Superfund Record of Decision Pensacola Naval Air Station OU 10 Pensacola FL


                                    EPA/ROD/R04-97/209
                                    1997
EPA Superfund
     Record of Decision:
     PENSACOLA NAVAL AIR STATION
     EPA ID: FL9170024567
     OU10
     PENSACOLA, FL
     09/15/1997

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          FINAL RECORD OF DECISION
          OPERABLE UNIT 10
          NAS PENSACOLA
          PENSACOLA, FLORIDA

          SOUTHNAVFACENGCOM
          Contract Number:
          N62467-89-D-0318
          CTO-083

          Prepared for:

          Comprehensive Long-Term Environmental Action Navy
          (CLEAN)
          Naval Air Station
          Pensacola, Florida

          Prepared by:

          EnSafe/Allen & Hoshall
          5720 Summer Trees Drive, Suite 8
          Memphis, Tennessee 38134
          (901) 383-9115

          June 16, 1997

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          UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                           REGION 4
                    ATLANTA FEDERAL CENTER
                  100 ALABAMA STREET, S.W.
                 ATLANTA, GEORGIA 30303-3104

                             SEP  16  1997

CERTIFIED MAIL,
RETURN RECEIPT REQUESTED

4WD-FFB

Commanding Officer
Naval Air Station Pensacola
190 Radford Boulevard
Pensacola,  Florida 32508-5217

SUBJ:   Record of Decision - Operable Unit 10
       NAS Pensacola NPL Site
        Pensacola,  Florida

Dear Sir:

    The U.S. Environmental Protection Agency (EPA) Region 4 has reviewed the above subject
decision document and concurs with the selected remedy for the Remedial Action at Operable Unit
10. This remedy is supported by the previously completed Remedial Investigation, Feasibility
Study and Baseline Risk Assessment Reports.

    The selected remedy consists of:  excavation and off-site disposal of soils in Area A,
leachability study of areas B, C, & D, with contingency excavation and off-site disposal should
soils fail the leachability test, and groundwater remediation under the Corrective Action Plan
for the Resource Conservation and Recovery Act (RCRA) permit modification.  This remedial action
is protective of human health and the environment, complies with Federal and State reguirements
that are legally applicable or relevant and appropriate to the remedial action and is cost
effective.

    EPA appreciates the coordination efforts of NAS Pensacola and the level of effort that was
put forth in the documents leading to this decision.  EPA looks forward to continuing the
exemplary working relationship with NAS Pensacola and Southern Division Naval Facilities
Engineering Command as we move toward final cleanup of the NPL site.

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                                  Table of Contents

DECLARATION OF THE RECORD OF DECISION 	 viii

1. 0    SITE LOCATION AND DESCRIPTION 	1

2 . 0    SITE HISTORY AND ENFORCEMENT ACTIVITIES 	9
       2 .1  General Site History 	9
       2 . 2  Site-Specific History 	9

3 . 0    HIGHLIGHTS OF COMMUNITY PARTICIPATION 	13

4 . 0    SCOPE AND ROLE OF THE OPERABLE UNIT 	15

5 . 0    SITE CHARACTERISTICS 	17
       5 .1    Nature and Extent of Soil  Contamination 	17
       5 .2    Nature and Extent of Sediment Contamination 	23
       5 .3    Nature and Extent of Surface Water Contamination 	23
       5.4    Nature and Extent of Groundwater Contamination 	24
       5 . 5    Fate and Transport 	30
              5.5.1  Sources of Contamination 	30
              5.5.2  Contaminant Migration 	30

6. 0    SUMMARY OF SITE RISKS 	35
       6.1    Chemicals of Potential Concern 	35
       6. 2    Exposure Assessment 	37
              6.2.1  Current Exposure 	38
              6.2.2  Future Exposure 	39
       6. 3    Toxicity Assessment 	46
       6.4    Risk Characterization 	50
       6.5    Soil Performance Standards for Groundwater Protection 	54
       6. 6    Risk Uncertainty 	56
       6.7    Human Health Risk Summary  	58
       6. 8    Ecological Considerations  	62

7.0    DESCRIPTION OF THE REMEDIAL ALTERNATIVES 	65
       7.1    Alternative 1:   No Action  	66
       7.2    Alternative 2:   Institutional Controls  	69
       7.3    Alternative 3:   Capping 	69
       7 . 4    Alternative 4:   Excavation with Offsite Disposal 	70
       7.5    Applicable or Relevant and Appropriate  Reguirements  (ARARs)	70

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8.0    COMPARATIVE ANALYSIS OF ALTERNATIVES 	77
       8 .1    Threshold Criteria  	79
              8.1.1  Overall  Protection  of  Human  Health  and  the  Environment  	79
              8.1.2  Compliance with ARARs  	80
       8.2    Primary Balancing Criteria 	80
              8.2.1  Long-Term Effectiveness  and  Permanence  	80
            8.2.2  Reduction of Toxicity,  Mobility,  and Volume through Treatment ..81
              8.2.3  Short-Term Effectiveness 	81
              8.2.4  Implementability  	82
              8.2.5  Cost  	82
       8 . 3    Modifying Criteria  	82
              8.3.1  State  Acceptance  	82
              8.3.2  Community Acceptance  	83

9 . 0    THE SELECTED REMEDY  	85
       9.1   Source Control 	85
       9.2   Groundwater Treatment and Monitoring 	87
       9.3   Extraction,  Treatment,  and  Discharge of Contaminated Groundwater 	88
       9.4   Compliance Testing 	88

10.0  STATUTORY DETERMINATIONS 	89
       10.1  Protection of  Human  Health  and the Environment  	89
       10.2  Attainment of  the ARARs  	89
       10.3  Cost-Effectiveness 	90
       10.4  Use of Permanent Solutions  to  the Maximum Extent  Practicable  	91
       10.5  Preference for Treatment  as a  Principal Element 	91

11.0  DOCUMENTATION OF SIGNIFICANT CHANGES  	93

                                   List  of Figures

Figure 1-1  Site Location Map 	3
Figure 1-2    Site Map 	5
Figure 5-1    Site 32,  PAH  and Chlorinated  Benzene Hot Spots 	19
Figure 5-2    Site 35,  Chlorinated Benzene  Hot Spot  	21
Figure 5-3    Surface Water and Sediment Sampling Locations  	25
Figure 5-4    Groundwater Area of Concern  	27
Figure 7-1    Areas of Concern 	67

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                                        List of Tables

Table 6-1     Chemicals of Potential Concern (ppm)  	36
Table 6-2     Exposure Point Concentrations 	40
Table 6-3     Parameters Used to Estimate Potential Exposures
            for Current Land Use Receptors  	42
Table 6-4     Parameters Used to Estimate Potential Exposures
              for Future Land Use Receptors 	44
Table 6-5     Toxicological Database Information for Chemicals of Potential Concern..48
Table 6-6     Risk and Hazard for Identified COCs and Pathways of Concerns 	52
Table 6-7     Remedial Goal Options for Surface Soil (0 to 1 foot depth interval) .... 60
Table 6-8     Remedial Goal Options for Shallow/Intermediate Groundwater 	61
Table 6-9     Remedial Goal Objectives for Deep Groundwater 	63
Table 7-1     Soil Remedial Objectives 	66
Table 7-2     Potential Location-Specific ARARs 	72
Table 7-3     Potential Action-Specific ARARs for the Selected Remedy and Contingent
              Remedial Action 	72
Table 7-4     Potential Chemical-Specific ARARs 	75
Table 8-1     Cost Comparison for Alternatives 	83
Table 9-1     Performance Standards for Soil 	86
Table 9-2     Performance Standards for Groundwater 	87
Table 9-3     Indicator Parameters for Groundwater Treatment 	88

                                 List of Appendices

Appendix A  Glossary
Appendix B  Responsiveness Summary

                                  List of Abbreviations

The following list contains many of the abbreviations, acronyms, and symbols used in this
document.  A glossary of technical terms is provided in Appendix A.

AOC      Area of concern
ARAR     Applicable or Relevant and Appropriate Reguirements

BEHP     Bis(2-ethythexyl)  phthalate
bis      Below land surface
BRA      Baseline Risk Assessment
GDI      Chronic Daily Intake
CERCLA  Comprehensive Environmental Response, Compensation, and Liability
        Act
CNET Chief of Naval Education and Training
COG      Chemical of Concern
COPC     Chemical of Potential Concern
CFR      Code of Federal Regulations
CSF      Cancer Slope Factor
cy       Cubic yard

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FDER     Florida Department of Environmental Regulation (since renamed Florida
        Department of Environmental Protection [FDEP])
FFA      Federal Facilities Agreement
FFS     Focused Feasibility Study
FS       Feasibility Study

HEAST    Health Effects Assessment Summary Tables
HI       Hazard Index
HQ       Hazard Quotient
HRS      Hazard Ranking System

ILCR     Incremental Lifetime Cancer Risk
IRIS     Integrated Risk Information System
ISDB     Industrial Sludge Drying Bed
IWTP     Industrial Wastewater Treatment Plant

Iwa     Lifetime Weighted Average

MCL     Maximum Contaimnant Level

NAS      Naval Air Station
NCP     National Oil and Hazardous Substances Pollution Contingency Plan
NPDES    National Pollutant Discharge Elimination System
NPL     National Priorities List

O&M     Operation and Maintenance
OU       Operable Unit

PAH      Polyaromatic Hydrocarbon
PCB     Polychlorinated Biphenyl
ppb      Part per billion
PRG      Preliminary Remediation Goal
PWC      Public Works Center

RAB      Restoration Advisory Board
RCRA     Resource Conservation and Recovery Act
RD/RA    Remedial Design/Remedial Action
RfD      Reference Dose
RGO      Remedial Goal Option
RME      Reasonable Maximum Exposure
RI       Remedial Investigation
ROD     Record of Decision

SVOC     Semivolatile Organic Compound
SWMU    Solid Waste Management Unit

TBC      To Be Considered
TEF      Toxicity Equivalency Factor
TRC     Technical Review Committee
USC     U.S. Code
USEPA    U.S.  Environmental Protection Agency
UST     Underground Storage Tank
VOC     Volatile Organic Compound

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                               DECLARATION OF THE RECORD OF DECISION

Site Name and Location

Operable Unit 10, Industrial Wastewater Treatment Plant
Naval Air Station Pensacola
Pensacola, Florida

Statement of Purpose

This decision document  (Record of Decision),  presents the selected remedy for Operable Unit 10
at Naval Air Station Pensacola, Pensacola, Florida, developed in accordance with the
Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA),  as
amended by the Superfund Amendments and Reauthorization Act of 1986  (SARA), 42 U.S.C. ° 9601 et
seq., and to the extent practicable, the National Contingency Plan (NCP),  40 Code of Federal
Regulations Part 300.

This decision is based on the administrative record for Operable Unit 10 at the Naval Air
Station Pensacola.

The U.S. Environmental Protection Agency and the Florida Department of Environmental Protection
concur with the selected remedy.

Assessment of the Operable Unit

Actual or threatened releases of hazardous substances from Operable Unit 10, if not addressed by
implementing the response action selected in this Record of Decision  (ROD), may present an
imminent and substantial endangerment to public health or the environment.

Description of the Selected Remedy

This action is the first and final action planned for the operable unit.  This alternative calls
for the design and implementation of response measures that will protect human health and the
environment.  The action addresses the sources of contamination as well as soil and groundwater
contamination.

The major components of the remedy are:

•      Excavation and disposal of soil above residential soil preliminary remediation goals
       (Area A) ;

•      Leachability study on Areas B, C,  and D to verify that contaminants  remaining in soil are
       not leaching to groundwater;

•      Contingency remedial action of Areas B,  C, and D to include excavation and disposal of
       soil that the leachability study verifies as a source of groundwater contamination;

•      The remedial design for groundwater treatment will be developed in the Corrective Action
       Plan for the Resource Conservation and Recovery Act (RCRA)  permit modification.

•      Groundwater monitoring program to ensure the groundwater treatment system will be
       effective and that contaminants will not migrate;

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•      Continued groundwater monitoring at sampling intervals to be determined during the
       remedial design for groundwater treatment developed in the Corrective Action Plan for the
       RCRA permit modification.   The groundwater monitoring program will continue until a
       five-year review concludes that the alternative has achieved the performance standards and
       remains protective of human health and the environment.

Statutory Determinations

The selected remedy with an active soil removal contingency for Areas B, C, and D is protective
of human health and the environment,  complies with federal and state reguirements that are
legally applicable or relevant and appropriate to the remedial action,  and is cost-effective.
Modification of the RCRA corrective action groundwater treatment system will include the
groundwater performance standards as a permit reguirement.  Attainment of standards will be
confirmed through groundwater monitoring.  This remedy with contingency satisfies the statutory
preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a
principal element.  Finally, this remedy uses a permanent solution and treatment technology to
the maximum extent practicable.

Because this remedy may result in hazardous substances remaining onsite, a review will be
conducted within five years after it commences to ensure that it continues to adeguately protect
human health and the environment.

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1.0 SITE LOCATION AND DESCRIPTION

Operable Unit (OU) 10 is on Magazine Point at the Naval Air Station (NAS) Pensacola, in
Escambia County, Florida, as shown on Figure 1-1. Ordnance and munitions are stored there.
In addition, domestic wastewater generated on station is treated on Magazine Point, which is
bounded to the north and west by Bayou Grande and east by Pensacola Bay. South of Magazine
Point is the former Chevalier Field, which is currently being converted to Chief of Naval
Education and Training (CNET) facilities. Except for the Industrial Wastewater Treatment Plant
(IWTP) conversion to domestic wastewater treatment only in October 1995, no other use changes
are expected for Magazine Point.

OU 10 comprises three sites which are shown on Figure 1-2: the former bridustrial Sludge Drying
Beds (ISDBs; Site 32); the former Wastewater Treatment Plant Ponds including the former surge
pond, stabilization pond, and polishing pond (Site 33); and miscellaneous IWTP Solid Waste
Management Units (SWMUs; Site 35) which are listed below.

Industrial grit chamber Industrial primary clarifier and oil/water separator

Industrial comminutor Aerobic sludge digester

Industrial sludge thickener Aeration (activated sludge) tank

Industrial sludge presses Surge tank

Waste oil storage tanks Sludge truck loading station

Acid storage tanks Parallel flocculators

Sludge bed pumping station Parallel final clarifiers

Pump dock Chlorine contact chamber

Ancillary piping, pumps, junction boxes, etc.

OU 10 occupies approximately 26 acres in an industrialized section of NAS Pensacola. The
former Chevalier Field area being converted to Naval Recruit Training Facilities will contain
barracks. Other residential areas are approximately 0.8 to 1.2 miles north and northwest of OU
10 across Bayou Grande.

The facility's main area is topographically higher than the surrounding areas and is dominated
by fill and development. Large amounts of fill are mounded into berms 4 to 7 feet high around
the closed stabilization and polishing ponds. An extensive plateau of fill 5 to 6 feet high is
at the former surge pond and associated berms. Vegetation is limited to grasses within the
fenced IWTP, and in several areas grass is absent, exposing a loose organic-poor sand. Marsh
vegetation has colonized the closed stabilization and polishing ponds. The area south of the
IWTP is a low-lying, heavily wooded swampy area. The area north of OU 10 is a wooded peninsula
with thick underbrush bounded on the cut by Pensacola Bay and on the west by Bayou Grande.

Depth to groundwater ranges from 0 to 4 feet below land surface (bis), depending on tidal
influence and ground surface elevation. Most runoff does not flow from the site but infiltrates
into the subsurface rapidly through the sandy surface soil; however, a channelized ditch drains
water toward the south. Erosional channels in the steeply sloped berms and flanks of the three
former ponds indicate surface runoff down these structures. Standing water was observed in the
Resource Conservation and Recovery Act (RCRA) clean-closed, cement-lined stabilization and

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polishing ponds at depths of approximately 6 to 8 inches. The asphalt cap of the closed ISDBs
slopes southward, resulting in a southerly surface runoff from the asphalt area toward a sump
intake to the wastewater treatment system near the chemical storage area.

Groundwater flow generally mimics the peninsular topography (with flow to the northwest, north,
northeast, east, and southeast) and discharges to Pensacola Bay and Bayou Grande. Groundwater

is not currently used as a potable water source at OU 10 nor at NAS Pensacola.

Potable water for NAS Pensacola is received from Corry Station approximately 4 miles north. An
NAS Pensacola supply well, which is screened between 105 and 160 feet bis, is approximately
0.75 miles west-southwest of OU 10. The well is used for backup supplies only during periods
of peak demand. The zone in which the supply well is screened is protected by the presence of
a 12- to 15-foot-thick, low-permeability clay layer. Groundwater contamination has not been
detected in this zone at OU 10 nor in the supply well.

Access to the IWTP proper is limited by a fence. In addition, OU 10 is bounded by thick
vegetation and trees to the north and south. To the east and west, Pensacola Bay and
Bayou Grande limit site access. Groundwater is not currently being used onsite for any purpose.
In addition, contaminated groundwater is not expected to transport to a drinking water supply
due to the proximity of Pensacola Bay and Bayou Grande.

2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES

2.1 General Site History

NAS Pensacola was ranked using the Hazard Ranking System (HRS) in 1988 and given an HRS score of
42.4, based on groundwater and surface water pathway scores. In December 1989, the base was
placed on the U.S. Environmental Protection Agency's (USEPA) National Priorities List (NPL).

The Federal Facilities Agreement (FFA) , signed in October 1990, outlined the regulatory path to
be followed at NAS Pensacola. NAS Pensacola must complete not only the regulatory obligations
associated with its NPL listing, but it also must satisfy the ongoing reguirements of a RCRA
permit issued in 1988. That permit addresses the treatment, storage, and disposal of hazardous
materials and waste and also the investigation and remediation of any releases of hazardous
waste and/or constituents from SWMUs. RCRA governs ongoing use of hazardous materials, and the
rules of the operating permit. RCRA and the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) investigations and actions are coordinated through
the FFA, streamlining the cleanup process.

2.2 Site-Specific History

Wastewater has been treated on Magazine Point since 1941 at various treatment facilities. In
1941, an Imhoff tank was installed north of the present IWTP. The tank treated, only Magazine
Point area sewage. The current facility was constructed in 1948 to process primarily domestic
wastewater. The Imhoff tank north of the facility was abandoned subseguently. The facility was
upgraded in 1971 to treat both industrial and domestic wastewater separately. Before 1971, the
facility was receiving industrial waste from paint and plating operations at the Building 709
complex. Industrial waste was received via the sanitary sewer line and processed with domestic
sewage.

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In 1978, the domestic sludge generated at the IWTP was found to be hazardous by the Florida
Department of Environmental Regulation (FDER; since renamed Florida Department of Environmental
Protection [FDEP]) due to chromium concentrations, reguiring it to be disposed of in the same
manner as industrial sludge. After chromium concentrations decreased, FDER allowed the domestic
sludge to be disposed as a nonhazardous waste.

In 1981, FDER designated the IWTP surge pond as a hazardous waste surface impoundment; it
received an average of 880,000 gallons of waste per day. The wastewater contained high
concentrations of organic solvents, phenols, chromium electroplating wastes (including cyanide
and other heavy metals), and wastes from a chemical conversion coating process for aluminum.
As a result of the hazardous waste designation, a RCRA detection groundwater monitoring program
was implemented. Leakage from the surge pond was estimated to be as high as 5,800 gallons per
day.

In 1984, the ISDBs were removed from service. RCRA detection monitoring identified groundwater
contamination attributable to the surge pond. As a result, a RCRA assessment monitoring program
was implemented to determine the extent of contamination.

In 1985, FDER issued a temporary RCRA operation permit (No. HT17-68087) to the U.S. Navy Public
Works Center (PWC) for the surge pond. A new permit (No. H017-127026) was issued in September
1987.

In 1986, a RCRA Corrective Action Program was implemented at the IWTP to comply with conditions
in the FDER Temporary Operating Permit No. HT17-68087. Based on results of the RCRA assessment
monitoring program, a groundwater recovery system was designed and installed to remediate
contaminated groundwater.

In January 1987, a comprehensive groundwater monitoring evaluation was conducted by the USEPA.
Groundwater samples were collected from seven shallow wells (0 to 15 feet) and one deep
monitoring well. In February 1987, the groundwater recovery system was placed in operation.

In September 1987, FDER issued RCRA Permit No. H017-127026 to the U.S. Navy PWC to operate the
surge pond. The permit stipulated the continued operation of the corrective action system (the
recovery wells) and the implementation of two guarterly groundwater monitoring programs: (1)
point-of-compliance monitoring at the surge pond and (2) corrective action monitoring to
determine the effectiveness of ongoing groundwater remediation. Well sets and parameters for
analysis were separately defined for each monitoring program. The first guarterly groundwater
sampling for corrective action and point-of-compliance programs was initiated in November 1987.

In January 1988, FDER issued closure permits to the U.S. Navy PWC for the polishing pond,
stabilization pond, and the ISDBs (No. HF17-134657). Liguids removed from the impoundments were
processed through the IWTP. Sludge was removed and transported to a hazardous waste disposal
facility. Upon closure, the clay liner and/or subsurface soil of each impoundment were sampled
and analyzed. The subseguent laboratory report indicated only low concentrations of phenol in
liners or soil beneath the stabilization and polishing ponds; and hence, FDER granted clean
closure status to these impoundments. Samples from the liner or soil beneath the ISDBs,
however, indicated several contaminants.

A closure permit for the surge pond (No. HF17-148989) was issued in November 1988 to the U.S.
Navy PWC. Upon closure, the clay liner and/or subsurface soil were sampled and analyzed. As
with the ISDBs, several contaminants were identified. Conseguently, both the surge pond and
ISDBs were capped with low-permeability covers (clay and asphalt, respectively) as a condition
of closure in 1989. A groundwater monitoring program was developed to ensure the effectiveness
of the caps.

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In September 1991, FDER issued permit No. HF17-170951, changing the monitoring reguirement for
each monitoring program from guarterly to semiannually.

In 1992, regulatory focus of environmental investigation at the IWTP shifted from RCRA to
CERCLA.  A Remedial Investigation/Feasibility Study  (RI/FS) work plan for OU 10  (formerly called
Group 0) was submitted to meet CERCLA reguirements.   A Sampling and Analysis Plan was submitted
in October 1992 for the present study.
Between December 1992 and October 1995, EnSafe/Allen & Hoshall performed an RI at OU 10 on
behalf of the Navy.  The RI was designed to assess the nature and extent of contamination to
support a remedy selection.  Fieldwork for the RI included installing monitoring wells and
sampling soil, sediment, surface water, and groundwater.

In 1994 and 1995, a time-critical removal action was performed on the Imhoff tank north of the
IWTP.  Approximately 148 tons of hazardous waste were removed from the tank.  In addition, 619
tons of nonhazardous soil, gravel, and construction debris were removed and landfilled.
Confirmatory samples collected at the extent of the excavation did not detect volatile organic
compounds (VOCs), semivolatile organic compounds  (SVOCs) or polychlorinated biphenyls  (PCBs).
Metals and pesticide concentrations detected were below preliminary remedial goals  (PRGs).

3.0   HIGHLIGHTS OF COMMUNITY PARTICIPATION

Throughout the site's history, the community has been kept abreast of activities in accordance
with CERCLA Sections 113(k) (2) (B) (i-v) and 117.  In January 1989, a Technical Review Committee
(TRC) was formed to review recommendations for and monitor progress of the investigation and
remediation efforts at NAS Pensacola.  The TRC was made up of representatives of the Navy,
USEPA, FDER, and the local community.  In addition,  a mailing list of interested community
members and organizations was established and maintained by the NAS Pensacola Public Affairs
Office.  In July 1995, a Restoration Advisory Board  (RAB) was established as a forum for
communication between the community and decision-makers.  The RAB absorbed the TRC and added
members from the community and local organizations.   The RAB members work together to monitor
progress of the investigation and to review remediation activities and recommendations at NAS
Pensacola.  RAB meetings are held regularly, advertised, and are open to the public.

Before the removal action at Site 32, an article and a public notice were published in the
Pensacola News Journal on July 26, 1994, and August 31, 1994.  Site-related documents were made
available to the public in the administrative record at information repositories maintained at
the NAS Pensacola Library, the West Florida Regional Library, and the John C. Pace Library of
the University of West Florida.

After finalizing the RI and Focused Feasibility Study  (FFS) reports, the preferred alternative
for OU 10 was presented in the Proposed Remedial Action Plan, also called the Proposed Plan.

Everyone on the NAS Pensacola mailing list was sent a copy of the Proposed Plan.  The notice
of availability of the Proposed Plan, RI, and FFS documents was published in the Pensacola News
Journal on February 15, 1996.  A public comment period was held from February 19 to April 4,
1996, to encourage public participation in the remedy-selection process.  In addition, a public
meeting was held on February 27, 1996, at Pensacola Junior College, Warrington Campus, Building
3000, for the Navy to present its preferred remedy for OU 10.  The public meeting minutes have
been transcribed, and a copy of the transcript is available to the public at the aforementioned
repositories.  Responses to comments received during the comment period are contained in
Appendix B.

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4.0    SCOPE AND ROLE OF THE OPERABLE UNIT

This selected remedy is the first and final remedial action for the site.  The function of this
remedy is to reduce the risk to human health and environment associated with exposure to
contaminated groundwater and soil.

The selected remedial alternative will address conditions which pose a threat to human health
and the environment including:

•      Contaminated groundwater (may impact drinking water supplies or nearby ecological
       receptors);  and

•      Contaminated soil (presents a continuing source of contamination to groundwater and a
       potential excess risk to a future child resident).

Pathways of exposure include:

•      Dermal contact and ingestion of contaminated soil.

•      Ingestion and inhalation of contaminated groundwater.

•      Aguatic exposure to groundwater discharging to surface waters.

The major components of the remedy are:

•      Excavation and disposal of soil above residential  soil PRGs (Area A);

•      Leachability study on Areas B, C,  and D to verify  that contaminants remaining in soil are
       not leaching to groundwater;

•      Contingency remedial action of Areas B,  C, and D to include excavation and disposal of
       soil that the leachability study verifies as a source of groundwater contamination;

•      The remedial design for groundwater treatment will be developed in the Corrective Action
       Plan for the Resource Conservation and Recovery Act  (RCRA)  permit modification;

•      Groundwater monitoring program to ensure the groundwater treatment system will be
       effective and that contaminants will not migrate;  and

•      Continued groundwater monitoring at sampling intervals to be determined during the
       remedial design for groundwater treatment developed in the Corrective Action Plan for the
       RCRA permit modification.   The groundwater monitoring program will continue until a
       five-year review concludes that the alternative has continually attained the performance
       standards and remains protective of human health and the environment.

This remedy addresses the first and final cleanup action planned for OU 10,  where groundwater
contains elevated concentrations of contaminants similar to those in site soil.  Although this
water bearing zone is affected, the contamination is not  affecting the public drinking water
supply.  The purpose of this proposed action is to prevent current or future unacceptable
exposure to contaminated soil and groundwater,  and to reduce the contaminant migration.  The
remedy will allow for unrestricted land use.

This is the only Record of Decision  (ROD) contemplated for OU 10.  Separate investigations and

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assessments are being conducted for the other sites at NAS Pensacola in accordance with
CERCLA. Therefore, this ROD applies only to OU 10.

5.0 SITE CHARACTERISTICS

This section of the ROD presents an overview of the nature and extent of contamination at OU 10
with respect to known or suspected sources of contamination, types of contamination, and
affected media. Known or potential routes of migration of contaminants also are discussed.

5.1 Nature and Extent of Soil Contamination

Site 32

Contamination by organic compounds in Site 32 soil consists primarily of dichlorobenzene isomers
(predominantly 1,4-dichlorobenzene), polyaromatic hydrocarbons (PAHs), cyanide, and localized
pesticide and PCB concentrations. Inorganic contamination consists of heavy metals including
cadmium, chromium, and lead. Organic contaminants are concentrated primarily in the relict
drainage swale area east/northeast of the former ISDBs. Secondary organic soil contamination
occurs in a horizon above the water table at the southeast edge of the former ISDBS, in the
domestic sludge drying beds, and near-surface soil at the northwest slope from the ISDBs. Metals
concentrations are elevated in the swale (especially in the northeast portion). The spatial
distribution of these contaminants suggests the sources are related to past operation of the
three sludge drying units, with most environmental contamination related to the former ISDBs and
their historical surface overflow drainage into the adjoining swale and potential wetlands.

The only PRG exceedances were for benzo(a)pyrene and dibenz(a,h)anthracene in Area A, as Figure
5-1 shows. A volume of 185 cubic yards (CYs) was estimated for Area A based on assumed
dimensions of 50 feet by 50 feet by 2 feet deep. The actual volume may differ and will be
refined during confirmation sampling.

Areas B and C contained benzene and naphthalene exceeding their Florida leachability guidance
concentrations. Estimated volumes were 120 and 270 CYs, respectively, based on outer sampling
locations.

Sites 33 and 35

Two general types of organic contamination were detected in Sites 33 and 35 soil. The most
pervasive contaminants are PAHs, pesticides, and PCBs. In general, concentrations are lower in
magnitude than those detected at Site 32. The irregular and poorly delineated distribution of
contaminants suggests that historically documented source areas (surge pond and stabilization
pond) and several potential localized sources (i.e., miscellaneous spills, leaks, and/or line
breaks) may have contributed to soil contamination. The spatial distribution of the
contaminants indicates impacted soil at the southeastern corner of the former surge pond and
around the surge tank. In addition, the spatial distribution indicates impacted soil from an
undefined source near the chlorine contact chamber.

A second type of sod contamination appears restricted to the oily horizon at the water table
around the area of the former waste oil underground storage tank (UST). Organic contamination
includes dichlorobenzenes and other PAHs, 2-butanone, xylenes, and PCBs. Heavy metals also were
detected. The contaminant source is thought to be leakage from the former waste oil tank. In
conclusion, the boring coverage and analytical results indicate multiple sources of localized
soil contamination.

As shown in Figure 5-2, Area D exceeded the Florida leachability standards for chlorinated

-------
benzenes and naphthalene. The extent of contamination was estimated to be 50 feet wide by 50
feet long by 4 feet deep for an estimated volume of 370 CYs. No other PRG exceedance for soil
was noted at Sites 33 and 35.

5.2 Nature and Extent of Sediment Contamination

Sediment was collected from the drainage ditch forming the southern boundary of the study area
south of the bilge water facility. Sediment sampling locations are shown in Figure 5-3.
Contaminants in the sediment include fluoranthene, pesticides, PCBs, cadmium, chromium, and
lead. The overall distribution of contaminants indicates sources from direct surface drainage
into the ditch from the former north end of Chevalier Field, drainage into the ditch from the
southern part of the IWTP, and probable site pesticide application. The metals distribution
increases toward the bay, probably representing hydrodynamic accumulation of finer-grained
sediment containing adsorbed metals. Storms put the ditch in direct contact with the bay. The
Southern Drainage Ditch and other wetlands will be investigated further during the Site 41 RI.
Impacts to Pensacola Bay from the Southern Drainage Ditch will be evaluated during the Site 42
RI.

Sediment samples were not collected from the north-south ditch draining the IWTP yard. This
drainage ditch connects with the southern ditch between Stations 33M01 and 33M02. Soil sample
33S15 was collected adjacent to, but not directly in, this north-south feeder ditch. This soil
sample had some of the lowest detected concentrations at the IWTP. The north-south feeder ditch
will be further evaluated during the Site 41 RI.

5.3 Nature and Extent of Surface Water Contamination

Surface water samples were collected from the southern drainage ditch at the same locations as
the sediment sampling stations (Figure 5-3). Contamination detected in these samples consisted
of nonchlorinated aromatics, pesticides, cadmium, chromium, and lead. The nature and
distribution of these contaminants suggest the sources are most likely related to the bilge
water plant spill and normal pesticide application around the plant area. Cadmium (5.2 parts
per billion [ppb]) and lead (2-4 ppb) exceeded their surface water standards of 0.72 ppb and 1.5
ppb at location 33W01.

The bilge water plant spill is separate from the RI and will be investigated under the auspices
of the FDEP petroleum program. The wetlands will be investigated further in the Site 41 RI.

5 . 4 Nature and Extent of Groundwater Contamination

Shallow Groundwater

Organic contamination present in shallow groundwater consists of volatiles (chlorobenzene and
toluene), semivolatiles (dichlorobenzene isomers), and pesticides. The approximate extent of
groundwater contamination is shown in Figure 5-4. Inorganic contamination consists of heavy
metals (cadmium, chromium, and lead) and major metals (iron and manganese) for which federal
and state standards have been established. Chlorobenzene and 1,2- and 1,4-dichlorobenzene
standards were not exceeded. However, the standards for cadmium (5 ppb) and lead (15 ppb) were
exceeded in one CERCIA-sampled well (GM-71 and 13GS07) each, and the standards for iron and
manganese were consistently exceeded. Metals concentrations were below all applicable standards
in filtered aliguots.

-------
Overall, the distribution of chlorinated aromatics in the shallow groundwater suggests the
contaminant source is associated with the closed ISDBs, the drainage swale area, and the former
waste oil UST. The distribution of metals in the shallow groundwater suggests the closed ISDBs,
the swale area, the closed surge pond, and the former acid spill area as likely sources.

Intermediate Groundwater

Intermediate groundwater shows significant contaminant increases over those identified in
shallow groundwater. Contaminants include chlorinated aliphatics, 2-butanone, chlorinated
aromatics, major metals, and comparatively lower concentrations of nonchlorinated VOCs, phenols,
pesticides, and heavy metals. Of the chlorinated aliphatics, detected, standards for
tetrachloroethylene were met or exceeded in four CERCLA-sampled wells. For trichloroethene,
standards were met or exceeded in three CERCLA-sampled wells, and for vinyl chloride, standards
were exceeded in one well.

Of the chlorinated aromatics, the standards for chlorobenzene were exceeded in three
CERCLA-sampled wells (33G12, 33G16, and 33G20); for 1,2-dichlorobenzene in three wells (33G12,
33G16, and 33G20), and for 1,4-dichlorobenzene in four CERCLA-sampled wells (33G12, 33G16,
33G20, and RW-3).

For the metals, the standards for cadmium, chromium, and beryllium were exceeded in one
CERCLA-sampled well (GM-66). Of the major metals, the standards for iron and manganese were
consistently exceeded, and the standard for sodium was exceeded in several wells. Again, metals
concentrations were below applicable standards for filtered aliguots.

The overall distribution of contamination is consistent with the ISDBs, the swale area, the
former waste oil UST, the surge pond, and the former acid spill as sources. Pesticide
concentrations indicate either widespread leaching, downward migration through the shallow zone,
or sediment carrydown in drilling.

The in-place recovery system at the site has little apparent influence on the shallow
groundwater, but has had a pronounced effect on the intermediate depth. Evaluation of the data
indicates flow in the intermediate depth in the southern part of the site is influenced by RW-7
and, in the northern part by RW-3. Flow in the central part of the site, however, remains to
the east toward the bay, and may allow offsite contaminant migration.

Deep Groundwater

Heavy metals and major metals concentrations in the deep well sampled were similar to those of
intermediate depth. The standard for sodium was exceeded, reflecting saltwater influence.

5.5 Fate and Transport

5.5.1 Sources of Contamination

Areas of soil contamination were identified at the former ISDBs, the swale area, and at the
former waste oil UST. SVOCs, including chlorinated benzenes and PAHs, as well as PCBs and
metals, were detected in this area, with lesser phenol, pesticide, and cyanide concentrations.
A second area of elevated contamination relative to surrounding areas can be found in a broad
and ill-defined region including the former surge pond (boring 33S12), the present surge tank
(33S11), and the former waste line breach area (33S10) . The principal soil contaminants in this

-------
area include PAHs, pesticides, and PCBs. The potential for contaminant migration is expected to
be greatest in these areas.

Soil pesticide concentrations average less than 20 ppb and do not exceed 1,000 ppb at any
location; therefore, based on soil-phase partitioning, it is expected little pesticide mass is
available for leaching. Soil SVOC concentrations were nondetect to less than 500 ppb over 90%
of the study area, based on sample data. However, SVOC concentrations were detected in excess
of 1 part per million (ppm) in the former ISDBs and swale area, at the former waste oil UST, and
around the former surge pond, present surge tank, and historic waste line breach. In these
limited areas, leaching of SVOCs may threaten underlying water-bearing zones. Metals
concentrations in soil were generally low except in the swale area, as well as in some isolated
areas with lower (but significant) concentrations. The greatest threat to underlying
water-bearing zones is in these areas.

5.5.2 Contaminant Migration

Leaching from Soil to Groundwater

Contamination identified in soil of the former ISDBs, swale area, former waste oil UST, former
surge pond, surge tank, and waste line breach area may enter groundwater by three mechanisms:
1) contaminants may be leached from the soil by downward percolation of rainwater toward the
water table, 2) into groundwater through direct continual contact with groundwater either from
contaminant horizons identified at normal water table, or 3) from seasonally submerged soil
during periods of elevated water table. Soil at the IWTP in general is very permeable,
resulting in guick infiltration and minimal contact time between percolating water and soil
above the water table.

Soil in the swale area, however, is fill material of sands and appreciable silts with
discontinuous zones of clayey material. Permeability of this soil would be substantially lower
than elsewhere at the study area, resulting in longer contact time with percolating water.
Shallow monitoring wells around and downgradient of the former ISDBs and swale area exhibited
relatively low to nondetect concentrations of metals and most organics, except chlorinated
benzenes. The swale area including 33G01 is in the area of highest soil contamination. These
high contaminant concentrations were recorded during an unusually wet season with percolation of
rainwater through the contaminated soil. The resultant concentrations in shallow groundwater
suggest the contaminated soil is releasing chlorinated benzenes at rates substantial enough to
cause a detectable impact on groundwater, but other contaminants may be more tightly retained.

Soil contamination at the water table exists as black oily horizons around the site of the
former waste oil UST and around the southern portion of the former ISDBs and as a darkened
horizon around the surge tank and former surge pond. Detected concentrations in Areas A, B, C,
and D exceed Florida leachability values protective of groundwater. The contaminated soil may
be continuously or seasonally in contact with shallow groundwater, allowing for maximum contact
time for leaching. Low to nondetect concentrations in RCRA-sampled wells, downgradient of and
adjacent to the former surge pond, and GM-8, downgradient and near the black oily horizon
around the southern portion of the ISDBs, do not indicate any appreciable leaching of
contaminants from their respective horizons at the water table. CERCLA well 33G02 shows
chlorinated benzenes, suggesting groundwater and/or rainwater percolation may be leaching
contaminants from the black oily horizon around the former waste oil UST.

The compound classes of PAH semivolatiles, pesticides, and PCBs are generally considered to
have limited to very limited potential for migration due to their low solubility and high
affinity for soil particles and organic carbon. Physical analyses on soil samples from the
swale area and near the former surge pond indicate total organic carbon contents of 480 and 470

-------
milligrams per kilogram (mg/kg) dry weight, respectively. The potential for metals migration
depends highly on pH, redox potential, and cation exchange capacity of the bearing soil. Cation
exchange capacities measured on soil from the two contaminant sources in guestion are at 3.9
meg/lOOg in the swale area and 5.2 meg/lOOg near the former surge pond. The very low metal and
PAH concentrations, extremely low pesticide concentrations, and nondetected concentrations of
PCBs suggest soil across the site, and possibly the oily organic-rich material in the swale
area, is retaining these compounds by sorption processes.

Surface Water Transport

The generally high soil permeabilities around the IWTP limit any substantial transfer of
contamination via surface water flow. Although the site was investigated during an unusually
wet winter, overland flow was not observed. The southern drainage ditch surface waters seem to
collect by seepage or storm water culvert discharge from the surrounding industrially used land,
including the IWTP, the bilge water treatment plant, the helicopter rotor-testing facility, and
the former Chevalier Field. Although water was not flowing in these ditches, it is possible
that accelerated seepage during heavy rains may produce some surface water movement.
Contaminants transfer from soil to surface water by the same leaching processes discussed above
under soil-to-groundwater pathways, mediated by groundwater guality characteristics.

Contaminant transport within the drainage ditch surface water has been investigated by the
hydrologic study and southern drainage ditch sampling. The ditch surface waters were determined
to be more a surface expression of groundwater than a conduit for surface water transport; any
migration of water and contaminants within the ditch is probably related to groundwater flow
velocities. The impact of OU 10 on the Southern Drainage Ditch and area wetlands will be
further evaluated during the Site 41, NAS Pensacola Wetlands, RI.

Groundwater Transport

Groundwater analytical results indicate contaminants are migrating with groundwater flow.
Contaminant concentrations are evaluated around and hydraulically downgradient of the former
ISDBs, downgradient of the surge tank, by the former waste oil UST, and at 33G15. Based on
potentiometric measurements, groundwater contamination is migrating laterally east from the
former ISDBs/swale area and the former waste oil UST, and north/northwest from the present
surge tank. Two recovery wells at the heart of the former ISDBs and the swale area
contamination apparently have not prevented or reversed the eastward migration of contaminated
groundwater from the area. However, they are influencing flow in the southern and northern
portions of the IWTP yard. Downward vertical hydraulic gradients between shallow and
intermediate groundwater depths, eguivalent in magnitude to lateral gradients, indicate a strong
tendency for downward contaminant migration in conjunction with lateral movement. Elevated
contaminant concentrations at intermediate depth may be a conseguence of this downward flow
component.

Upward vertical hydraulic gradients between deep and intermediate groundwater depths, together
with the presence of a 12- to 15-foot-thick, low-permeability clay layer between the two, may
preclude any downward contaminant migration into the deep groundwater. Contaminant
concentrations, historically found in deep wells soon after installation and nondetect later,
indicate these trace contaminants were introduced while installing deep wells.

The groundwater contaminant migration rate is conservatively estimated to egual groundwater
velocity. Based on groundwater velocities, the rate of contaminant movement from the former
ISDBs and swale area toward well pair 33G05 and 33G12 (east of the ISDBs) is expected to average
approximately 0.54 feet/day in shallow groundwater, and approximately 0.017 ft/day in
intermediate groundwater. Groundwater contamination at well pair 33G03 and 33G08 (west of the

-------
ISDBs) is expected to flow north, away from the surge tank. Contaminated groundwater movement
at 33G15 (north of the ISDBs) is likely influenced by nearby recovery well RW-3.

Analytical results of filtered and unfiltered sample aliguots indicate that metals in
groundwater are strongly partitioned onto particulate matter. Therefore, movement of metals
contamination depends on the ability of the particulate matter to move with groundwater. High
hydrogen sulfide concentrations in groundwater may favor precipitation of metals from the
dissolved phase, further associating metal constituents with particulates or as colloidal
suspension.

Potential Receptors and Impacted Media

The primary medium impacted by site activity has been the surficial zone of the Surficial/Sand-
and-Gravel Aquifer. Shallow and intermediate monitoring wells for this zone presently and
historically have yielded impacted groundwater. Organic contaminant concentrations are lower
than when the former surge pond and ISDBs operated. The greatest impacts have been observed
around and downgradient of the former ISDBs and swale area, downgradient of the surge tank,
and at 33G15. Several chlorinated aliphatic compounds and 1,4-dichlorobenzene exceed standards
in area wells. Both impacted and unimpacted groundwater in this aguifer has been shown to be
highly turbid and contains natural iron, manganese, and sodium concentrations exceeding
standards. A large portion of the aguifer yields dark brown, highly organic pore water with an
acrid hydrogen sulfide odor. Groundwater from the surficial zone is not used nor anticipated to
be used as a potable water supply.

The surface water and sediment of Pensacola Bay and Bayou Grande are media that could
potentially be impacted by contaminated groundwater migrating from the IWTP. These coastal
waters have been classified by the FDEP as Class III waters, indicating their use for recreation
and maintaining a well-balanced fish and wildlife population. Potential impacts on these water
bodies will be addressed in upcoming RI/FSs for Bayou Grande (Site 40) and Pensacola Bay (Site
42) .

6.0 SUMMARY OF SITE RISKS

A baseline risk assessment (BRA) has been conducted for OU 10, and the results are presented in
Section 10 of the RI report. The BRA was based on contaminated environmental site media as
identified in the RI. It was conducted to assess the resulting impact to human health and
environment if contaminated soil and groundwater onsite were not remediated. Actual or
threatened releases of hazardous substances from this site, if not addressed by implementing the
response action selected in this ROD, may present an imminent and substantial endangerment to
public health or the environment.

6.1 Chemicals of Potential Concern

Substances detected at OU 10 were screened against available information to develop a list or
group of chemicals referred to as chemicals of potential concern (COPCs). The information
consists of both federal and State of Florida cleanup criteria, soil and groundwater standards,
and reference concentrations. COPCs are selected after comparison to screening concentrations
(risk-based and reference), intrinsic toxicological properties, persistence, fate and transport
characteristics, and cross-media transfer potential. Any COPC that is carried through the risk
assessment process and found to contribute to a pathway that exceeds a 10 -6 risk or hazard
index (HI) greater than 1 for any of the exposure scenarios evaluated in this risk assessment
and has an incremental lifetime cancer risk (ILCR) greater than 10 -6 or hazard quotient (HQ)
greater than 0.1 is referred to as a chemical of concern (COG). Table 6-1 summarizes COPCs for
these pathways.

-------
Surface water, sediment, and deep groundwater pathways did not produce any significant risk
levels.

Essential elements may be screened out of a risk assessment if it is shown that concentrations
detected are not associated with adverse health effects. Therefore, the following nutrients
were eliminated: calcium, iron, magnesium, potassium, and sodium.

Site operations have been converted to domestic treatment only, and there is no indication the
domestic treatment operations will be discontinued. Onsite groundwater is not being used at
present; however, it is considered a viable source of groundwater for future consumption.

6.2 Exposure Assessment

Whether a chemical is actually a concern to human health depends upon the likelihood of
exposure, i.e., whether the exposure pathway is currently complete or could be complete in the
future. A complete exposure pathway (a seguence of events leading to contact with a chemical)
is defined by the following four elements:

• Source and mechanism of release;

• Transport medium (e.g., surface water, air) and mechanisms of migration through the
medium;

• Presence or potential presence of a receptor at the exposure point; and

• Route of exposure (ingestion, inhalation, dermal absorption).
If all four elements are present, the pathway is considered complete.

All potential exposure pathways that could connect chemical sources at OU 10 with potential
receptors were evaluated. All possible pathways were first hypothesized and evaluated for
completeness using the above criteria. Current pathways represent exposure pathways that could
exist under current conditions while future pathways represent exposure pathways that could
exist, in the future, if current exposure conditions change.

6.2.1 Current Exposure

Under current land use conditions at OU 10, access to areas of concern is restricted to
authorized personnel only. The plant has been converted to domestic treatment only; however,
there are no reported plans to decommission the facility. As a result, current exposure
scenarios will continue unaltered for the foreseeable future. Potential exposures under present
land use are summarized below:

-------
Potential Exposure Scenarios - Current Conditions

Media                 Exposure Pathway                 Receptor

Soil                  Incidental Inhalation             Onsite Worker
                      Dermal Contact                  Trespasser

Surface Water           Incidental  Ingestion           Trespasser

Sediment               Incidental Ingestion            Trespasser
                      Dermal Contact

6.2.2   Future Exposure

Complete exposure pathways could exist when based on an estimate of the reasonable maximum
exposure (RME) expected to occur under future conditions.  Although unlikely, it is assumed that
OU 10 may be developed as a residential area, which could also provide reasonable opportunities

for recreational activities.  If so, future residents could be exposed to soil via incidental
ingestion and dermal contact routes of exposure associated with living in the area.  Potential
exposures for future land use are summarized below:

Potential Exposure Scenarios - Future Conditions

Media              Pathway                      Receptors

Soil               Incidental Ingestion           Site Resident
                   Dermal Contact

Groundwater         Ingestion                   Site Resident
                   Inhalation

Surface Water     Incidental Ingestion            Site Resident
                                              (Recreational Use)

Sediment            Incidental Ingestion          Site Resident
                   Dermal Contact                 (Recreational Use)

Exposure Point Concentration

Exposure point concentrations for each COG and exposure assumptions for each pathway were
used to estimate chronic daily intakes  (GDIs) for potentially complete pathways.  GDIs were then
used in conjunction with cancer potency factors and noncarcinogenic reference doses to evaluate
risk.

The 95th percentile for reported concentrations of COCs in each media evaluated were calculated
as exposure point concentrations for the RME in each exposure scenario.  Exposure point
concentrations are summarized in Table 6-2.

-------
                                    Table 6-2
                         Exposure Point Concentrations
                                         Exposure Point Concentrations
    Media and Chemical
Frequency of
    Detection
                                                              RME
                                                                           Background
Soil  (mg/kg)

Aluminum
Arsenic
Cadmium
Chromium
Manganese
Titanium
Yttrium
PCB-1260
trans-Nonachlor
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b,k)fluoranthene
Dibenzo(a,h)anthracene
Indeno(1,2,3-cd)pyrene
Bis (2-chloroethyl)ether
    17/18
       3/18
       7/18
      17/18
      18/18
       9/9
       4/9
       5/17
        1/9
         1/18
        1/18
         4/18
         1/18
         2/18
          1/18
17500
                 3833
3.5
23
910
537
53
1.85
0.405
0.0062
7.5
6.2
7
1.4
4.8
0.83
1.6
N/A
6.2
21.4
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Shallow/Intermediate Groundwater  (mg/L)
1,1-Dichloroethane
1,2-Dichlorobenzene
1,2-Dichloroethene  (total)
1,3-Dichlorobenzene
1,4-Dichlorobenzene
2,4-Dichlorophenol
Acenaphthene
       10/27
       11/27
       Chromium
        7/27
       11/27
        2/27
       3/27
          0.065
           1.17
          0.00276
           0.274
           0.442
          0.00153
          0.00187
N/A
N/A
N/A
N/A
N/A
N/A
N/A

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                                    Table 6-2
                         Exposure Point Concentrations
                                        Exposure Point Concentrations
    Media and Chemical
Frequency of
     Detection
                                                             RME
                                                                           Background
Aluminum
Arsenic
Benzene
Bis (2-ethylhexyl)phthalate
Cadmium
Carbon disulfide
Chlorobenzene
Chromium
Dieldrin
Hexachloroethane
Lead
Manganese
Mercury
Naphthalene
Tetrachloroethene
Trichloroethene
Vanadium
Vinyl chloride
Deep Groundwater  (mg/L)
Aluminum
Arsenic
Surface Water  (mg/L)
Aluminum
Cadmium
27/27
13/27
1/27
1/27
1/27
4/27
15/27
14/27
4/27
1/27
13/27
27/27
16/27
2/27
3/27
4/27
8/27
1/27
1/1
1/1
4/4
1/4
8.66
0.0077
0.0016
0.00804
0.01094
0.0023
0.3208
0.01905
0.000003
0.001083
0.006352
0.19341
0.000624
0.00781
0.00731
0.0017
0.02172
0.00321
11.8
0.0048
1.28
0.0052
3.82
N/A
N/A
N/A
0.0096
N/A
N/A
0.0325
N/A
N/A
N/A
0.022
N/A
N/A
N/A
N/A
0.007
N/A
N/A
N/A
N/A
N/A

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                                    Table 6-2
                         Exposure Point Concentrations
                                        Exposure Point Concentrations
    Media and Chemical

Manganese
4,4'-DDD
Heptachlor epoxide

Sediment  (mg/kg)

Aluminum
Arsenic
Cadmium
Chromium
Freguency of
     Detection

      4/4
      2/4
        1/4
      4/4
      3/4
      2/4
      4/4
   RME

   0.28
 0.00011
0.0000013
  4150
   6.2
  34.6
  1180
Background

      N/A
       N/A
       N/A
      N/A
      N/A
      N/A
      N/A
Notes:
RME -  Reasonable Maximum Exposure
The number of samples for three non-TCL/TAL COPCs is nine rather than 18 due to the analyte list
used by USEPA Region IV BSD during supplemental sampling for OU 10 surface soil.
All results are in parts per million (ppm).
Potential future exposure scenarios included all exposures examined under current conditions.
The same exposure assumptions used to evaluate future conditions were used for current
conditions. Assumptions are listed in Table 6-3 for current land use and Table 6-4 for future
land use.

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                                   Table 6-3
                 Parameters Used to Estimate Potential Exposures
                          for Current Land Use Receptors

                                Trespassing Child

        Pathway Parameters                    Age 7-16           Onsite Worker            Units

Incidental Ingestion of Sediment/Soil

Ingestion Rate                                100  a               50 b             ing/day

Exposure Frequency                             52 c                 250  b             days/year

Exposure Duration                              10 c              25 b                     years

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                                   Table 6-3
                 Parameters Used to Estimate Potential Exposures
                          for Current Land Use Receptors
        Pathway Parameters
Trespassing Child

              Age 7-16
                                                                 Onsite Worker
                             Units
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
              45  d
             3,650 e
           25,550 f
        70 b
  9,125 e
25,550 f
                    kg
                  days
            days
Dermal Contact with Sediment/Soil
Skin Surface Area
Adherence Factor
Absorption Factor
Exposure Frequency
            3,950  g
                1  h
                CSV
                52 c
4,100 g
         1 h
         CSV
       250 b
           cm 2
               mg/cm 2
              unitless
             days/year
Dermal Contact with Sediment/Soil
Exposure Duration
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
               10  c
              45  d
             3,650 e
           25,550 f
        25 b
        70 b
     9,125 e
    25,550 f
                 years
                    kg
                  days
                  days
Incidental Ingestion of Surface Water
Ingestion Rate
Exposure Time
Exposure Frequency
Exposure Duration
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
             0.05  a
              2.6  a
               52 c
               10  c
              45  d
              3,650 e
           25,550 f
       NA
NA
NA
NA
NA
NA

NA
liters/hour
  hours/day
  days/year
      years
       kg
       days
       days
Notes:
a- USEPA  (1989) Risk Assessment Guidance for Superfund Vol. I, Human Health Evaluation Manual
   (Part A) .
b - USEPA  (1991) Risk Assessment Guidance for Superfund Vol. I, Human Health Evaluation Manual
    Supplemental Guidance, "Standard Default Exposure Factors," Interim Final, Office of Solid
    Waste and Emergency Response (OSWER) Directive:  9285.6-03.
c - Assumes a trespass scenario of an adolescent age 7-16 with an exposure duration of 10 years
    and a exposure frequency of 52 days per year.
d - Adolescent body weight is the average value for the range of body weights for boys and girls
    ages 7-16 taken from USEPA  (1990) Exposure Factors Handbook, USEPA/600/8-89/043.
e - Calculated as the product of ED  (years)  x 365 days/year.
f - Calculated as the product of 70 years (assumed lifetime) x 365 days per year.
g - Skin surface area (i.e.,  worker - head,  forearms and hands) provided by USEPA Region 4.  For
trespassing children, skin surface area was computed as 25% of the age group mean total body
surface per Dermal Guidance.
h - Specific guidance from USEPA Region 4 (February 11, 1992 New Interim Region 4 Guidance).
NA - Not applicable
CSV -  Chemical-specific value

-------
                                     Table 6-4
                   Parameters Used to Estimate Potential Exposures
                            for Future Land Use Receptors
       Pathway Parameters

Incidental Ingestion of Soil

Ingestion Rate
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
                                       Resident Adult
  100 a
   350 b
   24 c
    24 c
  70 a
  8,760 d
25,550 e
                  Resident  Child
   200 a
   350 b
     6 a
     6 a
    15 a
 2,190 d
25,550 e
                       Units
         mg/day
      days/year
          years
          years
              kg
           days
           days
Dermal Contact with Soil
Skin Surface Area
Adherence Factor
Absorption Factor
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer

Drinking Water Ingestion

Ingestion Rate
Exposure Frequency
Exposure Duration
4,100 f
i g
CSV
350 b
24 c
24 c
70 a
8,760 d
25,550 e
2,000 f
i g
CSV
350 b
6 a
6 a
15 a
2,190 d
25,550 e
      2  e
   350 b
    24 c
  1 a
   350 b
     6 a
                                                  cm 2
                                               mg/cm 2
                                              unitless
                                             days/year
                                               years
                                                 years
                                                    kg
                                                  days
                                                  days
liters/day
      days/year
       years

-------
                                     Table 6-4
                  Parameters Used to Estimate Potential Exposures
                            for Future Land Use Receptors
        Pathway Parameters

Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
  Resident Adult

    24 c
  70 a
  8,760 d
25,550 e
     Resident Child

        6 a
  15 a
    2,190 d
25,550 e
       Units

      years
          kg
       days
       days
Inhalation of Volatilized Groundwater Constituents
Ingestion Rate
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
Incidental Ingestion of Sediment
Ingestion Rate
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
2 a
350 b
24 c
24 c
70 a
8,760 d
25,550 e
17 h
104 i
24 c
24 c
70 a
8,760 d
25,550 e
1
350
6
6
15
2,190
25,550
34
140
6
6
15
2,190
25,550
a
b
c
c
a
d
e
h
i
c
c
a
d
e
                                               m 3/day
                                                days/year
                                                    years
                                                    years
                                                       kg
                                                     days
                                                     days

                                                   mg/day
                                                days/year
                                                    years
                                                    years
                                                       kg
                                                     days
                                                 days
Dermal Contact with Sediment
Skin Surface Area
Adherence Factor
Absorption Factor
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
 .100 f
    1 g
    CSV
   104 i
   24 c
    24 c
  70 a
    2,000  f
        1 g
       CSV
      140  i
        6 c
        6 c
       15 a
       cm 2
    mg/cm 2
unitless
  days/year
       years
      years
         kg

-------
Table 6-4
Parameters Used to Estimate Potential Exposures
for Future Land Use Receptors
Pathway Parameters

Averaging Time-Noncancer
Averaging Time-Cancer

Incidental Ingestion of Surface Water

Ingestion Rate
Exposure Time
Exposure Frequency
Exposure Duration
Exposure Duration LWA
Body Weight
Averaging Time-Noncancer
Averaging Time-Cancer
Resident Adult

8,760 d
25,550 e
0.05 a
2.6 a
104 i
24 c
24 c
70 a
8,760 d
25,550 e
Resident Child

2,190 d
25,550 e
0.05 a
2.6 a
140 i
6 c
6 c
15 a
2,190 d
25,550 e
Units
days
days
liters/hour
hours/day
days/year
years
years
kg
days
days
Notes:
a - USEPA (1989) Risk Assessment Guidance for Superfund Vol. I, Human Health Evaluation Manual
(Part A).
b - Assumes a residential exposure frequency of 365 days per year with one two-week vacation.
c - USEPA (1991), Risk Assessment Guidance for Superfund Vol. I, Human Health Evaluation
Manual (Part B, Development of Risk-based Preliminary Remediation Goals), OSWER Directive
9285.7-01B.
d - Calculated as the product of ED (years) x 365 days/year.
e - Calculated as the product of 70 years (assumed lifetime) x 365 days per year.
f - Skin surface area (i.e., adult resident - head, forearms and hands; child resident - head,
arms, hands, and legs) provided by USEPA Region 4.
g - Specific guidance from USEPA Region 4 (February 11, 1992 New Interim Region 4 Guidance).
h - Values for sediment ingestion rate are based on a soil ingestion rates of 100 milligrams
per day for adults and 200 milligrams per day for children and a recreational exposure
time of 2.6 hours per day (over a 16-waking hour day.)
i - Recreational exposure frequency assumed to be 104 days per year for adults and 140 days
per year for children.
NA - Not applicable.
CSV - Chemical-specific value.
LWA - Lifetime Weighted Average

-------
6.3 Toxicity Assessment

A cancer slope factor (CSF) and a reference dose (RfD) are applied to estimate risk of cancer
from an exposure and the potential for noncarcinogenic effects to occur from exposure. CSFs
have been developed by USEPA's Carcinogenic Assessment Group for estimating excess lifetime
cancer risk associated with exposure to potentially carcinogenic contaminants of concern. CSFs
which are expressed in units of (mg/kg/day) -1, are multiplied by estimated intake of a
potential carcinogen in mg/kg/day, to provide an upper-bound estimate of the excess lifetime
cancer risk associated with exposure at that intake level. The term "upper-bound" reflects the
conservative estimate of risk calculated from the CSF. Use of this approach makes
underestimation of actual cancer risk highly unlikely. CSFs are derived from the results of
human epidemiological studies or chronic animal bioassays to which animal-to-human extrapolation
and uncertainty factors have been applied.

This increased cancer risk is expressed by terms such as 1E-6. To state that a chemical
exposure causes a 1E-6 added upper limit risk of cancer means that if 1,000,000 people are
exposed, one additional incident of cancer is expected to occur. The calculations and
assumptions yield an upper limit estimate which assures that no more than one case is expected
and, in fact, there may be no additional cases of cancer. USEPA policy has established that an
upper limit cancer risk falling below or within the range of 1E-6 to 1E-4 is acceptable.

RfDs have been developed by USEPA for indicating the potential for adverse health effects from
exposure to COCs exhibiting noncarcinogenic effects. RfDs, which are expressed in units of
mg/kg/day, are estimates of lifetime daily exposure levels for humans, including sensitive
individuals, that are likely to be without risk of an adverse affect. Estimated intakes of COCs
from environmental media (e.g., amount of COCs ingested from contaminated groundwater) can be
compared to the RfD. RfDs are derived from results of human epidemiological studies or chronic
animal bioassays to which animal-to-human extrapolation and uncertainty factors have been
applied (e.g., to account for use of animal data to predict effects on humans). If the
estimated exposure to a chemical expressed as mg/kg/day is less than the RfD, exposure is not
expected to cause any noncarcinogenic effects, even if exposure is continued for a lifetime. In
other words, if the estimated dose divided by the RfD is less than 1.0, there is no concern for
adverse noncarcinogenic effects.

Exposure point concentrations and toxicity potency factors used to calculate human health risk
are summarized in Table 6-5.

-------
                                      Table 6-5
        lexicological Database Information for Chemicals of Potential Concern
     Chemical

Acenaphthene
Aluminum
Arsenic
Benzene
Benzo(a)anthracene a
Benzo(a)pyrene g

Benzo(b)fluoranthene g

Benzo(k)fluoranthene g

Beryllium

Bis(2-chloroethyl)ether

Bis(2-ethylhexyl)phthalate

Cadmium (food)
Cadmium (water)
Carbon disulfide
Chlorobenzene
Chromium
Copper
1,1-Dichloroethane
1,2-Dichlorobenzene
1,2-Dichloroethene (total)
1,3-Dichlorobenzene
    Oral
Reference Dose
   (mg/kg/day)
      Inhalation
Reference Dose
      (mg/kg/day)
TEF
                Cancer
            Classification
0.06 a
1 d
0.0003 a
ND
ND
ND

ND

ND

0.005 a

ND

0.02 a

0.001 a
0.0005 a
0.1 a
0.02 a
0.005 a
0.0371 b
0.1 b
0.09 a
0.009 b
0.089 d
ND
ND
ND
0.00171 e
ND
ND

ND

ND

ND

ND

ND

ND
ND
0.0029 b
0.00571 c
ND
ND
0.143 c
0.04 c
ND
ND
NA
NA
NA
NA
0.1
1

0.1

0.01

NA

NA

NA

NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
ND
A
A
B2
Oral Reference Dose
(mg/kg/day)
Oral Reference Dose
(mg/kg/day)
Oral Reference Dose
(mg/kg/day)
Oral Reference Dose
(mg/kg/day)
Oral Reference Dose
(mg/kg/day)
Oral Reference Dose
(mg/kg/day)
D/B1
D/B1
D
C
A(inh)
D
D
ND
ND
ND

-------
                                      Table 6-5
        lexicological Database Information for Chemicals of Potential Concern
     Chemical

1,4-Dichlorobenzene

2,4-Dichlorophenol
4,4'-DDD

Dibenz(a,h)anthracene a

Dieldrin

Heptachlor epoxide
Hexachloroethane
Indeno(1,2,3-cd)pyrene g
Lead
Magnesium
Manganese
Mercury
Naphthalene
PCB Aroclor-1260
Tetrachloroethene
Thallium b
Titanium
Trichloroethene
Vanadium
Vinyl chloride
Yttrium
trans-Nonachlor
                                 Oral
                             Reference Dose
      Inhalation
Reference Dose
                                                                                            Cancer
(mg/kg/day)
ND

0.003 a
ND

ND

0.00005 a

0.000013 a
0.001 a
ND
ND
0.014
0.005 a
0.0003 b
ND
0.00007 e
0.01 a
0.00008 a
ND
0.006 e
0.007 b
ND
ND
ND
(mg/kg/day)
0.229 e

ND
ND

ND

ND

ND
ND
ND
ND
ND
0.0000143 a
0.0000857 b
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
TEF
NA

NA
NA

1

NA

NA
NA
0.1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Classification
Oral Reference
(mg/kg/day)
D
Oral Reference
(mg/kg/day)
Oral Reference
(mg/kg/day)
Oral Reference
(mg/kg/day)
B2
C
B2
Bl
ND
D
D
D
B2
C
ND
ND
B2
D
A
ND
ND

Dose


Dose

Dose

Dose

-------
Notes:
a     -       Integrated Risk Information System (IRIS)
b      -      Health Effects Assessment Summary Tables (HEAST).
c      -      HEAST alternative method
d      -      Other USEPA documents including USEPA,  Region 3's  "Risk-based Screening
            Concentrations Table, Third Quarter 1994. July 1994."
e      -      USEPA Environmental Criteria and Assessment Office - Cincinnati
g      -      The oral and inhalation cancer potency factors of  7.3 and 6.1 [(mg/kg/day)-1],  for
            benzo(a)pyrene, respectively, were used for all other PAHs.  As reported in the
            Exposure Assessment Section of the risk assessment,  toxicity eguivalency factors
              (TEFs)  were applied to carcinogenic PAHs to convert their concentrations to an
            eguivalent concentration of benzo(a)pyrene.
h      -      The oral reference dose for thallium carbonate was substituted for thallium.
ND     -      Not determined due to lack of information in available toxicological databases.
NA     -      Not applicable or available.
A      -      Sufficient evidence in epidemiologic studies to support casual association between
            exposure and cancer
Bl     -      Limited evidence in epidemiological studies
B2     -      Sufficient evidence from animal studies
C      -      Limited evidence from animal studies and inadeguate or no data in humans
D      -      Inadeguate or no human and animal evidence of carcinogenicity
E      -      No evidence of carcinogenicity in at least two adeguate animal tests in different
            species or in adeguate epidemiologic and animal studies

-------
6.4 Risk Characterization

For carcinogens, risk is estimated as the incremental probability of an individual developing
cancer over a lifetime as a result of exposure to the carcinogen. Excess life time cancer risk
is calculated from the following eguation:

RISK = GDI X CSF
where:
risk = a unit less probability (e.g., 2 x 10 -5) of an individual developing cancer

GDI = chronic daily intake averaged over 70 years (mg/kg-day)

CSF = slope factor, expressed as (mg/kg-day) -1

These risks are probabilities that are generally expressed in scientific notation (e.g., 1X10 -6
or IE - 6). An excess lifetime cancer risk of 1 X 10 -6 indicates that, as a reasonable maximum
estimate, an individual has a one in 1,000,000 chance of developing cancer as a result of
site-related exposure to a carcinogen over a 70-year lifetime under specific exposure conditions
at OU 10.

The potential for noncarcinogenic effects is evaluated by comparing an exposure level over a
specified time (e.g., lifetime) with a reference dose derived for a similar exposure period.
The ratio of exposure to toxicity is called an HQ. By adding the HQs for all COCs that affect
the same target organ within a medium or across all media to which a given population may
reasonably be exposed, the HI can be generated.

The HQ is calculated as follows:

Noncancer HQ = CDI/RfD
where:
GDI = Chronic Daily Intake

RfD = Reference Dose

GDI and RfD are expressed in the same units and represent the same exposure period
(i.e., chronic, subchronic, or short-term).

To evaluate estimated cancer risks, a risk level lower than 1x10 -6 is considered a minimal or
de minimis risk. The USEPA accepts a risk range of 1x10 -6 to 1x10 -4 before a response action
is reguired. However, the State of Florida does not accept risk greater than 1x10-6. A risk
level greater than 1x10 -6 is evaluated further to determine a remedial action to decrease the
estimated risk to acceptable levels.

An HI of less than unity (1.0) indicates the exposures are not expected to cause adverse health
effects. An HI greater than one (1.0) reguires further evaluation. For example, although HQs
of the several chemicals present are added and exceed 1.0, further evaluation may show that
their toxicities are not additive because each chemical affects different target organs. When
total effects are evaluated on an effect and target organ basis, the HI of the separate
chemicals may be at acceptable concentrations.

-------
Carcinogenic risks and noncarcinogenic hazards were evaluated for potential exposures to
media-specific COCs in surface soil, surface water, surface sediment, and groundwater.   Receptor
populations were potentially exposed workers, trespassers, and future residents who could,
theoretically, use groundwater for a household water source.  Risks and hazards for the
identified COCs are summarized in Table 6-6.

Estimated potential exposure to COCs in surface water or sediment did not result in unacceptable
carcinogenic risk or noncarcinogenic hazard.  Current site workers and potential child
trespassers did not have an individual pathway or combined single medium pathway with an HI in
excess of 0.6 or an ILCR greater than 2E-6.  The cross-pathway HI and cancer risk for these two
receptor types were also within the acceptable carcinogenic risk range.  These projections
indicate that neither group is at significant risk of deleterious health effects resulting from
RME to all media.

These receptor groups do not warrant further consideration.

-------
                                    Table 6-6
            Risk and Hazard for Identified COCs and Pathways of Concerns
                                                                Potential Future Land Use
                   Chemical
Resident Adult
       HI
Resident Child
           HI
Resident Iwa
          ILCR
Soil Ingestion Pathway
Chromium  (as VI)
Aluminum
Benzo(a)pyrene
Dibenz(a,h)anthracene
     0.2
    0.023
     ND
      ND
           2.3
           0.224
           ND
                      ND
             ND

            3.50e-06
            8.00e-07
Soil Ingestion Pathway Hazard
Soil Ingestion Pathway Risk
Soil Dermal Contact Pathway
Chromium
Benzo(a)pyrene
Dibenz(a,h)anthracene
Soil Dermal Contact Hazard
Soil Dermal Contact Risk
    0.1
     ND
      ND
       0
           0.1
           ND
           ND
                           0
                                          4.00e-06
             ND
            1.40e-06
            3.10e-07
                                                                                            2.00e-06
Shallow/Intermediate Groundwater Ingestion Pathway
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Aluminum
Arsenic
      0.4
      0.08
      0.1
    0.24
    0.7
           0.8
           0.2
           0.1
           0.55
           1.7
             ND
             ND
             1.60e-04
             ND
             2.00e-04

-------
                                         Table 6-6
                Risk and Hazard for Identified COCs and Pathways of Concerns

                                                   Potential Future Land Use
                      Chemical
                                 Resident Adult
                                        HI
Resident Child
       HI
Resident Iwa
     ILCR
Bis(2-ethylbexyl)phthalate                          0.01
Cadmium  (water)                                       0.6
Chlorobenzene                                         0.4
Chromium                                              0.1
Manganese                                             1.06
Mercury                                               0.06
Tetrachloroethene                                     0.02
Vinyl chloride                                        ND
Shallow/Intermediate Groundwater Ingestion Hazard     4
Shallow/Intermediate Groundwater Ingestion Risk

Shallow/Intermediate Groundwater Inhalation pathway
                                                        0.03
                                                          1.4
                                                          1
                                                          0.24
                                                          2.47
                                                          0.13
                                                          0.1
                                                          ND
                                                          9
                       1.67e-06
                         ND
                         ND
                         ND
                         ND
                         ND
                       5.70e-06
                       9.10e-05

                       5.00e-04
1,2-Dichlorobenzene
1,3-Dichlorobenzene
                                                          1.9
                                                          0.2
                         ND
                         ND
Shallow/Intermediate Groundwater Inhalation Pathway
1,4-Dichlorobenzene
Chlorobenzene
Tetrachloroethene
Vinyl chloride
Shallow/Intermediate Inhalation Hazard
Shallow/Intermediate Inhalation Risk
0.1
1.5
0.02
ND
2
0.1
3.6
0.05
ND
6
1.60e-04
ND
2.21e-07
1.40e-05

                                                                          2.00e-04
Deep Groundwater Ingestion Pathway
Aluminum
Arsenic
Deep Groundwater Ingestion Hazard
                                        0.1
                                        0.4
                                        1
       0.2
       1
       1
       ND
     1.25e-04
Notes:
HI
Lwa
ILCR
ND
Hazard Index
Lifetime Weighted Average
Incremental Lifetime Cancer Risk
Not/detected

-------
6.5
       Soil Performance Standards for Groundwater Protection
The potential for groundwater contamination due to site COCs was also assessed by comparing
constituent concentrations in soil with guidance concentrations protective of groundwater (as
identified in FDEP's Soil Cleanup Goals).   These values were used because they are more
conservative estimates for groundwater protection than USEPA values.  These concentrations are
"to be considered" (TBC)  criteria for the site.  Nineteen COCs were identified as exceeding
guidance concentrations when soil concentrations were compared to leaching criterion:
Type A

Chlorobenzene
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Bis(2-ethythexyl)phthalate (BEHP)
Naphthalene
Type C

Benzo(a)pyrene
Phenanthrene
Pentachlorophenol
Bis(2-chloroethyl)ether
                                        Type B

                                        Xylene
                                        Phenol
                                        Acenaphthene
                                        Dieldrin
                                             Endosulfan
                                        Acetone
                                        DDE
                                        DDT
                                        alpha-BHC

Type A constituents were defined as those exceeding Florida guidance concentrations for
leachability in soil and promulgated maximum contaminant levels (MCLs)  or Florida guidance
concentrations in groundwater.  Type A compounds in groundwater (except BEHP) are
concentrated beneath and east (downgradient) of Sites 32 and 33; these compounds are targeted
by the RCRA groundwater recovery system, as they were present in RCRA units at Sites 32
and 33.  Soil containing these compounds (except for BEHP)  is adjacent to or east of Sites 32
and 33.  Because of this, it is not possible to distinguish between groundwater contamination
attributable to soil contamination or the former RCRA units.  For this reason, FDEP
leachability-based guidance concentrations for Type A constituents have been retained as site
COCs for developing PRGs.   (BEHP, a common laboratory contaminant, is not expected to be present
in site soil, and therefore has not been retained as a site COG.)

Type B compounds were present in both soil and groundwater.  They exceeded Florida guidance
concentrations for leachability in soil, but were below MCLs or Florida guidance concentrations
in groundwater.  Type B compounds are present in soil above FDEP guidance concentrations at
various locations at OU 10, primarily single-boring detections; contaminant mass associated with
these detections is expected to be low.  The spatial distribution of Type B compounds in
groundwater does not necessarily correlate with soil borings containing soil contamination above
FDEP leachability-based guidance concentrations.  However,  groundwater contamination associated
with these compounds is also concentrated primarily beneath Site 32 and is being addressed by
the RCRA groundwater recovery system.  Because groundwater monitoring is reguired as part of the
RCRA groundwater recovery program, Type B constituents were not included in developing
site-specific PRGs.

Type C compounds were present in soil at concentrations exceeding Florida guidance
concentrations for leachability in soil, but not detected in groundwater. The spatial
distribution of Type C compounds in soil above FDEP guidance concentrations is limited to
primarily single-boring detections; contaminant mass associated with these detections is
expected to be low.

Because these compounds are not impacting groundwater, and ongoing groundwater monitoring is
reguired under the RCRA groundwater recovery program, these compounds were not included in
developing site-specific PRGs.

-------
The State of Florida considers these TBC criteria applicable to OU 10.

6.6 Risk Uncertainty

The following areas of uncertainty were associated with the estimation of chemical uptake from
exposure to groundwater.

Exposure scenarios based on USEPA guidance use conservative assumptions, which means actual risk
will not be greater than the estimate and may be lower. For this reason, estimated cancer risks
based on USEPA guidance, such as these presented in this document, may not represent actual
risks to the population.

Because of data set limitations, the 95th percentile may exceed the maximum concentration
reported in some evaluations. This may occur when there are a large number of nondetects and
the detection limits are unusually high due to interferences in the analyses. In these cases,
consistent with USEPA Region IV guidance, the maximum reported values were used as exposure
point concentrations to estimate human exposures. Although use of maximum values is generally
recognized as an appropriate screening approach, it should be recognized that this procedure may
overestimate actual exposure.

This is also the case for use of detection limits as nondetect values when a chemical has been
reported as not detected in most of the samples collected and analyzed. Since some nondetects
may be zero, assuming that a concentration equal to half the detection limit is present instead
of zero may overestimate actual chemical concentrations onsite. This is particularly true if
interfering chemicals affect the analyses and the nondetect value is elevated.

Environmental sampling and analysis can contain significant errors and artifacts. At this site,
data are believed to adequately and accurately represent current conditions.

When long-term health effects are evaluated, it is assumed that chemical concentrations are
constant for the exposure period being evaluated. This may not be accurate since reported
chemical concentrations are changing due to various degradation processes (i.e., dilution by
uncontaminated water, sorption, dispersion of contaminated groundwater, volatilization,
biodegradation, chemical degradation, and photo degradation). Use of steady-state conditions
will likely overestimate exposure.

Exposures to vapors and dust at the site, dermal contact with groundwater from household uses
other than bathing (i.e., laundry, washing dishes), and other possible exposures to surface soil
and surface water were not evaluated. Although these and other exposures could occur, magnitudes
of these exposures are expected to be much lower than exposures evaluated, and would not
quantitatively affect the total health impact from the site.

Since groundwater in the surrounding area is not used for drinking water or for other household
water needs, exposures related to drinking and bathing are theoretical and relate to potential
future exposures. This is unlikely since the domestic treatment plant is still operating and
the area will remain industrial.

The following are uncertainties associated with estimation of risks:

In hazard and risk evaluations, risks or hazards presented by several chemicals reported for the
same exposure have been added to provide a sum of estimated total risk or hazard for that
particular exposure. This is a conservative assumption and is scientifically accurate only in
those instances where health effects of individual chemicals are directed at the same effect and
same target organ. Effects may be additive, synergistic, or antagonistic. Since a large number

-------
of chemicals have no similarity as to their noncarcinogenic action or target of their action,
this approach may overestimate risk.

Risks calculated from slope factors are derived using a linearized multistage procedure;
therefore, they are likely to be conservative upper-bound estimates. Actual risks may be much
lower.

There is a degree of uncertainty regarding the RfD for manganese in the groundwater ingestion
scenario. There is currently a debate whether it is appropriate to separate exposures from food
and water as currently done by Integrated Risk Information System (IRIS) for some chemicals and,

in particular, for manganese and some other inorganics. Due to the high degree of uncertainty
associated with the present RfD of 0.005 mg/kg/day for manganese, the RfD determination is
scheduled for USEPA review. The current USEPA RfD for manganese in water of 0.005 mg/kg/day was
used to evaluate risks concerning manganese drinking water intake.

6.7 Human Health Risk Summary

Risk and/or hazard associated with exposure to all environmental media (and combinations) was
within USEPA's generally acceptable ranges for both current site workers and potential current
child trespassers.

For an unlikely hypothetical future site resident, exposure media were shown to exceed
acceptable residential goals. These media included surface soil, shallow/intermediate
groundwater, and deep groundwater.

Surface Soil RGOs

Table 6-7 provides remedial goal options (RGOs) for the combined surface soil pathway (ingestion
and dermal contact). The RGOs for benzo(a)pyrene and dibenz(a,h)anthracene apply to the
identified hot spot. Remediating soil in the limited area will reduce potential human health
risk to below acceptable goals.

Shallow/Intermediate Groundwater RGOs

Table 6-8 provides RGOs for the combined shallow/intermediate groundwater pathways (ingestion/
inhalation exposures). Arsenic, chromium, hexachloroethane, and mercury are below corresponding
applicable or relevant and appropriate regulations (ARARs) which may influence remediation
concentrations deemed necessary. Arsenic and cadmium, which account for greater than 30% of the
hazard, may be associated with saltwater intrusion. Manganese is considered to be associated
with natural geology.

-------
                                                             Table 6-7
                                 Remedial Goal Options for Surface Soil  (0 to 1 foot depth interval)
                 Carcinogenic Risk-Based RGOs
                           Risk Goal
                                                Hazard-Based RGOs
                                        Hazard Quotient Goal
                     Risk-Based
Reference     screening
       Chemical

Aluminum

Chromium VI

Chromium III

Benzo(a)pyrene

Dibenzo(a,h)anthracene
1E-04 IE-OS 1E-06 10
NA
NA
NA
126
126
NA
NA
NA
13
13
NA
NA
NA
1.3
1.3
744898
3724
744898
NA
NA
1
74490
372
74490
NA
NA
Unadjusted Concentration Value soil soil
0.1 EPC (mg/kg) (mg/kg) (mg/kg) Source Hi-child Risk-Lwa
7449
37
7449
NA
NA
17500
910
910
6.2
1.4
3833 3700
6.1 39
6.1 7800
NA 0.088
NA 0.088
RBCr 0.2349315
RBCr
RBCr
RBCr 0
RBCr 0
0
2.4432877

4.9E-06
1.109E-06
Notes:
NA
ND
RBCr

EPC
  Indicates an RGO was not applicable for this chemical under risk and/or hazard-based conditions.
  Indicates the chemical was not detected in reference (background)  surface soil samples.
  Indicates the risk (1E-6)  or hazard (HQ = 0.1)  based screening value as presented in USEPA Region 3,  "Risk-Based Screening Concentration Tables",
March 18, 1994.
  Exposure Point Concentration
No risk-based RGOs were calculated for the combined soil pathway  (ingestion and dermal) because the combined risk was computed to be < 1E-4.
Noncarcinogenic hazard-based RGOs were computed on the future child site resident scenario with combined ingestion and dermal exposure  (where applicable).
Carcinogenic risk-based RGOs were computed based on the future site resident lifetime weighted average scenario with combined ingestion and inhalation exposure
(where applicable).
The RGO for trivalent chromium is approximately 200 times that of hexavalent chromium.

-------
                       Carcinogenic Risk-Based RGOs
                                                  Table 6-8
                         Remedial Goal Options for Shallow/Intermediate Groundwater

                                            Hazard-Based RGOs Hazard Goal
          Chemical

1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Aluminum
Arsenic
Benzene
Bis(2-ethylhexyl)phthalate
Cadmium
Chlorobenzene
Chromium
Hexachloroethane
Manganese
Mercury
Tetrachloroethene
Vinyl Chloride
l.OOe-04
              l.OOe-05
                            l.OOe-06
                                            10
                                                               0.1
EPC (mg/L)
NA
NA
1.40e-01
NA
38E-03
1.10e-01
4.80e-01
NA
NA
NA
2.40e-01
NA
NA
1.20e-01
0.0031


1.

3.
1.
5.



2.


1.
3.
NA
NA
OOe-02
NA
8E-04
OOe-02
OOe-02
NA
NA
NA
OOe-02
NA
NA
20e-02
10e-04


1.

3,
1.
4,



0,


1.
0,
NA
NA
.4E-03
NA
.8E-05
.14E-03
.78E-03
NA
NA
NA
.00244
NA
NA
.20e-03
.000031
4.
6.
17.
156
0.
0.
3.
0.
0.
0.
0.
0.
0.
0.
35
96
92
.40
05
24
11
08
70
78
08
78
05
78
0.
0.
1.
15
0.
0.
0.
0.
0
0.
0.
0.
0.
0.
NA
435
696
792
.64
005
024
311
008
.07
078
008
078
005
078
NA
0
0
0
1
0.
0
0
0.
0
0
0
0
0.
0

.043
.070
.179
.564
0005
.002
.031
0008
.007
.008
.001
.008
0005
.008
NA
1.17
0.274
0.442
8.66
0.0077
0.0016
0.008
0.011
0.321
0.0191
0.0011
0.193
0.000624
0.0073
0.00321
  Reference
Concentration
   (mg/L)

     NA
     NA
     NA
    3.82
     NA
     NA
     NA
   0.0096
     NA
   0.0325
     NA
    0.022
     NA
     NA
     NA
ARAR  (mg/L)   Source
0.6
0.01
0.075
0.2
0.05
0.001
0.006
0.005
0.1
0.1
0.01
0.05
0.002
0.003
0.001
FPDWS
FSDWS-OL
FPDWS
FSDWS-OL
FPDWS
FPDWS
FPDWS
FPDWS
FPDWS
FPDWS
FDWS-C
FSDWS
FPDWS
FPDWS
FPDWS
Notes:
NA  -  Indicates an RGO was not applicable for this chemical under risk and/or hazard-based conditions.
ND  -  Indicates the chemical was not detected in reference (background)  wells.
Noncarcinogenic hazard-based RGOs were computed based on the future child site resident scenario with combined ingestion and inhalation exposure  (where
applicable).
Carcinogenic risk-based RGOs were computed based on the future site resident lifetime weighted average scenario with combined ingestion and inhalation exposure
(where applicable).
FPDWS  -      Means Florida Primary Drinking Water Standard.
FSDWS-OL-     Indicates Florida secondary drinking water standard.
FDWS-C -      Indicates Florida guidance concentration based on carcinogenicity.
*      -     Indicates the inhalation pathway was not considered in establishing RGOs.
EPC    -     Exposure Point Concentration
mg/L   -     miligrams per liter

-------
Deep Groundwater RGOs

The RGOs for deep groundwater pathway are provided in Table 6-9. Each COG is potentially
related to saltwater intrusion and/or suspended sediment in samples. The arsenic concentration
is below its corresponding ARAR.

6.8 Ecological Considerations

Ecological risk was assessed to determine actual or potential effects of contamination at OU 10
to ecological receptors such as plants and animals. This assessment focused on both land at OU
10 and contamination in groundwater discharging to nearby surface water bodies. Potential
impacts to wetlands near OU 10 and the southern drainage ditch will be evaluated during the Site
41, NAS Pensacola Wetlands, RI. Potential impacts to Pensacola Bay (Site 42) and Bayou Grande
(Site 40) from groundwater contaminants will be assessed during RIs at those sites. Risk from
soil north of the IWTP is limited to metals in surface soil. Risk associated with concentrations
present is most likely minimal. Because the IWTP is industrial and there is considerable human
activity, wildlife habitat is absent and avian and terrestrial wildlife are not drawn to the
site. Contact with soil would be limited to animals traveling across the area only. Therefore,
soil contaminant concentrations identified do not present an unacceptable risk to the
environment.

An initial groundwater study was conducted to evaluate whether ecological effects occur from
contaminated groundwater discharging into surface water bodies. The only organic compound
detected in shallow groundwater that may possibly impact ecological receptors in surface water
was dieldrin. Metals that could potentially affect ecological receptors include: cadmium,
chromium, lead, mercury, and zinc. All contaminants will be studied further during the
Pensacola Bay, Bayou Grande, and NAS Pensacola Wetlands investigations.

-------
    Chemical

  Aluminum*

  Arsenic*
                                                                         Table 6-9
                                                      Remedial Goal Objectives for Deep Groundwater

                                                    Noncarcinogenic Hazard-Based RGOs  (mg/L)
                                                               Hazard Index Goal
               Carcinogenic Risk-Based RGOs Risk Goal
l.OOe-04

   NA

 4E-03
 IE-OS

  NA

4E-04
 1E-06

  NA

4E-05
 10

 NA

0.05
                     Exposure Point
                      Concentration
 1          0.1         (mg/L)

 NA          NA          11.8

0.005      0.0005       0.0048
  Reference
Concentration
  (mg/L)

     ND

     ND
  ARAR
 (mg/L)       Source

0.05-0.2   FSDWS/SMCL

   0.05     FPDWS/SMCL
Notes:
NA        -   Indicates in RGO was not applicable for this chemical under risk and/or hazard-based conditions.
ND        -   Indicates the chemical was not detected in reference (background)  wells.
FSDWS     -   Means Florida Secondary Drinking Water Standard,  SMCL means Secondary Maximum Contaminant Levels
*         -   Indicates the inhalation pathway was not considered for deep groundwater COCs in establishing RGOs.
mg/L      -   milligrams per liter
Noncarcinogenic hazard-based RGOs were computed based on the future child site resident scenario with combined ingestion and inhalation exposure  (where
applicable).
Carcinogenic risk-based RGOs were computed based on the future site resident lifetime weighted average scenario with combined ingestion and inhalation exposure
(where applicable).

-------
7.0 DESCRIPTION OF THE REMEDIAL ALTERNATIVES

The OU 10 FFS report presented the results of the detailed analysis of four potential remedial
action alternatives. These alternatives have been developed to provide a range of remedial
actions for the site. This section of the ROD summarizes the four alternatives that are
described in the FFS report, which include:

• No action with continued groundwater treatment under the RCRA program;

• Institutional controls with groundwater treatment under the RCRA program modified to
meet CERCLA reguirements;

• Capping with groundwater treatment under the institutional controls alternative; and

• Excavation with groundwater treatment under the institutional controls alternative.

Four remedial action alternatives were developed to address contaminated groundwater and soil
and various areas of concern (AOCs) within OU 10. Performance standards are defined in Section
9. The AOCs were identified by comparing media-specific contaminant concentrations detected at
OU 10 to media-specific remediation goals developed in the FFS. The AOCs identified for OU 10
include:

• Contaminated soil above performance standards

• Contaminated soil above FDEP leachability guidance (TBCs)

• Contaminated groundwater above performance standards

Figure 7-1 shows the general location of the above-mentioned AOCs for soil and groundwater.
Table 7-1 summarizes the remedial objectives for soil. A concise description of how each
alternative will address contamination at OU 10 as well as estimated cost follows.

-------
        Objective

Eliminate human health
risk above 1x10 -6 for
residential land use.

Protect groundwater from
leachable compounds.
                           Table 7-1
                 Soil Remedial Objectives

                                Contaminated Media

     Location                  Estimated Volume  (CY)

West of closed ISDBs  (Area A)                    185
Swale  (Area B)
Swale  (Area C)
North of operations building
(Area D)
130
270
370
        Rationale

         Benzo(a)pyrene and
   dibenz(a,h)anthracene
above risk levels

Chlorinated benzenes and
naphthalene above
performance standards

-------
7.1 Alternative 1: No Action

Capital Cost: $0
Annual Operation and Maintenance (O&M) Costs: $0
Net Present Worth $0

The National Oil and Hazardous Substances Pollution Contingency Plan (NCP) requires
consideration of a no-action alternative to serve as a baseline against which other alternatives
are compared. In the no-action alternative, no further action will be taken to contain, remove,
or treat soil contaminated above risk- or leachability-based performance standards. Recovered
groundwater will continue to be treated and disposed at the wastewater treatment plant in
accordance with the RCRA permit.

Health risks for the future resident will remain and no chemical-specific ARARs will be met.
This alternative does not meet the effectiveness criterion as it does not reduce future child
exposures to benzo(a)pyrene and dibenz(a,h)anthracene.

7.2 Alternative 2: Institutional Controls

Capital Cost: $130,000
Annual O&M Costs: $0.00
Net Present Worth: $130,000

During the RD/RA period after the ROD is issued, a leachability study will be conducted to
demonstrate whether contaminants in soil above Florida cleanup goals are contributing
significantly to groundwater contamination onsite. If the leachability study demonstrates that
groundwater is being impacted by soil contaminants, Alternative 4 is the contingency remedy and
the capital costs of the alternative would increase by $247,000 to a total of $377,000.

Institutional controls will maintain industrial use and limit exposure to contaminated
groundwater.

This alternative eliminates risk to potential child residents by not allowing the site to be
residential. In addition, the Navy will meet the groundwater performance standards.
Modification of the RCRA corrective action groundwater treatment system will include the
groundwater performance standards as a permit requirement. Attainment of standards will be
confirmed through groundwater monitoring. Because the RCRA system is operating and can be
modified to meet the performance standards for groundwater onsite, no other alternatives for
groundwater are evaluated.

7.3 Alternative 3: Capping

Capital Cost: $79,000
Annual O&M Costs (for 30 years): $6,000
Net Present Worth: $185,000

In the capping alternative, all four areas will be capped with asphalt. Caps will reduce risk
of contact with contaminated soil and reduce quantity of leachate generated when rainwater
filters through contaminated soil. The present worth cost of this alternative is estimated at
$185,000, assuming 30 years of maintenance.

-------
7.4 Alternative 4: Excavation with Offsite Disposal

Area A Excavation with Offsite Disposal $56,500
Area B Excavation with Offsite Disposal $47,850
Area C Excavation with Offsite Disposal $66,550
Area D Excavation with Offsite Disposal $76,100
Total Capital Cost: $247,000

Annual O&M Costs: $0
Net Present Worth: $247,000

In the excavation and offsite disposal alternative, soil exceeding PRGs will be removed from
OU 10 and disposed at an approved Subtitle D landfill to remove all current and future threats
to human health and the environment posed by soil contamination. This alternative will provide
for unrestricted land use at OU 10. Soil will be sampled at the excavation extent to verify
that soil remaining meets performance standards. The excavation will be backfilled with clean
soil.

Total costs presented above for the four area removals are $247,000 including engineering
services/report preparation, and contingency costs. The cost estimate supplied by the Navy for
engineering services/report preparation is $100,000. Dewatering may be reguired during removal
activities. Short-term dewatering costs are expected to be $10,000 per week for eguipment
rental and operation.

7.5 Applicable or Relevant and Appropriate Reguirements (ARARs)

The remedial action for OU 10, under CERCLA Section 121(d), must comply with federal and
state environmental laws that are either applicable or relevant and appropriate. Applicable
reguirements are those standards, criteria, or limitations promulgated under federal or state
law that specifically address a hazardous substance, pollutant, contaminant, remedial action,
location, or other circumstance at a CERCLA site. Relevant and appropriate reguirements are
those that, while not applicable, still address problems or situations sufficiently similar to
those encountered onsite that their use is well-suited to the particular site. TBC criteria are
nonpromulgated advisories and guidance that are not legally binding, but should be considered in
determining the necessary level of cleanup to protect health or the environment.

The affected groundwater in the aguifer beneath OU 10 has been classified by USEPA and Florida
as Class IIA and G-l, a source of drinking water. It is Florida and USEPA's policy that
groundwater resources be protected and restored to their beneficial uses. A complete definition
for USEPA's groundwater classification is provided in the Guidelines for Groundwater
Classification under the EPA Groundwater Protection Strategy, Final Draft, December 1986.
Florida groundwater classification is defined in Chapter 62-520, Groundwater Classes, Standards,
and Exemptions.

While TBCs do not have the status of ARARS, the approach to determining whether a remedial
action is protective of human health and the environment involves considering TBCs along with
ARARs.

Location-specific ARARs are restrictions placed on the concentration of hazardous substances or
the conduct of activities solely on the basis of location. Examples of location-specific ARARs
include state and federal reguirements to protect floodplains, critical habitats, and wetlands,
along with solid and hazardous waste facility siting criteria. Table 7-2 summarizes the
potential location-specific ARARs for OU 10.

-------
                                                Table 7-2
                                   Potential Location-Specific ARARs

                            Location                                      Citation

TBC      Several wetlands on Magazine Point fit the        Executive Order 11990
         definition of a wetland                           Wetlands Protection Policy

R&A      Sets forth minimum requirements for design,       RCRA Location Requirements
         construction, and operation for RCRA              40 CFR 264.18(c)
         facilities within a 100-year floodplain

Notes:
R&A    -      Relevant and appropriate requirements which while they are not  "applicable" to a hazardous
            substance, pollutant, contaminant,  remedial action, location,  or other circumstance at OU 10,
            address problems or situations sufficiently similar to those encountered at this site that their use is
            well-suited.
TBC    -      To-Be-Considered Criteria are nonpromulgated advisories and guidance that are not legally binding,
            but should be considered in determining the necessary level of cleanup for protection of health or
            the environment.
CFR    -      Code of Federal  Regulations

-------
Action-specific ARARs are technology- or activity-based requirements or limitations on actions
taken with respect to hazardous wastes.  These requirements are triqqered by the particular
remedial activities that are selected to accomplish a remedy.  Since there are usually several
alternative actions for any remedial site, various requirements can be ARARs.  Table 7-3 lists
potential action-specific ARARs and TBCs for the selected and continqency soil remedy for
OU 10.

                                                Table 7-3
        Potential Action-Specific ARARs for the Selected Remedy and Contingent Remedial Action

                          Location                                      Citation

Clean Water Act - 33 U.S.C. °° 1251-1376

 R&A       40 CFR Part 131 - Ambient Water          Ambient water standards for the protection of human
          Quality Criteria                         health and aquatic life.

 R&A      40 CFR Part 122, 125, 129, 136 -         Requires permits for the discharqe of pollutants for any
          Clean Water Act Discharqe Limits         point source into waters of the United States.
          NPDES Permit, 40 CFR 403.5 -
          Pretreatment Standards

-------
Table 7-3
Potential Action-Specific ARARs for the Selected Remedy and Contingent Remedial Action
Location

Clean Water Act - 33 U.S.C. °° 1251-1376

R&A 40 CFR Part 141 National Primary
Drinking Water Standards

Resource Conservation and Recovery Act - 42 U.S.C.
Citation
Specifies sampling, analytical, and monitoring
reguirements for public water systems.

00 6901-6987
R&A 40 CFR Part 261 - Identification &
Listing of Hazardous Wastes

R&A 40 CFR Part 262 - Standards
Applicable to Generators of Hazardous
Waste
Characterization of hazardous waste.
General reguirements for identifying and managing
hazardous wastes and manifest reguirements for
hazardous wastes
R&A 40 CFR Part 263 - Standards
Applicable to Transporters of
Hazardous Waste
Establishes standards which apply to transporting
hazardous waste within the U.S., if reguired under 40
CFR 262.
R&A 40 CFR Part 264 - Standards for
Owners and Operators of Hazardous
Waste Treatment, Storage, and
Disposal Facilities

R&A 40 CFR 268 - RCRA Land Disposal
Restrictions.

R&A 49 CFR Parts 107 and 171-179 -
Department of Transportation Rules
for the Transport of Hazardous
Substances.
Establishes minimum national standards which define the
acceptable management of hazardous wastes for owners
and operators of facilities which treat, store, or dispose
of hazardous wastes.

Certain classes of waste are restricted from land disposal
without acceptable treatment.

Regulates the labeling, packaging, and transportation of
solid and hazardous wastes offsite.

-------
Clean Air Act - 42 U.S.C. °° 7401-7642
 R&A     40 CFR Part 50 - National Primary
         and Secondary Ambient Air Quality
         Standards
                                      Establishes standards for ambient air quality to protect
                                     public health and welfare.
State of Florida Regulation

 R&A     FAC Title 62 Chapter 62-4
         Florida Rules on Permits

 R&A     Florida Hazardous Substance Release
         Notification
                                     Establishes requirements and procedures for all
                                     permitting.

                                     Establishes notification requirements for hazardous
                                     substance releases.
 R&A     Florida Hazardous Waste Rules
         Title 62 Chapter 62-730
 TBC     Well Permits
                                     Establishes standards for generators,  and transporters of
                                      hazardous wastes,  and owners and operators of hazardous
                                     waste facilities,  outlining permitting requirements.

                                     Establishes local criteria for design and installation of
                                     monitoring wells.
Notes:
R&A
TBC
Relevant and appropriate requirements which,  while they are not "applicable" to a hazardous
  substance,  pollutant,  contaminant,  remedial action,  location,  or other circumstance  onsite,  address
  problems  or situations sufficiently similar to those encountered at OU 10  that  their use  is  well-suited
to the site.
To-Be-Considered Criteria are nonpromulgated advisories and guidance that are not legally binding,
  but should  be considered in determining the necessary level  of cleanup for protection of  health or
the environment.

-------
Chemical-specific ARARs are specific numerical quantity restrictions on individually listed
chemicals in specific media. Examples of chemical-specific ARARs include the MCLs specified
under the Safe Drinking Water Act as well as the ambient water quality criteria that are
enumerated under the Clean Water Act. Since there are usually numerous chemicals of concern
for any remedial site, various numerical quantity requirements can be ARARs. Table 7-4 lists
potential chemical-specific ARARs for OU 10.
Table 7-4
Potential Chemical-Specific ARARs
Citation
Location
Clean Water Act - 33 U.S.C. °° 1251-1376

A 40 CFR Part 131 - Ambient Water Quality
Criteria
Suqqested ambient standards for the protection of
human health and aquatic life.
Resource Conservation and Recovery Act - 42 U.S.C. °° 6901-6987

R&A
40 CFR Part 261 - Identification and
Listinq of Hazardous Wastes
Defines solid wastes subject to regulation as
hazardous wastes under 40 CFR Parts 263-265 and
Parts 124, 270, and 271.
R&A
40 CFR Part 262 - Standards Applicable to Establishes standards for qenerators of hazardous
Generators of Hazardous Waste waste.
Clean Air Act - 42 U.S.C. °° 7401-7642
R&A 40 CFR Part 50 - National Primary and
Secondary Ambient Air Quality Standards
Safe Drinkinq Water Act - 40 U.S.C.
300
R&A 40 CFR Part 141 - National Primary
Drinkinq Water Standards

R&A PL No. 99-339 100 Stat. 462 (1996) -
Maximum Contaminant Level Goals
(MCLGs)
Establishes standards for ambient air quality to
protect public health.
Establishes MCLs which are health-based standards
for public water systems.

Establishes drinkinq water quality qoals set at
levels of no known or anticipated adverse health
effects with an adequate marqin of safety.

-------
State of Florida Regulations

   A
 Florida Water Quality Standards
Title 62 Chapter 62-3
   A       Florida Surface Water Standards Title 62
            Chapter 62-301 and 62-302

   A       Florida Groundwater Classes, Standards,
           and Exemptions Chapter 62-520

   A       Florida Drinking Water Standards,
           Monitoring and Reporting
           Title 62 Chapter 62-550

    A        Florida Ambient Air Quality Standards
   TBC       Florida Soil Cleanup Goals
 Establishes minimum water guality criteria for
groundwater.

        Establishes  water guality standards for all  waters  of
 the state.

Establishes protective minimum criteria for state
groundwater.

Establishes MCLs for drinking water,  and
secondary reguirements.
                                              Establishes standards for ambient air guality to
                                                  protect public health.

                                              Establishes cleanup concentrations for contaminants
                                                      in Florida soil.
Notes:
A
R&A
  Applicable reguirements promulgated under law to specifically address a hazardous substance,
    pollutant,  contaminant,  remedial  action location,  or other circumstance  at  OU 10.

    Relevant and appropriate reguirements  which,  while they are not  "applicable"  to a  hazardous
    substance,  pollutant,  contaminant,  remedial action,  location,  or other circumstance  at  OU 10,
    address  problems  or situations  sufficiently similar to those encountered at OU 10  that  their use  is
    well-suited to OU 10.
TBC
    To-Be-Considered Criteria are  nonpromulgated advisories  and guidance  that  are  not  legally binding,
    but should be  considered in determining the  necessary level of cleanup  for protection of  health or
    the environment.

-------
8.0     COMPARATIVE ANALYSIS OF ALTERNATIVES

This section of the ROD provides the basis for determining which alternative provides the best
balance with respect to the statutory balancing criteria in Section 121 of CERCLA, 42 U.S.C.
Section 9621, and in the NCP,  40 Code of Federal Regulations, Section 300.430.  The major
objective of the FFS was to develop, screen, and evaluate alternatives for remediating OU 10.  A
variety of alternatives and technologies were identified as candidates to remediate
contamination at OU 10.  These were screened based on their feasibility with respect to the
contaminants present and site characteristics.  After the initial screening, the remaining
alternatives/technologies were combined into potential remedial alternatives and evaluated in
detail.  The remedial alternative was selected from the screening process using the following
nine evaluation criteria:

•      Overall protection of human health and the environment;

•      Compliance with applicable and/or relevant federal or state public health or environmental
       standards;

•      Long-term effectiveness and permanence;

•      Reduction of toxicity,  mobility,  or volume of hazardous  substances or contaminants;

•      Short-term effectiveness or the impacts a remedy might have on the community,  workers,
       or the environment during the course of implementation;

•      Implementability, that  is, the administrative or technical capacity to carry out the
       alternative;

•      Cost-effectiveness considering costs for construction, operation,  and maintenance of the
       alternative over the life of the project,  including additional costs should it fail;

•      Acceptance by the state; and

•      Acceptance by the community.

The NCP categorizes the nine criteria into three groups:

•      Threshold Criteria - Overall protection of human health and the environment and
       compliance with ARARs (or invoking a waiver)  are threshold criteria that must be
       satisfied in order for  an alternative to be eligible for selection;

•      Primary Balancing Criteria - Long-term effectiveness and permanence; reduction of
       toxicity, mobility,  or  volume; short-term effectiveness; implementability;  and cost are
       primary balancing factors used to weigh major trade-offs among alternative  hazardous
       waste management strategies; and

•      Modifying Criteria - State and community acceptance are  modifying criteria  that are
       formally taken into account after public comments are received on the proposed plan and
       incorporated in the ROD.

The selected alternative must meet the threshold criteria and comply with all ARARs or be
granted a waiver for compliance with ARARs.  Any alternative that does not satisfy both of these
reguirements is not eligible for selection.  The Primary Balancing Criteria are the technical
criteria upon which the detailed analysis of alternatives is primarily based.  The final two

-------
criteria, known as Modifying Criteria, assess the acceptance of the alternative.

The following analysis summarizes the evaluation of alternatives for remediating OU 10 under
each criterion. Each alternative is compared for achievement of a specific criterion.

8.1 Threshold Criteria

All alternatives considered for selection must comply with the threshold criteria, overall
protection of human health and the environment, and compliance with ARARs.

8.1.1 Overall Protection of Human Health and the Environment

This criterion evaluates, overall, the degree of protectiveness afforded to human health and the
environment. It assesses the overall adeguacy of each alternative.

The no-action alternative will not mitigate the risks associated with contamination at or
originating from OU 10. Therefore, this alternative is not protective of human health and the
environment and will no longer be discussed.

Alternative 2 will use institutional controls and a leachability study to protect human health
and the environment by maintaining industrial use. If the leachability study shows that
contaminants in soil are adversely impacting groundwater, the contingency excavation remedial
action will be implemented. Groundwater will be remediated by modifying the RCRA Corrective
Action Plan to meet the performance standards listed in Section 9. This alternative protects
human health and the environment by restoring the Class IIA/G-1 aguifer and preventing any
potential migration of the contaminated plume.

Alternative 3 will protect human health by capping the contaminated areas, thus reducing the
amount of rainfall infiltrating through the contaminants. Alternative 4 will excavate the
contaminated soil, thereby providing the best and most immediate protection of human health and
the environment. Alternatives 3 and 4 will meet groundwater performance standards by modifying
the RCRA Corrective Action Plan as described under Alternative 2.

8.1.2 Compliance with ARARs

Alternatives 2, 3, and 4 will meet all of their respective ARARs. Groundwater ARARs include
MCLs and Florida drinking water standards that establish chemical-specific limits on certain
contaminants in community water systems. For Alternatives 2, 3, and 4, remedial action will
include further sampling and analysis of groundwater to ensure that groundwater beneath OU 10
will meet ARARs through groundwater treatment in a reasonable time frame. Alternatives 2, 3,
and 4 will be able to meet all federal and state standards for contaminants and proposed
actions.

8.2 Primary Balancing Criteria

8.2.1 Long-Term Effectiveness and Permanence

Alternatives 2, 3, and 4 with provide long-term effectiveness and permanence. All of these
alternatives will use treatment technologies to reduce hazards posed by contaminants in
groundwater. The selected alternative will be evaluated 5 years after implementation to
determine its effectiveness in achieving the reguired cleanup objectives.

Assuming the leachability tests indicate contamination is not moving into groundwater, the use
of institutional controls will provide long-term effectiveness and a permanent solution.

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The impermeable caps proposed under Alternative 3 will provide long-term effectiveness and
permanence in preventing the migration of water through the contaminated soil. To ensure
continued effectiveness, the caps will reguire continued maintenance and monitoring for at least
five years after performance standards were met to ensure continued effectiveness.

With the removal of contaminated soil under Alternative 4, the source will be eliminated. This
results in long-term effectiveness and a permanent cleanup. However, Alternative 4 will present
long-term liabilities associated with disposal of contaminated soil in a secure landfill or
treatment facility.

8.2.2 Reduction of Toxicity, Mobility, and Volume through Treatment

Alternatives 2, 3, and 4 will provide for groundwater remediation and treatment by modifying the
RCRA permit. Alternative 2 does not provide for soil treatment unless the leachability study
shows the contaminants are adversely impacting groundwater. Alternative 3 will reduce the
toxicity, volume, and mobility of the soil contaminants by capping the areas. Toxicity, volume,
and mobility of soil contaminants will be reduced through excavation in Alternative 4.

Therefore, Alternatives 3 and 4 (and Alternative 2 if the contingency soil excavation remedial
action is implemented) will best satisfy CERCLA's statutory preference for treatment and use of
treatment to reduce toxicity, mobility, and volume of contaminants.

8.2.3 Short-Term Effectiveness

Alternative 2 is expected to have the least short-term effectiveness because contamination is
left in place. Its effectiveness will be achieved by land use restrictions. The contingent
remedial action with Alternative 2 will ensure that if contaminants in soil are adversely
impacting groundwater, the effectiveness of Alternative 4 will be achieved.

Alternative 3 will also be effective in the short-term. Alternative 3 (capping with groundwater
treatment) will more guickly reduce the amount of contaminants leaching from soil. Alternative
4 is the most effective in the short-term by excavating the contaminated soil. The excavation
activities may impose risks by disturbing the contaminants in soil; however, it is not expected
to pose unacceptable short-term environmental or health hazard which cannot be controlled.

The installation of groundwater wells in each alternative or as reguired in the RCRA permit
modification may impose risks by disturbing the contamination in the soil or groundwater;
however, it is not expected to pose unacceptable short-term environmental or health hazards
which cannot be controlled.

8.2.4 Implementability

Alternative 2 is the simplest to implement and operate. Alternatives 3 and 4 are more
technically difficult to implement. Alternative 4 reguires offsite disposal of contaminated
soil at regulated offsite facilities. Implementation of groundwater treatment is the same for
Alternatives 2, 3, and 4.

8.2.5 Cost

Cost details are provided in the FFS and are summarized in Table 8-1. Alternative 2,
institutional controls, has the lowest present worth cost and Alternative 4, excavation, has the
highest. Alternative 4 is significantly more expensive because of the transportation and
disposal costs for the contaminated soil. Alternative 3 costs are higher than Alternative 2
because of the maintenance reguired on the asphalt caps. The contingency remedial action in

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Alternative 2 includes the treatment costs associated with Alternative 4; however,  it is
expected that the leachability study will show that the contaminants in soil are not adversely
impacting the groundwater.  Alternative 2 provides for the best ratio of costs to benefit
received through the permanent reduction of risk to human health and the environment.  A
comparison of the estimated costs indicates Alternative 2 is the most cost effective means of
achieving the permanent reduction of risk to human health and the environment at OU 10.

8.3     Modifying Criteria

8.3.1   State Acceptance

The State of Florida has concurred with the remedy selected for OU 10.

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    Alternative
                                           Table 8-1
                               Cost Comparison for Alternatives
           Direct and Indirect Costs
                                                  Annual O&M Costs
                                                                      Total Net Present Worth
Alternative 1
                            None
                                                         None
                                                                               None
Alternative 2

Alternative 3

alternative 4
          Area A
          Area B
          Area C
          Area D
                 $130,000 b

                 $102,000 b

                 $247,000 b
                  $56,500
                  $47,850
                  $66,550
                  $76,100
 None

$6,000

 None
$130,000 a,b

$185,000 b

$247,000 b
 $56,500
 $47,850
 $66,550
 $76,100
Notes:
Net present worth costs, where appropriate, were calculated using a 6% discount rate over 30
years.
a - If the leachability study determines that threats to groundwater are unacceptable, present
    worth costs may increase to $377,000 (including Alternative 4 costs).
b - This includes cost estimates of engineering services/report preparation  ($50,000 for
     Alternatives 2 and 3, $100,000 for Alternative 4) that were supplied by the Navy.
 i.3.2
Community Acceptance
Based on comments expressed at the February 27, 1996, public meeting and receipt of written
comments during the comment period, it appears that the Pensacola community generally agrees
with the selected remedy.  Specific responses to issues raised by the community can be found in
Appendix B, the Responsiveness Summary.
9.0
        THE SELECTED REMEDY
Based upon consideration of the reguirements of CERCLA, the NCP, the detailed analysis of
alternatives and public and state comments, the Navy has selected two components of the
preferred alternative  (e.g., leachability study on Areas B, C, and D with excavation as a
contingency and groundwater treatment under RCRA)  and a component of Alternative 4  (e.g.,
excavation of Area A).   At the completion of this remedy, the risk associated with OU 10 will be
protective of human health and the environment.

The selected alternative for OU 10 is consistent with the reguirements of Section 121 of CERCLA
and the NCP.  The selected alternative will reduce the mobility, toxicity, and volume of
contaminated groundwater onsite.  In addition, the selected alternative is protective of human
health and the environment, will attain all federal and state ARARs, is cost-effective, and uses
permanent solutions to the maximum extent practicable.

Based on the information available at this time, the remedy represents the best balance among
the criteria used to evaluate remedies.  The remedy is believed to be protective of human health
and the environment, will attain ARARs, will be cost-effective, and will use permanent solutions
and alternative treatment technologies or resource recovery technologies to the maximum extent
practicable.

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9.1
        Source Control
Source control remediation will address removing contaminated soil onsite and preventing
potential migration of soil contaminants to groundwater.  Source control shall include
excavation and disposal of contaminated soil from Area A, a leachability study on Areas B, C,
and D to verify that contaminants in soil are not adversely impacting groundwater, and
groundwater remediation under the RCRA Corrective Action Plan permit modification.

The major components of source control to be implemented include:

•      Excavation and disposal of Area A.

•      Leachability study on Areas B,  C,  and D.

•      The Navy will consider reguiring a contingency remedial action,  as discussed in
      Alternative 4, if the leachability study indicates that the contaminants in soil are
      adversely impacting groundwater.  Soil excavation will extend until contaminant
      concentrations are  below the performance standards listed in Table 9-1 or below
      concentrations determined to be protective of groundwater during the leachability study.

                                            Table 9-1
                                Performance Standards for Soil
         Contaminant
Benzo(a)pyrene
Dibenz(a,h)anthracene
Chlorobenzene
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Naphthalene
                                            Performance Standards
1,
1,

5,



300
300
600
800
400
900
100
a
a
b
b
b
b
b
Notes:
a
Calculated value based on an acceptable risk or a HQ of 1 assuming combined ingestion
and skin contact with the soil.  It is assumed that a resident child eats 200 milligrams
per day of soil and has 2,000 cm 2 of exposed skin and is exposed for 350 days a year
for six years and weighs 33 pounds (15 kilograms).
Exceedance of Florida leachability value protective of groundwater to below the drinking
water standards.

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9.2
Groundwater Treatment and Monitoring
Groundwater remediation and monitoring will be implemented at OU 10 to treat contaminated
groundwater and to prevent movement of contamination to nearby surface water bodies as
determined during the remedial design developed in the Corrective Action Plan for the RCRA
permit modification.  The major components of groundwater remediation/monitoring to be
implemented include:

•      Implementation of a groundwater remediation system that meets performance standards
       listed in Table 9-2.  The remedial design for groundwater treatment will be developed in
       the Corrective Action Plan for the RCRA permit modification.

•      Groundwater monitoring will continue at sampling intervals established during the remedial
       design developed in the Corrective Action Plan for the RCRA permit modification.   The
       groundwater monitoring program will continue until a five-year review concludes that the
       alternative has continuously attained the performance standards and remains protective of
       human health and the environment.

                                      Table 9-2
                           Performance Standards for Groundwater
         Contaminant
1.2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Benzene
Bis (2-ethyhexyl)phthalate
Cadmium
Chlorobenzene
Hexachloroethane
Tetrachlorothene
Vinyl chloride
                                             Performance Standards (ppb)
                                                      100
                                                       10
                                                      600 a
                                                       10 b
                                                       75 a
                                                        1 a
                                                        6 a
                                                        5 a
  a
  b
3 a
1 a
Notes:
a   -   Florida Primary Drinking Water Standard or MCL, whichever is lower.
b   -   Florida Guidance Concentration based on carcinogenicity or organoleptic thresholds.
N/A -   Not applicable

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9.3
Extraction, Treatment, and Discharge of Contaminated Groundwater Performance Standards
Groundwater shall be remediated until the maximum concentrations listed in Table 9-3 are
attained at the wells designated during the design as compliance points. These parameters are
indicator contaminants that encompass the area of standard exceedances for groundwater.

Table 9-3
Performance Standards for Groundwater
Contaminant
1,2-Dichlorobenzene
1,3-Dichlorobenzene
1,4-Dichlorobenzene
Chlorobenzene
Performance Standards
600 a
10 b
75 a
100 a
(ppb)
Notes:
a - Florida Primary Drinking Water Standard or MCL, whichever is lower.
b - Florida Groundwater Guidance Concentration for organoleptic thresholds.

9.4 Compliance Testing

Groundwater shall be monitored in accordance with the Corrective Action Plan for the RCRA
permit modification.

10.0 STATUTORY DETERMINATIONS

Under CERCLA Section 121, 42 U. S.C. ° 9621, the Navy must select remedies that are protective
of human health and the environment, comply with ARARs (unless a statutory waiver is justified),
are cost-effective, and use permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable. In addition, CERCLA prefers
remedies employing treatment that permanently and significantly reduces the volume, toxicity, or
mobility of hazardous wastes as its principal element. The following sections discuss how the
selected remedy at OU 10 meets these statutory reguirements.
10.1
Protection of Human Health and the Environment
The selected remedy with contingency protects human health and the environment by eliminating,
reducing, and controlling risk through soil excavation as delineated through performance
standards described in Section 9. Contaminated groundwater will be treated to meet the
performance standards through remediation under the RCRA permit modification.
10.2
Attainment of the ARARs
Remedial actions performed under CERCLA, Section 121, 42 U.S.C. ° 9621 must comply with
all ARARs. All alternatives considered for OU 10 were evaluated based on the degree to which
they comply with these reguirements. The selected remedy with contingent remedial action of
Areas B, C, and D meets or exceeds identified ARARs.

The selected remedy with contingent remedial action meets or exceeds ARARs identified in
Tables 7-2, 3, and 4. The following is a short narrative in support of attainment of the
pertinent ARARs.

Chemical-Specific ARARs

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Groundwater restoration performance standards identified as MCLs are the groundwater protection
standards set in this ROD as performance standards for remedial action.

Action-Specific ARARs

Performance and treatment standards are consistent with RCRA ARARs identified in Table 7-3, and
these regulations will be incorporated into the design and implementation of this remedy. All
groundwater treatment standards will be met as per the RCRA permit.

Location-Specific ARARs

Performance standards are consistent with ARARs identified in Tables 7-2.

Waivers

Section 121 (d)(4)(C) of CERCLA, 42 U.S.C. ° 9621(d)(4)(c), provides that an ARAR may be waived
when compliance is technically impracticable from an engineering perspective.

Other Guidance to be Considered

Other guidance TBCs include health-based advisories and guidance. TBCs have been used in
estimating incremental cancer risk numbers for remedial activities at the sites and in
determining RCRA applications to contaminated media. TBCs for OU 10 include Guidelines for
Groundwater Classification under the EPA Groundwater Protection Strategy, Final Draft, December
1986.

10.3 Cost-Effectiveness

The Navy believes the selected remedy will eliminate risk to human health at an estimated cost
of $186,500. If soil contamination is adversely affecting groundwater, soil excavation costs
for Areas B, C, and D will be $190,500 for a potential total cost of $377,000.

10.4 Use of Permanent Solutions to the Maximum Extent Practicable

The Navy, with USEPA and Florida concurrence, has determined that the selected remedy represents
the maximum extent to which permanent solutions and treatment technologies can be used in a
cost-effective manner for final remediation at OU 10 at NAS Pensacola. Of those alternatives
that are protective of human health and the environment and comply with ARARs, the Navy, with
USEPA and Florida concurrence, has determined that this selected remedy provides the best
balance of trade-offs in terms of long-term effectiveness and permanence; reduction in toxicity,
mobility, or volume achieved through treatment; short-term effectiveness; implementability; and
cost, while also considering the statutory preference for treatment as a principal element and
consideration of state and community acceptance. The selected remedy will satisfy the statutory
preference for treatment of Area A and will satisfy the statutory preference for treatment of
Areas B, C, and D if the contingency remedial action is implemented. The selected remedy
provides for long-term effectiveness and permanence; is easily implemented; reduces toxicity,
mobility, or volume; and is cost-effective.

10.5 Preference for Treatment as a Principal Element

The selected remedy with contingency uses treatment technologies to the extent practicable. The
statutory preference for remedies that employ treatment as a principal element is satisfied.

11.0 DOCUMENTATION OF SIGNIFICANT CHANGES

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The proposed plan for OU 10 released in February 1996 identified Alternative 2, Institutional
Controls, with Alternative 4, Excavation and Disposal, as a contingency as the preferred
alternative.  The Navy has evaluated the alternative and has determined that it prefers the land
have unrestricted use.  The final remedy combines two components of the preferred alternative
(e.g., leachability study on Areas B, C, and D with excavation as a contingency and groundwater
treatment under RCRA)  and a component of a different alternative (e.g., excavation of Area A)
presented in the FS report and proposed plan.

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                                       Appendix A
                                        Glossary

This glossary defines terms used in this record of decision describing CERCLA activities.  The
definitions apply specifically to this record of decision and may have other meanings when used
in different circumstances.

ADMINISTRATIVE RECORD:  A file that contains all information used by the lead agency to make its
decision in selecting a response action under CERCLA.  This file is to be available for public
review and a copy is to be established at or near the site, usually at one of the information
repositories.  Also a duplicate is filed in a central location, such as a regional or state
office.

AQUIFER:  An underground formation of materials such as sand, soil, or gravel that can store
and supply groundwater to wells and springs.  Most aquifers used in the United States are within
a thousand feet of the earth's surface.

BASELINE RISK ASSESSMENT:  A study conducted as a supplement to a remedial investigation to
determine the nature and extent of contamination at a Superfund site and the risk posed to
public health and/or the environment.

CARCINOGEN:  A substance that can cause cancer.

CLEANUP:  Actions taken to deal with a release or threatened release of hazardous substances
that could affect public health and/or the environment.  The noun "cleanup" is often used
broadly to describe various response actions or phases of remedial responses such as Remedial
Investigation/Feasibility Study.

COMMENT PERIOD:  A time during which the public can review and comment on various documents and
actions taken, either by the Department of Defense installation or the USEPA.  For example, a
comment period is provided when USEPA proposes to add sites to the National Priorities List.

COMMUNITY RELATIONS:  USEPA's, and subsequently Naval Air Station Pensacola's, program to inform
and involve the public in the Superfund process and respond to community concerns.

COMPREHENSIVE ENVIRONMENTAL RESPONSE, COMPENSATION, AND LIABILITY ACT  (CERCLA):   A federal law
passed in 1980 and modified in 1986 by the Superfund Amendments and Reauthorization Act  (SARA).
The act created a special tax that goes into a trust fund, commonly known as "Superfund," to
investigate and clean up abandoned or uncontrolled hazardous waste sites.

Under the program the USEPA can either:

       •      Pay for site cleanup when parties responsible for the contamination cannot be
              located or are unwilling or unable to perform the work.

       •      Take legal action to force parties responsible for site  contamination to clean up
              the site or reimburse the federal government for the cost of the cleanup.

DEFENSE ENVIRONMENTAL RESTORATION ACCOUNT (DERA):  An account established by Congress to fund
Department of Defense hazardous waste site cleanups, building demolition, and hazardous waste
minimization. The account was established under the Superfund Amendments and Reauthorization
Act.

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DRINKING WATER STANDARDS: Standards for quality of drinking water that are set by both the
USEPA and the FDEP.

EXPLANATION OF DIFFERENCES: After adoption of final remedial action plan, if any remedial or
enforcement action is taken, or if any settlement or consent decree is entered into, and if the
settlement or decree differs significantly from the final plan, the lead agency is required to
publish an explanation of any significant differences and why they were made.

FEASIBILITY STUDY: See Remedial Investigation/Feasibility Study.

GROUNDWATER: Water beneath the earth's surface that fills pores between materials such as sand,
soil or gravel. In aquifers, groundwater occurs in sufficient quantities that it can be used
for drinking water, irrigation, and other purposes.

HAZARD RANKING SYSTEM (HRS): A scoring system used to evaluate relative risks to public health
and the environment from releases or threatened releases of hazardous substances. USEPA and
states use the HRS to calculate a site score, from 0 to 100, based on the actual or potential
release of hazardous substances from a site through air, surface water, or groundwater to affect
people. This score is the primary factor used to decide if a hazardous site should be placed on
the NPL.

HAZARDOUS SUBSTANCES: Any material that poses a threat to public health and/or the environment.
Typical hazardous substances are materials that are toxic, corrosive, ignitable, explosive, or
chemically reactive.

INFORMATION REPOSITORY: A file containing information, technical reports, and reference
documents regarding a Superfund site. Information repositories for Naval Air Station Pensacola
are at the West Florida Regional Library, 200 West Gregory Street, Pensacola, Florida; John C.
Pace Library, University of West Florida; and the NAS Pensacola Library, Building 633, Naval Air
Station, Pensacola, Florida.

MAXIMUM CONTAMINANT LEVEL: National standards for acceptable concentrations of contaminants in
drinking water. These are legally enforceable standards set by the USEPA under the Safe
Drinking Water Act.

MONITORING WELLS: Wells drilled at specific locations on or off a hazardous waste site where
groundwater can be sampled at selected depths and studied to assess the groundwater flow
direction and the types and amounts of contaminants present, etc.

NATIONAL PRIORITIES LIST (NPL): The USEPA1s list of the most serious uncontrolled or abandoned
hazardous waste sites identified for possible long-term remedial response using money from the
trust fund. The list is based primarily on the score a site receives on the Hazard Ranking
System. USEPA is required to update the NPL at least once a year.

PARTS PER BILLION (ppb)/PARTS PER MILLION (ppm): Units commonly used to express low
concentrations of contaminants. For example, 1 ounce of trichloroethylene in a million ounces
of water is 1 ppm; 1 ounce of trichloroethylene in a billion ounces of water is 1 ppb. If one
drop of trichloroethylene is mixed in a competition-size swimming pool, the water will contain
about 1 ppb of trichloroethylene.

PRELIMINARY REMEDIATION GOALS: Screening concentrations that are provided by the USEPA and the
FDEP and are used in the assessment of the site for comparative purposes prior to remedial goals
being set during the baseline risk assessment.

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PROPOSED PLAN:  A public participation requirement of SARA in which the lead agency summarizes
for the public the preferred cleanup strategy, and the rationale for the preference, reviews the
alternatives presented in the detailed analysis of the remedial investigation/feasibility study,
and presents any waivers to cleanup standards of Section 121(d)(4)  that may be Proposed. This
may be prepared either as a fact sheet or as a separate document.  In either case, it must
actively solicit public review and comment on all alternatives under agency consideration.

RECORD OF DECISION (ROD):  A public document that explains which cleanup alternative(s) will be
used at NPL sites.  The Record of Decision is based on information and technical analysis
generated during the remedial investigation/feasibility study and consideration of public
comments and community concerns.

REMEDIAL ACTION (RA):   The actual construction or implementation phase that follows the remedial
design and the selected cleanup alternative at a site on the NPL.

REMEDIAL INVESTIGATION/FEASIBILITY STUDY  (RI/FS):  Investigation and analytical studies usually
performed at the same time in an interactive process, and together referred to as the "RI/FS."
They are intended to:   (1) gather the data necessary to determine the type and extent of
contamination at a Superfund site; (2)  establish criteria for cleaning up the site; (3) identify
and screen cleanup alternatives for remedial action; and (4) analyze in detail the technology,
and costs of the alternatives.

REMEDIAL RESPONSE:  A long-term action that stops or substantially reduces a release or
threatened release of hazardous substances that is serious, but does not pose an immediate
threat to public health and/or the environment.

REMOVAL ACTION:  An immediate action performed guickly to address a release or threatened
release of hazardous substances.

RESOURCE CONSERVATION AND RECOVERY ACT (RCRA):  A federal law that established a regulatory
system to track hazardous substances from the time of generation to disposal.  The law requires
safe and secure procedures to be used in treating, transporting, storing, and disposing of
hazardous substances.   RCRA is designed to prevent new, uncontrolled hazardous waste sites.

RESPONSE ACTION:  As defined by Section 101(25) of CERCLA,  means remove, removal, remedy, or
remedial action, including enforcement activities related thereto.

RESPONSIVENESS SUMMARY:  A summary of oral and written public comments received by the lead
agency during a comment period on key documents,  and the response to these comments prepared by
the lead agency.  The responsiveness summary is a key part of the ROD, highlighting community
concerns for USEPA decision-makers.

SECONDARY DRINKING WATER STANDARDS:  Secondary drinking water regulations are set by the USEPA
and the FDEP.  These guidelines are not designed to protect public health, instead they are
intended to protect "public welfare" by providing guidelines regarding the taste, odor, color,
and other aesthetic aspects of drinking water which do not present a health risk.

SUPERFUND:  The trust fund established by CERCLA which can be drawn upon to plan and conduct
cleanups of past hazardous waste disposal sites,  and current releases or threats of releases
of nonpetroleum products.  Superfund is often divided into removal, remedial, and enforcement
components .

SUPERFUND AMENDMENTS AND REAUTHORIZATION ACT  (SARA):  The public law enacted on October 17,
1986, to reauthorize the funding provisions, and to amend the authorities and requirements of

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CERCLA and associated laws.  Section 120 of SARA requires that all federal facilities "be
subject to and comply with, this act in the same manner and to the same extent as any
non-governmental entity."

SURFACE WATER:  Bodies of water that are aboveground, such as rivers, lakes, and streams.

VOLATILE ORGANIC COMPOUND:  An organic  (carbon-containing) compound that evaporates  (volatizes)
readily at room temperature.

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                               Appendix B
                          Responsiveness Summary
Overview
During the public comment period, the U.S. Navy proposed a preferred remedy to address soil and
groundwater contamination at OU 10 on NAS Pensacola.  This preferred remedy was selected in
coordination with the USEPA and the FDEP.  The NAS Pensacola Restoration Advisory Board, a group
of community volunteers, reviewed the technical details of the selected remedy.

The sections below describe the background of community involvement on the project and comments
received during the public comment period.

Background of Community Involvement

Throughout the site's history, the community has been kept abreast of site activities through
press releases to the local newspaper and television stations that reported on site activities.
Site-related documents were made available to the public in the administrative record at
information repositories maintained at the NAS Pensacola Library, the West Florida Regional
Library, and the John C. Pace Library of the University of West Florida.

On February 15, 1996, newspaper announcements were placed to announce the date and location of
the public meeting to present the proposed plan, the public comment period (February 19 through
April 4, 1996) and included a short description of the proposed plan.  The announcement appeared
in the Pensacola News Journal.  In conjunction with these newspaper announcements, copies of the
proposed plan were mailed to addresses on the Installation Restoration Program mailing list.  A
public meeting was held at the Pensacola Junior College Warrington Campus on February 27, 1996.
In addition to the five Restoration Advisory Board community members, one citizen attended.

A responsiveness summary is reguired to document how the Navy addressed citizen comments and
concerns, raised during the public comment period.  All comments summarized in the appendix
have been factored into the final decisions of the remedial action for OU 10 at NAS Pensacola.

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Summary of Major Questions and Comments Received During the Public Comment Period and the
Navy's Responses
1.
Comment

Will the contaminants detected in soil affect the
NAS Pensacola drinking water?
Should the NAS Pensacola residents be given
carbon-filtering devices or millipore filters to put
on all faucets used for drinking water?
3.
If the contaminated soil is excavated and dumped
somewhere else, will it leach into the groundwater
at that location?
Response

The aguifer beneath OU 10 is considered a potable
water source by the State of Florida. However, NAS
Pensacola receives all of its potable water from Corry
Station, approximately 4 miles away. In addition,
Bayou Grande and Pensacola Bay limit groundwater use
to the north, east, and west of the site.

The RCRA groundwater treatment system will also be
modified to contain and remediate the contaminants
detected in OU 10 groundwater. If the leachability
study finds the contaminated soil to be adversely
impacting groundwater, the soil will be removed.

NAS Pensacola receives all of its potable water from
Corry Station, approximately 4 miles away. The
potable water is tested regularly and does not pose a
risk to the NAS Pensacola residents. If contaminant
are detected in the potable water supply, NAS
Pensacola residents are notified and appropriate action
is taken. Therefore, filtering systems are not reguired
currently for NAS Pensacola residents.

As explained in the Feasibility Study report, excavation
effectively protects human health and the environment.
If the soil is removed for offsite disposal, the soil will
be taken to an approved facility that is eguipped to
handle this type of waste.

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4.   Will the asphalt cap allow the contaminants to
    continue to leach into the soil and eventually
    contaminate the aquifer?
5.   How will groundwater contamination reaching
    Pensacola Bay be addressed?
6.   Is the area safe for industrial users?
7.   If the leachability study shows that the soil is
    adversely impacting groundwater,  how much will
    it cost to implement both Alternatives 2 and 4?
As explained in the Feasibility Study report, capping
effectively protects human health and the environment.
Capping contaminated soil reduces the amount of
rainwater that can move through the contaminated soil
and pick up contaminants along the way, thereby
reducing the impact to groundwater.

Pensacola Bay, Bayou Grande, and NAS Pensacola
wetlands will be addressed during the remedial
investigations of those sites.  Groundwater
contamination at OU 10 will be remediated by
modifying the existing RCRA corrective Action Plan to
remediate the contaminated groundwater before it
reaches the bay.

The baseline risk assessment concluded that there was
no unacceptable risk to industrial users of the site.  Any
excavation work would be monitored to prevent
unacceptable exposure.

If the leachability study shows the soil to be adversely
impacting groundwater, the costs include both the
$130,000 estimated for Alternative 2 and the $247,000
estimated for Alternative 4 totaling $377,000.

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