORS  (a)

SEMI-AQUATIC WILDLIFE(b)

     Muskrat
                       Hazard Index

     Belted Kingfisher

               4,4-DDE
               4,4-DDT
               Selenium

                       Hazard Index

     Maritime Garter Snake

                       Hazard Index

     Mink
               4,4-DDE
               Aroclor-1260
               Selenium

                       Hazard Index
     Osprey
               Selenium
                       Hazard Index
  ACUTE
EXPOSURES
 CHRONIC
EXPOSURES
                                  RIVER HOT SPOT
     0.23
    1.1[d]

       1.3



    0.0062
                                               0.79
                       0.11
  0.49[c]
  0.13[c]
  0.17[d]

      1.1
                      0.013
                    0.37[e]
                    01.6[f]
                    0.95[g]

                        3.3
                                           0.25
                        0.014
                                         0.0021
                                                                                     0.013
                                                 1.4
                                                               0.065
                                                                                  0.00087
NOTES:
[a] The analytes that contribute to risk are identified for those wildlife receptors that have a hazard
    index greater than 1. Hazard guotients are listed for these analytes.
[b] The information listed below is a summary of Tables Y10-5 through Y10-7 in Appendix Y of the RI
    report  (ABB-ES, 1997c).
[c] Risk based on the following effects:  LOAEL for decreased eggshell thickness in barn owls; chronic
    ingestion study.
[d] Risk based on the following effects:  NOAEL for teratogenic effects in mallard ducks; 3-month
    ingestion study.
[e] Risk based on the following effects:  LOAEL for reproductive productivity in rats; 3-generation
    ingestion study.
[f] Risk based on the following effects:  LOAEL for multiple effects in beagle dogs; chronic ingestion
    study.
[g] Risk based on the following effects:  LOAEL for decreased breeding in rats; chronic ingestion  study.
[h] Risk based on the following effects:  LOAEL for mortality in rats; acute ingestion study.
--: Analyte not a substantial risk contributor for this exposure scenario.

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                                      TABIiE 6-7
        SUMMARY OF ECOLOGICAL RISK ASSESSMENT FOR SEDIMENT AND SURFACE WATER
                 FLIGHTLINE DRAINAGE DITCH STUDY AREA - STREAM HABITAT

                         OPERABLE UNIT 13 RECORD OF DECISION
                               LORING AIR FORCE BASE
ECOLOGICAL RECEPTORS EVALUATED

                      PRIMARY RISK CONTRIBUTORS

SEMI-AQUATIC WILDLIFE[b]

      Muskrat
                     4,4'-ODD
                     Aroclor-1260
                     gamma-Chlordane
                     Lead

                          Hazard Index
      Great Blue Heron
                     gamma-Chlordane
                     Endosulfan sulfate
                     4,4-DDT

                          Hazard Index

      Maritime Garter Snake
      Mink
      Belted Kingfisher
                          Hazard Index
                          Hazard Index
                          Hazard Index
    ACUTE
 EXPOSURES[a]
  0.42[c]
  0.33[c]

  0.30[g]

      3.0
  0.38[i]
  O.lltj]
      1.4
                                                             0.18
                                                            0.038
                                                            0.071
   CHRONIC
EXPOSURES [a]
  0.77[d]
    H[e]
    54[f]
    47 [h]
  0.79[f]
   0.3[k]
  0.99[1]

      3.4
                                                                              0.23
                                                                             0.024
                                                                             0.073
    NOTES:
    [a]  The analytes that contribute to risk are identified for those wildlife receptors that
        have a hazard index greater than 1. Hazard guotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y7-12 and Y7-13 in Appendix Y of the
        RI  report (ABB-ES, 1997c).
    [c]  Risk estimated based on the following effects:
    [d]  Risk estimated based on the following effects:
        multi-generation ingestion study.
    [e]  Risk estimated based on the following effects:
        multi-generation ingestion study.
    [f]  Risk estimated based on the following effects:
        mice; chronic ingestion study.
    [g]  Risk estimated based on the following effects:
    [h]  Risk estimated based on the following effects:
        mortality in rats; single oral dose.
    [i]  Risk estimated based on the following effects:
        oral dose.
    [j]  Risk estimated based on the following effects:
        oral dose.
    [k]  Risk estimated based on the following effects:
        mice; chronic ingestion study.
    [1]  Risk estimated based on the following effects:
        black duck;  chronic ingestion study.
     -:  Analyte is not a substantial risk contributor for this exposure scenario.
mortality in rats; single oral dose.
LOAEL for reproductive effects in rats;

reduced litter size in rats;

LOAEL for regional liver hypertrophy in

mortality in rats; single oral dose.
NOAEL for developmental effects in

LOAEL for mortality in pheasant; single

LOAEL for mortality in mallard; single

LOAEL for ovarian cyst development in

LOAEL for reduced eggshell thickness in

-------
                                      TABIiE 6-8
         SUMMARY OF ECOLOGICAL RISK ASSESSMENT FOR SEDIMENT AND SURFACE SOIL
              FLIGHTLINE DRAINAGE DITCH STUDY AREA - FLOODPLAIN HABITAT
                        OPERABLE UNIT 13 RECORD OF DECISION
                                LORING AIR FORCE BASE
ECOLOGICAL RECEPTORS EVALUATED
                      PRIMARY RISK
       CONTRIBUTORS

TERRESTRIAL WILDLIFE (b]
    ACUTE
  EXPOSURES[a]
  CHRONIC
EXPOSURES [a]
       Short-tail Shrew
                      Benzo(b,k)fluoranthene
                      Chrysene
                      Endrin aldehyde
                      Lead
                      Manganese
                      Selenium
         2[c]
         0[c]
         7[d]
         3[e]
         2[g]
        12 [d]
      5.2[f]
      3.8[h]
                           Hazard Index
                                                                 27
                                                                                  22
       American Woodcock
                      Benzo(a)pyrene
                      Benzo(b,k)fluoranthene
                      Chrysene
                      Endrin aldehyde
                      Lead
                      Manganese
                      Selenium
         0[c]
         7[c]
         2[c]
         6[g]
        15 [d]
                        2.2[k]
                           Hazard Index
                                                                 34
                                                                                 7.4
       Garter Snake
                           Hazard Index
                                                               0.51
                                                                                0.19
       Red Fox
                      Selenium
                           Hazard Index
                                                                6.9
                                                                                0.75
       Barred Owl
                      Benzo(b,k)fluoranthene
                      Benzo(g,h,i)perylene
                      Indeno(1,2,3-cd)pyrene
                      Endrin aldehyde
                      Selenium
                           Hazard Index                         9.2             0.26
    NOTES:
    [a]  The analytes that contribute to risk are identified for those wildlife receptors that
        have a hazard index greater than 1. Hazard guotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y7-8 and Y7-9 in Appendix Y of the
        RI  report (ABB-ES, 1997c).
    [c]  Risk estimate based on the following effects:
    [d]  Risk estimate based on the following effects:
    [e]  Risk estimate based on the following effects:
    [f]  Risk estimate based on the following effects:
    [g]  Risk estimate based on the following effects:
    [h]  Risk estimate based on the following effects:
    [i]  Risk estimate based on the following effects:
    [j]  Risk estimate based on the following effects:
    [k]  Risk estimate based on the following effects:
        doves.
    [1]  Risk estimate based on the following effects:
decreased fertility and litter size in mice.
mortality in rats.
mortality in guinea pigs.
NOAEL for developmental effects in rats.
NOAEL for mortality in mice.
decreased growth rates in rodents and livestock.
decreased breeding in rats.
mortality in rock doves.
kidney pathology and learning deficiencies in rock

mortality in birds.
    -:  Analyte not a substantial risk contributor for this exposure scenario.

-------
                                    TABIiE 6-10
                 SUMMARY OF ECOLOGICAL RISK ASSESSMENT FOR SEDIMENT
             FLIGHTLINE DRAINAGE DITCH STUDY AREA - AQUATIC DITCH HABITAT

                         OPERABLE UNIT 13 RECORD OF DECISION
                                LORING AIR FORCE BASE
ECOLOGICAL RECEPTORS EVALUATED
                      PRIMARY RISK
       CONTRIBUTORS

TERRESTRIAL WILDLIFE [b]

        Short-tail Shrew
             Benzo(b,k)fluoranthene
             Selenium

                  Hazard Index
  ACUTE
EXPOSURES[a]
   49[d]

     53
  CHRONIC
EXPOSURES [a]
                                                                              2.0
        American Woodcock
             Benzo(b,k)fluoranthene
             Selenium

                  Hazard Index
   64 [d]
                                                                             0.012
        Garter Snake
             Selenium
                  Hazard index
 1.1[d]

    1.1
                                                                            0.0015
        Red Fox
             Selenium
                  Hazard Index
                                                           3.0[d]

                                                             3.3
                                                                          0.00051
        Barred Owl
                  Hazard Index
                                                            0.91
                                                                         0.000029
    NOTES:

    [a]  The analytes that contribute to risk are identified for those wildlife receptors  that have  a
        hazard index greater than 1. Hazard quotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y7-16 and Y7-17 in Appendix Y of the  RI
        report (ABB-ES 1997c).
    [c]  Risk estimate based on the following effects:  decreased fertility and litter  size in mice.
    [d]  Risk estimate based on the following effects:  mortality in rats.
    [e]  Risk estimate based on the following effects:  decreased breeding in rats.
    -:  Analyte not a substantial risk contributor for this exposure scenario.

-------
                                     TABIiE 6-11
               SUMMARY OF ECOLOGICAL RISK ASSESSMENT FOR SURFACE SOIL
           FLIGHTLINE DRAINAGE DITCH STUDY AREA - TERRESTRIAL DITCH HABITAT

                        OPERABLE UNIT 13 RECORD OF DECISION
                               LORING AIR FORCE BASE
ECOLOGICAL RECEPTORS EVALUATED

                      PRIMARY RISK
       CONTRIBUTORS

TERRESTRIAL WILDLIFE [b]

                 Short-tail shrew
                      Selenium
                           Hazard Index

                 American Woodcock
                      Benzo(b,k)fluoranthene
                      Selenium

                           Hazard Index

                Garter Snake

                           Hazard Index

                 Red Fox
                     Selenium

                           Hazard Index

                 Barred Owl
                     Selenium

                           Hazard Index
   ACUTE
 EXPOSURES[a]
29[c]

  34



38 [c]

  44



 0.64
                  CHRONIC
                EXPOSURES [a]
                                                                                2.9[d]

                                                                                   4.0
                        0.039
                       0.0047
    2.3


0.89[c]

    1.3
                       0.0014
                                                                              0.00021
    NOTES:

    [a]  The analytes that contribute to risk are identified for those wildlife receptors that have  a
        hazard index greater than 1. Hazard quotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y7-18 and Y7-19 in Appendix Y  of the RI
        report (ABB-ES 1997c).
    [c]  Risk estimate based on the following effects:  mortality in rats.
    [d]  Risk estimate based on the following effects:  decreased breeding in rats.
    [e]  Risk estimate based on the following effects:  decreased fertility and litter  size in mice.
    -:  Analyte not a substantial risk contributor for this exposure scenario.

-------

It is likely that aquatic organisms that occur in the FLDD Study Area, including Ditch G06, are being
adversely affected by existing contaminant levels in sediment. The majority of the risk is associated
with exposures to SVOCs, Aroclor-1260, and many different pesticides. His for some semi-aguatic wildlife
receptors were estimated to exceed 1, but because of the small magnitude of risk and the number of
conservative assumptions used, it is unlikely that most semi-aguatic wildlife receptors would be
adversely affected in the FLDD habitat. Based on risk evaluations for terrestrial wildlife receptors
that occur in the FLDD floodplain habitat, receptors may be adversely affected as a result of contaminant
exposure. Potential effects would be limited based on the magnitude of risk estimates.

Inorganic analyte concentrations detected in the aguatic and terrestrial ditches associated with the FLDD
and the floodplain, exceed the toxicological benchmarks used to screen risks to terrestrial plants and
soil invertebrates. However, maximum concentrations of the risk-contributing analytes are not
substantially higher than background concentrations.

The inhalation exposure pathway appears to be insignificant for ecological receptors. The incremental
risk to wildlife receptors associated with discharge of groundwater to the FLDD stream habitat was also
evaluated and determined to be insignificant. The evaluation of wide-ranging wildlife exposures indicates
that risks to these receptors are similar to those limited to the FLDD stream habitat.

East Branch of Greenlaw Brook

The human health COCs for the EBGB are presented in the OU 13 FS (ABB-ES, 1997a). Quantitative estimates
of carcinogenic and noncarcinogenic risks associated with exposure to contaminated media, using both the
average and RME scenarios, are summarized in Table 6-12.

Total current and future receptor risk are within the USEPA carcinogenic risk range for average and RME
scenarios. Total receptor risk for the RME scenario exceeds the MEDEP cancer risk guidance value. It is
not appropriate to sum the noncarcinogenic risks for the child and adult components of the total
receptor; however, the hazard index for the child under the RME scenario exceeds an HI of 1. Potential
current and future carcinogenic risks for all surface soil, sediment and surface water data sets are
within or below the USEPA carcinogenic risk range. Only potential carcinogenic risks for adult RME
exposure to sediment, and child RME exposure to the PCB sediment hot spot, exceed the MEDEP cancer risk
guidance value. Noncarcinogenic risk associated with childhood exposure to sediment at the PCB hot spot
under the RME scenario exceeds an HI of 1. Carcinogenic and noncarcinogenic risks associated with the
ingestion of fish fillets from the EBGB exceed regulatory guidelines. Aroclor-1260 is the primary risk
contributor for both carcinogenic and noncarcinogenic effects. Qualitative evaluation of storm-event and
snowmelt data indicate that high-flow conditions do not result in an increased human health risk
associated with exposure to surface water and sediment.

Ecological COCs for the different habitats identified in the EBGB are presented in the OU 13 FS (ABB-ES,
1997a) . The primary risk contributors and the associated risks for the different habitats are summarized
in Tables 6-13 through 6-18.

Stream Habitat. Aguatic receptors may be at risk as a result of exposure to stream surface water and
sediment. His based on maximum surface water and sediment concentrations are 650 and 3,100,
respectively. Aroclor-1260 contributes more than 95 percent of the calculated risk to the stream
sediment at the PCB hot spot, with a maximum HI of 23,000. Adverse population-level impacts are unlikely
to occur to semi-aguatic wildlife in the stream habitat, although risks to receptors sensitive to PCB
exposures are possible in the PCB hot spot.

Palustrine Habitat. Sensitive aguatic receptors may be at risk from potential exposure to areas of PCB
and pesticide contaminants in stream sediments; however, population-level effects are unlikely. Some
inorganic analytes exceed plant reference toxicity values (RTVs) but phytotoxicity is unlikely to occur
at near background concentrations and plants are not considered at risk from exposure to palustrine
sediments. Based on the slight RTV exceedances and the conservative nature of the screening process, it
is unlikely that adverse population-level impacts would occur to invertebrates and semi-aguatic receptors
inhabiting the palustrine habitat in the vicinity of the EBGB.

-------
                                           TABIiE 6-12
                                   QUANTITATIVE RISK SUMMARY
                            GREENLAW BROOK (EAST BRANCH) STUDY AREA

                              OPERABLE UNIT 13 RECORD OF DECISION
                                     LORING AIR FORCE BASE
                                                                                                      MEAN EPC
                                                                                              Total a
                                                                                              Cancer
                                                                                             Risk
                                                            Total a
                                                            Hazard
                                                           Index
                                             MAXIMUM EPC
                                     Total a          Total a
                                     Cancer            Hazard
                                    Risk               Index
CURRENT USE
DITCH SURFACE SOIL

Incidental Ingestion of Soil:  Child  (6-16 Years)
Dermal Contact with Soil:  Child  (6-16 Years)
Inhalation Exposure to particulates and volatiles:
Child (6-16 Years)
                                                                         TOTAL:  CHILD
3E-07
7E-08
2E-10
3E-07
     0.01
    0.005
0.0000004
     0.02
1E-06
3E-06
4E-10
4E-06
    0.05
     0.1
0.000001
     0.2
DITCH SURFACE SOIL (HOT SPOT)

Incidental Ingestion of Soil:  Child  (6 - 16 Years)
Dermal Contact with Soil:  Child  (6-16 Years)
Inhalation Exposure to particulates and Volatiles:  Child  (6-10 Years)
                                                                        TOTAL:  CHILD
3E-06
8E-07
4E-10
3E-06
0.09
0.03
ND
0.1
4E-06
8E-06
4E-10
IE-OS
                                                                                                    0.1
                                                                                                    0.3
                                                                                                     ND
                                                                                                    0.4
DITCH AND STREAM SEDIMENT
Incidental Ingestion of Sediment Child  (6 - 16 Years) Wading
Dermal Contact of Sediment Child (6 - 16 Years) Wading
                                                                        TOTAL:
                                          6E-07
                                          7E-04
                            CHILD WADING  7E-07
                  0.03
                 0.005
                  0.04
                        3E-06
                        5E-06
                        9E-04
                     0.2
                     0.3
                     0.5
SEDIMENT (EAST BRANCH)

Incidental Ingestion of Sediment Adult Wading
Dermal contact of Sediment Adult Wading
                                                                        TOTAL:
                                          1E-06
                                          2E-07
                            ADULT WADIN6  1E-06
                  0.02
                 0.003
                  0.03
                        5E-06
                        IE-OS
                        2E-05
                     0.1
                     0.2
                     0.3
COMPOSITE RECEPTOR (CHILD PLUS ADULT) RISKS WADING:  SEDIMENT
                                                                                              2E-06
                                                                                                                   NC
                                                                                                                                    3E-05
                                                                                                                                                          NC

-------
                                            TABIiE 6-12
                                    QUANTITATIVE RISK SUMMARY
                             GREENLAW BROOK  (EAST BRANCH) STUDY AREA

                              OPERABLE UNIT 13 RECORD OF DECISION
                                      LORING AIR FORCE BASE
                                                                                                       MEAN EPC
                                                                                               Total  a           Total  a
                                                                                               Cancer            Hazard
                                                                                               Risk               Index
                                             MAXIMUM EPC
                                     Total a          Total a
                                     Cancer            Hazard
                                     Risk               Index
SEDIMENT(PCB HOT SPOT)

Incidental Ingestion of Sediment:  Child  (6-16 Years) Wading
Dermal contact of Sediment:  Child  (6-16 Years) Wading
                                                                 TOTAL:  CHILD WADING
IE-OS
4E-06
IE-OS
   0.4
   0.2
   0.5
2E-05
6E-05
8E-05
SEDIMENT  (PAH/DDD HOT SPOT)

Incidental Ingestion of Sediment:  Child  (6-16 Years) Wading
Dermal Contact of Sediment:  Child  (6-16 Years) Wading
                                                                 TOTAL:  CHILD WADING
7E-07
   ND
7E-07
0.0007
0.0008
 0.001
7E-07
   ND
7E-07
0.0007
 0.005
 0.006
TOTAL SEDIMENT RISK
Child Wading  (Sediment plus Sediment  [PCB Hot Spot] plus Sediment  [PAH/DDD Hot  Spot])
Adult Wading  (Sediment  [East Branch])

COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS WADING:  SEDIMENT

SURFACE WATER
IE-OS
1E-06

IE-OS
   0.5
  0.03

    NC
9E-05
2E-05

1E-04
     4
   0.3

    NC
Incidental Ingestion of Surface Water:  Child  (6-16 Years) Wading
Dermal Contact of Surface Water:  Child  (6-16 Years) Wading
                                                                  TOTAL:  CHILD WADING
8E-10
IE-OS
IE-OS
 0.001
 0.002
 0.003
9E-10
2E-08
2E-08
  0.01
  0.02
  0.03
SURFACE WATER  (EAST BRANCH)

Incidental Ingestion of Surface Water:  Adult Wading
Dermal Contact of Surface Water:  Adult Wading
                                                                  TOTAL:  ADULT WADING
1E-09
3E-08
3E-08
0.0007
 0.002
 0.003
1E-09
4E-08
4E-08
 0.006
  0.02
  0.02

-------
                                            TABIiE 6-12
                                     QUANTITATIVE RISK SUMMARY
                               GREENLAW BROOK  (EAST BRANCH  STUDY AREA)

                              OPERABLE UNIT 12 RECORD OF DECISION
                                     LORING AIR FORCE BASE
TOTAL RISK SURFACE WATER

 Child Wading (Surface Water)
 Adult Wading (Surface Water  [East Branch])

COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS WADING:  SURFACE WATER

TOTAL RECEPTOR RISK  (SURFACE SOIL, SEDIMENT, AND SURFACE WATER)

 Child (6-16 Years) Exposure to Surface Soil, Sediment, and Surface Water
 Adult Exposure to Sediment and Surface Water

COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS PLAYING AND WADING

FISH FILLETS EGGS

 Incidental Ingestion of Fish Fillets:  Child
 Incidental Ingestion of Fish Fillets:  Adult

COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS EATING FISH

FUTURE USE

DITCH SURFACE SOIL

 Incidental Ingestion of Soil:  Child  (6-16 Years)
 Dermal Contact with Soil:  Child  (6-16 Years)
 Inhalation Exposure to Particulates and Volatiles:  Child  (6-16 Years)
                                                                                                       MEAN EPC
                                                                                               Total a           Total a
                                                                                               Cancer            Hazard
                                                                                               Risk              Index
2E-03
                   NC
                                            MAXIMUM EPC
                                    Total a          Total a
                                    Cancer            Hazard
                                    Risk               Index
1E-08
3E-08
4E-08
IE-OS
1E-06
IE-OS
7E-04
2E-03
0.003
0.003
NC
0.7
0.03
NC
53
30
2E-08
4E-08
6E-08
1E-04
2E-05
1E-04
1E-03
2E-03
0.03
0.02
NC
4
0.3
NC
78
45
                                     3E-03
                                                          NC
                                                                         TOTAL:   CHILD
3E-07
7E-08
2E-10
3E-07
0.01
0.005
0.0000004
0.02
1E-06
3E-06
4E-10
4E-06
0.05
0.1
0.000001
0.2

-------
                                            TABIiE 6-12
                                     QUANTITATIVE RISK SUMMARY
                               GREENLAW BROOK  (EAST BRANCH STUDY AREA)

                              OPERABLE UNIT 12 RECORD OF DECISION
                                     LORING AIR FORCE BASE
DITCH SURFACE SOIL (HOT SPOT)

 Incidental Ingestion of Soil:  Child  (6-16 Years)
 Dermal Contact with Soil:  Child  (6-16 Years
 Inhalation Exposure to Particulates and volatiles:  Child  (6-16 Years)
                                                                                                      MEAN EPC
                                                                       TOTAL:
                                                                               CHILD
                                                                                              Total a
                                                                                              Cancer
                                                                                              Risk
3E-06
8E-07
4E-10
3E-06
                Total a
                Hazard
                Index
  0.09
  0.03
    ND
   0.1
                           MAXIMUM EPC
                   Total a          Total a
                   Cancer            Hazard
                   Risk               Index
4E-06
8E-06
4E-10
IE-OS
   0.1
   0.3
    ND
   0.4
DITCH AND STREAM SEDIMENT
 Incidental Ingestion of Sediment:  Child  (6-16 Years) Wading
 Dermal Contact of Sediment:  Child (6-16 Years) Wading
                                                                       TOTAL:
                                                                               CHILD WADING
6E-07
7E-06
7E-07
  0.03
 0.005
  0.04
3E-06
5E-06
9E-06
   0.2
   0.3
   0.5
SEDIMENT (EAST BRANCH)
 Incidental Ingestion of Sediment:  Adult Wading
 Dermal Contact of Sediment:  Adult Wading
                                                                       TOTAL:
                                                                               ADULT WADING
1E-06
2E-07
1E-06
  0.02
 0.003
  0.03
5E-06
IE-OS
2E-05
   0.1
   0.2
   0.3
COMPOSITE RECEPTOR (CHILD PLUS ADULT) RISKS WADING:  SEDIMENT

SEDIMENT (PCB HOT SPOT)

 Incidental Ingestion of Sediment:  Child  (6-16 Years) Wading
 Dermal Contact of Sediment:  Child  (6-16 Years) Wading
                                                                       TOTAL:  CHILD WADING
                                                                                                2E-06
IE-OS
4E-06
IE-OS
                                                                                                                    NC
   0.4
   0.2
   0.5
                                                                                                                                     3E-05
2E-05
6E-05
8E-05
                                                                                                                                                          NC
SEDIMENT (PAH/DDD HOT SPOT)

 Incidental Ingestion of Sediment:  Child  (6-16 Years) Wading
 Dermal Contact of Sediment:  Child (6-16 Years) Wading
                                                                       TOTAL:
                                                                               CHILD WADING
7E-07
   ND
7E-07
0.0007
0.0008
 0.001
7E-07
   ND
7E-07
0.0007
 0.005
 0.006

-------
                                            TABIiE 6-12
                                     QUANTITATIVE RISK SUMMARY
                               GREENLAW BROOK  (EAST BRANCH STUDY AREA)

                              OPERABLE UNIT 12 RECORD OF DECISION
                                     LORING AIR FORCE BASE
                                                                                                       MEAN EPC
                                                                                               Total  a           Total a
                                                                                               Cancer            Hazard
                                                                                               Risk               Index
                                             MAXIMUM EPC
                                     Total a          Total a
                                     Cancer            Hazard
                                     Risk               Index
TOTAL SEDIMENT RISK
 Child Wading (Sediment plus Sediment  [PCB Hot Spot] plus Sediment  [PAH/DDD Hot  Spot])
 Adult Wading (Sediment [East Branch])
IE-OS
1E-06
  0.5
 0.03
9E-05
2E-05
    4
  0.3
COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS WADING: SEDIMENT

SURFACE WATER
                                                                                                IE-OS
                                                                                                                    NC
                                                                                                                                   1E-04
                                                                                                                                                          NC
 Incidental Ingestion of Surface Water:  Child  (6-16 Years) Wading
 Dermal Contact of Surface Water:  Child  (6-16 Years) Wading
                                                                    TOTAL:  CHILD WADING
2E-08
2E-07

2E-07
0.002
 0.01

 0.01
2E-08
2E-07

2E-07
 0.01
 0.03

 0.04
SURFACE WATER (EAST BRANCH)

 Incidental Ingestion of Surface Water:  Adult Wading
 Dermal Contact of Surface Water:  Adult Wading
                                                                    TOTAL:  ADULT WADING
3E-08
4E-07

4E-07
0.002
 0.01

 0.01
3E-08
4E-07

4E-07
0.007
 0.03

 0.03
TOTAL RISK SURFACE WATER
 Child Wading (Surface Water)
 Adult Wading (Surface Water  [East Branch]
2E-07
4E-07
 0.01
 0.01
2E-07
4E-07
 0.04
 0.03
COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS WADING:  SURFACE WATER
                                                                                               6E-07
                                                                                                                     NC
                                                                                                                                   6E-07
                                                                                                                                                          NC
TOTAL RECEPTOR RISKS  (SURFACE SOIL, SEDIMENT, AND SURFACE WATER)

 Child (6-16 Years) Exposure to Surface Soil, Sediment, and Surface Water
 Adult Exposure to Sediment and Surface Water
IE-OS
1E-06
  0.7
 0.04
1E-04
2E-05
    4
  0.3
COMPOSITE RECEPTOR  (CHILD PLUS ADULT) RISKS PLAYING AND WADING
                                                                                               IE-OS
                                                                                                                     NC
                                                                                                                                   1E-04
                                                                                                                                                          NC

-------
                                                  TABIiE 6-12
                                            QUANTITATIVE RISK SUMMARY
                                      GREENLAW BROOK (EAST BRANCH STUDY AREA)

                                     OPERABLE UNIT 12 RECORD OF DECISION
                                            LORING AIR FORCE BASE
                                                                                                             MEAN EPC
                                                                                                     Total a
                                                                                                     Cancer
                                                                                                     Risk
                 Total a
                 Hazard
                 Index
                          MAXIMUM EPC
                  Total a          Total a
                  Cancer            Hazard
                  Risk               Index
       FISH FILLETS EGGS
        Incidental Ingestion of Fish Fillets:  Child
        Incidental Ingestion of Fish Fillets:  Adult

       COMPOSITE RECEPTOR (CHILD PLUS ADULT) RISKS EATING FISH
7E-04
2E-03

2E-03
53
30

 NC
1E-03
2E-03

3E-03
78
45

 NC
       NOTES:
       a Totals may not appear accurate due to the rounding; but, in fact, are based on addition of individual cancer risks and hazard indices prior to rounding.
       EPC = Exposure Point Concentration
       NC = Not calculated because noncancer risks are not additive between the child and adult receptors.
       ND = Toxicity data not available for quantitative evaluation.
       NE = not evaluated.
       NA = No carcinogenic CPCs detected.

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                                      TABIiE 6-17
           SUMMARY OF ESTIMATED RISK TO SEMI-AQUATIC WILDLIFE FROM SEDIMENT
             GREENLAW BROOK  (EAST BRANCH) STUDY AREA - PALUSTRINE HABITAT

                         OPERABLE UNIT 13 RECORD OF DECISION
                               LORING AIR FORCE BASE

ECOLOGICAL RECEPTORS EVALUATED

                      PRIMARY RISK                                      ACUTE           CHRONIC
          CONTRIBUTORS                                               EXPOSURES[a]    EXPOSURES  [a]

SEMI-AQUATIC WILDLIFE[b]

      Muskrat

                     Lead                                                       -          0.32[c]
                     Selenium                                               2.0[d]          1.7[e]

                          Hazard Index                                        2.5            2.3

      Great Blue Heron

                     Lead                                                       -          0.18[f]
                     Nickel                                                     -          O.llfg]
                     Selenium                                               9.3[d]         0.71[h]

                          Hazard Index                                        9.6            1.3

      Maritime Garter Snake

                          Hazard Index                                       0.42           0.075

      Short-tailed Shrew

                      Lead                                                      -           1.1[c]
                      Nickel                                               0.76[i]
                      Selenium                                               20[d]           17[e]

                          Hazard Index                                         22              19


    NOTES:
    [a]  The analytes that contribute to risk are identified for those wildlife receptors that  have  a
        hazard index greater than 1. Hazard quotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y9-14 and Y9-15 in Appendix Y  of the RI
        report (ABB-ES, 1997c).
    [c]  Risk estimate based on the following effects:  NOAEL for reproductive effects in rats;
        multi-generation feeding study.
    [d]  Risk estimate based on the following effects:  LOAEL for mortality in rats; single  oral dose.
    [e]  Risk estimate based on the following effects:  LOAEL for reproductive effects in rats; chronic
        study.
    [f]  Risk estimate based on the following effects:  LOAEL for kidney pathology and learning
        deficiencies in rock dove.
    [g]  Risk estimate based on the following effects:  LOAEL for survivorship effects in Japanese guail;
        acute ingestion study.
    [h]  Risk estimate based on the following effects:  NOAEL for teratogenic effects in mallards;
        subchronic study.
    [i]  Risk estimate based on the following effects:  LOAEL for mortality in rats; single  oral dose.
     -:  Analyte is not a substantial risk contributor for this exposure scenario.

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Ditch Habitat. Maximum concentrations of some inorganics exceed plant and invertebrate RTVs. However,
because background concentrations are generally comparable to maximum detected site concentrations, and
average site concentrations are generally below RTVs, the spatial extent of potential phytotoxicity
likely would be limited. Lethal and sublethal effects to terrestrial wildlife receptors are possible but
population-level effects are not likely.

West Branch of Greenlaw Brook

The human health COCs for the WBGB are presented in the OU 13 FS (ABB-ES, 1997a). Quantitative estimates
of carcinogenic and noncarcinogenic risks associated with exposure to contaminated media, using both the
average and RME scenarios, are summarized in Table 6-19.

Total current and future receptor risks are within the USEPA carcinogenic risk range for the average and
the RME scenarios. Total receptor risk under the RME scenario slightly exceeds the MEDEP cancer risk
guidance value. Potential current and future carcinogenic risks for all surface soil, sediment, and
surface water data sets are within or below the USEPA carcinogenic risk range, and at or below the MEDEP
cancer risk guidance value.

It is not appropriate to sum the noncarcinogenic risk for the child and adult components of the total
receptor; however, the hazard index for the child under the RME scenarios exceeds an HI of 1. Current
and future noncarcinogenic risks for all surface soil and sediment data sets are less than an HI of 1.
For surface water data sets, His are less than or egual to 1, except for the RME child-wading scenario.
Inorganic analytes in surface water were the primary risk contributors.

Carcinogenic risks associated with ingestion of fish fillets from Malabeam Lake, Chapman Pit, and Green
Pond exceeded regulatory guidelines. Noncarcinogenic risks for fish ingested from Chapman Pit and Green
Pond exceed an HI of 1, and risks associated with Malabeam Lake are less than an HI of 1. PCBs are the
primary risk contributors for both carcinogenic and noncarcinogenic effects at Chapman Pit and Green
Pond.

Ecological COCs for the different habitats identified in the WBGB are presented in the OU 13 FS (ABB-ES,
1997a). The primary risk contributors and the associated risks for the different habitats are summarized
in Tables 6-20 through 6-27.

Stream Habitat. Exposures to surface water COCs could result in adverse effects to aguatic receptors,
although the majority of risk contributors were detected at concentrations only somewhat elevated above
background conditions. Some semi-aguatic wildlife receptors may be at risk from acute exposures to some
inorganics although adverse population-level impacts are unlikely to occur considering the magnitude of
the risk and the conservative approach used in the EPA. The evaluation of snowmelt and storm-event data
indicate that episodic events do not represent an unusual level of risks to ecological receptors. Future
exposures from groundwater contaminants predicted to discharge into the stream habitat are estimated to
have limited incremental effect on risk calculated in this ERA.

Palustrine Habitat. Aguatic receptors are likely to suffer adverse effects from exposure to palustrine
surface water and sediment. Inorganic analytes are the primary risk contributors in surface water.
Pesticides, Aroclor-1260, and inorganics are the primary risk contributors in sediment. An evaluation of
risk for plants indicates that exposure to inorganic analytes is likely to cause adverse affects. Risk
estimates for soil invertebrates indicate that exposure to some inorganic analytes may cause negligible
adverse effects.

Exposure modeling results indicate that adverse population-level impacts may occur to some semi-aguatic
wildlife receptors. Inorganic analytes are the primary risk contributors. The evaluation of snowmelt
and storm-event samples for the palustrine habitat found no indication that these episodic exposure
events represent an unusual level of risks to ecological receptors. With one exception
(tetrachloroethylene in pore water in the WBGB wetland west of the guarry), incremental risks attributed
to future groundwater discharge are anticipated to be negligible.

Lacustrine Habitat. Aguatic receptors may suffer adverse effects from exposure to lacustrine surface
water and sediment. Surface water risks are attributed to inorganic analytes. For lacustrine sediment,

-------
population level effects may occur from exposure to Aroclor-1260 and endosulfan II, particularly within
Green Pond, where maximum concentrations of these compounds were detected.

Population-level effects for most semi-aquatic wildlife receptors from exposure to lacustrine
surface-water and sediment COCs are not likely to occur. The evaluation of snowmelt and storm-event
samples for the palustrine habitat found no indication that these episodic exposure events represent an
unusual level of risk to ecological receptors. Incremental risks attributed to future groundwater
discharge are anticipated to be negligible.

Aguatic Ditch Habitat. Aguatic receptors may suffer adverse effects from exposure to aguatic ditch
surface water and sediment. Surface water risks are primarily attributed to two inorganic analytes,
however, these analytes only slightly exceed observed background levels. For aguatic ditch sediment, it
is likely that exposure to PAHs may cause adverse effect to aguatic organisms.

Risk for plants from exposure to sediment in the aguatic ditches indicates that phytotoxic effects may
occur within the three ditches adjacent to the NBA and would most likely be associated with exposure to
chromium and zinc. Background levels of these inorganic analytes exceed their RTVs, suggesting that risk
may be overestimated. Risk estimates for soil invertebrates exposed to sediment indicate that minimal
adverse effects are possible but unlikely. Exposure to sediment may cause limited adverse
population-level effects to some semi-aguatic wildlife.

Terrestrial Ditch Habitat. An evaluation of risk for plants exposed to surface soil and sediment in
terrestrial ditches indicates that inorganic analytes may cause slight adverse effects. Negligible
adverse effects may occur for soil invertebrates potentially exposed to surface soil and sediment in the
ditches. Exposure modeling results suggest that no adverse effects from ingestion of soil or sediment,
from food chain exposures, are anticipated for most of the wildlife receptors in the terrestrial ditch
habitat.

6.3 BUTTERFIELD BROOK/LIMESTONE STREAM STUDY AREA

The HHRA and ERA for the BB/LS Study Area are summarized below. The human health COCs for the BB/LS are
presented in the OU 13 FS (ABB-ES, 1997a). Quantitative estimates of carcinogenic and noncarcinogenic
risks associated with exposure to contaminated media, using both the average and RME scenarios, are
summarized in Table 6-28.

Total current and future receptor risks do not exceed the USEPA carcinogenic risk range or the MEDEP
cancer risk guidance value for the average and RME scenarios. Potential current and future carcinogenic
risks for a surface soil, sediment, and surface water data sets are within or below the USEPA
carcinogenic risk range and at or below the MEDEP cancer risk guidance value. Noncarcinogenic risk for
the total receptor does not exceed an HI of 1. Current and future noncarcinogenic risks for all surface
soil, sediment, and surface water data sets are significantly less than an HI of 1.

Carcinogenic and noncarcinogenic risks associated with the ingestion of fish fillets from Butterfield
Brook and East Loring Lake exceed regulatory guidelines. The pesticide,
4,4'-dichlorodiphenyldichloroethylene (4,4'-DDE) is the primary risk contributor for carcinogenic effects
at Butterfield Brook and the primary risk contributor for carcinogenic and noncarcinogenic effects East
Loring Lake. The pesticide, 4,4'-dichlorodiphenyltrichloroethylene (4,4'-DDT) is the primary risk
contributor for noncarcinogenic effects at Butterfield Brook.

Qualitative evaluation of storm-event data indicate that episodic high-flow conditions do not result in
an increased human health risk associated with exposure to surface water and sediment.

Ecological COCs for the different habitats identified in the BB/LS Study Area are presented in the OU 13
FS (ABB-ES, 1997a) . The primary risk contributors and the associated risks for the different habitats
are summarized in Tables 6-29 through 6-38 and discussed in the following paragraphs.

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                                     TABIiE 6-21
    SUMMARY OF ESTIMATED RISK TO SEMI-AQUATIC WILDLIFE FROM SEDIMENT AND SURFACE WATER
              GREENLAW BROOK (WEST BRANCH) STUDY AREA - STREAM HABITAT

                         OPERABLE UNIT 13 RECORD OF DECISION
                               LORING AIR FORCE BASE

ECOLOGICAL RECEPTORS EVALUATED
                      PRIMARY RISK
             CONTRIBUTORS
                                                                  ACUTE
                                                               EXPOSURES[a]
SEMI-AQUATIC WILDLIFE[b]

      Muskrat
                     Aluminum
                     Manganese
                          Hazard Index
     Great Blue Heron
                     Aluminum
                     Manganese
                     Selenium

                          Hazard Index
      Maritime Garter Snake

                          Hazard Index
                          Hazard Index
Mink

Belted Kingfisher

               Selenium

                    Hazard Index
                                                                             2.9
                                                                    1.46[c]
                                                                    0.23[f]
                                                                    0.59[g]

                                                                       1.5
                                                                           0.079
                                                                            0.62
   CHRONIC
EXPOSURES [a]
                                                                                       3.3[d]
                                                                                              5.7
      0.71[d]
      0.53[e]
      O.llfh]

         1.8
                                                                                             0.16
                                                                                             0.18
                                                                           0.89[g]

                                                                              1.1             0.32
    NOTES:
    [a]  The analytes that contribute to risk are identified for those wildlife receptors that have a
         hazard index greater than 1. Hazard guotients are listed for these analytes.
    [b]  The information listed below is a summary of Tables Y9-34 and Y9-35 in Appendix Y of the RI
        report (ABB-ES, 1997c).
    [c]  Risk estimate based on the following effects:
        ingestion study.
    [d]  Risk estimate based on the following effects:
        multi-generation feeding study.
    [e]  Risk estimate based on the following effects:
        rodents/livestock; subchronic ingestion study.
    [f]  Risk estimate based on the following effects:
        study.
    [g]  Risk estimate based on the following effects:
    [h]  Risk estimate based on the following effects:
        subchronic ingestion study.
     -:  Analyte is not a substantial risk contributor for this exposure scenario.




                                                 LOAEL for reduced growth in rats;  subchronic

                                                 LOAEL for reduced weight gain in newborn mice;

                                                 LOAEL for decreased growth rate in

                                                 NOAEL for mortality in mice; chronic  ingestion

                                                 LOAEL for mortality in rats; single oral dose.
                                                 NOAEL for teratogenic effects in mallards;

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                                          TABIiE 6-25
       SUMMARY OF ESTIMATED RISK TO SEMI-AQUATIC WILDLIFE FROM SEDIMENT AND SURFACE WATER
                 GREENLAW BROOK (WEST BRANCH) STUDY AREA - LACUSTRINE HABITAT

                            OPERABLE UNIT 13 RECORD OF DECISION
                                   LORING AIR FORCE BASE

ECOLOGICAL RECEPTORS EVALUATED
             PRIMARY RISK
             CONTRIBUTORS
                                     ACUTE EXPOSURES [a]
               CHRONIC EXPOSURES [a]
SEMI-AQUATIC WILDLIFE  [b]

       Muskrat
               Aluminum
                         Hazard Index
                                                    1.8
                                                                                4.3(d)
                                                                                   4.9
Great Blue Heron
               Aluminum
                         Hazard Index
                                                    0.59
                                                                                   0.67(d)
                                                                                   1.0
Maritime Garter Snake
                         Hazard Index
                                                   0.035
                                                                                  0.08
Mink
                         Hazard Index
                                                   0.074
                                                                                  0.41
Osprey
                         Hazard Index
                                                    0.12
                                                                                 0.047
NOTES:
     The analytes that contribute to risk are identified for those wildlife receptors that have a hazard
     index greater than 1.  Hazard quotients we listed for these analytes.
     The information listed below is a summary of information listed in Tables Y9-38 and Y9-39 in
     Appendix Y of the RI report  (ABB-ES, 1996).
     Risk estimate based on the following effects:
     ingestion study.
     Risk estimate based on the following effects:
[a]

[b]

[c]

[d]
LOAEL for reduced growth in rats:  subchronic

LOAEL for reduced weight gain in newborn mice;
     multi-generational feeding study.
     Analyte is not a substantial risk contributor for this exposure scenario.

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                                          TABIiE 6-38
       SUMMARY OF ESTIMATED RISK TO TERRESTRIAL WILDLIFE FROM SEDIMENT AND  SURFACE  SOIL
                BUTTERFIELD BROOK/LIMESTONE STREAM STUDY AREA - DITCH HABITAT

                              OPERABLE UNIT 13 RECORD OF DECISION
                                     LORING AIR FORCE BASE

     ECOLOGICAL RECEPTORS EVALUATED
              PRIMARY RISK
          CONTRIBUTORS

     TERRESTRIAL WILDLIFE [b]

          Short-tailed shrew
                      Aluminum
                      Nickel
                      Selenium
          American Woodcock
                      Aluminum
                      Selenium
          Garter Snake
                      ACUTE
                   EXPOSURES  [a]
             6.8[c]

              23[e]

Hazard Index     32
                        7.9[c]
                         30[e]
                                Hazard Index
                                Hazard Index
                                                 40
                                               0.58
          Red Fox
          Barred Owl
Selenium                1.8[e]

            Hazard Index    2.4


Selenium                1.4[e]

          Hazard Index    2.0
                             CHRONIC
                           EXPOSURES  [a]
                                        6.4[d]

                                        6.2[f]

                                            13
                                                                 0.20
                                                                0.023
                                                                0.005
                                                              0.0013
NOTES:
[a]  The analytes that contribute to risk are identified for those wildlife  receptors  that  have
     a hazard index greater than 1. Hazard quotients are listed for  these  analytes.
[b]  The information listed below is a summery of Tables Yll-21 and  Yll-22 in Appendix Y of the
     RI report  (ABB-ES, 1997c).
[c]  Risk estimate based on the following effects
     subchronic.
[d]  Risk estimate based an the following effects
     chronic.
[e]  Risk estimate based on the following effects
[f]  Risk estimate based on the following effects
                              LOAEL for reduced growth in rats; oral

                              reduced body weight gain of newborn rats; oral

                              mortality in rats; single oral dose.
                              decreased breeding in rats; oral chronic.
     Analyte is not a substantial risk contributor for this exposures  scenario.

-------
Stream Habitat. Aquatic receptors may be at risk as a result of exposure to stream surface water and
sediment. Two inorganic COCs account for the majority of estimated risk. A food chain exposure model
was used to estimate exposure doses to five semi-aquatic wildlife species; those dose estimates were
compared to RTVs. Some RTV exceedances occurred, but based on their magnitude and the conservative
approach used in the ERA, adverse population-level impacts are unlikely to occur in the stream habitat.

Palustrine Habitat. Aquatic receptors may be at risk as a result of exposure to surface water and
sediment. Three surface water inorganic COCs account for the majority of estimated risk. With
sediments, several pesticides and inorganics were the primary risk contributors for aquatic receptors.
Sediment invertebrates and wetland plants growing in the palustrine habitat also may be affected from
exposure to inorganic COCs. However, toxicological benchmarks for both plants and invertebrates are
often considerably lower than LAFB background inorganic concentrations, indicating they are very
conservative and tend to overestimate ecological impacts. Based on slight RTV exceedances for
representative semi-aquatic wildlife species, and the conservative nature of the screening process, it is
unlikely that adverse population-level impacts would occur to semi-aquatic receptors in the palustrine
habitat.

Lacustrine Habitat. Aquatic receptors may be at risk as a result of exposure to surface water and
sediment. For surface water, inorganic COCs account for the majority of estimated risk. With sediments,
several pesticides and inorganics were the primary risk contributors for aquatic receptors. Based on
slight RTV exceedances for representative semi-aquatic wildlife species, and the conservative nature of
the screening process, it is unlikely that adverse population-level impacts would occur to semi-aquatic
receptors in the lacustrine habitat with the BB/LS Study Area.

Ditch Habitat. Risks to aquatic receptors is unlikely to be substantial in nature due to the magnitude
of the risk and the maximum COG concentrations being only one or two times greater than background.
Impacts to terrestrial plants and soil invertebrates are not expected from exposure to ditch sediment and
surface soil. Potential effects were predicted for most semi-aquatic representative species; however, the
maximum concentrations of inorganic analytes driving the risk were only slightly elevated above
background, indicating that risks were overestimated and probably unlikely to occur. The evaluation of
snowmelt and storm-event data indicate that episodic events do not represent an unusual level of risks to
ecological receptors. Future exposures from groundwater contaminants predicted to discharge into the
stream habitat are estimated to have limited incremental effect on risk calculated in this ERA.

7.0 DEVELOPMENT AND SCREENING OF ALTERNATIVES

Seven alternatives were developed and screened in the OU 13 FS (ABB-ES, 1997a). This section describes
the response objectives and the development and screening of alternatives.

The USAF has determined that no further action is necessary for surface water and sediment in the WB/BB
Study Area based on the anticipated lack of future impacts (ABB-ES, 1997c). Therefore, no remedial
alternatives were developed for the WB/BB Study Area.

7.1 STATUTORY REQUIREMENTS/RESPONSE OBJECTIVES

Under its legal authorities, the USAF's primary responsibility at NPL sites is to undertake remedial
actions that are protective of human health and the environment In addition, Section 121 of CERCLA
establishes several other statutory requirements and preferences, including: a requirement that the
USAF'S remedial action, when complete, must comply with all federal and more stringent state
environmental standards, requirements, criteria, or limitations, unless a waiver is granted; a
requirement that the USAF select a remedial action that is cost-effective and that utilizes permanent
solutions and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable; and a preference for remedies in which treatment that permanently and significantly reduces
the volume, toxicity, or mobility of the hazardous substances is a principal element over remedies not
involving such treatment. Response alternatives were developed to be consistent with these Congressional
mandates.

Based on preliminary information relating to types of contaminants, environmental media of concern, and
potential exposure pathways, remedial action objectives were developed to aid in the development and
screening of alternatives. These remedial action objective were developed to mitigate existing and
future potential threats to public health and the environment. These response objectives are:

• to prevent or minimize ingestion of and dermal contact with contaminated soil/sediment by
human and ecological receptors;

• to prevent human ingestion of contaminated fish;

-------
       •      to minimize migration of contaminated soil/sediment;  and

       •      avoid destruction of existing ecological habitat where the risk associated with short-term
              habitat loss outweighs the reduction in risk potentially realized by site remediation.

7.2 TECHNOLOGY AND ALTERNATIVE DEVELOPMENT AND SCREENING

CERCLA and the National Oil and Hazardous Substances Pollution Contingency Plan  (NCP) have set forth the
process by which remedial actions are evaluated and selected.  In accordance with these reguirements, a
range of alternatives were developed for OU 13 that consider the specific drainage-system features that
make each site unigue, including soil type, affected acreage, and hydrologic features.

With respect to source control, the OU 13 FS  (ABB-ES, 1997a) developed a range of alternatives
considering the CERCIA STATUTORY preference for a treatment that reduces the toxicity, mobility, or
volume of the 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 guantities 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.

Although the RI results indicate unacceptable risks associated with surface water in some areas (i.e.,
FLDD and FLDD Wetland), an FS was not recommended for this medium because remediating soil and sediment
is expected to adeguately reduce risks associated with surface water.

Seven remedial alternatives were developed and screened in Section 5 of the OF 13 FS for each site where
there are potential risks from soil and sediment exposure. Tables 5-8 through 5-13 in the FS identify the
alternatives that were retained through the screening process for each area, as well as those that were
eliminated from further consideration.  The alternatives retained for each site are as follows:
FLDD
FLDD Wetland
EBGB
              No Action
              Capping - Land Use Restrictions
              Removal - Volume Reduction - Disposal
              Removal - Disposal
              No Action
              Land Use Restrictions
              Sediment Traps - Land Use Restrictions
              Removal - Volume Reduction - Treatment
              Removal - Disposal
              No Action
              Land Use Restrictions
              Sediment Traps - Land Use Restrictions
              Removal - Disposal
WBGB  (including NDA drainagewavs)
              No Action
              Land Use Restrictions
              Removal - Volume Reduction - Treatment
              Removal - Disposal
LMR

       •      No Action

-------
UTS Wetland

       •      No Action
       •      Land Use Restrictions
       •      Removal - Volume Reduction - Treatment
       •      Removal - Disposal
Ditch GO6

       •      No Action
       •      Removal - Volume Reduction - Treatment
       •      Removal - Disposal

                           8.0 DESCRIPTION OF ALTERNATIVES

This section provides a narrative summary of each alternative evaluated in the FS.  A detailed assessment
of each alternative can be found in Sections 7 through 13 of the OF 13 FS  (ABB-ES,  1997a).   The
alternatives developed in the FS include:

       •      No Action
       •      Land Use Restrictions
       •      Sediment Traps  - Land Use Restrictions
       •      Capping - Land  Use Restrictions
       •      Removal - Volume Reduction - Disposal
       •      Removal - Volume Reduction - Treatment
       •      Removal - Disposal

8.1 NO ACTION

The No Action alternative was evaluated for each area within OU 13, as reguired by the NCP, to provide a
baseline against which other alternatives could be compared during detailed analysis.  The No Action
alternative does not include any remedial action components to reduce or control risks.  However, the No
Action alternative would implement an environmental monitoring program to assess the long-term conditions
of the site's ecology.  The ecological effects would be assessed by comparing these monitoring results to
baseline conditions established during the baseline ecological risk assessment conducted as part of the
OU 13 RI.

The environmental monitoring program would include chemical physical, and biological testing.  Data
collected during the environmental monitoring program would be evaluated during the five-year site
reviews.  Five-year site reviews are performed to assess whether human health and the environment are
adeguately protected.

8.2 LAND USE RESTRICTIONS

The Land Use Restrictions alternative would include the following components:

       •      pre-design wetland mitigation studies
       •      site preparation
       •      fence construction
       •      institutional controls
       •      wetlands mitigation
       •      long-term environmental and wetlands mitigation monitoring
       •      continued fish  advisory
       •      five-year site  reviews

8.3 SEDIMENT TRAPS - LAND USE RESTRICTIONS

The Sediment Traps - Land Use Restrictions alternative would include construction of barriers at select
locations within the drainageways; to trap contaminated sediment which would be removed and disposed at a
landfill on a regular basis.   The alternative would include the following components:

       •      pre-design studies
       •      pre-design wetland mitigation studies
       •      site preparation
       •      fence construction
       •      institutional controls
       •      sediment excavation/dredging and disposal

-------
       •      sediment barrier construction
       •      wetlands mitigation
       •      annual sediment removal
       •      long-term environmental and wetlands mitigation monitoring
       •      continued fish advisory
       •      five-year site reviews

8.4 CAPPING - LAND USE RESTRICTIONS

The Capping - Land Use Restrictions alternative would include diverting stormwater from the drainageway
as necessary, and constructing a cap over the contaminated soil and sediment in the drainageway channel.
The alternative would include the following components:

       •      pre-design studies
       •      pre-design wetland mitigation studies
       •      site preparation
       •      institutional controls
       •      stormwater management
       •      soil/sediment consolidation
       •      cap construction
       •      wetlands mitigation
       •      long-term environmental and wetlands mitigation monitoring
       •      five-year site reviews

8.5 REMOVAL - VOLUME REDUCTION - DISPOSAL

The Removal - Volume Reduction - Disposal alternative would include excavating and dredging the
contaminated soil and sediment from the drainageway, screening the excavated material to reduce the
volume, and disposal of the soil and sediment in a landfill.  The alternative would include the following
components:

       •      pre-design studies
       •      pre-design wetland mitigation studies
       •      site preparation
       •      stormwater management
       •      soil/sediment excavation
       •      soil/sediment screening and washing of removed rocks
       •      soil/sediment disposal
       •      backfilling with clean borrow
       •      wetlands mitigation
       •      long-term environmental and wetlands mitigation monitoring
       •      five-year site reviews

The volume reduction component of the alternative would remove the oversized material from the soil and
sediment, and reduce the guantity of material reguiring disposal at a landfill.  The oversized material
would be washed and used with clean borrow to backfill the drainageway to its original grade.  Backfill
materials would be selected to closely match existing soils in terms of soil type, particle size
gradation, organic content, and stream structural components  (e.g., logs and branches).

Contaminated soil and sediment would be disposed of at the on-base LF-3 as subgrade material prior to
construction of the landfill cover system which has been designed to comply with reguirements of the
Resource Conservation and Recovery Act (RCRA).   Some contaminated material may also be disposed of at an
off-base licensed treatment or disposal facility approved by the USEPA and MEDEP.  Only non-hazardous
material can be disposed of at LF-3.  If any of the soil and sediment is determined to be characteristic
hazardous waste, as defined by RCRA, it will be subject to RCRA Land Disposal Restrictions (LDRs).
Additionally, soil and sediment containing concentrations of PCBs greater than 50 parts per million is
subject to the reguirements of the Toxic Substances Control Act.

8.6 REMOVAL - VOLUME REDUCTION - TREATMENT

The Removal - Volume Reduction - Treatment alternative would be similar to the Removal - Volume Reduction
- disposal alternative, except that the soil and sediment would be treated instead of disposed in a
landfill. lie alternative would include the following components:

       •      pre-design studies
       •      pre-design wetland mitigation studies

-------
       •      site preparation
       •      stormwater management
       •      soil/sediment excavation or dredging
       •      soil/sediment screening,  washing of removed rocks,  and dewatering of soil/sediment
       •      on-site soil/sediment treatment
       •      backfilling with clean borrow
       •      disposal/reuse of treated soil/sediment
       •      wetlands mitigation
       •      long-term environmental and wetlands mitigation monitoring
       •      continued fish advisory
       •      five-year site reviews

Treatment of the excavated soil and sediment would likely be performed at one centralized treatment area
on-base.  Technologies evaluated in the FS for treatment of organic contaminants included incineration,
thermal desorption, and solvent extraction.  The stabilization and solidification technology was
evaluated for immobilization of inorganic contaminants.  Because treatment of the excavated soil and
sediment from the OU 13 areas would reguire one or more construction seasons to complete; clean borrow
and screened/washed oversized material would be used to backfill the drainageways, and the treated
material would be disposed or reused at an approved area on-base.

8.7 REMOVAL - DISPOSAL

The Removal - Disposal alternative would be similar to the Removal - Volume Reduction - Disposal
alternative, except that the soil and sediment would not be reduced in volume prior to disposal.  Where
practical, boulders and large cobbles would be removed; however,  screening of soil/sediment and washing
of removed rocks would not be performed.  The alternative would include the following components:

       •      pre-design studies
       •      pre-design wetland mitigation studies
       •      site preparation
       •      stormwater management
       •      soil/sediment excavation or dredging
       •      removal of boulders and large cobbles
       •      soil/sediment disposal at a landfill
       •      backfilling with clean borrow
       •      wetlands mitigation
       •      long-term environmental and wetlands mitigation monitoring
       •      continued fish advisory
       •      five-year site reviews

                          9.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

Section 121(b)(1) of CERCLA presents several factors that, at a minimum, the USAF is reguired to consider
in its assessment of alternatives.  Building upon these specific statutory mandates, the NCP articulates
nine criteria to be used in assessing the individual remedial alternatives.

9.1 EVALUATION CRITERIA USED FOR DETAILED ANALYSIS

A detailed analysis was performed on the alternatives using the NCP's nine evaluation criteria in order
to select a site remedy. Subsection 9.2 contains a summary of the comparison of each alternative's
strengths and weaknesses with respect to the nine evaluation criteria.  The evaluation criteria are
summarized in Subsections 9.1.1 through 9.13.

9.1.1 Threshold Criteria

The two threshold criteria described below must be met in order for the alternatives to be eligible for
selection in accordance with the NCP.

       •      Overall protection of human health and the environment addresses whether or not the remedy
              provides adeguate protection and describes how risks posed through each pathway are
              eliminated,  reduced,  or controlled through treatment,  engineering controls,  or institutional
              controls.

       •      Compliance with applicable or relevant and appropriate reguirements (ARARs)  addresses
              whether or not the remedy will meet all of the ARARs of other federal and state
              environmental laws and/or provide grounds for invoking a waiver.

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9.1.2 Primary Balancing Criteria

The following five criteria are utilized to compare and evaluate the elements of one alternative to
another that meet the threshold criteria.

       •      Long-term effectiveness and permanence addresses the criteria that are utilized to assess
              alternatives for long-term effectiveness and permanence they afford,  along with the degree
              of certainty that they will prove successful.
       •      Reduction of toxicity,  mobility,  or volume through treatment addresses the degree to which
              alternatives employ recycling or treatment that reduces to)toxicity,  mobility,  or volume,
              including how treatment is used to address the principal threats posed by the site.

       •      Short-term effectiveness addresses the period of time needed to achieve protection and any
              adverse impacts on human health and the environment that may be posed during the
              construction and implementation period,  until cleanup goals are achieved.

       •      Implementability addresses the technical and administrative feasibility of a remedy,
              including the availability of materials and services needed to implement a particular
              option.

       •      Cost includes estimated capital costs (indirect and direct)  and annual operation and
              maintenance (O&M)  costs, as well as present-worth costs.

9.1.3 Modifying Criteria

The modifying criteria are used on the final evaluation of remedial alternatives generally after the USAF
has received public comment on the RI Report, FS, and Proposed Plan.

       •      State acceptance addresses the state's position and key concerns related to the preferred
              alternative and other alternatives, and the state's comments on ARARs and to be considered
              information or the proposed use of waivers.

       •      Community acceptance addresses the public's general response to the alternatives described
              in the FS and Proposed Plan.

9.2 SUMMARY OF COMPARATIVE ANALYSIS

Remedial alternatives were evaluated for each area within OU 13.  During the detailed analysis of each
individual alternative, a comparative analysis was conducted, focusing on the relative performance of
each alternative against the nine criteria. The complete comparative analysis is presented in Sections 7
through 13 of the OU 13 FS,  (ABB-ES, 1997a).  A tabular assessment of each alternative according to the
first seven criteria can be found in Tables 9-1 through 9-6 of this ROD. The remaining two criteria are
summarized in the following paragraphs.

State Acceptance.  The MEDEP, as a party of the FFA, has provided comments on the FS and Proposed Plan,
and has documented its concurrence with the remedial action as stated in Section 13 of this ROD.  A copy
of the MEDEP's letter of concurrence is presented in Appendix C of this ROD.

Community Acceptance.  The Proposed Plan presents the preferred alternatives for OU 13, Removal -
Disposal of contaminated surface soil and sediment that exceeds remediation goals for six locations and
the No Action alternative for the LMR. From April 14, 1997 through May 13, 1997, the USAF held a public
comment period to accept public input.  A public meeting was held on May 8, 1997 to discuss the Proposed
Plan and to accept any oral comments.

Community acceptance of the Proposed Plan was evaluated based on comments received at the public meeting
and during the public comment period.  This is documented in the transcript of the public meeting in
Appendix A, and in the Responsiveness Summary in Appendix B of this ROD.

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                                    10.0  THE SEIiECTED REMEDY

The selected remedy for OU 13 includes two remedial alternatives; Removal - Disposal and No Action.  No
further action is necessary for much of OU 13 because there is no unacceptable risk to human health or
the environment.

Removal - Disposal is the selected remedy for areas within OU 13 that exceed remediation goals.  These
areas have been identified to include:
              FLDD
              FLDD Wetland
              EBGB (from Pennsylvania Road to the Ski Chalet)
       •       NDA Drainageways (north and south)
              Ditch GO6
       •       UTS Wetland (northern portion)

The State Fish Advisory, currently in effect, will continue to be enforced until the fish are determined
to be acceptable for consumption.  Areas covered by the advisory include Chapman Pit Green Pond, Greenlaw
Brook, and the LMR and its tributaries from the Madawaska Dam Reservoir south to the Aroostook River.

The No Action alternative has been selected for the LMR because there is no unacceptable risk associated
with surface soil, sediment, and surface water.  The No Action alternative will include an environmental
monitoring program and five-year site reviews to assess whether human health and the environment continue
to be adeguately protected.

No further action is necessary at the other areas within OU 13 because there is no unacceptable risk to
human health or the environment.

10.1  REMEDIATION GOALS

The USAF has established, with concurrence of the regulatory agencies, site-specific remediation goals
(RGs) that will be protective of human health and the environment.  RGs were established based on USEPA
Risk Assessment Guidance for Superfund (USEPA, 1991), LAFB Risk Assessment Methodology  (HAZWRAP, 1994) ,
and MEDEP Risk Assessment Guidance  (MEDEP, 1994).  Rgs and the compounds for which they have been
established are listed in Tables 10-1 through 10-7.

10.2  DESCRIPTION OF REMEDIAL COMPONENTS

The following subsections describe the Removal - Disposal and No Action alternatives developed by the
USAF for OU 13.

10.2.1  Removal - Disposal

The following paragraphs describe the Removal - Disposal alternative the USAF developed for areas that
exceed remediation goals.  These areas have been identified to include the FLDD, FLDD Wetland, EBGB  (from
Pennsylvania Road to the Ski Chalet), north and south NDA Drainageways, Ditch G06, and UTS Wetland
(northern portion).  Implementation of the selected alternative will include the following activities:

       •       pre-design studies to delineate the extent of remediation for design purposes;
       •       pre-design wetland mitigation studies (i.e.,  wetland delineations and function-value
              assessments)  to evaluate the impacts resulting from remedial activities;
       •       site preparation and mobilization;
       •       cutting and clearing;
       •       stormwater management;
       •       sediment excavation;
       •       sediment disposal at LF-3;  some material may reguire disposal at off-base facilities;
       •       backfilling the excavations with material that closely matches the excavated material;
       •       compensatory wetlands mitigation and demobilization;
       •       long-term environmental and wetlands mitigation monitoring;
       •       continued fish advisory for Chapman Pit,  Green Pond, Greenlaw Brook,  and the LMR and its
              tributaries from the Madawaska Dam Reservoir south to the Aroostook River; and
       •       five-year site reviews.

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                                 TABIiE 10-5
                        FISH TISSUE REMEDIATION GOALS
EAST BRANCH GREENLAW BROOK, CHAPMAN PIT, GREEN POND, AND LITTLE MADAWASKA RIVER

                    OPERABLE UNIT 13 RECORD OF DECISION
                           LORING AIR FORCE BASE
  CONTAMINANT OF CONCERN 1
4,4'-ODD
4,4'-DDE
4,4'-DDT
Aroclor-1242
Aroclor-1260
Heptaclor
Chlordane, Alpha
Chlordane, Gamma
MAXIMUM DETECTED
 CONCENTRATION 2
      (mg/kg)

      0.076
      0.044
      0.14
      0.074
       2.1
     0.0031
      0.042
      0.014
PROTECTION OF
HUMAN HEALTH 3
    (mg/kg)

     0.018
     0.013
     0.013
     0.0022
     0.0022
    0.00098
     0.0034
     0.0034
        ACTION LEVEL 4
            (mg/kg)

               NA
5 (Total DDT,  DDE, and TDE)
5 (Total DDT,  DDE, and TDE)
               NA
               NA
              0.3
     0.3 (Total Chlordane)
     0.3 (Total Chlordane)
Notes:

1       Contaminants of concern identified in fish tissue at  one  or more  of  the  affected areas.
2       Maximum detected concentration out of all the affected  areas.
3       The lesser value of a carcinogenic risk-based concentration calculated with  the  target  cancer
        risk set at 1x10 -6 and a noncarcinogenic risk-based  concentration with  the  hazard guotient
        set at 1.  Development of human health risk-based concentrations  is  documented in Appendix
        A.I of the OU 13 FS  (ABB-ES, 1997a).
4       Action Levels for Poisonous or Deleterious Substances in  Human  Food  and  Animal Feed (DHHS,
        1992) .
mg/kg   =      milligrams per kilogram
DDE     =      dichlorodiphenyldichloroethylene
ODD     =      dichlorodiphenyldichloroethane
DDT     =      dichlorodiphenyltrichloroethylene
NA      =      Not available

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The components are described in the following paragraphs.

Pre-design Studies. Pre-design studies are reguired to delineate the areas reguiring remediation, for
refining the sediment transport models, for collecting and interpreting hydrologic data that can be used
in the design of stormwater diversion structures, and for identifying suitable backfill material. The
details of the pre-design studies will be presented in the Remedial Action Work Plan (RAWP) to be
prepared by the Remedial Action Contractor (RAG). The RAWP will be submitted to the USEPA and MEDEP for
review and approval prior to implementation.

Upon completion of the pre-design delineation, the risk management process provided in the RAWP will be
followed for weighing the reduction in risk to receptors versus the adverse affects to wetland
communities impacted by remedial activities. Based on the results of the risk management process, the
limits of the excavation may potentially be refined.

Pre-design Wetland Mitigation Studies. The pre-design wetland mitigation studies will include wetland
delineations and function-value assessments. Pre-design wetland mitigation studies are reguired for
evaluating the impacts to the areas that would occur as a result of remedial activities. The process
used for evaluating impacts to the areas, and for developing a plan to mitigate the impacts, will be
consistent with the process presented in the OU 13 Mitigation Process Plan (MPP), developed for the
Wetlands Management Program (ABB-ES and Woodlot Alternatives, 1995).

Impacts to the areas from remedial activities will be monitored by number of acres impacted, wetland type
and class, and function. This information will be used to identify the compensatory mitigation reguired
for damage done to the existing areas. A mitigation plan will be prepared for regulatory review and
approval during the remedial design process.

Site Preparation and Mobilization. Site preparation will include construction of access roads, stockpile
areas, decontamination pads, staging areas for construction eguipment, a mobile laboratory, and
construction-support trailers. Eguipment mobilized to the site will include earth-moving eguipment
(e.g., excavators, front-end loaders, and bulldozers), dumptrucks, and construction-support trailers.

Cutting and Clearing. Cutting and clearing of trees and brush will be reguired for construction of
access roads and within the areas of excavation. To reduce the impact of cutting and clearing on areas
downgradient of the excavation areas, erosion-control measures will be installed and maintained
throughout the construction period.

Stormwater Management. Stormwater management will be reguired to prevent erosion and migration of
potentially contaminated sediments into non-contaminated areas, and to minimize impacts to existing
wetlands. Stormwater management may include stormwater diversion ditches, stormwater retention basins,
or temporary bypass piping. Sampling and analysis of the stormwater will be conducted and treatment or
disposal may be necessary for some of the water. A Stormwater Management Plan will be included in the
RAWP prepared by the RAG. The plan will be reviewed and approved by the USEPA and MEDEP prior to
implementation.

Sediment Excavation. Figures 10-1 through 10-6 show the proposed excavation limits for each area as
presented in the FS. Actual excavation limits for each area will be established based on the pre-design
studies. Following cutting and clearing activities, the soil and sediment exceeding the established RGs
will be removed by excavating and/or dredging. Where practical, boulders and large cobbles will be
removed during excavation, stockpiled, and reused along with clean soil as backfill material.
Confirmation sampling will be conducted to verify that RGs have been achieved.

Some of the excavated material may reguire dewatering prior to disposal. Dewatering procedures will be
included in the RAWP prepared by the RAG.

Based on the OU 13 RI surface soil and sediment data, and in order to be protective of ecological
receptors, RG exceedances are limited to a depth of approximately 2 feet below ground surface. The FS
estimated a total volume of approximately 93,000 cubic yards (cy) of contaminated soil and sediment.
However, the actual limits of excavation will be based on the additional data collected during the
pre-design studies. The estimated volumes presented in the FS for each area are as follows:

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FLDD 8,520 cy
FLDD Wetland 36,100 cy
EBGB 38,300 cy
NBA Drainageways 5,370 cy
Ditch G06 200 cy
UTS Wetland 4,600 cy

TOTAL VOLUME APPROXIMATELY 93,090 cy

Sediment Disposal. Soil and sediment removed from the areas will be loaded into dumptrucks and
transported to LF-3 for disposal as subgrade material prior to construction of the LF-3 landfill cover
system. In accordance with the OU 2 ROD, subgrade material may not be used if it is determined to be
hazardous and subject to RCRA LDRs; therefore, some excavated material may reguire disposal at an
off-base licensed facility.

Backfilling Excavations. The excavations will be backfilled and regraded to the approximate
configuration of the original areas. As part of the pre-design activities, a borrow study will be
conducted to identify suitable backfill. Backfill materials will be selected to closely match the
existing soils in terms of soil type, particle size gradation, organic content, and stream structural
components (e.g., logs and branches).

Compensatory Wetlands Mitigation and Demobilization. Compensatory wetlands mitigation will be
implemented according to the final mitigation plan. A wetlands scientist will monitor implementation of
the final mitigation plan. To comply with MPP criteria for restoration of wetlands, the following ratios
of restored to impacted wetland will be included in the final mitigation plan:

• 1.15:1 for restoration in Class II or Class III wetlands
• 2:1 for restoration in Class I wetlands

The actual extent of wetlands reguiring mitigation will be presented in the mitigation plan. The FS
estimated approximately 29 acres of wetlands would be impacted as a result of remedial activities. The
estimated acreage presented in the FS for each area is as follows:

FLDD 4.8 acres
FLDD Wetland 10.0 acres
EBGB 10.0 acres
NDA Drainageways 1.7 acres
Ditch G06 0.5 acres
UTS Wetland 2.0 acres

TOTAL PROJECTED IMPACTED WETLANDS APPROXIMATELY 29 acres

Long-Term Environmental and Wetlands Mitigation Monitoring. Environmental monitoring will be conducted
to assess the effectiveness of the implemented remedy. Environmental monitoring will include chemical,
physical, and biological testing. The actual monitoring program will be submitted to the USEPA and MEDEP
for review and approval prior to implementation.

In accordance with the MPP, a mitigation monitoring plan will be prepared prior to implementing wetlands
restoration. A wetlands scientist will monitor wetlands restoration for a minimum of five years as
defined in the MPP, beginning the first year after restoration. An annual evaluation report that
presents the results of vegetation, soil, and hydrology measurements will be prepared and submitted to
the USEPA and MEDEP.

Continued Fish Advisory. A State Fish advisory is currently in effect warning against the ingestion of
fish contaminated with PCBs. The Fish Advisory is in effect at designated areas on-base, including
Chapman Pit, Green Pond, and Greenlaw Brook. Fish Advisory is also in effect for the LMR and its
tributaries from the Madawaska Dam Reservoir south to the Aroostook River. The Fish Advisory will
continue until the fish are determined to be acceptable for consumption, based on the environmental
monitoring data.

Five-year Site Reviews. The USAF will review the environmental monitoring data at least once every five
years in accordance with applicable USEPA guidance. The five-year site reviews are intended to evaluate
whether the response action continues to protect human health and the environment, assess site
conditions, and propose further actions, if necessary.

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10.2.2 No Action

The No Action alternative has been selected for surface soil, sediment, and surface water for the LMR
because there is no unacceptable risk associated with these media. The No Action alternative does not
include any remedial action components to reduce or control risks. However, the No Action alternative
will include an environmental monitoring program (see Subsection 10.2.1) to assess the long-term
conditions of the site's ecology. The ecological effects will be assessed by comparing the long-term
monitoring results to baseline conditions established during the baseline ecological risk assessment
conducted as part of the OU 13 RI.

The No Action alternative will also include five-year site reviews. The long-term environmental
monitoring data will be evaluated during the five-year site reviews to assess whether human health and
the environment are adeguately protected.

No further action is necessary for the remaining areas in OU 13 because of limited and sporadic
contamination, anticipated lack of future impacts, and/or no unacceptable risk to human and ecological
receptors.

10.2.3 Future Action - Chapman Pit

A removal action to address elevated levels of inorganics in soil/sediment in the vicinity of Chapman Pit
is scheduled for the 1997 construction season. The removal action is not part of this ROD, but will be
addressed in a future ROD.

11.0 STATUTORY DETERMINATIONS

This section discusses how the selected remedy meets the statutory reguirements of CERCLA and the NCP.

11.1 THE SEIiECTED REMEDY IS PROTECTIVE OF HUMftN HEALTH AND THE ENVIRONMENT

The Removal - Disposal alternative would be protective of human health and the environment because
removal of the contaminated soil and sediment from the site and disposing of the material at a landfill
minimizes direct contact, incidental ingestion of soil and sediment by humans and animals, and further
stream transport and windborne migration.

Continuation of the Fish Advisory for the LMR, Chapman Pit, Green Pond, and Greenlaw Brook will continue
to minimize human health exposure to PCBs from fish consumption.

11.2 THE SELECTED REMEDY ATTAINS ARARs

The selected remedy will attain all federal and state ARARs that apply to OU 13. Tables 11-1 through 11-3
present a tabular summary of the chemical, location, and action-specific ARARs for the selected remedy,
including the regulatory citation, a brief summary of the reguirement, and how it will be attained.

11.3 THE SELECTED REMEDIAL ACTION IS COST-EFFECTIVE

In the USAF's judgment, the selected remedy is cost-effective, that is the remedy affords overall
effectiveness proportional to its cost. In selecting the remedy, once the USAF identified alternatives
that were protective of human health and the environment and that attain ARARs, the USAF evaluated the
overall effectiveness of each alternative by assessing the relevant three criteria in combination:
long-term effectiveness and permanence; reduction in toxicity, mobility, or volume through treatment; and
short-term effectiveness. The relationship of the overall effectiveness of the remedial alternatives was
determined to be proportional to its cost.

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                                                                                TABLE 11-1
                                                       CHEMICAL-SPECIFIC ARARs,  CRITERIA, ADVISORIES, AND GUIDANCE
     MEDIA
                   REQUIREMENT
                                                                                                                                      ACTION TO BE TAKEN TO ATTAIN ARAR
SOIL/SEDIMENT/WASTE MATERIAL
                   CWA AWQC  (33  USC 1251
                   et seq.)
                                               CWA AWQC are health-based  criteria developed for
                                               carcinogenic and nonearcinogenie  compounds and water
                                               quality parameters.  AWQC  are  set at  levels protective of
                                               human health for two routes  of exposure:   (1)  drinking
                                               water and consuming fish,  and  (2 )  only consuming fish.
                                               Remedial actions involving contaminated surface water
                                               must consider the uses of  the  water and the
                                               circumstances of the release of threatened release; this
                                               determines whether AWQC  are  relevant  and appropriate.
                                                                               AWQC were used to develop sediment
                                                                               remediation goals and will be used to develop
                                                                               discharge limits for wastewater discharged  to
                                                                               surface  waters during remedial activities,  either
                                                                               directly or indirectly through the LAFB WWTP.
                                                                               Surface  water currently meets these standards
                                                                               and is  expected to continue to do so after  the
                                                                               action  is completed.
Federal Guidance
and Criteria To
Be Considered
USEPA Interim Sediment
Criteria Values for
Nonpolar Hydrophobic
Organic Contaminants;
(SCD No. 17; May 1988)
To Be           These criteria  were  developed by USEPA for 16 organic
Considered      compounds and represent  contaminant levels in
                sediments that  are currently considered protective of
                aquatic life.
                                                                  These criteria  represent non-polluted threshold values  for
                                                                  inorganics  in sediments.
                                                                                                              These criteria  are  used to evaluate sediment
                                                                                                              quality and  develop sediment clean-up criteria.
                   USEPA  Sediment  Quality
                   Criteria  for  the  Protection
                   of Benthie  Organisms for
                   Endrin, Dieldrin,
                   Fluoranthene,
                   Acenaphthrene,  and
                   Phenanthene
                    (USEPA-822-R-93-011
                   through -017)
                   NOAA,  Incidence  of
                   Adverse  Biological Effects
                   within Ranges  of Chemical
                   Concentrations in Marine
                   and Estuarine  Sediments
                    (1994)
                                               These criteria represent  toxic  effect  levels resulting from   These criteria  are  used to evaluate sediment
                                               exposure of aquatic organisms to  selected organics and        quality and  develop sediment clean-up values.
                                               inorganics.
                   Ontario MOE,  Guidelines
                   for  Protection  and
                   Management  of Aquatic
                   Sediment  Quality in
                   Ontario  (1993)
                               To  Be
                               Considered
                 These criteria  represent toxic effects levels resulting  from   These  criteria are used to evaluate sediment
                 exposure of  aquatic organisms to selected organics and         quality and develop sediment clean-up values.
                 inorganics.

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                                                                                TABLE 11-1
                                                       CHEMICAL-SPECIFIC ARARS,  CRITERIA, ADVISORIES, AND GUIDANCE
     MEDIA
                   REQUIREMENT
State Guidance
and Criteria To
Be Considered
                   Maine  Regulations
                   Relating  to  Water Quality
                   Criteria  for Toxic Pollutants
                    (06-096 CMR,
                   Chapter 584)
Maine Procedural
Guidelines for Establishing
Standards for the
Remediation of Oil-
Contaminated Soil  and
Ground Water in Maine
(February 1, 1995)
                                 Relevant and
                                 Appropriate
This rule limits the concentrations of certain materials    AWQC will  be  used to develop discharge limits for
allowed in Maine waters  to  prevent  the occurrence of        wastewater discharged to surface waters during
pollutants in toxic amounts as  required by state and        remedial activities,  either directly or indirectly
federal law.  Except if  naturally occurring,  ambient levels through the LAFB  WWTP.
of toxic pollutants shall not exceed the CWA AWQC.
Where AWQC do not exist, the Board  of Environmental
Protection shall adopt site-specific numerical criteria.

This policy sets forth soil and groundwater clean-up levels  These standards  are considered during clean-up
for hydrocarbon-contaminated soils  and is based on           level development along with site-sped fie risk
MEDEP's Hydrocarbon Spill Decision  Tree with three           assessment data.
levels of clean-up goals; stringent,  intermediate, and
baseline.
ARAR     =  Applicable  or  Relevant and Appropriate Requirement
AWQC     =  Ambient Water  Quality Criteria
CMR      =  Code of Maine  Regulations
CWA      =  Clean Water Act
LAFB     =  Loring Air  Force  Base
MEDEP    =  Maine Department  of Environmental Protection
MOE      =  Ministry  of the Environment
NOAA     =  National  Oceanic  and Atmospheric Administration
SCO      =  Standards Criteria Division
USC      =  United States  Code
USEPA    =  U.S. Environmental Protection Agency
WWTP     =  Wastewater  Treatment Plant

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                                                                                TABLE 11-2
                                                        LOCATION-SPECIFIC ARARS CRITERIA, ADVISORIES, AMD GUIDANCE
    MEDI7
             REQUIREMENT
                                                                            REQUIREMENT SYNOPSIS
                                                                                                                                ACTION TO BE TAKEN TO ATTAIN ARAR
WETLAND/FLOODPLAINS
             Protection  of Wetlands and
             Floodplains,  Executive Order
              (EO)  11990  and EO 11998 (40
             CFR  6, Appendix A)
Applicable      Sets  forth  USEPA policy for carrying out the provisions
                of  the  Wetland Executive Order  (EO 11990) and
                Floodplains Executive Order (EO 11988) .  Under  this
                order,  federal agencies are required to minimi ze  the
                destruction,  loss,  or degradation of wetlands;  preserve
                and enhance natural and beneficial values of wetlands,
                and minimi ze  potential harm to or within floodplains  and
                to  avoid the  long-  and short-term adverse impact  with
                modi fications to floodplains.
This requirement will  be  used during the
development of alternatives.   If no practical
alternative exists,  potential harm must be
minimi zed and action taken to restore the natural
and beneficial values  of  the  wetland.  Alternatives
that involve excavating wetland soil or sediment
will be designed to  minimi ze  impacts on the
wetlands.
             CWA  Section  404(b)(l)
             Guidelines  for Specification of
             Disposal  Sites for Dredged or
             Fill Material  (40 CFR 230)
                Section  404  of the CWA regulates the discharge  of
                dredged  or  fill material into U.S. waters, including
                wetlands.   The purpose of Section 404 is to  ensure  that
                proposed discharges are evaluated with respect  to
                impact on the aquatic ecosystem.
If the alternative  involves  dredged or fill material
discharge to a wetland  during construction of
access roads, the substantive requirements of
this Act will be met.
                                                Relevant        Section  10  of the Rivers and Harbors Act of  1899
                                                and             requires authorization from the Secretary  of the  Army,
                                                Appropriate     acting through the USAGE,  for the construction  of any
                                                                structure in or over any "navigable water  of the  U.S.," the
                                                                excavation  from or deposition of material  in such waters,
                                                                or  any obstruction or alteration in such waters.
                                                                               Permits are not required  for  CERCLA on-site
                                                                               actions.  The substantive  requirements will be
                                                                               met.
             Wetlands  Protection (06-096
             CMR,  Chapter  310,  Section 1)
Applicable      These  regulations outline requirements for certain
                activities  adjacent to any freshwater wetland  greater than
                10  acres  or with an associated stream, brook,  or  pond.
                The  activities must not unreasonably interfere with
                certain natural features, such as natural flow or quality of
                any waters,  not harm signi fleant aquatic habitat,
                freshwater  fisheries,  or other aquatic life.
Remedial activities will  meet  activity standards.
Substantive requirements  of these regulations
must be met for actions taken  within 100 feet of
a wetland or stream.

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                                                                                TABLE 11-2
                                                       LOCATION-SPECIFIC ARARs CRITERIA, ADVISORIES, AND GUIDANCE

                                                                   OPERABLE  UNIT 13 RECORD OF DECISION
                                                                         LORING AIR FORCE BASE
             REQUIREMENT
                                                                               REQUIREMENT SYNOPSIS
                                                                                                                                 ACTION TO BE TAKEN TO ATTAIN ARAR
             Maine Standards  for
             Classification of  Fresh Surface
             Waters  (38 MRSA  °  465)
Applicable      This  statute  established a water quality class!fication
                system  which  allowed for management of surface waters
                so  as to  protect the quality of those waters and,  where
                water quality standards were not being achieved,  to
                enhance water quality.   This class!fication system is
                based on  water quality standards which designated the
                uses  and  related characteristics of those uses  for each
                class of  water and which also establish water quality
                criteria  necessary to protect those uses and related
                characteristics.  The State assigned water quality
                class!fication to each surface water body which
                designate the intended minimum level of quality  for  the
                body  of water.
These requirements will  be  met  if an alternative
involves discharging water  to a surface water
body.
             Maine Natural  Resources           Relevant
             Protection Act,  Permit-by-        and
             Rule Standards (06-096 CMR,        Appropriate
             Chapter  305)
                This  rule  prescribes standards for sped fie  activities  that
                may take place in or adj acent to wetlands and water
                bodies.  The  standards are designed to ensure that the
                disturbed  soil material is stabili zed to prevent  erosion
                and siltation of the water.
Proposed activities  involving disturbance of soil
material and discharge  of  treatment water within
100 feet of the normal  high-water line will be
designed to incorporate applicable standards.
             Maine Site  Location
             Development  Law and
             Regulations  (38 MRSA
             Sections  481-490;  06-096
             CMR, Chapter 375)
                This  act  and these regulations govern development  and
                includes  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 regulation provide that there shall be
                no  unreasonable adverse effects on sped fied items
                (including air quality, runoff/infiltration  relationships and
                surface-water quality), no unreasonable alteration of
                climate or natural drainageways,  and provisions  for
                erosion and sedimentation control and noise  control.
Remedial action will meet  requirements that are
relevant and appropriate  to  OU 13.
OTHER NATURAL RESOURCE
Federal
             Fish and Wildli fe  Coordination
             Act  (16 USC  661)
Relevant        This  act  requires that any federal agency proposing  to
and             modi fy  a  body of water must consult with the U.S.  Fish
Appropriate     and Wildli fe  Service,  National Marine Fisheries  Service,
                and other related state agencies.
Noti fication is not  required for actions taken
on-site at a CERCLA  site.   However,  actions will
be taken to minimize impacts to wetlands.

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                                                                                TABLE 11-2
                                                       LOCATION-SPECIFIC ARARs CRITERIA, ADVISORIES, AND GUIDANCE

                                                                   OPERABLE  UNIT 13 RECORD OF DECISION
                                                                         LORING AIR FORCE BASE
           REQUIREMENT
                                                                                REQUIREMENT SYNOPSIS
                                                                                                                                 ACTION TO BE TAKEN TO ATTAIN ARAR
         Migratory Bird  Treaty Act (16
         USC 703-712)
                              Applicable      This act prohibits the  hunting,  possessing,  killing, or
                                              capturing of the listed migratory birds,  birds in danger of
                                              extinction, and those birds'  eggs of nests.
Long-term impacts will  not  result.   Remedial
activities will be delayed  until  after the ground-
nesting migratory bird  breeding season is over.
state    Maine Inland  Fisheries and
         Wildlife  Laws  and Regulations
         12 MRSA Chapter  713,
         Section 7751)
                              Relevant        The state of Maine has  authority to research, list,  and
                              and             protect any species  deemed  endangered or threatened
                              Appropriate     These species are listed  as either endangered or
                                              threatened in the state regulations.   The Maine
                                              Department of Inland Fisheries  and Wildlife also has
                                              developed the following administrative categories for
                                              species not considered  endangered or threatened but
                                              considered important for  research and further evaluation:
                                              Maine Watch list, Special Concern List,  and
                                              Indeterminate Category.   The Department  determines
                                              appropriate use(s) of various habitats on a case-by-case
                                              basis.   The Maine lists may di ffer from the federal lists of
                                              endangered species.
No currently listed  endangered or threatened
species in the site  area  have  been identi fied.
However, new species may  be  added to the list.
Activities must not  impact an  endangered or
threatened species.
                                                                                                                                Where such special areas exist, these  state
                                                                                                                                programs will become involved  in  the proj ect
                                                                                                                                and/or permit review process.
ARAR
CERCLA
CMR
CWA
EO
MRSA
OU
USAGE
USC
USEPA
Applicable of Relevant  and Appropriate Requirement
Comprehensive Environmental Response,  Compensation, and Liability  Act  of  1980
Code of Maine Regulations
Clean Water Act
Executive Order
Maine Revised Statutes  Annotate
Operable Unit
U.S. Army Corp of Engineers
United States Code
U.S. Environmental  Protection Agency

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                                                                                TABLE 11-3
                                                        ACTION-SPECIFIC ARARs FOR REMOVAL-DISPOSAL ALTERNATIVE
                   REQUIREMENT
                                                                          REQUIREMENT SYNOPSIS
                                                                                                                         ACTION TO BE TAKEN TO ATTAIN ARAR
                 Maine Ambient  Air
                 Quality Standards
                  (38 MRSA 584;  06-
                 096 CMR,
                 Chapter 110)
This chapter establishes  ambient  air quality
standards that are maximum levels of a particular
pollutant permitted in  the ambient air.
Standards for particulate  matter-150 Ig/m 3,
24-hour average concentration.   This standard
would apply to excavation  or  construction activities
with the potential of  generating significant  dust.
SOIL/SEDIMENT/
WASTE/MATERIAL
                 RCRA  -  Identification
                 and Listing  of
                 Hazardous  Wastes;
                 Toxicity
                 Characteristics (40
                 CFA 261.24)
                                                          Analytical  results  will  be evaluated against the
                                                          criteria and  definitions of hazardous waste.  The
                                                          criteria and  definition  of hazardous waste will be
                                                          referred to and  utilized in development of remedial
                                                          alternatives  and during  remedial actions.
                                                             Land  disposal  of RCRA hazardous waste is
                                                             restricted  without  specified treatment.  For the LDRs
                                                             to be  applicable,  it must be determined that the
                                                             waste  meets the  definition of one of the sped fied
                                                             restricted  wastes  and remedial action constitutes
                                                             placement.   For  each hazardous waste, the LDRs
                                                             sped fy  that  the waste must be treated either by a
                                                             treatment technology of to a concentration level
                                                             prior  to disposal  in a RCRA Subtitle C permitted
                                                             facility,
                                                          Waste materials  from OU 13 will be evaluated to
                                                          determine whether  the waste is hazardous.   If so,
                                                          the materials will not be disposed of on-base, but
                                                          will be treated  in accordance with LDRs prior to
                                                          disposal at  an off-bass facility.
                                           Applicable        This  regulation governs the storage and final
                                                             disposal  of  PCBs by incineration of in a chemical
                                                             waste  landfill.   The regulation also sped fies
                                                             procedures to  be followed in decontaminating
                                                             containers and moveable equipment used in
                                                             storage areas.
                                                          Storage, disposal  and decontamination
                                                          requirements  specified in this regulation will be
                                                          applied if  soil  or sediment with PCB concentrations
                                                          greater than  of  equal to 50 ppm are encountered.
                                                             This policy governs the cleanup of PCB spills
                                                             occurring  after May 4,  1987.  Because this policy
                                                             not a  regulation and only applies to recent spill
                                                              (reported  within 24 hours of occurrence), these
                                                             requirements are not applicable, but will be
                                                             considered.
                                                          This policy will  be  considered during the
                                                          development of  remedial  alternatives for areas with
                                                          detected  PCBs at  concentrations greater than or
                                                          equal to  50 ppm.

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                                                                  TABLE  11-3
                                           ACTION-SPECIFIC ARARs  FOR  REMOVAL-DISPOSAL ALTERNATIVE
                                                     OPERABLE UNIT  13  RECORD OF DECISION
                                                            LORING  AIR FORCE BASE
  REQUIREMENT
                                                       REQUIREMENT  SYNOPSIS
                                                                                                       ACTION  TO  BE  TAKEN TO ATTAIN ARAR
                          Relevant and      USEPA procedures  for making  information available
                          Appropriate       to the public; rules for  claims of business
                                            confidentiality.
Requirements  for
Miscellaneous Units
(40 CFR 264.600 -
264.999)
Relevant and      Requirements  for owners and operations of  facilities
Appropriate       that  treat,  store,  or dispose of hazardous waste  in
                  miscellaneous units.
                                                          Treatment alternatives not specifically regulated
                                                          under other  sections  of RCRA must be met to
                                                          prevent the  release of hazardous constituents into
                                                          the environment.
RCRA Subtitle C.
Subpart B - General
Standards  (40 CFR
264.10-264.30 -
264.18)
                  Requirements  regarding waste analysis, security,
                  training,  inspections, and location applicable  to  a
                  facility which stores, treats, or disposes of
                  hazardous waste (e.g., a TSD facility)
RCRA Subtitle C,
Subpart C -
Preparedness and
Preparation  (40 CFR
264.30 - 264.37)
Relevant and      Requirements  to design and operation, equipment,
Appropriate       And  communications associated with a TSD  facility,
                  and  to  arrangements with local response
                  departments.
                                                          These requirements  will  be met if handling
                                                          hazardous waste.
RCRA Subtitle C,
Subpart D -
Contingency Plan
and Emergency
Procedures  (40 CFR
264.50 - 264.56)
Relevant and
Appropriate
Emergency Planning procedures  for a TSD facility.
These requirements will be met  if handling
hazardous waste.
Standards for
Owners and
Operators of
Hazardous Waste
Treatment, Storage
and Disposal
facilities  (40 CFR
264)
Relevant and      Define  requirements for RCRA facility operations
Appropriate       and management  including impoundments,
                  wastepiles,  land treatment,  landfills, incinerators,
                  storage,  closure and post closure.
                                                          Operations, management  and safety requirements
                                                          in effect  for  all  portions of remedial process, if
                                                          hazardous  waste  is being handled.

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                                                                               TABLE 11-3
                                                       ACTION-SPECIFIC  ARARs FOR REMOVAL-DISPOSAL ALTERNATIVE
               REQUIREMENT
                                                                       REQUIREMENT SYNOPSIS
                                                                                                                     ACTION TO BE TAKEN TO ATTAIN ARAR
             Standards
             Applicable  to
             Generators  of
             Hazardous Waste
              (40 CFR  262)

             Maine Hazardous
             Waste Management
             Rules  (06-096  CMR,
             Chapters 800-802,
             850, 851, and  853-
             857; MRSA 1319)
                        Relevant  and      RCRA Subtitle C established  standards applicable
                        Appropriate       to treatment, storage,  and disposal  of hazardous
                                          waste and closure, of  hazardous  waste facilities.
                        Relevant  and      These rules set forth Maine's  definitions and criteria
                        Appropriate       for establishing whether waste materials are
                                          hazardous and subj ect to associated hazardous
                                          waste regulations.
Sediments will be tested  to  determine whether they
contain characteristic hazardous  waste.   If so,
treatment of disposal of  the sediment would occur
at an off-site facility complying with the
requirements of these regulations.

These regulations supplement RCRA requirements.
Those criteria and definitions  more  stringent than
RCRA take precedence over federal requirements.
             Maine  Solid  Waste
             Management Rules
              (06-096  CMR,
             Chapters 400-409;
             38 MRSA  1306 and
             1310-N)
                        Relevant  and      These rules regulate the  operation of solid waste
                        Appropriate       facilities and define  the types  of wastes that are
                                          acceptable under the facility1s  license.   They also
                                          outline how to character!ze  the  waste prior to
                                          disposal in the landfill.
ARAR
CFR
CMR
LDRs
MRSA
OU
PCB
ppm
RCRA
TSCA
TSD
USEPA
Ig/m 3
Applicable or Relevant  and Appropriate Requirement
Code of Federal Regulations
Code of Maine Regulations
Land Disposal Restrictions
Maine Revised Statutes  Annotated
Operable Unit
polychlorinated biphenyl
parts per million
Resource Conservation and  Recovery Act
Toxic Substances Control Act
treatment, storage,  disposal
U.S. Environmental  Protection Agency
micrograms per cubic meter

-------
The costs of the remedial alternatives  (i.e., Removal - Disposal for six locations and No Action for the
LMR) are:

     FLDD                                                       $1,824,000
     FLDD Wetland                                               $5,037,000
     EBGB                                                       $4,812,000
     NBA Drainageways                                           $1,281,000
     Ditch G06                                                  $  290,000
     UTS Wetland                                                $  929,000
     LMR                                                        $   82,000

     ESTIMATED TOTAL COST (NET PRESENT WORTH)                   $14,255,000

The selection of these alternatives represents a reasonable value with regard to the other alternatives.
Compared to the other alternatives that provide overall protection to human health and the environment
and comply with ARARs, the selected remedy is less expensive.

11.4    THE SEIiECTED REMEDY UTILIZES PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT OR RESOURCE RECOVERY
        TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE

Once the USAF identified those alternatives that attain or, as appropriate, waive ARARs, and that are
protective of human health and the environment, the USAF identified the alternative that utilizes
permanent solutions and alternative treatment technologies or resource recovery technologies to the
maximum extent practicable.  This determination was made by identifying the alternative that provides the
best balance of trade-offs among alternatives, in terms of:  1) long-term effectiveness and permanence;
2) reduction in 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, or volume through treatment, and considered the preference for
treatment as a principal element, the bias against off-site land disposal of untreated waste, and
community and state acceptance.

The selected remedy, in conjunction with the LF-3 cover system, provides the best balance of trade-offs
among the alternatives.  The selected remedy provides long-term protection of human health and the
environment because contaminated soil and sediment will be removed from the site and contained below a
well-maintained landfill cover system.  Once the cover system construction is complete, migration of
contaminants and access to the soil and sediment will be reduced.  Potential for migration and erosion of
contaminated soil and sediment from the OU 13 areas will be greatly reduced with the conclusion of
excavation activities.

The selected remedy will not reduce the toxicity, mobility, or volume through treatment of the source
area contaminants.  However, the selected remedy will reduce mobility through containment and will reduce
rainwater infiltration, erosion, and direct contact with the contaminated soil and sediment.

The selected remedy would require health and safety training for workers who operate the excavation
equipment and conduct monitoring.  Adverse effects on workers are not anticipated as long as safe working
practices are followed.  Adverse effects on the community would not be expected as a result of
implementation of the selected remedy.  The selected remedy will impact ecological receptors during
excavation activities and destruction of wetlands.  The wetlands will be restored in accordance with
state and federal regulations and an approved mitigation plan.

Installation of the selected remedy involves easily implementable, reliable, and available technologies.
Construction activities for the Removal-Disposal alternative can be initiated and completed during the
1997 construction season; which will expedite remediation of OU 13, and allow the LF-3 cover system to be
constructed in 1998 as currently scheduled.

The selected remedy is cost-effective because it provides a reasonable value with regard to the other
alternatives.  It provides overall protection to human health and the environment, complies with ARARs,
meets the response objectives, and is the least expensive.

11.5   THE SELECTED REMEDY DOES NOT SATISFY THE PREFERENCE FOR TREATMENT WHICH PERMANENTLY AND
       SIGNIFICANTLY REDUCES THE TOXICITY, MOBILITY, OR VOLUME OF THE HAZARDOUS SUBSTANCES AS A PRINCIPAL
       ELEMENT

The selected remedy will not reduce toxicity, mobility, or volume through treatment of source area
contaminants as a principal element.  However, the selected remedy, in combination with the LF-3 cover
system, will reduce mobility through containment and will reduce rainwater infiltration, erosion, and

-------
direct contact with the contaminated soil and sediment. In view of the large volume of soil and
sediments that would require treatment and the high cost of such treatment relative to use of the
material as necessary subgrade fill for the LF-3 cover system, it is not practicable to treat the
excavated material.

12.0 DOCUMENTATION OF NO SIGNIFICANT CHANGES

The USAF presented a Proposed Plan (ABB-ES, 1997b) outlining the proposed alternative of Removal and
Disposal for areas that exceed remediation goals. These areas include the FLDD, FLDD Wetland, EBGB (from
Pennsylvania Road to the Ski Chalet), north and south NBA Drainageways, Ditch G06, and the UTS Wetland
(northern portion). The USAF recommended continuation of the State Fish Advisory currently in effect at
designated on- and off-base areas. The No Action alternative was selected for the LMR because there is
no unacceptable risk associated with surface soil, sediment, and surface water. No further action was
proposed for the remaining areas within OU 13. A removal action to address elevated levels of inorganics
in soil/sediment in the vicinity of Chapman Pit is scheduled for the 1997 construction season.

The Proposed Plan was presented to the public, and public comments have been considered prior to the
selection of the preferred alternatives.

No significant changes have been made to the preferred alternatives described in the Proposed Plan.

13.0 STATE ROIiE

The MEDEP, as a party of the FFA, has reviewed the various alternatives. The MEDEP has also reviewed the
RI Report, Risk Assessment, and FS 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 OU 13. A copy of the letter of concurrence is presented
in Appendix C of this ROD.

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          GLOSSARY OF ACRONYMS AND ABBREVIATIONS
ABB-ES    ABB Environmental Services, Inc.
AFBCA     Air Force Base Conversion Agency
ARAR      Applicable or Relevant and Appropriate Requirements
BB/LS     Butterfield Brook/Limestone Stream
BTEX      benzene, toluene, ethylbenzene, and xylenes
CERCLA    Comprehensive Environmental Response, Compensation, and Liability Act
COG       contaminant of concern
CRP       Community Relations Plan
CRQL      Contract Required Quantitation Limit
cy        cubic yards
DDE       di chlorodiphenyldi chloroethylene
DDT       di chlorodiphenyltri chloroethylene
EBGB      East Branch of Greenlaw Brook
ERA       ecoloqical risk assessment
FFA       Federal Facility Agreement
FLA       Flightline Area
FLDD      Flightline Drainage Ditch
FS        Feasibility Study
FTF       Fuels Tank Farm
HAZWRAP   Hazardous Waste Remedial Actions Program
HHRA      human health risk assessment
HI        hazard index
IRP       Installation Restoration Program
LAFB      Loring Air Force Base
LDR       Land Disposal Restrictions
LF        Landfill
LMR       Little Madawaska River
MEDEP     Maine Department of Environmental Protection
mg/kg     milligram per kilogram
MPP       Mitigation Process Plan
NCP       National Oil and Hazardous Substances Pollution Contingency Plan
NDA       Nose Dock Area
NPL       National Priorities List
O&M       operation and maintenance
OU        Operable Unit
PAH       polynuclear aromatic hydrocarbons
PCB       polychlorinated biphenyls
RAB       Restoration Advisory Board
RAG       Remedial Action Contractor
RAWP      Remedial Action Work Plan
RCRA      Resource Conservation and Recovery Act
RG        Remediation Goals
RI        Remedial Investigation
RME       reasonable maximum exposure
RMSA      Refueling Maintenance Shop Area
ROD       Record of Decision
RTV       reference toxicity value
SCF       Spill Containment Facility
SVOC      semivolatile organic compound
TPH       total petroleum hydrocarbons
USAF      U.S. Air Force
USEPA     U.S. Environmental Protection Agency
UTS       Underground Transformer Site
VMB       Vehicle Maintenance Building
VOC       volatile organic compound
WB/BB     Wolverton Brook/Brandy Brook
WBGB      West Branch of Greenlaw Brook

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                           REFERENCES

 ABB  Environmental Services, Inc.  (ABB-ES) and Woodlot Alternatives, Inc., 1995.
       "Operable Unit  (OU 13) Mitigation Process Plan, Wetlands Management
       Program"; Installation Restoration Program; prepared for HAZWRAP;
       Portland, Maine; Topsham, Maine; June 1995.

 ABB  Environmental Services, Inc.  (ABB-ES), 1997a.  "Operable Unit 13  (OU 13)
       Feasibility Study Report"; Final; Installation Restoration Program; prepared
       for HAZWRAP; Portland, Maine; April 1997.

 ABB  Environmental Services, Inc.  (ABB-ES), 1997b.  "Proposed Plan for Operable
       Unit 13"; Final; Installation Restoration Program; prepared for HAZWRAP;
       Portland, Maine; April 1997.

 ABB   Environmental Services, Inc., (ABB-ES), 1997c.  "Basewide Surface
       Water/Sediment Operable Unit  (OU 13) Remedial Investigation Report";
       Final; Installation Restoration Program; prepared for HAZWRAP; Portland,
       Maine; April 1997.

 CH 2M Hill, 1984.  "Records Search Report"; Installation Restoration Program;
       Loring Air Force Base; prepared for HAZWRAP; Limestone, Maine; January 1984.

 Department of Health and Human Services (DHHS), 1992.  "Action Levels for
       Poisonous or Deleterious Substances in Human Food and Animal Feed";
       Public Health Service, Food and Drug Administration; Washington, D.C.

 Federal Facility Agreement  (FFA) Under CERCLA Section 120, The Matter of
       Loring Air Force Base by U.S. Environmental Protection Agency Region I
       State of Maine, and the U.S. Department of the Air Force, January 30, 1991.

 Hazardous Waste Remedial Actions Program  (HAZWRAP), 1994.  "Loring Air
       Force Base Risk Assessment Methodology"; Final; Environmental Restoration
       and Waste Management Programs, Oak Ridge, Tennessee; August, 1994.

Maine Department of Environmental Protection  (MEDEP), 1994.  "State of Maine
       Draft Guidance Manual for Human Health Risk Assessment at Hazardous
       Substance Sites"; Augusta, Maine; June 1994.

  U.S. Environmental Protection Agency  (USEPA), 1991.  "Risk Assessment Guidance
       for Superfund, Volume I:  Human Health Evaluation Manual  (Part B,
       Development of Risk-Based Preliminary Remediation Goals)"; Publication
       9298.7-013; December 1991.

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                                  APPENDIX A

                     TRANSCRIPT OF  THE  PUBLIC MEETING (MAY 8, 1997)

STATE OF MAINE                                                     AROOSTOOK, ss.
                                PUBLIC  HEARING

                    PROPOSED PLAN FOR:   OPERABLE UNIT 13

                                      COPY

                                  MAY 8,  1997
                                     8:00 PM
                               FIVE SEASONS INN
                                CARIBOU,  MAINE
                        BENNETT  LEGAL  TRANSCRIPT SERVICES
                                    P.O.  BOX 947
                             CARIBOU,  ME.  04736-0947
                                   (207)  498-2729

-------
 1                  TABLEOFCONTENTS





 2





 3   PETER FORBES                   3





 4   MAYNARD ST. PETER              4





 5





 6





 7





 8                          EXHIBITS





 9





10





11





12





13





14





15





16





17





18





19





20





21





22





23





24





25

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 1                           MAY 8,  1997





 2                                    MR.  FORBES:   Good evening.





 3        Welcome to the public hearing to receive comments on the





 4        proposed plan for Operable Unit  13 at Loring Air Force





 5        Base.   Today's date is May 8th,  1997.  My name is Peter





 6        Forbes, the Remedial Project Manager for the





 7        Installation,  Restoration Program at Loring.  Seated with





 9        me is  Naji Akladiss, the Remedial Project Manager for the





 9        Maine  DEP.  Also in the audience is Michael Nalipinski,





10        the Remedial Project Manager from the US Environmental





11        Protection Agency.   They will assist me in receiving your





12        comments.





13            This hearing is being held in accordance with





14        provisions of the Comprehensive  Environmental Response





15        Compensation & Liability Act or  CERCLA,  as amended in





16        1986.   Also known as Superfund.





17            This act requires federal facilities on the National





18        Priorities List to present clean up proposals to the





19        local  community for comment and  consideration before the





20        final  clean up decisions are made.  The purpose of this





21        hearing is to receive comments on the proposed plan for





22        Operable Unit 13.





23            Mr. Philip Bennett from Aroostook Legal Reporters





24        will serve as the court reporter tonight, preparing a





25        verbatim record of the proceedings.  The verbatim record

-------
 1        will become a part of the final clean up plan.   The court





 2        reporter will be able to make a complete record only if





 3        he's able to hear and understand what you say.   With that





 4        in mind, please follow these ground rules.   Speak only





 5        after I recognize you and please address your remarks to





 6        me.  State your name and the organization that you





 7        represent and present your statement.  Do not begin





 8        speaking until you've reached the microphone and speak





 9        slowly and clearly into the microphone.





10            If you've prepared your statement beforehand, you





11        may read it aloud or you way paraphrase it and place it





12        on this table.





13            Are there any individuals wishing to make a comment





14        or a statement at this time?  Yes, Maynard.





15                                      MAYNARD ST. PETER:  I have





16        a copy here for you, Peter.





17                                      MR. FORBES:  Thank you.





18                                      MAYNARD ST. PETER:  I'd





19        like to read this into the record, please.





20                                      MR. STRAINGE:   Can you state





21        your name, please, for the record.





22                                      MAYNARD ST. PETER:  Maynard





23        St. Peter, member of the RAB Board.  Peter,  I have read





24        the proposed plan for Operable Unit 13 and I am in





25        agreement with the base clean up teams in that the

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 1        contaminated soil must be removed to an acceptable level.





 2            I do have a major problem with this proposal's





 3        continued use of the term wetlands in regard to the




 4        Greenlaw Brooks and its tributaries.  Both branches of





 5        the Greenlaw Brook did and still do have wetlands as





 6        their headwaters.  But the length of the brooks





 7        themselves were a continual series of beaver dams




 8        connected by fast running water with very little





 9        wetlands.  This is how it was.





10            It was a creation of Loring that created the





11        wetlands.  The destruction of the beaver dams and the




12        continual effort by the Department of Defense in not





13        allowing the beavers to reclaim Loring has produced those





14        areas now defined as wetlands.  Before Loring this area





15        was one of Aroostook's greatest fisheries, supporting





16        more than 20 beaver dams.  It was also a primary recharge




17        area for the Gary Mill aguifer located beneath Loring.





18            Had the environmental laws of today been in effect





19        in the late forties, Loring could not nor would it have





20        ever been built here.  Had the national government




21        invoked the right of domain,  you can rest assured that





22        the State of Maine would have had a clause mandating that





23        on their departure they would have had to put things back





24        the way they were.





25            Although we cannot undo the past,  any effort at

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 1        restoration today must emphasize and look at this area as





 2        what it was,  not what it is.





 3            I am recommending that the base clean up team revise





 4        the document,  acknowledging this fact.   That all





 5        references to the Greenlaw Brook and its tributary





 6        wetlands,  except for those directly related to the





 7        headwaters,  be changed to reflect what they really are--





 8        destroyed fish habitat.





 9            I am also reguesting that all restoration efforts in





10        association with the Greenlaw Brook be directed toward





11        the recovery of the fishery that once existed here.





12            As a Citizen of Maine we deserve no less,  the people





13        of Aroostook expect no less,  the residents of Limestone





14        and Caribou are asking for no less.





15            The Maine Department of Environmental Protection and





16        the US Environmental Protection Agency must support us in





17        our effort to reclaim this inland fisheries.





18                                      MR. FORBES:  Thank you,





19        Maynard.





20                                      MR. ST. PETER:  Okay.





21                                      MR. FORBES:  Okay, are





22        there any other comments?  Anyone else wishing to make a





23        statement or a comment?   Well, seeing that there are no





24        other people stepping forward with a comment tonight, it





25        is 8:10 p.m.,  May 8th, 1997,  and I declare the public

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 1        hearing to receive comments on the proposed plan for





 2        Operable Unit 13 at Loring Air Force Base closed.





 3





 4                       CERTIFICATION





 5





 6        I HEREBY CERTIFY THAT the foregoing is a true and correct





 7        transcript of the public hearing taken on the





 8        aforementioned date.





 9





10





11   





12





13





14





15





16





17





18





19





20





21





22





23





24





25   STATE OF MAINE                                       AROOSTOOK,  ss.

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                                 APPENDIX B

                           RESPONSIVENESS SUMMARY

                                    FINAL

                            LORING AIR FORCE BASE

                            OPERABLE UNIT (OU) 13

                                  May 1997

                                Prepared for:

                      Air Force Base Conversion Agency
                        Loring Air Force Base, Maine
                                (207) 328-7109


                                Prepared by:

          Service Center:  Hazardous Waste Remedial Actions Program
                       Oak Ridge, Tennessee 37831-7606

                 Contractor:  ABB Environmental Services, Inc.
                              Portland, Maine 04112

                               Project No. 9975-16

                              TABLE OF CONTENTS

Section                         Title                           Page No.

PREFACE 	P-l

1.0  OVERVIEW OF THE REMEDIAL ALTERNATIVE
     RECOMMENDED IN THE PROPOSED PLAN 	1-1

2.0  BACKGROUND ON COMMUNITY INVOLVEMENT AND
     CONCERNS 	2-1

3.0  SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC
     COMMENT PERIOD AND USAF RESPONSES 	3-1

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PREFACE

The United States Air Force (USAF) held a 30-day comment period from April 14 to May 13, 1997, to provide
an opportunity for the public to comment on the Proposed Plan and other documents developed for Operable
Unit 13 (OU 13) at the former Loring Air Force Base (LAFB). OU 13 is the basewide surface water and
sediment operable unit. The Proposed Plan is the document that identifies remedial action objectives,
evaluates remedial alternatives, and recommends the alternative that best meets the evaluation criteria
for OU 13.

The USAF made a recommendation of its preferred alternative in the OU 13 Proposed Plan. Removal and
Disposal of contaminated soil and sediment was recommended for areas that exceed remediation goals.
These areas include the Flightline Drainage Ditch (FLDD), FLDD Wetland, East Branch of Greenlaw Brook
(EBGB) from Pennsylvania Road to the Ski Chalet, north and south Nose Dock Area (NDA) Drainageways, Ditch
GO6, and the northern portion of the Underground Transformer Site (UTS) Wetland. The USAF recommended
continuation of the State Fish Advisory Currently in effect at designated on- and off-base areas. The No
Action alternative was recommended for the Little Madawaska River (LMR) because there is no unacceptable
risk associated with surface soil, sediment and surface water. The USAF has determined that no further
action is necessary for the remaining areas within OU 13.

The Proposed Plan was issued April 10, 1997. All documents on which the preferred alternative was based
were placed in the Administrative Record for review. The Administrative Record is a collection of
documents considered by the USAF when selecting the remedial action for OU 13.

The purpose of this Responsiveness Summary is to document USAF responses to the guestions and comments
raised during the public comment period regarding the proposed alternative for OU 13. The USAF
considered all comments in this document before selecting a final remedial alternative to address soil
and sediment contamination from OU 13.

This Responsiveness Summary is organized into the following sections:

1.0 Overview of the Remedial Alternative Recommended in the Proposed Plan.

2.0 Background on Community Involvement and Concerns.

3.0 Summary of Comments Received During the Public Comment Period and USAF Responses.

1.0 OVERVIEW OF THE REMEDIAL ALTERNATIVE RECOMMENDED IN THE PROPOSED PLAN

The selected remedy for OU 13 includes two remedial alternatives; 1) Removal and Disposal and 2) No
Action. No further action is necessary for much of OU 13 because there is no unacceptable risk to human
health or the environment. The selected remedy for contaminated surface soil and sediment that exceed
remediation goals in the FLDD, FLDD Wetland, BBGB (from Pennsylvania Road to the Ski Chalet), north and
south NDA Drainageways, Ditch G06, and the UTS Wetland (northern portion) is Removal and Disposal. The
major components of the remedy include:

• pre-design studies to delineate the extent of remediation for design purposes;
• pre-design wetland mitigation studies (i.e., wetland delineations and function-value
assessments) to evaluate the impacts resulting from remedial activities;
• site preparation and mobilization;
• cutting and clearing;
• stormwater management;
• sediment excavation;
• sediment disposal at LF-3, some material may reguire disposal at off-base facilities;
• backfilling the excavations with material that closely matches the excavated material;
• compensatory wetlands mitigation and demobilization;
• long-term environmental and wetlands mitigation monitoring;
• continued fish advisory; and
• five-year site reviews.

The State Fish Advisory, currently in effect at designated on- and off-base areas, will remain in effect
until the fish are determined to be acceptable for consumption.

The No Action alternative has been selected for the LMR because there is no unacceptable risk associated
with surface soil, sediment, and surface water. The components of the alternative include environmental
monitoring and five-year site reviews to evaluate the long-term conditions of the site's ecology and to
assess whether human health and the environmental continue to be adeguately protected.

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The USAF has determined that no further action is necessary for the remaining areas within OU 13 because
there is no unacceptable risk to human health or the environment.

These actions will achieve the following remedial response objectives developed for OU 13:

       •      prevent or minimize ingestion of and dermal contact with contaminated soil/sediment by human
              and ecological receptors;
       •      prevent human ingestion of contaminated fish;
       •      minimize migration of contaminated soil/sediment;  and
       •      avoid destruction of existing ecological habitat where risk associated with short-term
              habitat loss outweighs the reduction in risk potentially realized by site remediation.

                          2.0    BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS

Throughout LAFB's history, the community has been active and involved in base activities.  The USAF and
US Environmental Protection Agency  (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 houses, as well as Restoration Advisory Board  (RAB) meetings.  Membership of the RAB is
composed of USAF, USEPA, Maine Department of Environmental Protection (MEDEP),  local officials, and
community representatives.

The LAFB Community Relations Plan  (CRP)  was released in August 1991 and revised in May 1995.  The CRP
outlined a program to address community concerns and keep citizens informed and involved during remedial
activities.  The CRP can be found in the Administrative Record.

On June 24, 1992, the USAF made the LAFB Administrative Record available for public review.  The
Administrative Record is currently available for public review at the Air Force Base Conversion Agency
(AFBCA) Office, 5100 Texas Road, Limestone, Maine.

From April 14 through May 13, 1997, the USAF held a public comment period to accept public input on the
alternatives presented in the OU 13 Feasibility Study and Proposed Plan, as well as other documents
previously released to the public.  On May 8, 1997, AFBCA personnel and regulatory representatives held a
public meeting to discuss the Proposed Plan and to accept any oral comments.  Based on the public
comments, the public is in agreement regarding the preferred alternatives for OU 13 presented in the
Proposed Plan.

          3.0    SUMMARY OF COMMENTS RECEIVED DURING THE PUBLIC COMMENT PERIOD  AND USAF RESPONSES

This Responsiveness Summary addresses comments received by the USAF during the public comment period from
April 14 to May 13, 1997, relative to the Proposed Plan for OU 13 at the former LAFB.  Comments include
those received verbally during the public hearing and letters received during the public comment period.
The comments and corresponding responses are included in the following paragraphs.

1.    Comment:  One commenter stated that he is pleased with the cleanup activities being conducted at
LAFB.  The commenter also stated that he hopes the USAF will be able to restore Greenlaw Brook to its
condition 40 years ago, and that the Greenlaw Brook will become a high guality fishery again.

USAF Response:  The selected remedial alternative consists of excavation and removal of contaminated
surface soil and sediments from streams, wetlands, and drainage ditches in numerous areas, and
restoration of the wetlands affected during the removal process.  The removal activities will be
disruptive to the habitats being remediated, however the regulatory agencies, ecological specialists,
wetland scientists, the U.S. Fish and Wildlife Service  (USFWS) , and the USAF are in agreement that the
removals are necessary to facilitate recovery of the ecosystem.  By removing the sources  (contaminated
soil and sediments), water guality will improve, the food chain will be able to re-establish in formerly
contaminated areas, and the fishery will undoubtedly recover.  The rate of recovery will be greatly
increased with the removal of contaminants; however, restoration to conditions prior to base construction
will reguire time.  Full restoration of the habitats and fishery will also reguire continued vigilance by
future owners and tenants of base property.

The USAF intends to conduct long-term monitoring of the recovery of the ecological communities impacted
by former base activities, including periodic analysis of contaminants in fish tissue.  The State Fish
Advisory currently in effect for portions of the Little Madawaska River watershed near the base will be
able to be lifted at some point in the future when the "catch-and-release" policy is no longer necessary.
The local community will also be kept informed as to the status of the recovery of the fishery.

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2. Comment: One commenter agreed that contaminated soil and sediment must be removed to acceptable
levels. The commenter stated that both branches of the Greenlaw Brook have wetlands at their headwaters,
but that the brooks themselves used to be a series of beaver dams connected by fast running waters, with
very little wetlands present. Before the creation of Loring Air Force Base, the area used to be one of
Aroostook County's greatest fisheries. With the creation of Loring and destruction of the beaver dams,
the fast running waters are gone and wetlands have developed.

The commenter reguested that the document be revised to reflect that the "wetlands" that have been
created are really "destroyed fish habitat". The commenter also reguested that all restoration efforts
associated with Greenlaw Brook be directed towards the recovery of the fishery that once existed before
the development of Loring; restoration should focus on the way the area was, not what it is now.

USAF Response: The USAF understands the concerns raised by the commenter; that wetlands now exist in
some areas that once were fish habitat. However, these wetlands provide a diverse habitat for a wide
range of aguatic wildlife that form the foundation of the fishery and are very valuable to the area's
overall ecology, both for aguatic and terrestrial wildlife.

As stated in the USAF's Response to Comment 1, by removing the sources of contamination, water guality
and the food chain will recover, and the fishery will improve correspondingly. Due to the creation of
LAFB and other development in the area over the years, it is not feasible to restore the area to the
conditions of 40 or 50 years ago. However, now that LAFB is no longer active, and significant areas of
contamination will be removed, the ecosystem will recover and beaver activity will eventually increase.
Beaver dams will have a positive effect on the streams and brooks, helping to return the areas to
pre-Loring conditions, although there will be a significant and inevitable recovery period after the
removals are completed. Wetland restoration specialists have been retained by the USAF specifically to
design and supervise the wetland restorations to be conducted in the removal areas. USEPA, USFWS, and
MEDEP wetland scientists will also be contributing to the planning and supervision of the restorations.

Additionally, in accordance with the Record of Decision for the Disposal of Loring Air Force Base, Maine
(April 1996), approximately 4,500 acres of LAFB property will be transferred to the USFWS. The acreage
has been designated for three uses. Approximately 3,900 acres will be used as part of the National
Wildlife Refuge System. Included in these parcels are the East Branch of Greenlaw Brook and a large
portion of the West Branch of Greenlaw Brook. Approximately 20 acres will be used for wildlife habitat
conservation and approximately 560 acres of vacant land on the shores of the Little Madawaska River, will
be used for fishery, wildlife, and wetlands protection.

3. Comment: One commenter agreed with the preferred alternative that the USAF is proposing. However,
the commenter is concerned with the ecological restoration activities. The area used to be an important
fishery utilized by Native Americans. However, the construction of LAFB altered the watershed drainage
patterns, changing the flow of water through the area, resulting in deterioration of the fish habitat.
The commenter reguested the USAF consider restoring the ecosystem to conditions that preceded occupation
of the area by the Department of Defense, including measures to enhance the fish habitat. Suggested
measures include returning non-contaminated organic and inorganics debris to the stream and only
partially backfilling excavated areas to increase the depth of pools within the stream bed. Additionally,
to enhance diversity in the affected wetland and riparian ecosystems, the commenter reguested the USAF
consider restoring suitable portions of the de-vegetated areas with the brown ash species.

USAF Response: Please see the responses to the preceding comments for a partial response to this
comment. The suggestion of returning non-contaminated organic and inorganic debris to the remediated
areas will be part of the restoration thought process, and the creation of deeper pools will also be
considered. Additionally, brown ash will be included in the selection of vegetation to be used in the
restoration process. As mentioned, wetland restoration scientists have been retained by the USAF
specifically to aid in the restoration efforts, and specialists from the regulatory agencies and USFWS
are fully involved at this time in the process as well.

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                                        APPENDIX C
                                   IiETTER OF CONCURRENCE

    



       •       stormwater management,
       •       sediment excavation;
       •       sediment disposal at  Landfill 3,  some material may require disposal at off-base facilities;
       •       backfilling the excavations with material that closely matches the excavated material;
       •       compensatory wetlands mitigation and demobilization;
       •       long-term environmental and wetlands mitigation monitoring;
       •       continued fish advisory;  and
       •       five-year site reviews.

The State Fish Advisory, currently in effect at designated on- and off-base areas, will remain in effect
until the fish are determined to be acceptable for consumption.

The No action alternative has been selected for the Little Madawaska River because there is no
unacceptable risk associated with surface soil, sediment, and surface water.  The components of the
alternative include environmental monitoring and five-year site reviews to evaluate the long-term
conditions of the site's ecology and to assess whether human health and the environmental continue to be
adequately protected.

The above actions will achieve the following remedial response objectives developed for OU 13:

       •       prevent or minimize ingestion of and dermal contact with contaminated
       •       soil/sediment by human and ecological receptors;
       •       prevent human ingestion of contaminated fish;
       •       minimize migration of contaminated soil/sediment;  and
       •       avoid destruction of  existing ecological habitat where risk associated with short-term
              habitat loss outweighs the reductions in risk  potentially realized by site remediation.

The USAF Will review the environmental monitoring data at least once every five years in accordance with
applicable USEPA guidance.  The five-year site reviews are intended to evaluate whether the response
action continues to protect human health and the environment, assess site conditions, and propose further
actions,  if necessary.

The MEDEP's concurrence in the selected remedy, as described above, should not be construed as the
State's concurrence with any conclusions of law or findings of fact which may he set forth in the Record
of Decision.  The State reserves any and all rights to challenge any such finding of fact or conclusion
of law in any other context.  This concurrence is bused upon the State's understanding that the MEDEP
will continue to participate in the Federal Facilities Agreement and in the review and approval of
operational, design, and monitoring plans.

The MEDEP looks forward to working with the Department of the Air Force and the USEPA to resolve the
environmental problems posed by this site.  If you need additional information, do not hesitate to
contact myself or members of my staff.

Sincerely,

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