UNITED STATES ARMY PROTECTIVENESS STATEMENTRAB Restoration Advisory Board RAO Remedial Action Objective RAR Remedial Action Report RBC Risk Based Concentrations RCRA Resource Conservation

Fort Wainwright Five-Year Review

UNITED STATES ARMYPROTECTIVENESS STATEMENT

Based on the Statutory Determinations set forth in the Records of Decision for Operable Units1, 2, 3, 4, and 5, and the results of this Five-Year Review, the United States Army hereby findsthat the remedies for all five Fort Wainwright NPL Site operable units are expected to beprotective of human health and the environment upon completion, and in the interim, thatexposure pathways that could result in unacceptable risk are being controlled.

Colonel, U.S. ArmyGarrison CommanderU.S. Army, Alaska


REGULATORY AGENCY CONCURRENCES

Signature sheet for the first Five-Year Review of Records ofDecision, Fort Wainwright, Alaska

EPA’s concurrence with the findings of this five year review is based on the informationpresented in the accompanying Five-Year review Report, First Five-Year Review Report forFort Wainwright, Alaska.

Michael F. Gearheard, Director DateEnvironmental Cleanup OfficeU.S. Environmental Protection Agency, Region 10

ADEC’s concurrence with the findings of this five year review is based on the informationpresented in the accompanying Five-Year review Report, First Five-Year Review Report forFort Wainwright, Alaska.

------------------------------------------------------------- ----------------------------------

Jennifer Roberts, Section Manager DateADEC Contaminated Sites


REGULATORY AGENCY CONCURRENCES

Signature sheet for the first Five-Year Review of Records ofDecision, Fort Wainwright, Alaska

EPA’s concurrence with the findings of this five year review is based on the informationpresented in the accompanying Five-Year review Report, First Five-Year Review Report forFort Wainwright, Alaska.

------------------------------------------------------------- ----------------------------------

Michael F. Gearheard, Director DateEnvironmental Cleanup OfficeU.S. Environmental Protection Agency, Region 10

ADEC’s concurrence with the findings of this five year review is based on the informationpresented in the accompanying Five-Year review Report, First Five-Year Review Report forFort Wainwright, Alaska.

Jennifer Roberts, Section Manager DateADEC Contaminated Sites


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TABLE OF CONTENTS

LIST OF ACRONYMS viii

EXECUTIVE SUMMARY xi

FIVE-YEAR REVIEW SUMMARY FORM xii

1 INTRODUCTION 1-1

1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.2 Statutory Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

1.3 Agency Oversight Agreements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.3.1 Federal Facility Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2

1.3.2 Remedy Protectiveness, Optimization and Cost-Effectiveness . . . . . . . . . . . . . . . . . . 1-2

1.4 Public Involvement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.4.1 Community Involvement at Fort Wainwright . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3

1.4.2 Restoration Advisory Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

1.4.3 Community Involvement During Five-Year Review . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

2 APPROACH

2-1 Report Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.2 Five Year Review Team . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

2.3 Five-Year Review Tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.3.1 Document Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-2

2.3.2 ARARs and Numeric Cleanup Goal Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

2.3.3 Site Inspections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

3 FORT WAINWRIGHT NPL SITE BACKGROUND 3-1

3.1 Post History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.2 CERCLA History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1

3.3 Land and Resource Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-2

3.4 Physical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3


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3.5 History of Contamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4

4 OPERABLE UNIT 4-1

4.1 OU1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

4.2 801 Drum Burial Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2

4.2.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3

4.2.3 Remedy Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

4.2.4 Status of Remediation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-6

4.2.5 Five-Year Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-9

5 OPERABLE UNIT 2 5-1

5.1 OU2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2 Building 1168 Leach Well . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1

5.2.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2




5.3 OU2 – DRMO Yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

5.3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

5.3.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10

5.3.3 Remedy Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12

5.3.4 Status of Remediation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14

5.3.5 Five-Year Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16


6.1 OU3 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19

6.2 Remedial Area 1b – Below Birch Hill Tank Farm, and Truck Fill Stand . . . . . . . . . . 6-19


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6.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-19

6.2.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-20




6.3 Remedial Area 2 – Valve Pits and Railcar Off-Loading Facility . . . . . . . . . . . . . . . . . 6-30

6.3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30

6.3.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30



6.4 Remedial Area 3 – Mileposts 2.7, 3.0, and 15.75 . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40

6.4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40

6.4.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40




6.5 OU3 Explanation of Significant Differences (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49


7.1 OU4 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.2 Fire Training Pits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.3 Landfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1

7.3.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2





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7.4 OU4 -- Coal storage yard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

7.4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11

7.4.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-11





8.1 OU5 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

8.2 West Quartermaster’s Fueling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

8.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1

8.2.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-2




8.3 East Quartermaster’s Fueling System (EQFS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

8.3.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13

8.3.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-13




8.4 Remedial Area 1A -- Birch Hill Above Ground Storage Tanks . . . . . . . . . . . . . . . . . 8-21

8.4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21

8.4.2 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-21



8.5 Other OU5 ROD Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25


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8.5.1 OB/OD Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25

8.5.2 Chena River Surface Water and Sediments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-25

8.5.3 Status of Aquatic Assessment Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-26

8.6 Institutional Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27

8.6.1 IC Commitments in OU5 ROD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-27

8.6.2 Status of IC Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-28

9 PHYTOREMEDIATION OF PESTICIDE CONTAMINATED SOIL 9-1

10 SITE-WIDE SUMMARY AND RECOMMENDATIONS 10-1

10.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

10.1.1 ROD Commitments are Being Met . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

10.1.2 Public Information Repositories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

10.1.3 Institutional Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

10.1.4 Groundwater Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

10.2 Operable Unit and Source Area Specific . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-2

11 PROTECTIVENESS STATEMENTS 11-1

12 NEXT REVIEW 12-1

13 REFERENCES 13-1

APPENDICES


viii

LIST OF ACRONYMS

AAC Alaska Administrative CodeADEC Alaska Department of Environmental ConservationARARs Applicable or Relevant and Appropriate Requirements AS Air spargingAS/SVE Air Sparging and Soil Vapor ExtractionAST Aboveground Storage TankAWQS Alaska Water Quality StandardBGS Below Ground SurfaceBTEX Benzene, Toluene, Ethylbenzene, and Xylene(s)CANOL Canadian Oil LineCCL Contaminant Candidate ListCERCLA Comprehensive Environmental Response, Compensation, and Liability

ActCFR Code of Federal RegulationsCOC Contaminant of ConcernCOPC Contaminant of Potential ConcernCRREL Cold Regions Research and Engineering LaboratoryCYS Coal Storage YardDCA DichloroethaneDCE DichloroetheneDERA Defense Environmental Restoration ActDPW Directorate of Public WorksDRMO Defense Reutilization Maintenance OrganizationDRO Diesel Range (Petroleum Hydrocarbon) Organic CompoundsDSERTS Defense Site Environmental Restoration Tracking SystemEPA United States Environmental Protection AgencyESD Explanation of Significant DifferencesEPA Environmental Protection AgencyFFA Federal Facility AgreementFR Federal RegisterFS Feasibility StudyFTP Fire Training Pits


ix

GIS Geographic Information SystemGRO Gasoline Range (Petroleum Hydrocarbon) Organic CompoundsHASP Health And Safety PlanIAG Interagency AgreementIC Institutional ControlIRP Installation Restoration ProgramITR Independent Technical ReviewLTM Long Term MonitoringMCLs Maximum Contaminant LevelsMCLG Maximum Contaminant Level GoalNCP National Oil And Hazardous Substances Pollution Contingency PlanNPL National Priorities ListNFA No Further ActionO&M Operation and MaintenanceOM&M Operation, Maintenance and MonitoringORC Oxygen Release CompoundOU Operable UnitPA Preliminary AssessmentPAH Polycyclic aromatic hydrocarbonPA/SI Preliminary Assessment/ Site InvestigationPCE PerchloroethylenePDRAR Preliminary Draft Remedial Action ReportPOL Petroleum, Oil And LubricantPRG Preliminary Remediation GoalPSE Preliminary Site EvaluationRA Remedial ActionRAB Restoration Advisory BoardRAO Remedial Action ObjectiveRAR Remedial Action ReportRBC Risk Based ConcentrationsRCRA Resource Conservation and Recovery ActRD Remedial DesignRD/RA Remedial Design/Remedial ActionRI Remedial Investigation


x

RI/FS Remedial Investigation/Feasibility StudyROD Record of DecisionROLF Railcar Off-Loading FacilityRPM Remedial Project ManagerRRO Residual Range OrganicSARA Superfund Amendments and Reauthorization Act of 1986 SI Site InvestigationSOP Standard Operating ProcedureSVE Soil Vapor ExtractionSVOC Semivolatile Organic CompoundThe RPMs USARAK, EPA, and ADEC remedial program managers under the FFA

and Two-Party AgreementTAH Total Aromatic HydrocarbonTAqH Total Aqueous HydrocarbonTBC To Be Considered (in addition to ARARs)TCA TrichloroethaneTCE TrichloroetheneTFS Truck Fill StandTPA Two-Party AgreementUSARAK United States Army AlaskaUST Underground Storage TankVOC Volatile Organic Compound


xi

EXECUTIVE SUMMARY

The United States Army Alaska (USARAK) conducted the first Five-Year Review of the remedialactions at the Fort Wainwright National Priorities List (NPL) site, Fairbanks, Alaska, from Aprilthrough September 2001. This report presents the results of that review.

The purpose of this review is to ensure that remedial actions selected in the Records of Decision(RODs) for the Fort Wainwright Operable Units (OUs) are being implemented and that theycontinue to be protective of human health and the environment. To achieve this purpose, thisreview evaluates the status of implementation of the selected remedies, identifies significantvariances from the RODs, and makes recommendations for reconciling variances and/or forimproving performance of remedial actions.

This statutory review is required by the Comprehensive Environmental Response, Compensation,and Liability Act (CERCLA) since all of the RODs for this site were signed after the effective date ofthe Superfund Amendments and Reauthorization Act of 1986 (SARA) and some of the remedialactions result in hazardous substances, pollutants, or contaminants remaining at the site abovelevels that allow for unlimited use and unrestricted exposure.

The Fort Wainwright NPL site is comprised of five operable units (OUs). Records of Decision(RODs) specifying environmental remedies for eleven source areas within the OUs have beensigned for all of the OUs. Subareas have been defined in several of the source areas for thesystematic management and monitoring the results of remediation.

The steps taken in conducting this Five-Year Review focused on answering the following questions:

• Is the remedy functioning as intended in the decision documents?

• Are the exposure assumptions, toxicity data, cleanup levels, and remedial actionobjectives still valid?

• Has any other information come to light that could call into question the protectiveness ofthe remedy?

The answers to these questions provided the basis for making conclusions regarding the continuedprotectiveness of the remedies specified in the ROD for each OU.

The Five-Year Review found that the remedies for all five Fort Wainwright NPL Site operable unitsare expected to be protective of human health and the environment upon completion, and in theinterim, that exposure pathways that could result in unacceptable risk are being controlled.


xii

FIVE-YEAR REVIEW SUMMARY FORMSITE IDENTIFICATION

Site name (from WasteLAN): Fort Wainwright, Alaska

EPA ID (from WasteLAN): AK6210022426

Region: 10 State: AK City/County: Fairbanks, Fairbanks North Star Borough

SITE STATUS

NPL status: :Final 9 Deleted 9 Other (specify)

Remediation status (choose all that apply): : Under Construction : Operating 9 Complete

Multiple OUs?* : YES NO Construction completion date: 2002

Has site been put into reuse? 9 YES 9 : NO Active Army installation

REVIEW STATUS

Review agency: : EPA : State 9 Tribe : Other Federal Agency U.S. Army

Author name: U.S. Army, Alaska (USARAK)

Review period:** 3/29/2001 to 9/30/2001

Date(s) of site inspection: 4/26-27/2001

Type of review: :Statutory9 Policy (Post-SARA : Pre-SARA 9 NPL-Removal only

9 Non-NPL Remedial Action Site 9 NPL State/Tribe-lead9 Regional Discretion)

Review number: : 1 (first) 9 2 (second) 3 (third) 9 Other (specify) Triggering action:9 Actual RAA Onsite Construction at OU # : Actual RA Start at OU #39 Construction Completion 9 Previous Five-Year Review Report9 Other (specify)

Triggering action date (from WasteLAN): 5/30/1996

Due date (five years after triggering action date): 9/30/2001

*[“OU” refers to operable unit.]

**[Review period should correspond to the actual start and end dates for the five-year review in WasteLan.]


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Five-Year Review Summary FormVariances:

• Variances are discussed in the “Five-Year Assessment” paragraphs devoted to answering the question“Has any Other Information Come to Light That Could Call Into Question the Protectiveness of theRemedy?” for each source area within the five operable units (OUs).

• No variances currently affecting protectiveness were identified during the five-year review.

• Most variances that were identified pertained to the need to periodically adjust institutional control (restricteduse area) boundaries as new monitoring data becomes available.

• An explanation of significant differences (ESD) is being prepared for OU3 to address increases in the extentand volume of contamination and other variances from the ROD that do not fundamentally alter the remedialapproach at this OU.

• An additional COC was identified in the OU5 West Quartermaster Fueling System (WQFS) source.However, the selected remedy for the WSFS remains protective in the short- and long-term.

• Other variances identified additional data to better understand contaminant fate and transport and theeffectiveness of remediation at some source areas.

Recommendations and Follow-Up Actions:

• Recommendations and Follow-up Actions are also discussed in the “Five-Year Assessment” paragraphsdevoted to answering the question “Has any Other Information Come to Light That Could Call Into Questionthe Protectiveness of the Remedy?” for each source area within the five operable units (OUs).

• A summary of recommendations and follow-up actions is included in Section 10 of this report.

• Most recommendations and follow-up items in this report address adjusting the institutional controlboundaries in the Army’s GIS database.

• Other recommendations and follow-up items pertain to minor modifications to groundwater monitoringprograms and to planning for continued Chena River aquatic assessment.

Protectiveness Statement(s):

• Protectiveness statements were developed using the sequential process described in EPA guidancefor conducting five-year reviews.

• At all of the OUs, the remedies are expected to be protective of human health and the environmentupon completion, and in the interim, exposure pathways that could result in unacceptable risks arebeing controlled.

• Protectiveness statements are developed in Section 11 of this report.


1-1 REV.01

1 INTRODUCTIONThe United States Army Alaska (USARAK) has conducted the first Five-Year Review of theremedial actions at the Fort Wainwright National Priorities List (NPL) site, Fairbanks, Alaska, fromApril through September 2001. Work in support of this review was performed by Wood CanyonGroup, Inc. (WCGI), and its subcontractors, ENSR Corporation and Voom Engineers. This reportpresents the results of the Five-Year Review.

1.1 Purpose

The purpose of this review is to ensure that remedial actions selected in the Records ofDecision (RODs) for the Fort Wainwright Operable Units (OUs) are being implemented and thatthey continue to be protective of human health and the environment. To achieve this purpose, thisreview evaluates the status of implementation of the selected remedies, identifies significantvariances from the RODs, and makes recommendations for reconciling variances and/or forimproving performance of remedial actions.

1.2 Statutory Review

This statutory review is required by the Comprehensive Environmental Response, Compensation,and Liability Act (CERCLA) since all of the RODs for this site were signed after the effective date ofthe Superfund Amendments and Reauthorization Act of 1986 (SARA) and some of the remedialactions result in hazardous substances, pollutants, or contaminants remaining at the site abovelevels that allow for unlimited use and unrestricted exposure.1

The National Oil And Hazardous Substances Pollution Contingency Plan (NCP) part300.430(f)(4)(ii) of the Code of Federal Regulations (CFR) specifies that “the lead agency shallreview such action no less often than every five years after the initiation of the selected remedialaction”. EPA Five-Year Review guidance states that “the first five-year review generally should becompleted and signed by the EPA Region within five years of the initial trigger date”, and “for thepurpose of a five-year review, a remedial action typically is initiated on the date of ‘actual RAon-site construction’ or the ‘actual RA start’ date for Federal facilities. The date of actual RA on-siteconstruction generally corresponds to the date the contractor begins work at a site for the remedialaction, typically the date of on-site mobilization.”2 The first remedial action at the Fort WainwrightNPL site was for OU3, initiated on May 30, 1996.3

1The Army must conduct Five-Year Reviews consistent with CERCLA and the National Oil and Hazardous Substances PollutionContingency Plan (NCP). CERCLA §121 (c), as amended, states:

If the President selects a remedial action that results in any hazardous substances, pollutants, orcontaminants remaining at the site, the President shall review such remedial action no less often than eachfive years after the initiation of such remedial action to assure that human health and the environment arebeing protected by the remedial action being implemented.

2 The definition of the “actual RA start” varies as outlined in the Superfund/Oil Program Implementation Manual (SPIM). OSWERDirective 9200.3-14-1G-P.3 Source: EPA WasteLAN


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Five-year review guidelines state that “an entire site is subject to a statutory review if any one of itsremedial actions is subject to a statutory review.”1 Therefore all five OUs at Fort Wainwright areincluded in this review.

1.3 Agency Oversight Agreements

1.3.1 Federal Facility Agreement

A Federal Facility Agreement (FFA) for Fort Wainwright was signed by the U.S. EnvironmentalProtection Agency (EPA, Region 10), the Alaska Department of Environmental Conservation(ADEC), and the United States Department of the Army in March 1992. The FFA ensures thatenvironmental impacts associated with past practices at Fort Wainwright are investigated andremedial actions are completed to protect human health and the environment. This agreement setsdeadlines, objectives, responsibilities, and procedural framework for implementing the InstallationRestoration Program (IRP) at Fort Wainwright.

The FFA establishes and describes the CERCLA process as applied to Fort Wainwright. It is in theFFA that the use of preliminary source evaluations (PSEs) was established to better define thescope of the RI/FS activities. The PSE approach was adopted to facilitate the use of informationpreviously collected under the Army's Installation Restoration Program (IRP) in order to identifyadditional areas of concern, to expedite interim remedial actions, and to screen the numerous sitesof potential concern to identify those sites that warranted remedial investigation (RI). PSE reportswere used as lead-in documents to OUs and the RI/FS process.

An additional goal of the FFA is to integrate the Army’s CERCLA response obligations andResource Conservation and Recovery Act (RCRA) corrective action obligations at this site. TheFFA states that remedial actions implemented under this agreement will be protective of humanhealth and the environment such that remediation of releases shall obviate the need for furthercorrective actions under RCRA (i.e., no further corrective action shall be required for source areas).

Each of the parties to the Fort Wainwright FFA is represented by a Remedial Project Manager(RPM).2 These RPMs meet quarterly, at a minimum, to discuss the Army’s progress regardingremedial actions selected in the RODs and to address related issues as they arise during thecourse of remedial action. The RPMs meet more frequently than quarterly when needed, androutinely make themselves available to each other for purposes of Fort Wainwright remediation(e.g., for technical reviews, modifying monitoring programs, etc.) and to meet the intent andcommitments of the FFA.

1.3.2 Remedy Protectiveness, Optimization and Cost-Effectiveness

Optimization of remedy and assessment of cost effectiveness is an on-going process for the FortWainwright NPL site. Performance of remedies is evaluated at all FFA meetings and discussed bythe RPMs more frequently, as needed. Upon approval of the RPMs, operation of

1 Source: Section 1.5.1, EPA Draft Five-Year Review Guidance2 “The RPMs” is used in this report to refer to these three representatives.


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treatment systems is modified as necessary to ensure efficacy and best use of resources. Suchmodifications have typically included adjusting periods of operation of soil vapor extraction and airsparging (SVE/AS) systems, decisions to terminate operation, decisions to restart operation,decommissioning treatment systems, and moving treatment systems to new locations. Changesare presented in system operations annual reports. Groundwater monitoring programs are updatedat least annually based on findings from the preceding year to ensure that well locations andsampling regimes are meeting the objectives of the RODs. Two-Party Agreement

Fort Wainwright also negotiated a Two-Party Agreement (TPA) with ADEC in 1992. ThisAgreement sets the framework to cooperatively address petroleum, oil and lubricant (POL)contamination caused primarily by leaking underground storage tanks and surface spills at the post.

The TPA acknowledged that all parties to the Federal Facility Agreement (FFA), being negotiated atthe time the TPA was signed, agreed to allow the Army to initially address the clean-up of theseareas of petroleum contamination in accordance with the state’s statutes, regulations, and InterimGuidance, with a review by the RPMs at the time of the OU5 ROD to ensure that petroleum siteswere being adequately addressed.

Appendix D to the OU5 ROD included the January 1998 “Recommended Action, Fort WainwrightPetroleum Strategy”, signed by the parties to the FFA. This appendix verified the strategiesdeveloped by the Army and ADEC to address the known POL contaminated source areas on FortWainwright.

1.4 Public Involvement

1.4.1 Community Involvement at Fort Wainwright

Community involvement activities began at Fort Wainwright in 1992 when community interviewswere conducted to support an Areawide Community Relations Plan (CRP) for Fort Wainwright. Thefinal version of the CRP was published in April 1993 and covered the status of investigations andcleanup activities for the five operable units on Fort Wainwright. The CRP was revised and updatedin 1997.

Fort Wainwright published their first quarterly newsletter in July 1993. Quarterly newsletters,covering information about all operable units, two-party agreement sites, and other restorationactivities, have been published quarterly and sent to interested community members since 1993.

Prior to the formation of the Restoration Advisory Board (RAB) Fort Wainwright conducted severalinformational public meetings. The first meeting was conducted in July 1993, which coveredinformation about each of the five operable units. In addition, operable unit specific public meetingswere held in conjunction with a public comment period for each of the associated Proposed Plans.The proposed plan public meetings presented investigative information and proposed cleanupplans for each of the operable units with a focus on receiving public comments on the proposedactions. The public was offered several different venues for providing public comments: written,verbal, and via a toll-free telephone comment line.


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In 1994 an Information Repository for Fort Wainwright restoration activities was established at theNoel Wien Library in Fairbanks and the Fort Wainwright Post Library. The Administrative Recordwas established and is currently maintained at the Directorate of Public Works library, Building3023, on Fort Wainwright. The Administrative Record has been updated annually since inception.

1.4.2 Restoration Advisory Board

A Restoration Advisory Board (RAB) was established for the Fort Wainwright NPL site in 1997. TheRAB includes members of the Fairbanks business community, installation residents, localenvironmental groups, local residents, and a member of the Tanana Chiefs Conference (an AlaskaNative organization). Government members include representatives of EPA Region 10 and ADEC.

RAB meetings are held quarterly, and public interest in the RAB has declined to a relativelyconsistent low level as major concerns have been addressed. The Army presents technicalbriefings for the RAB as needed, and members of the RAB have the opportunity to share theirconcerns about the site and provide advice on remediation studies and remedial actions. The Armycontinues to look for opportunities to keep the community informed and involved in the remediationprocess.

The Army’s IRP, the RAB, the FFA, and the TPA effectively ensure public involvement in andenvironmental agency oversight of the remediation process at Fort Wainwright. The active nature ofmilitary operations at Fort Wainwright ensures an ongoing federal presence and has contributed tothe Army’s ability to meet the commitments in the RODs.

1.4.3 Community Involvement During Five-Year Review

The Five-Year Review is an important milestone for public involvement at a National Priorities List(NPL) site. The public was informed of the Fort Wainwright Five-Year Review as follows:

• A notice of the Five-Year Review was e-mailed to Fort Wainwright RABmembers, who were encouraged to share the information with other membersof the community.

• The Five-Year Review was described in the April 2001 Fort WainwrightEnvironmental Restoration News.

• Notice of the March 2001 RAB meeting and the meeting agenda (whichincluded an item for discussion of the Five-Year Review), was published in theFairbanks Daily News Miner.

• The RAB meeting was listed in the events calendar of the Fairbanks DailyNews Miner, and meeting notices were posted at various locations at theUniversity of Alaska Fairbanks campus.

• The Army included a Five-Year Review update in the August EnvironmentalRestoration News.


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• Following completion of the Five-Year Review, a notice of availability will bepublished in the Daily News Miner notifying the public of the availability of thereview, and the Review Report will be added to the Administrative Record andplaced at the Fort Wainwright NPL site public information repositories. The resultsof the Five-Year Review will also be presented at the October 2001 RAB meeting.


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2 APPROACH

2.1 Report Organization

The Five-Year Review was performed in accordance with the Interim Army Guidance forConducting CERCLA Five-Year Reviews1 and EPA Comprehensive Five-Year Review Guidance.The EPA guidance document was in draft form at the beginning of the Fort Wainwright five-yearreview and became final2 after the five-year review was nearly complete. Because this and otherfive-year reviews throughout the nation were nearing completion at the time the final guidancedocument was issued, EPA Headquarters suggested that reviews already in final preparation becompleted as planned (i.e., without regard to the new guidance) but consider formulating theprotectiveness statements similar to the examples in the final guidance. The protectivenessstatements are based on the findings and recommendations and are structured as described in thefinal EPA five-year guidance document.

The basic report structure is derived from the draft EPA guidance document, modified toaccommodate all five Fort Wainwright RODs and multiple source areas within OUs. To the extentpossible, discussion related to all of the OUs appears at the beginning of the report andOU-specific discussion appears in the different OU sections of the report. Source areas areaddressed separately within the OU sections, while discussion of subareas is presented undersource area headings.

One of the goals of this report is to compile information from existing reports for all of the OUs intoa single status document. To make best use of resources, this report has taken much discussionand information from the RODs, other reports, and Army summaries. Findings that were overseen,reported, reviewed, and accepted by the Fort Wainwright RPMs, have generally been included inthe Five-Year Review report without further scrutiny.

The findings and recommendations sections of this report document ongoing issues and concerns,identify variances in the implementation of remedial actions, and suggest changes to ensure thatremedial actions undertaken pursuant to the RODs are adequately protective of human health andthe environment

2.2 Five Year Review Team.

This Five-Year Review was performed at the direction of the USARAK Directorate of Public Works(DPW) Environmental Office3 (federal lead agency for this site) with EPA Region 10 and ADECoversight pursuant to the FFA and TPA.

This work was conducted under contract to the Alaska District Corps of Engineers by Wood Canyon Group, Inc. (WCGI), and its subcontractors. Key project staff were:

1 Interim Army Guidance for Conducting CERCLA Five-Year Reviews2 Comprehensive Five-Year Review Guidance, EPA 540-R-01-007, OSWER No. 9355.7-03B-P, June 2001 3 Called “DPW” for the remainder of this report.


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Jerry Williams, ENSR Corporation – Project Manager

Bob Allen, VOOM Engineers – Project Engineer

Patricia Yould, WCGI – Principal in Charge

Michael Allwright, WCGI – Project Scientist

2.3 Five-Year Review Tasks

The objectives of the Five-Year Review are to answer the following questions:

• Are the remedies functioning as intended by the decision document?

• Are the assumptions used at the time of remedy selection still valid?

• Has any other information come to light that could call into question theprotectiveness of the remedy?

• Are human health and the environment being protected in the short- andlong-term?

The Five-Year Review has been accomplished by four major tasks:

• Review of relevant documents in the Administrative Record including but notlimited to the RODs, Explanation of Significant Differences (ESD), RemedialDesign/Remedial Action (RD/RA) Reports, Drawings and As-Builts todetermine the initial effectiveness of the remedies

• Review of Operation and Maintenance (O&M) Reports, Monitoring Plans, andAnnual Sampling Reports to determine the ongoing effectiveness andprotectiveness of the chosen remedies

• Review of chemical, location, and action-specific Applicable or Relevant andAppropriate Requirements (ARARs) identified in the RODs for each OU todetermine whether changes have occurred which might affect theprotectiveness of the remedies

• Site inspections to observe visible elements of remedies

• Interviews of operation and maintenance personnel and remediationcontractors

2.3.1 Document Review

Documents consulted in the course of this Five-Year Review include:


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• Comprehensive Five-Year Review Guidance, OSWER Directive 9355.7-03B-P (Draft, October 1999)

• RODs for OUs 1 through 5

• Remedial Designs (RDs) (including drawings and as-builts)

• Remedial Action Reports (RARs)

• O&M reports and manuals

• Ground water sampling results

• Other sampling results, monitoring data, and summaries

Table 2-1 is a compilation of reports and documents available at the time of this review. Keyinformation sources used in this review are identified in this table.

2.3.2 ARARs and Numeric Cleanup Goal Review

As part of this five-year review, significant ARARs for each ROD were reviewed for changes or thepromulgation of new laws since the ROD was signed that might be considered ARARs if the RODswere to be written today.1 As part of this review, remedial action objectives were reviewed, andcontaminant-specific standards used to set numeric cleanup goals in each ROD were compared topresent day values to assess continued protectiveness of the remedies. More specifically, currentMaximum Contaminant Levels (MCLs) and toxicity and/or carcinogenicity values were compared toMCLs and toxicity/carcinogenicity values at the time of the RODs.

The OU specific Remedial Action Objectives (RAOs), ARARs, and cleanup goals are discussed inthe OU sections of this report.

2.3.3 Site Inspections

Site inspections were conducted April 26-27, 2001, following the FFA meeting held earlier in theweek. Photographs taken during the site inspections are included in the appendices section of thisreportA. Because Fort Wainwright is a site with ongoing Army presence and agency oversight, itwas possible to discuss project status with a variety of people familiar with site history and status ofremediation.

1 New laws that might be considered ARARs today need only be addressed for Fort Wainwright if essential to ensure protectiveness ofthe remedies.


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The Fort Wainwright NPL site public information repositories were also inspected to confirmavailability of Administrative Record documents for public review. The findings andrecommendations from the repository inspections are included in the appendices section of thisreportB.


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3 FORT WAINWRIGHT NPL SITE BACKGROUNDThis section is an overview of the post wide Fort Wainwright NPL site. Background information onthe individual OUs is presented in the OU specific sections of this document.

3.1 Post History

The United States Army Fort Wainwright has been used by the Department of Defense (DOD) formilitary operations continuously since 1938. Originally known as LADD Army Airfield (LAAF), thepost was established for cold weather experimentation. During World War II, LAAF served as atransfer point in the lend-lease program. Between 1942 and 1945, almost 8, 000 combat andtransport aircraft were transferred to Soviet aircrews at LAAF. In 1947, the newly formed UnitedStates Air Force (USAF) assumed control of LAAF, which was redesignated as LADD. Air ForceBase (LAFB). LAFB served as a resupply and maintenance base for the Remote Distant EarlyWarning (DEW) sites and experimental ice stations in the Arctic Ocean. During the Korean conflict,LAFB served as part of the defense network, and was the site of the first Nike Hercules Missilelaunch from a tactical missile site in December 1959.

On January 1, 1961, the United States Army (USA) resumed control over LAFB. The USA renamedthe installation Fort Wainwright, after General Jonathan M. Wainwright, the commander of theforces defending the Bataann Peninsula in the Philippines at the beginning of World War II.

Fort Wainwright became the home of the 171st Infantry Brigade in 1963 and has housed variousArmy brigades and divisions over the years. In July 2001, the Army announced its intent to makethe 172nd Infantry Brigade, located at Forts Wainwright and Richardson, into one of the next fourinterim brigade combat teams (IBCTs) as part of its transformation to a more strategic andresponsive force.

3.2 CERCLA History

Fort Wainwright was proposed for placement the CERCLA National Priorities List (NPL) in July1989, due to releases of hazardous substances, pollutants, and contaminants into the environment.The Army’s investigation of contaminated sites at Fort Wainwright under the Installation RestorationProgram (IRP) began in 1989, and the post was added to the CERCLA National Priorities List in1990. EPA Region 10 and the ADEC began working closely with the Army to better understand thenature and extent of contamination at Fort Wainwright and its threat to human health and theenvironment. The three parties negotiated the Fort Wainwright NPL Site FFA, which was signed in1992, and the Army and ADEC also entered into a Two-Party Agreement to address POL sites in1992.

Attachment I to the FFA describes the investigation and restoration approach agreed upon by theArmy and the regulatory agency parties to the agreement. As of the signing of the FFA, 41 potentialcontaminant source areas were identified as warranting inclusion into OUs and 57 POL sourceswere identified through previous studies, reports and interviews. No further action was


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planned for 27 potential source areas based on the screening criteria outlined by the RPMs.Documents are located in the administrative record.1

The history of contamination and remediation of source areas are summarized in the OU-specificsections of this report. Sites were identified by the RPMs using the RCRA Facility Assessment,Westin Facility Assessment, Environmental Assessment 172nd Brigade numerous interviews, andthe Federal Facility Compliance Agreement. Formal preliminary assessments (PAs) were notconducted at Fort Wainwright. The preliminary source evaluations (PSEs) discussed in Section 1,lead into the remedial investigations (RIs), followed by feasibility studies (FSs) for the selection ofremedies, remedial designs (RDs), remedial action (RAs), O&M associated with remedial actions,and long-term monitoring (LTM).

Of the 77 Fort Wainwright contaminant “source areas”2 initially identified for further investigation,ten (10) are in various stages of remediation under the five CERCLA OUs Operable Units, eleven(11) are being managed under the TPA, three (3) are being addressed by the CERCLA ESDprocess, and the remaining fifty three (53) have been found to require no further action (NFA)3.Table 3-1 is a summary of the current disposition of each of the original sites, and Table 3-2describes the status of the NFA and Two-Party sites.

In FY99, a U.S. Army Independent Technical Review (ITR) was conducted at Fort Wainwright,focusing on the three active sites associated with Operable Unit 3 (FTWW-055, the Birch Hill TankFarm; FTWW-083, the Railroad Off-Loading Facility; and FTWW-084, the Fairbanks-EielsonPipeline Spills). This report indicated that the remedial actions underway were correct, adequate,and were protective of human health and the environment. The ITR team concluded that anExplanation of Significant Differences (ESD) be developed. An ESD documents new informationreceived or generated after signature of the ROD that could affect implementation of the originalremedy selected. Specifically, an ESD is being prepared for OU3 to document increased volumeand areal extent of contamination, increase in remedial cost, discovery of additional source areasand changes in some components of the selected remedy. This does not fundamentally alter theoverall remedial approach. Additional discussion of the ESD is included in Section 6.

3.3 Land and Resource Use

Fort Wainwright is located in the Fairbanks North Star Borough in interior Alaska and occupies 918,000 acres on the east side of Fairbanks. Fort Wainwright consists of a main post area, which is twomiles east of Fairbanks on the Chena and Tanana Rivers and has a cantonment area, a small armsrange complex, and a close in range complex. The main post was originally established as acold-weather testing station. The Tanana Flats Training Area is across the Tanana River from themain post, and the Yukon Training Area is 16 miles east-southeast of Fairbanks, adjacent toEielson Air Force Base.

1 Total = 95 areas.2 Source areas are locales where contamination has been verified to exist in concentrations that prevent unrestricted use of land orwater or that make these areas ongoing sources of pollution to the surrounding environmental media.3 Decisions to recommend no further action at source areas was based on: 1) the physical location could not be identified or located inthe investigation, 2) no visible sign of contamination was observed during the source area inspection, 3) the site was referred to theTwo-Party Agreement, or 4) environmental sampling results showed that contamination was present at levels below the protectivehuman-health-based levels.


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Fort Wainwright is located within the Fairbanks North Star Borough, which is lightly populated withseveral scattered developments. The City of Fairbanks (population 35,000) is on the westernboundary of Fort Wainwright, and the main cantonment area lies within Fairbanks North StarBorough

Primary missions at Fort Wainwright include training infantry soldiers in the arctic environment,testing equipment in arctic conditions, preparing troops for defense of the Pacific Rim, and rapiddeployment of troops worldwide. On-site industrial activities include operation, maintenance, andrepair of fixed-wing aircraft, helicopters, tactical and nontactical vehicles. On-site industrial activitiesinclude drinking water production, power generation, and steam heat production.

Groundwater is the only source of potable water used at Fort Wainwright and the Fairbanks area.Approximately 95% of Fort Wainwright’s potable water is supplied through a single distributionsystem fed by two large-capacity wells located in Building 3559, near the Post Power Plant. Thesewells are completed at a depth of approximately 80 feet below ground surface (bgs) and providebetween 1.5 million and 2.5 million gallons of water per day to the Post Water Treatment Plant forprocessing and distribution. In addition to the main drinking water supply wells, there are fiveemergency standby supply wells located around the cantonment area. These wells have beencompleted between 80 feet and 120 feet bgs and are capable of pumping approximately 250,000gallons per day per well.

Golden Heart Utilities has four developed wells located one and a quarter miles downgradient ofthe Post’s boundaries, on the banks of the Chena River. College Utilities has four developed wells(two of which are active) located approximately three and a half miles downgradient of the Post’sboundaries. These wells serve as the main drinking water supply for most of the City of Fairbanks.

For purposes of CERCLA and TPA remediation, groundwater use at, and potentially affected by,Fort Wainwright source areas is considered residential.

3.4 Physical Characteristics

Fort Wainwright is underlain by soil and unconsolidated sediment that consist of silt, sand, andgravel and range in thickness from 10 feet to more than 400 feet before encountering bedrock.A five-foot-thick surficial soil layer of fine-grained soil overlies the deeper alluvial deposits.Alluvial floodplain deposits underlay the surface soils and consist of varying proportions of sandand gravel which are commonly layered. Where present, permafrost forms discontinuous confininglayers that influence groundwater movement and distribution. The depth to permafrost, whenpresent, ranges from two feet to 40 feet bgs). The greater depths are found on cleared anddeveloped land surfaces, where thermal degradation of underlying permafrost occurs.

The Chena River flows through Fort Wainwright and the City of Fairbanks, and eventually into theTanana River south of the Post. The Tanana River borders the south portion of Fort Wainwright.The main aquifer in the Fort Wainwright area is the Tanana Basin alluvial aquifer, a buried rivervalley. This aquifer ranges from a few feet thick at the base of Birch hill to at least 300 feet thickunder the post’s main cantonment area. The aquifer may reach a thickness of 700 feet in theTanana River valley. Groundwater in the Tanana-Chena floodplain generally is considered to beunconfined in permafrost-free areas. A confined aquifer may develop


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seasonally where the depth to the water table is less than the depth of the seasonal frostpenetration.

Groundwater movement between the Tanana and Chena Rivers generally follows a northwestregional direction, similar to flow direction of the rivers. Seasonal changes in groundwater flowdirections of up to 180 degrees are not uncommon in the area due to the effects of changing riverstages in the Tanana River and, to a lesser extent, the Chena River. Groundwater levels near theChena River fluctuate greatly because of river stage and interactions with the Tanana River.Typically, groundwater levels rise during spring breakup and late summer runoff, and drop duringfall and winter when rainfall decreases and precipitation becomes snow.

3.5 History of Contamination

Beginning in 1938, fuels, waste solvents and pesticides were disposed of on the ground. Spillsassociated with fuel management, storage, transportation, and handling were common. In addition,waste oils, solvents, and contaminated fuels were incinerated at the post power plant and firetraining areas, a practice which was discontinued in 1993. Waste oils were used for dust controland for fire pit training exercises. Waste oils were commonly used for dust control. Undergroundstorage tanks (USTs) for waste oil, fuel, lubricants, and solvents were installed at mostmaintenance facilities. A majority of these tanks eventually leaked and released contaminants tosoil and groundwater. All existing USTs were removed and/or replaced with double walled,cathodically protected, tanks with leak detection systems.

Pesticides (insecticides, herbicides, fungicides, avicides and rodenticides) have been used over theyears to maintain grounds and structures and to prevent pest-related health problems. Pesticideswere reported to have been mixed on inadequate surfaces and/or stored in such a way to allowreleases to the soil.

Current Army practices no longer include uncontrolled or unpermitted releases of pollutants to theenvironment.


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4 OPERABLE UNIT

4.1 OU1 Background

OU1 originally consisted of 22 potential source areas, of which only four were carried throughremedial investigation (RI): the 801 Drum Burial Site, Site N-4, Building 1599, and Building2077. Subsequent IRP management of these source areas was based on the results of the RI, asfollows:

• Buildings 1599 and 2077 were referred to the Two Party Agreement, sincethe only contaminants of concern at these two locations consisted ofpetroleum hydrocarbons.

• Site N-4 was found to require no further action.

• The 801 Drum Burial Site is the only source area recommended for furtheraction under the OU1 ROD, based on potential risk to human health and theenvironment.

A no further action decision was made for the following source areas based on 1) the physicallocation could not be identified, 2) no visible sign of contamination was observed duringinspections, or 3) environmental sampling results showed that contamination was below theprotective human health based levels. Based on these criteria, the RPMs recommended thefollowing sources areas as requiring no further action under this ROD: the Utilidor Expansion DrumSite, the Beacon Tower Drum Site, the Blair Lakes Drum Site, Building 3015, Burial Site M, Building1128, Transformer Yard Drum Site, Trainor Gate Railroad Spur, the Runway Radioactive WasteSite, the Birch Hill Radioactive Waste Site, Building 1567, Site N-4, Transformer Storage Yard Eastof 3019, the Alaska Railroad Storage Yard, Building 2250, the Drum Site South of the Landfill, theEngineer Park Drum Site. A description of these no further action decisions can be found in theOU1 ROD and the administrative record.

An interim ROD was signed in 1995 for the Chemical Agent Dump Site. The IRA indicated thatchemical warfare materials were not present at this site and a no further action decision wasrecommended under this ROD. Information on this source can be found in the IRA ROD ChemicalAgent Dump Site and the administrative record.

Periods of use and dates related to the history of the 801 Drum Burial source area contaminationand remediation are summarized in the table which follows.1

1 Information obtained from the OU 1 IAP; OU 1 OM&M Plan; and the Five-Year Review Report Document Log.


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EVENT DATEDrum storage and disposal activities 1950s & 1960s

Buried drums discovered during construction of storm sewer. Geophysical survey conducted and two anomalies discovered. 1987

Fort Wainwright added to NPL August 1990

PSE conducted and 801 Drum Burial Site assigned to OU2 for RI/FS 1991

FFA signed 1992

TPA signed 1992

PSE2 conducted followed by excavation and removal of 92 drums from site,18 containing some amount of product. Drilling, installation, and sampling of6 groundwater monitoring wells and 18 microwells performed.

1992 & 1993

801 Drum Burial Site transferred from OU2 to OU1 and 3 additional monitoring wells installed. Geophysical survey conducted and fouradditional areas located for further investigation.

1994

Management Plan, OU1, Remedial Investigation/Feasibility Study issued August 1995

26 drums (8 containing some amount of product) removed during RI activities. Two additional monitoring wells installed and sampled. 1995

Additional geophysical surveys conducted and 118 drums were subsequently removed, 46 containing some amount of product. 850 cubicyards of pesticide-contaminated soil removed during excavation andstockpiled on site in two lined containment cells for later management. Six additional monitoring wells installed and the first quarterly groundwatersampling performed.

September 1996

Proposed Plan for Remediation for OU 1 issued February 1997

Stockpiled soil removed from site for final disposition 1997

OU1 Record of Decision signed June 1997

Additional excavations performed based on previous geophysical surveysbut no additional drums discovered October 1997

Final OM&M for 801 Drum Burial Site issued December 2000

Interim Remedial Action Report issued May 2001

4.2 801 Drum Burial Site

4.2.1 Overview

The 801 Drum Burial Site (Figure 4-1) is located between the west bank of the Chena Riverand Fegree Road and south of the Alaska railroad bridge. It covers an area of approximately20 acres. The site was discovered during construction of a storm sewer in the summer of 1992,as part of the 801 contract housing construction project. Numerous drums were reportedly


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removed from the area during initial construction. In the fall of 1992 and in 1995 excavation anddrum removal activities were undertaken. Sampling results showed elevated levels of POL,pesticides and solvents in soil and groundwater at this location. Additional drums were foundand removed during the 1995 remedial investigation 1996 follow up investigation. The Record ofDecision was signed June, 1997. Monitoring wells to determine potential contamination migrationwere installed; sampling is conducted currently on a yearly basis; every third year a comprehensiveevent conducted, the other two years only a small monitoring event takes place. Long-termmonitoring at the site will continue. Institutional controls (ICs) are in place, and an informational signwas installed at this source area in 2001 to inform the public of restricted activities at this site. EPAdetermined this remedy to be operational and functional as of May 30, 2001. The Operations,Maintenance and Manual has been written, and the Interim Remedial Action Report was receivedin April 2001.

4.2.2 Background

Physical Characteristics

The 801 Drum Burial Site is approximately 0.13 miles east of the 801 Military Housing Area on theeast side of River Road and near the west bank of the Chena River. The area is in a smalldepression between River Road and the Chena River and is currently undeveloped and vegetatedwith grass, brush and trees. Groundwater in the area of the Drum Burial Site is shallow, varyingfrom about 5 feet to 15 feet below ground surface (bgs) across the site. Groundwater levelmonitoring has shown groundwater flow direction to be generally consistent with the regionallywest-northwesterly flow direction. However, the groundwater flow direction and gradient fluctuateseasonally and with the water level and flow of the Chena River. During periods of high water andflow in the Chena River, the groundwater flow direction on site is generally to the west, away fromthe river. During low water and flow, usually in the winter and early spring, the groundwater flowdirection is eastward, toward the river.

History of Contamination

The 801 Drum Burial Site formerly was used as a drum storage area and disposal area. Drumsstored at this source area reportedly contained diesel fuel, gasoline, jet fuel, solvents, asphalt,pesticides, and lubricants. Aerial photographs from the 1950s and 1960s indicate that a pit wasin the southwest corner of the storage area. Subsequent aerial photographs show that the pit wasfilled. During summer 1992, buried drums were found during construction of a storm sewerthat runs west-east through the source area and outfalls in the Chena River. Numerous drumswere removed during these construction activities.

Land and Resource Use

The 801 Drum Burial Site is across River Road from a military housing area and between thehousing area and the Chena River. The ROD described land use at this source area asrecreational. The land use is expected to remain recreational due to its location and the access itprovides to the Chena River. River Road is elevated at this location, providing a physical barrierthat prevents typical surface water runoff from reaching the housing area. The road directs localsurface water runoff to the Chena River, which is directly adjacent to the source area.


4-4

Some nonmilitary residents north of the Chena River obtain drinking water from the College Utilitieswell located approximately 1.25 mile west of the post on the southern bank of the Chena River.Downgradient of the 801 Drum Burial Site, there are residential and commercial wells that provideresidential and bottled drinking water respectively. Residents of the 801 Military Housing Areaobtain their drinking water from the Golden Heart Utilities water system. Groundwater use isconsidered residential because water supply wells for the City of Fairbanks are located in the sameunconfined aquifer as groundwater contamination downgradient of the source area.

Pre-ROD Response

As part of the PSE process at the 801 Drum Removal Site in 1991, numerous geophysical surveyswere conducted, and over 126 drums were removed from this area during 1992-93. Drum contentswere sampled and found to contain aqueous liquid, organic solids, flammable organic liquid, andchlorinated organic liquid. During these removal actions, over 150 cubic feet of soil was removedand taken to a landfarming facility located south of the landfill. The excavation was lined withvisqueen and backfilled in imported sandy silt. The area was graded to match the original slope andexcavation.

Based on the findings of geophysical surveys, another removal action was conducted in 1996 andan additional 118 drums (some of which were found to contain fuels, solvents, pesticides, andlubricants) were removed. Approximately 850 cubic yards of pesticide and diesel range organics(DRO) contaminated soil was removed and stockpiled pending a treatability study anddetermination of ultimate disposition.

4.2.3 Remedy Selection

Nature of Contamination

Sampling conducted prior to and during the remedial investigation detected petroleumhydrocarbons, volatile organic compounds (VOCs), pesticides, and heavy metals in surface soil,subsurface soil, and groundwater; heavy metals in Chena River water samples; and VOCs,pesticides, and heavy metals in Chena River sediments. Of these, two organic compounds, twopesticides, and diesel range POL were reported in concentrations requiring remediation.

Preliminary data suggested that contaminant plumes in the groundwater were migrating from theknown source areas, however, migration rates were undetermined due to complexity ofgroundwater movement in the area. The results of the remedial investigation also suggested a highpotential for the contaminants to migrate to the Chena River and affect downgradient groundwaterusers if not controlled.

Remedial Action Objectives

A baseline risk assessment indicated the need for remedial action at the 801 Drum Burial Site, andthe following RAOs were established:


4-5

Groundwater

• Ensure that groundwater use at the 801 Drum Burial Site meets federal andstate standards.

• Minimize potential migration of contaminated groundwater to the Chena Riverand downgradient drinking water wells.

• Establish and maintain institutional controls to ensure that the groundwaterwill not be used until federal and state maximum concentration limits (MCLs)are attained, except for activities undertaken to initiate the selected remedies.

Soil

• Prevent further leaching of contaminants from soil to groundwater.

• Reduce risks associated with exposure to contaminated soil and drums.

• Prevent migration of soil contaminants to groundwater which could result ingroundwater contamination and exceedances of federal MCLs and AlaskaWater Quality Standards (AWQS) (18 Alaska Administrative Code [AAC] 70).

ARARs

The OU1 ROD cited the most significant ARARs for remedy selection at this source area to be:

• Federal and State of Alaska MCLs - Relevant and appropriate forgroundwater

• National Oil and Hazardous Substances Pollution Contingency Plan (NCP)off-site disposal rules - Applicable for disposal of drums and contaminated soil

Cleanup Goals

Based on the results of the baseline risk assessment for current (at the time of the ROD) andprojected land use at the source area, the following cleanup goals were established1:

Groundwater

Federal and State of Alaska drinking water MCLs were adopted as groundwater cleanup goals for1,1-dichloroethene, benzene, and vinyl chloride at the 801 Drum Burial Site. Concentrations

1 See OU1 ROD, Table 7-1.


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corresponding to calculated excess lifetime cancer risks of 1X10-6 for residential exposurescenarios were adopted as the cleanup goal for the pesticides aldrin and dieldrin since there wereno MCLs for these contaminants.

Soil

Soil cleanup goals for this source area were established for aldrin and dieldrin based on calculatedexcess lifetime cancer risks of 1X10-4 for a residential exposure scenario. Diesel range organics(DRO) will be cleaned to levels consistent with State of Alaska regulations (18 AAC 75).

Numeric values for the cleanup goals established in the ROD are summarized in Table 4-1.

Selected Remedy

The remedy selected for the 801 Drum Burial Site consisted of:

• Locating potential buried drums and, if found, removing and disposing ofdrums and contaminated soils, while restricting access to the source areaduring this work.

• Establishing and maintaining institutional controls to ensure that thegroundwater will not be used until federal and state maximum concentrationlimits (MCLs) are attained, except for activities undertaken to initiate theselected remedies. Institutional controls include restrictions governing siteaccess, construction and well development or placement as long ashazardous substances remain on site that preclude unrestricted use.

• Natural attenuation of groundwater with long-term groundwater monitoring

• A groundwater contingent remedy which includes an air sparging and soilvapor extraction (AS/SVE) system to specifically treat VOCs. This remedy willbe implemented if the plume shows an increasing trend over any threeconsecutive sampling events, or if designated monitoring points indicate theplume is migrating.

4.2.4 Status of Remediation

Drum and Soil Removal

Three separate removal actions for drums and soil were conducted in 1992 and 1996. Theseactions were conducted under the Army’s removal authority and were documented in DecisionDocuments, which have been placed in the Administrative Record. Based on geophysical


4-7

surveys conducted at this source area, it is believed that all drums were removed during theseefforts. Contaminated soil was excavated and treated.1

Groundwater Monitoring

Groundwater monitoring at this source area began after the signing of the ROD in September 1997and is ongoing. Monitoring is accomplished by means of sixteen wells constructed of 2-inchdiameter PVC screened across the water table and varying in depth from 20 to 40 feet belowground surface. Beginning in March 1998, the RPMs agreed that the groundwater monitoringfrequency could be reduced from quarterly to annual sampling based on results that demonstratedno new migration of contaminants and little or no change in contaminant concentrations at thewells.

In 1999, the monitoring program was modified to sample for pesticides in two of the wells in oddnumbered years and to sample all wells for pesticides and VOCs in even numbered years. In 2000,the monitoring program was reevaluated by the RPMs and the monitoring regime modified to that inplace today:

• Two wells will be sampled for pesticides in Spring 2001 and 2002.

• All wells will be sampled for pesticides, gasoline range organics (GRO), DROand metals in 2003. Eleven (11) of the wells will be sampled for VOCs.

• This sequence of sampling (2 wells for 2 years followed by all wells the 3rd

year) will be continued pending future review of monitoring results.

Results of the 2000 annual sampling indicate little or no change in the analytes tested since theDecember 1996 sampling event, with the exception that cis-1,2-dichloroethene was detected aboveMCLs. Plate 4-I (see appendices section of report) summarizes the results of groundwatermonitoring associated with this source area for the years 1997 to 2000. Target analyteconcentrations at perimeter wells along the eastern, southern and western margins of the siteeither remained constant (well AP-7163) or were non-detect, indicating that contaminant migrationis under control. Results from the 2001 sampling event further corroborated this finding, as noexceedances were reported and none of the analytes were detected in the two sentinel wellssampled.

Passive remediation is the selected remedy at this source area, and as a result, there is no systemoperations and maintenance per se. Monitoring wells are maintained as necessary, as is access tothe wells. EPA determined the remedy at the 801 Drum Burial Site to be operational and functional.An Operations, Maintenance and Monitoring Manual (OM&M) for the 801 Drum Burial Site, datedDecember 2000, provides specific procedures and protocol for ongoing maintenance andmonitoring for the source area. The RPMs review the results of groundwater sampling and analysisas the data become available, and review the groundwater monitoring program for this OU on anannual basis.

1 Section 9 discusses the phytoremediation treatability study.


4-8

Institutional Controls

ICs at the 801 source area have been implemented. An informational sign describing these ICs wasposted at the source area in 2001, and Fort Wainwright has established a post wide IC policy for allknown or suspected contaminated sites.1 This policy will be updated in December 2001.

This policy ensures that:

• No unauthorized intrusive actions take place at this source area,

• No potable water wells are installed on this source area, and

• No soil excavation can take place without prior briefings on potential concernsat the source area, knowledge of the procedures for handling contaminatedsoils on Fort Wainwright, and possession of a valid site-specific FortWainwright Excavation Permit.

USARAK DPW maintains a Geographic Information System (GIS) database with information on allof the contaminated sites on post. The DPW is responsible for ensuring ICs on Fort Wainwright.ICs will remain in place as long as hazardous substances remain on site at levels that precludeunrestricted use. Excavation and groundwater intrusion at this source area is restricted subject toapproval by DPW Environmental. There have been no unauthorized activities at this site, and theinstitutional controls are accomplishing the intended purpose.

Since there is no ongoing surface contamination at the 801 Drum Burial Site, access to the area fornon-intrusive activities is unrestricted. Figure 4-2 depicts the boundary of the area in which intrusiveactivities are restricted.

Contingent Remedy

Based on groundwater monitoring results to date, the drum and contaminated soil removals appearto have successfully controlled what had been an ongoing source of groundwater contamination.As a result, it has not been necessary to implement the contingent remedy, and SVE/AS is notanticipated at this time.

Site Inspection

The 801 Drum Burial Site was inspected on April 27, 2001. All wells appeared to be in goodcondition at that time, and no unusual conditions were observed.

1 Further details of the Army/Fort Wainwright IC policy can be found in the OU5 ROD, the U.S. Army Alaska Institutional ControlsStandard Operating Procedures [(APVR-RPW [200-1)], and a September 1999 Memorandum on Institutional Controls[(APVR-RPW-EV-(200-1c)] from Major General Dean W. Cash, Fort Richardson, Alaska.


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4.2.5 Five-Year Assessment

Are the Remedies Functioning as Intended by the Decision Document?

The selected remedies for the 801 Drum Burial Site are operating as intended. Monitoring results todate at the 801 Drum Burial Site1 indicate that there have been no significant changes incontaminant concentration. No increases in concentrations or additional contaminants have beenobserved during the monitoring program that would suggest on-going sources contributing to thecontamination.

Concentrations of volatile organic compounds and pesticides in the identified plume are generallystable with some minor variation over the monitoring period. Groundwater monitoring resultsindicate that the identified plume has not migrated from the source area and that the concentrationsreported in the 2000 and 2001 sampling results indicate no significant changes in concentrationsfor the pesticide and VOC analytes. Dieldrin and several VOCs remain above the MCLs in somelocations. ICs are in effect and will continue to restrict groundwater use.

The most recent monitoring data for the 801 Drum Burial Site was collected in March of 2001 at thetwo perimeter wells. No pesticides were detected in water samples taken from these wells.

The following table summarizes performance to date related to the RAOs for this source area:

REMEDIAL ACTION OBJECTIVE PERFORMANCE TO DATE

Ensure that groundwater at the 801 Drum BurialSite meets federal and State standards.

The contaminants dieldrin and severalVOCs remain above the MCLs ingroundwater.

Minimize potential migration of contaminatedgroundwater to the Chena River and downgradientdrinking water wells.

Perimeter wells indicate no migration ofcontaminants from the source area to theChena River or to the 801 housing area.Monitoring records indicate stableconcentrations of contaminants with littlevariation over the past few years.

1 Ref. ENSR 2001 Annual Groundwater Monitoring – 801 Drum Burial Site report


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Establish and maintain institutional controls toensure that the groundwater will not be used untilfederal and state MCLs are attained, except foractivities undertaken to initiate the selectedremedies detailed in the ROD. Institutional controlsinclude restrictions governing source area access,construction, and well development or placementas long as hazardous substances remain on site atlevels that preclude unrestricted use. The Armyshall ensure compliance with the institutionalcontrols in place at this source area becausenoncompliance will violate a requirement of theROD and therefore violate the Fort WainwrightFederal Facility Agreement between the Army, U.S.EPA, and ADEC.

Institutional controls are in place perAPVR-RPW (200-1) andAPVR-RPW-EV-(200-1c) and areeffectively controlling exposure pathwaysthat could result in unacceptable risk.

Prevent further leaching of contaminants from soilto groundwater.

Drum removal and pesticide contaminatedsoil removal were effective in removing thesource and further leaching ofcontaminants to groundwater.

Reduce risk associated with exposure tocontaminated soil and drums.

Drum and contaminated soil removal hasreduced this risk.

Prevent migration of soil contaminants togroundwater, which could result in groundwatercontamination and exceedances of state andfederal MCLs and Alaska Water Quality Standards.

Drum removal and pesticide contaminatedsoil removal are believed to have beeneffective in removing the source andfurther leaching of contaminants togroundwater. Ultimate effectiveness to bemeasured by achieving groundwaterRAOs.

Are the Assumptions Used at the Time of Remedy Selection Still Valid?

• The assumption that contamination in soil will not leach further into thegroundwater appears to be valid based on groundwater monitoring results todate (ENSR, 2001).

• The assumption that the groundwater contamination will not migrate off of thesite is validated by the groundwater monitoring results to date (ENSR, 2001).

• The assumption that the contamination will naturally attenuate is still valid,however the attenuation rate is very slow and the point in time whengroundwater cleanup goals will be achieved cannot be estimated from thegroundwater monitoring results at this time.

• The institutional controls are effectively restricting exposure to groundwater.


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• There are no known changes in exposure pathways or populations at risk.

• The MCLs used to establish groundwater cleanup goals for the 801 DrumBurial Site have not changed since the ROD.

• There have been no changes in MCLs for 1,1-dichloroethene, benzene, andvinyl chloride.

• There have been no changes in groundwater risk based cleanup levels forcontaminants without MCLs since the ROD.

• Risk factors associated with aldrin and dieldrin have not changed since theROD.1

Has any Other Information Come to Light That Could Call Into Question theProtectiveness of the Remedy?

• No other information has arisen that would question the protectiveness of thecurrent remedy.

Variances

VARIANCES CURRENTLY AFFECTS PROTECTIVENESS(Y/N)

ICs cover too large an area. ICs as drawn by theGIS database encompass a much larger area thanis affected by the OU1 contamination. The areamerges with OU3 at the Railcar Off-Loading Facility(ROLF) to the east and extends far to the southbeyond any identified contamination.

No

Recommendations and Follow-up Actions

Recommendations/ Follow-UpActions

PartyResponsible

OversightAgency

MilestoneDate

AffectsProtectiveness

(Y/N)

Redraw IC boundaries to moreclosely coincide with thecontaminated area.

U.S. Army EPA, ADEC 3/02 N

1 Based on review of IRIS history of changes for these contaminants.


5-1

5 OPERABLE UNIT 2

5.1 OU2 Background

OU2 originally consisted of the following eight source areas: the North Post Site, the 801 DrumBurial Site, the Engineers Park Drum Site, the Drum Site South of the Landfill, Building 3477, fourTar Sites, the Defense Reutilization and Marketing Office (DRMO) Yard, and the Building 1168Leach Well. All OU2 source areas underwent PSEs, which included historical record reviews and,as necessary, limited field investigations. Subsequent IRP management of these source areas wasbased on the results of the RI as follows:

• The 801 Drum Burial Site, Engineers Park Drum Site and the Drum Site South ofthe Landfill were all moved to the OU1 ROD.

• North Post Site was addressed under the TPA.

• Building 3477 and the Tar Sites were moved to NFA status

• Building 1168 Leach Well and the DRMO are the only two source areasrecommended for further action under OU2, based on potential risk to humanhealth and the environment.

5.2 Building 1168 Leach Well

5.2.1 Overview

Building 1168 (Figure 5-1) was constructed in 1950 as a lubricant oil and vehicle storagefacility and was converted to a POL laboratory around 1962. It is located near the westernboundary of Fort Wainwright, adjacent to Trainor Gate Road. The contamination covers anarea of approximately 50 feet from the leach well with a thickness of approximately 5 feet.The primary source of contamination was from a former leach well connected to an oil/waterseparator system. Contaminants found at this site included POL, solvents and heavy metals.The decision to treat this source was influenced by its proximity to post boundary (500 feet)and a public school (1,000 feet). Remedial action was undertaken for in-situ treatment ofcontamination. Installation of the air sparge/soil vapor extraction system was completed inNovember 19941, and active AS/SVE. continued through 1998. The system was turned offafter RAOs for non-POL contaminants were achieved, but groundwater monitoring hascontinued through 2001 to ensure that contaminant concentrations are stable before thesystem is decommissioned. The AS/SVE system is slated for removal from Building 1168in 2001, making system components available for use at other IRP sites on Fort Wainwright. Along-term monitoring plan has been agreed to by EPA, ADEC, and the Army. This plan will be

1 The Army has designated construction of this remedial action as complete for project tracking and accounting purposes.


5-2

reviewed and updated at least yearly. The Operations, Maintenance and Monitoring (OM&M) andInterim Remedial Action reports for this source area are complete.

5.2.2 Background

Periods of use and dates related to the history of Building 1168 contamination and remediationinclude the following1:

EVENT DATELube oil and vehicle storage facility operations. 1949 to 1962Converted into a petroleum test laboratory. 1962Groundwater survey conducted and EPA recommends further investigation. 1990Fort Wainwright NLP listed. August 1990FFA signed 1992TPA signed 1992PSE conducted 1992 and 1993RI conducted 1994Source area pilot-scale AI/SVE remediation system installed November 1994FS completed 1996ROD signed January 1997Building 1168 Demolished 1997Active AI/SVE treatment completed 1998RAR completed May 1999Final OM&M issued December 2000


The Building 1168 source area is within the main post confines and located north of Trainor GateRoad, adjacent to the Trainor gate entrance. The site is bounded by undeveloped land on threesides (north, east, and west) and Trainor Gate Road (south). A Fairbanks public school is within1,000 feet northwest of this site, and the 801 military housing area is approximately 300 feet southof the site. The nearest surface water body, the Chena River, is approximately 1800 feet to theeast. No surface water drainage pathways are evident.

Subsurface soil at this site consists of unconsolidated lenses of interlayered silt, silty sand andpoorly graded sand and gravel. Predominant groundwater flow is generally to the west-northwest following the trend of the Tanana River Valley, however seasonal changes in flow

1 Information obtained from the OU2 ROD, Building 1168 RAR, Building 1168 OM&M Manual, and the Five-Year Review ReportDocument Log.


5-3

direction may occur due to the influences of water level changes in the Chena River locatedapproximately 1,800 feet to the east.


Building 1168 was demolished during the summer of 199, and the former building site is now a flat,graded gravel lot. The current land use designation is “industrial”, which it is expected to remain forthe foreseeable future. Groundwater use is considered residential because water supply wells forthe City of Fairbanks are located in the same unconfined aquifer as groundwater contaminationdowngradient of the source area.


Contamination at Building 1168 originated from a leach well that received liquids collected in floordrains within Building 1168. From the 1950s to 1997, Building 1168 was used as a lubrication oiland vehicle storage/shop facility, and a POL laboratory. Floor drains in the building formerlydischarged into an oil/water separators designed to allow POL to flow into a storage tank andwastewater to flow through a 4-inch diameter buried waste line to a leach well approximately 100feet southwest of the former building. The oil/water separator system was decommissioned in 1993.Because of system malfunctions during the 40 years of service, some products entering theoil/water separator were inadvertently conveyed directly to the leach well, subsurface soil, andgroundwater. Products suspected to have entered the leach well include oil from engines andtransmissions, gasoline, diesel, jet fuel, and solvents.

Pre-ROD Response

The initial response to contamination identification at Building 1168 Leach Well was to install atreatability study AS/SVE system in 1994.



Contaminated soils associated with the leach well appears to be the source of contaminationdetected in the groundwater which is located approximately 12 feet to 17 feet BGS. Initial siteinvestigations discovered a zone of hydrocarbon contamination approximately four to five feet thickin subsurface soils near the groundwater interface and extending approximately 50 feet radiallyfrom the leach well. Contamination from these subsurface soils created a commingling benzeneand trichloroethene (TCE) plume in the groundwater 20 feet to 50 feet BGS. Initial chemicals ofconcern for remediation at this site included the following:

Groundwater

RI results confirmed the presence of the VOCs benzene, trichloroethene, vinyl chloride, 1,1-DCE,and 1,2-DCE in groundwater above MCLs.


5-4

Soil

Subsurface soils were found to contain DRO, GRO and benzene, toluene, ethylbenzene, andxylenes (BTEX). The release mechanism precluded significant surface contamination at this site.


RAOs for the Building 1168 Leach Well source area and the DRMO Yard are identical and werebased on federal and state ARARs. All groundwater RAOs were based on state and federal MCLs.Soil RAOs were based on State of Alaska cleanup levels for non-UST petroleum contamination.

The RAOs for groundwater at all OU2 source areas are:

• Restore groundwater to its beneficial use of drinking water quality within areasonable time frame through source control

• Reduce or prevent further migration of contaminated groundwater from thesource areas

• Prevent use of groundwater containing contaminants at levels above SafeDrinking Water Act and State of Alaska Drinking Water Standard MCLs andAlaska Water Quality Standards

• Use natural attenuation to attain Alaska Water Quality Standards (18 AAC 70)after reaching state and federal MCLs

The RAO for soil at all OU2 source area is:

• Prevent migration of soil contaminants to groundwater, which could result ingroundwater contamination and exceedances of state and federal MCLs andAlaska Water Quality Standards (18 AAC 70)

ARARs

The OU2 ROD cited the most significant applicable or relevant and appropriate requirements(ARARs) for remedy selection at this site to be:

• State and Federal MCLs - Relevant and appropriate for groundwater

• Alaska Water Quality Standards - Applicable

• Alaska Oil Pollution Regulations - Applicable

• Alaska Guidelines for Non-UST Petroleum Contaminated Soil - To beconsidered


5-5

Cleanup Goals

Groundwater

Federal and State of Alaska drinking water maximum contaminant levels (MCLs) were adopted asgroundwater cleanup goals for benzene, trichloroethene, vinyl chloride, 1,1-dichloroethene, and1,2-dichloroethene at the Building 1168 Leach Well source area.

Soil

The ROD stated that “Because soils contaminated with VOCs and petroleum-related compoundsare acting as a continuing source of contamination to groundwater, the remedial action goal for insitu soils is active remediation until contamination levels in groundwater are consistently belowstate and federal MCLs. State of Alaska cleanup levels for non-UST petroleum-contaminated soilwill be considered as a guideline for the treatment of in situ soils” at the Building 1168 Leach Wellsource area, and Table 7-2 of the ROD adopted ADEC soil cleanup matrix Level A cleanup goalsfor diesel range organics (DRO), gasoline range organics (GRO), benzene, and (total) BTEX at thissource area.

Numeric values for the cleanup goals established in the RODs are summarized in Table 5-1. Selected Remedy

The goal of this remedial action is to restore groundwater to its beneficial use as a drinking wateraquifer and to remediate soil to State of Alaska cleanup levels for non-UST petroleum-contaminated soil. To achieve the OU2 ROD objectives, the remedial action components specifiedfor the Building 1168 Leach Well Source Area included:

Soil Vapor Extraction and Air Sparging

• In situ treatment of groundwater via air sparging to remove volatile organiccompounds, thereby attaining state and federal drinking water standards.

• In situ treatment of soil via soil vapor extraction to prevent contaminated soilfrom acting as an ongoing source of contamination to groundwater.

• Treatment system evaluation and modification as necessary to optimizeeffectiveness.

• Periodic monitoring and evaluation of air emissions from the soil vaporextraction/air sparging treatment system to meet emission requirements.

• Periodic groundwater monitoring and off-gas measurements to determineattainment of RAOs

Natural Attenuation and Groundwater Monitoring

• Achieve Alaska Water Quality Standards through natural attenuation afteractive treatment attains state and federal maximum contaminant levels.


5-6


• Maintain ICs, including restricted access and well development restrictions, aslong as hazardous substances remain on site at levels that precludeunrestricted use.


Leach Well

In 1994, a pilot scale remediation system was installed around the leach well to determine whetheran in situ treatment system was technically feasible in source area soil and groundwater. Thesystem was modified and expanded in 1996 and 1997 to optimize the effectiveness based onmonitoring data evaluation. The treatment system was designed to operate in the summer months(May through October) only, and operated seasonally until December 1998 when the system wasshut down following achievement of the remedial action objectives. A small rebound in benzene tojust above the MCL was identified in May 2000, but subsequent sampling in September 2000 andMay 2001 show the benzene concentration has dropped below the MCL.


Groundwater monitoring frequency was decreased from quarterly to annual following attainment ofMCLs and system shut down in 1998. However, some minor rebound in concentrations ofcontaminants has occurred since the treatment system was shut down, and, following review by theRPMs, groundwater monitoring frequency was increased to a semiannual basis subject toreconsideration after the May 2002 sampling event.

In general, sample results indicate that groundwater contamination at the site has decreased since1994. This has been attributed mainly to the operation of the treatment system from 1994 to 1998.Plate 5-I summarizes the available results of source area groundwater monitoring data from 1994to 2000 (see appendices section of report). GRO has not exceeded the groundwater cleanup levelssince June 1998 and TCE has not exceeded the MCL since October of 1997. Benzene has alsobeen below the MCL since September of 1998 except for a single spike of 6.5 :g/L in well AP-6809during the May 2000 sampling event. A subsequent benzene concentration of 3.58 :g/L wasdetected in this well during the September 2000 sampling event. DRO levels dropped significantlyin wells GP1 and GP2 at the onset of treatment while PS23 exhibited a slight trend towarddecreasing concentrations. Concentrations at all three locations were below ADEC GroundwaterCleanup Standards at the January 1998 sampling event. Following discontinuation of activetreatment, DRO levels have remained constant in PS23 while GP1 and AP-6809 and HC1 (bothinstalled in June 1998) have exhibited rebound above the ADEC cleanup level of 1.5:g/L.

The Building 1168 site is located near the western boundary of Fort Wainwright and is monitoredby picket wells along the boundary line. No contamination has been detected in any of thesewells above the MCLs. Trichlorofluoromethane was the only contaminant detected in thepicket wells during 2000 sampling activities, but the detected concentrations (1.74:g/L and21.0:g/L) were well below the Risk Based Concentration (RBC) of 1300:g/L. The source of the


5-7

trichlorofluoromethane has not been established but is assumed to not be associated with theBuilding 1168 Leach Well.


Fort Wainwright has established a post wide IC policy for all known or suspected contaminatedsites.1





USARAK DPW maintains a Geographic Information System (GIS) database with information on allof the contaminated sites on post. The DPW is responsible for ensuring ICs on Fort Wainwright.ICs will remain in place as long as hazardous substances remain on site at levels that precludeunrestricted use. Excavation and groundwater intrusion at this source area is restricted subject toapproval by DPW Environmental.

Figure 5-2 depicts the Building 1168 area subject to restricted use under the IC policy.

Site Inspection

A site inspection was conducted on April 27, 2001 and included inspecting the condition of themonitoring wells and treatment system container. All wells appeared to be in good condition. Thesystem was in place but not operating as discussed above.



Remedial Action Performance

The selected remedies for Building 1168 are operating as intended. The remediation goals weremet using AS/SVE in the contaminated area. Groundwater monitoring results indicate that theidentified plume has not migrated from the site area. The concentrations identified in the May 2000sampling indicate a slight rebound resulting in benzene concentration just above the



5-8

MCL before dropping back below the MCL in September 2000. Further rebound is judged unlikely,and no significant increases in concentrations of VOCs or other organic contaminants isanticipated.

2000 annual monitoring data indicate that benzene concentrations rebounded to 6.5 ug/L in May inthe down-gradient well AP-6809, just above the MCL of 5.0 ug/L. In the September 2000 monitoringevent the concentration of benzene in that well was 3.9 ug/L, and in May 2001 the benzeneconcentration remained below the MCL at 4.48 ug/L (HartCrowser Annual Monitoring Reports).

Contamination has not been detected above MCLs in the picket wells along the post boundary line.

Plate 5-1 summarizes the results of groundwater monitoring associated with this source area.

Implementation of Institutional controls.

ICs are in effect and will continue to restrict groundwater usage.

System Operations/O&M

The AS/SVE system that was installed and operated at Building 1168 to treat the soil andgroundwater is no longer in use but has not yet been removed from this location. Restarting thesystem was considered following the detection of a rebound in benzene concentration in one well.However, since the benzene concentration has returned to below the MCL for the past year, thesystem will not be restarted. Groundwater monitoring will proceed on a semiannual basis until May2002 sampling and analysis further confirms benzene to have stabilized at a concentration belowthe MCL.

The following table summarizes performance to date related to the RAOs for this source area.

Remedial Action Objective Performance to Date

Restore groundwater to its benefical use of drinkingwater quality within a reasonable time framethrough source control

MCLs have been reached, however DRO remainsabove the ADEC 18 AAC 75 groundwater cleanuplevel.

Reduce or prevent further migration ofcontaminated groundwater from the source areas

Little or no migration of contaminants from thesource area to groundwater is occuring based onresults from the groundwater monitoring program.

Prevent use of groundwater containingcontaminants at levels above Safe Drinking WaterAct and State of Alaska Drinking Water StandardMCLs and Alaska Water Quality Standards(AWQS)

ICs are in effect to restrict groundwater use.

Use natural attenuation to attain AWQS (18 AAC70) after reaching state and federal MCLs

Natural attenuation is the primary remedial actionsince discontinuing the AS/SVE system operation.


5-9


• The assumption that contamination in soil will not leach further into the groundwaterappears to be valid based on groundwater monitoring results. The assumption that thegroundwater contamination will not migrate off of the site is validated by the groundwatermonitoring results on site and at the boundary picket wells.

• Despite the temporary rebound in benzene, the assumption that the contamination willnaturally attenuate is still correct, however the rate for DRO is slow and can not beaccurately estimated from the groundwater monitoring results at this time. ICs are in effectand will continue to restrict groundwater usage.


• The MCLs used to establish the groundwater cleanup goals for the Building 1168 LeachWell source area have not changed since the ROD.

Has any Other Information Come to Light That Could Call Into Question the Protectivenessof the Remedy?

No other information has arisen that would question the protectiveness of the current remedy.

Variances

Variances Currently Affects Protectiveness (Y/N)

IC location is drawn on 2-party site rather thanthe leach well in OU2

Not likely that any wells will be installed in thislocation.


The IC boundary should encompass the area of potential exposure to both Leach Well and TPAsite contamination. No changes are recommended for the current remedial actions or groundwatermonitoring program. Data from the groundwater monitoring program should be evaluated as it isreported to assure no off-site migration of contaminants and to evaluate progress of naturalattenuation.

Recommendations/Follow-up Actions

PartyResponsible

OversightAgency

MilestoneDate

Affects Protectiveness(Y/N)

Redraw the ICboundary around theentire source area(CERCLA and TPA)

U.S. Army EPA,ADEC 3/02 N


5-10

5.3 OU2 – DRMO Yard

5.3.1 Overview

Contamination was originally identified at six subareas at the DRMO yard (Figure 5-3). Twosubareas with petroleum and solvent contamination are part of OU2, and the others are addressedin the TPA or were identified in the ROD as requiring no further action (NFA). Contaminants foundat the DRMO Yard were solvents and petroleum in the soil and groundwater. The site is locatedalong Badger Road, northwest of the intersection of Badger Road and the Old RichardsonHighway, on the eastern boundary of Fort Wainwright. The salvage yard is a fenced compoundcovering approximately 25 acres. Spills occurred routinely at the DRMO Yard in the past. TheRemedial Investigation/Feasibility Study was completed in October 1994. The ROD was signed inApril 1997, with the chosen alternative being air sparging/soil vapor extraction with groundwatermonitoring. The AS/SVE system was installed during the summer of 1997, and new groundwatermonitoring wells were installed outside the northwest fence line, at the DRMO water supply well, atBuilding 5010, and inside the south fence line. The monitoring wells outside the northwest fenceline are picket wells to provide information related to off-site migration of contaminants from thissource area towards Channel B, a man made trench constructed as part of the Chena River floodcontrol project.

5.3.2 Background

The DRMO Yard source area was divided into six sub-areas for remedial investigation purposes.Of these six subareas, three (DRMO2, DRMO3, and DRMO5) were found to havepetroleum-related contamination without commingling with other contaminants of concern. Thesesites are addressed under the TPA. Contamination in another of the subareas (DRMO6) wasdetermined to warrant no further action. Two of the subareas (DRMO-1 and DRMO-4) were carriedthrough to remedial action under CERCLA. DRMO1 and DRMO5 design study treatment systemsfor petroleum contamination are being operated under the TPA and will not be discussed further inthis section.

There are currently three active remediation systems in place at the DRMO Yard: 1) the DRMO1design study treatment system, 2) the DRMO5 design study treatment system, and 3) the OU2ROD design study treatment system. The OU2 ROD treatment system located in DRMO1, is beingoperated under CERCLA; DRMO1 and DRMO5 treatment is being conducted under the TPA.

Periods of use and dates related to the history of DRMO yard contamination and remediationinclude the following1:

EVENT DATE

Vechicle storage and vehicle maintenance shop activities 1945 to 1961

Site converted to salvage yard and drum storage 1961

1 Information obtained from OU2 ROD; August 1999 OU2 RAR; 1999 Monitoring Report, North Post, DRMO1, and DRMO5 Sites; DraftComprehensive Annual Monitoring Report (February 2000); and the Five-Year Review Report Document Log.


5-11

Diesel spill near Building 5001 Early 80s

Removal of eight USTs (cleanup of associated soils are being addressedunder the TPA) 1988 to 1996

FFA signed 1992

TPA signed 1992

Installation and semiannual sampling of 14 monitoring wells at the DRMO yard aspart of the Arctic Surplus site investigation 1990 to 1993

Fort Wainwright NPL listed August 1990

Soil and groundwater contamination discovered north of Building 5001 duringinvestigation for construction of a building foundation July 1992

PSE2, Phase 2, conducted at DRMO yard to assess extent of soilcontamination September 1992

Proposed Plan for Remediation made available to public April 1996

OU2 RI and FS issued 1996

AS/SVE systems installed at sub-areas DRMO1 and DRMO5 as part of apetroleum hydrocarbon treatability study (performed under the TPA) Summer of 1996

OU2 Record of Decision signed January 1997

ROD Design Study System in sub-area DRMO1 is commissioned July 1997

OU2 RAR completed August 1999

Final DRMO OM&M issued December 2000

Final OU2 Design Study System OM&M issued June 2001


The DRMO Yard is an approximately 25 acre, fenced compound located near the eastern end ofthe post on the west side of Badger Road. The yard is bordered by the Alaska Railroad tracks onthe south and a channel of the Chena River Flood Control Project on the west. Groundwater flow isgenerally toward the west following the regional flow of the Tanana River Valley. At the westernboundary there may be some minor short term influences due to water level fluctuations in the manmade channel (Channel B) located on the western boundary of the DRMO Yard.


The DRMO Yard’s function is to store obsolete, surplus, unserviceable equipment and supplies fortransfer to another authorized user, for public auctions, or for destruction and disposal. The yardcontains numerous aisles of surplus appliances, tires, transformers, and wire. Additionally, it servesas the hazardous material transfer point for Fort Wainwright, Fort Greely, and Eielson Air ForceBase and operates as a storage facility in accordance with the Fort Wainwright RCRA Part BPermit. The land use is currently designated “industrial” and is expected to retain that designationfor the foreseeable future.


5-12

Three residential areas are nearby the DRMO Yard. The first is approximately 1400 feet to thenorth, the second is approximately 1,000 feet to the northeast, and the third is approximately 400feet to the southwest. All three subdivisions use groundwater as their drinking water source andtheir wells are located in the same unconfined aquifer as that associated with the DRMO Yardgroundwater contamination. Groundwater in the area generally flows west to northwest, away fromthese residential areas; however, fluctuations in flow direction occur.

A Class C public drinking water well and fire suppression system exist on site, but their use hasbeen restricted by institutional controls enacted under a State of Alaska Plan Approval to Construct.The ROD specified that, with the exception of emergencies, the fire suppression water tank not berefilled from the DRMO Yard water supply well until after MCLs are met. Groundwater use isconsidered to be residential.


From 1945 to 1961, the DRMO Yard was used for vehicle storage and contained a vehiclemaintenance shop. In 1961 the source area was converted into a salvage yard and was used tostore drums of waste oil; pesticides; solvents; vehicle fluids such as antifreeze and hydraulic fluid;asphalt; and electrical transformers, some of which may have contained polychlorinated biphenyls(PCBs). Many drums reportedly leaked. Items such as mattresses, wood furniture and possiblyplastics were incinerated routinely in a burn pit and it is likely that the drummed fluids were alsodisposed of by burning. Waste oil, which historically contained heavy metals, solvents, PCBs, andother contaminants, was used to control dust on roads in the DRMO Yard during the 1970s andearly 1980s. During the early 1980s, an estimated 3, 000 gallons to 8, 000 gallons of No. 1 dieselfuel were spilled near the former location of building 5001. Cleanup activities of that spill includedspreading the contaminated soil throughout the yard. Storage and destruction records weremaintained by DRMO Yard personnel for three years and then were destroyed. Complete recordsof DRMO Yard activities are therefore unavailable.

Pre-ROD Response

From 1988 to 1996, eight leaking underground petroleum storage tanks, ranging in size from 500gallons to 10, 000 gallons were removed from the DRMO Yard. Cleanup of the associatedpetroleum-contaminated soil and groundwater is being conducted under the TPA.



DRMO1 (OU2 Treatment System)

The DRMO1 subarea was the site of waste oil drum and transformer storage, but no discretesource was identified for the PCE, TCE, DRO, and GRO contamination at this location. A welldefined plume of groundwater contaminated with PCE and TCE was delineated at DRMO1 during1995 RI activities.

In addition to the above contaminants, 1,1-dichloroethene (DCE) and 1,2-DCE are knownbreakdown products of PCE and TCE. Although not detected during the RI, these compounds wereconsidered to be contaminants of potential concern in formulating the RAOs for the DRMO


5-13

Yard. The location of the PCE or TCE release has been determined to be in the active treatmentzone.

DRMO4

Benzene and PCE contamination at the DRMO-O4 source area appears to have resulted frommiscellaneous releases associated with activities occurring along a railroad spur, resulting in asmaller groundwater contamination plume and lower contaminant concentrations than wasevidenced in DRMO1.


RAOs for the DRMO Yard and the Building 1168 Leach Well source area are identical and weredescribed in Section 5.2.3.

ARARS

ARARs for the DRMO Yard and the Building 1168 Leach Well source area are identical and weredescribed in Section 5.2.3.

Cleanup Goals

Groundwater

Federal and State of Alaska drinking water maximum contaminant levels (MCLs) were adopted asgroundwater cleanup goals for benzene, tetrachloroethene, trichloroethene, vinyl chloride,1,1-dichloroethene, and 1,2-dichloroethene at the DRMO Yard source area.

Soil

ADEC soil cleanup matrix cleanup levels were adopted as preliminary remediation goals for dieselrange organics (DRO) in the DRMO Yard source area.

Numeric values for the cleanup goals established in the RODs are summarized in Table 5-1.

Selected Remedy

The goal of this remedial action is to restore groundwater to its beneficial use as a drinking wateraquifer and to remediate soil to State of Alaska cleanup levels for non-UST petroleum-contaminated soil. To achieve the OU2 ROD objectives, the remedial action components specifiedfor the DRMO source area included:

DRMO Yard

• In situ treatment of groundwater via air sparging to remove volatile organiccompounds, thereby attaining RAOs

• In situ treatment of soil via soil vapor extraction to prevent contaminated soilfrom acting as an ongoing source of contamination to groundwater


5-14

• Treatment system evaluation and modification as necessary to optimizeeffectiveness

• Periodic monitoring and evaluation of air emissions from the soil vaporextraction/air sparging treatment system to meet emission requirements

• Periodic groundwater monitoring and off-gas measurements to determineattainment of RAOs

• Natural Attenuation and Groundwater Monitoring

• Achieve AWQS through natural attenuation after active treatment attains stateand federal maximum contaminant levels


• Maintain Institutional Controls, including restricted access, well developmentrestrictions and prohibition against refilling fire suppression water tank fromthe on-site well, as long as hazardous substances remain on site at levels thatpreclude unrestricted use.


DRMO Yard

The OU2 AS/SVE Treatment System was installed at the DRMO1 source area in thesummer of 1997. The system is composed of a blower enclosure, 4 manifold boxes, anda well field. The AS and SVE blowers, electrical components, and soil gas vaportreatment equipment are housed in the enclosure. The AS well field consists of 52 ASprobes with screens 2 feet in length at an approximate depth of 32.5 feet bgs. The SVEcollection is through 16 horizontal screens, each 10 feet in length and buried to a depthof 5 feet bgs within the AS well field.

This AS/SVE system was initially bisected by a soil stockpile. The stockpile wassuspected of contributing to groundwater contamination, potentially limiting theeffectiveness of remediation. After removal of the stockpile, a monitoring well wasinstalled at that location. Sampling results for this well indicated that the AS/SVE systemwas effectively covering the contaminated area. The AS/SVE system is designed tooperate only in the summer months (May through October) and has operated seasonallysince 1997.

Long term monitoring is being conducted at DRMO4. The RPMs made the decision toadd another monitoring well to further delineate groundwater contamination at DRMO4during the July 2001 FFA meeting.


5-15


DRMO1 (OU2 Treatment System)

Groundwater monitoring at DRMO1 is performed on a semiannual basis. The groundwatermonitoring component includes sampling and analysis of the seven OU2 Treatment System wellslocated in and adjacent to the DRMO Yard.

One of these wells, AP-5825, typically associated with the DRMO1 treatment system, has alsobeen sampled for OU2 Treatment System analytes. Additionally, DRMO picket wells located alongthe northwest boundary of the yard have been used to provide a comprehensive analysis of thePCE/TCE plume associated with the OU2 Treatment System.

Four of the five wells located within the predicted PCE/TCE plume have seen significant decreasesin PCE levels since initiation of the OU2 treatment system. The PCE concentration in well AP-6803,located in the main OU2 Treatment System field, has decreased by an order of magnitude since1995 but rebounded slightly in 2000. This rebound is believed to be the result of a rise in the localwater table prior to the 2000 sampling event resulting in flushing of contaminants. The PCEconcentration at this well remains above the RAO. PCE and TCE concentrations in wells AP-7559and AP-7560 are below RAOs. TCE exceeds the RAO in well AP-6804, and are close to the RAOin well AP-6807. The overall decrease in contaminant levels seen in the area of the predictedplume is attributed to the OU2 Treatment System.

PCE/TCE concentrations in the picket wells have consistently been below the RAOs. ObservedPCE concentrations have been limited to the center cluster and have been less than the TCEconcentrations observed. TCE concentrations have been constant at between 2 and 3 µg/L. DROlevels have been at or slightly above the method detection limit since their installation in 1997 andhave not exceeded the ADEC groundwater cleanup level of 1.5 mg/L. GRO has additionally beenwell below the cleanup level since 1997.

DRMO4

The only VOC exceeding its RAO in the DRMO4 subarea is TCE, reported at 36.4 µg/L inSeptember 2000 sampling results. This concentration is an order of ten greater than the TCEconcentration in July 1994. This increase corresponds to a similar magnitude decrease in PCE,suggesting that PCE is degrading to TCE.

Plate 5-II provides an overview of groundwater monitoring results the DRMO Yard.


Access to the site is restricted by a chain-link fence. Controlled access is maintained by theoperators of the DRMO facility. Excavation in the site area is restricted and groundwater intrusion isrestricted. The on-site production well is restricted from filling the fire suppressant tank except inemergency. The IC limits as drawn by GIS are within the fenced area of the DRMO Yard, howeverthe contamination is shown to extend beyond the fenced area to the north in wells AP-6807 andAP-6804 (Figure 5-4 and Plate 5-II).


5-16

Fort Wainwright has established a post wide IC policy for all known or suspected contaminatedsites.1



• No new potable water wells will be installed on this source area, and



Site Inspection

A site inspection was conducted on April 27, 2001. Inspection activities included checking thecondition of the monitoring wells and the completeness of the remediation equipment. The AS/SVEequipment is not equipped to operate during the winter and was idle at the time of the visit. Thefeasibility of operating the AS portion of the treatment system year round is being evaluated at thistime.



Air Sparging and Soil Vapor Extraction

The remedies selected to address VOC contamination at the DRMO Yard site are operating asintended. Groundwater monitoring results indicate that the identified plume has not migrated fromthe site area and that VOC concentrations have generally decreased since the time of the ROD,although no significant changes in VOC concentrations have been observed in the results of 2000and 2001 sampling (HartCrowser Annual Monitoring Reports).

The DRMO1 OU2 Treatment System has been effective in reducing PCE and TCE groundwaterconcentrations in the treatment area. SVE recovery rates have now slowed, indicating that the SVEcomponent of the treatment system may be less effective in removing VOCs than earlier in itsoperation.



5-17 REV. 01

Natural Attenuation with Groundwater Monitoring

Natural attenuation with groundwater monitoring is planned to begin following the attainment ofMCLs. Natural attenuation with groundwater monitoring will continue until Alaska drinking waterstandards are attained.


ICs are in effect and will continue to restrict site access and groundwater usage1.



Restore groundwater to its beneficial use ofdrinking water quality within a reasonable timeframe through source control

Groundwater monitoring reports show reduction inchemicals of concern (COCs) at DRMO1 andapparent degradation of PCE to TCE in DRMO4since the ROD

Reduce or prevent further migration ofcontaminated groundwater from the source areas

Groundwater monitoring since the ROD indicatesthat there has been no further migration ofcontamination from the source area.

Prevent use of groundwater containingcontaminants at levels above Safe Drinking WaterAct and State of Alaska Drinking Water StandardMCLs and Alaska Water Quality Standards (AWQS

ICs restrict groundwater use in this area.

Use natural attenuation to attain AWQS (18 AAC70) after reaching state and federal MCLs

Following attainment of MCLs natural attenuationwill be evaluated by groundwater monitoring.


• The assumption that contamination in soil will not leach further into the groundwaterappears to be valid based on groundwater monitoring results. The assumption that thegroundwater contamination will not migrate off of the site is validated by the groundwatermonitoring results on site and at the picket wells. The assumption that the contaminationwill naturally attenuate is still correct, however the rate is slow and has not beenestimated rigorously from the groundwater monitoring results at this time. ICs are ineffect and will continue to restrict groundwater usage.


1 Post-wide IC policy is outlined in greater detail in the OU5 ROD, the U.S. Army Alaska Institutional Controls Standard OperatingProcedures [(APVR-RPW [200-1)], and a September 1999 Memorandum on Institutional Controls [(APVR-RPW-EV-(200-1c)] fromMajor General Dean W. Cash – Fort Richardson, Alaska.


5-18 REV. 01

• The MCLs used to establish the groundwater cleanup goals for the DRMO Yard sourcearea have not changed since the ROD.



Variances.


IC boundary does not encompass the groundwaterplume to the north of the fenced area.

Not likely that groundwater would be accessedin this location.


The IC limits as drawn by GIS are within the fenced area of the DRMO Yard, however thecontamination is shown to extend beyond the fenced area to the north in wells AP-6807 and AP-6804. IC limits should be redrawn to include the plume extent to the north. No other changes arerecommended for the current remedial actions or groundwater monitoring program. Data from thegroundwater monitoring program should be evaluated as it is reported to assure no off-sitemigration of contaminants and to evaluate progress of natural attenuation following attainment ofMCLs and completion of active treatment.


PartyResponsible

OversightAgency

MilestoneDate

Affects Protectiveness(Y/N)

Redraw the ICboundary to extend tothe north toencompass thegroundwater plume

U.S. . Army EPA,ADEC 3/02 N


6-1 REV. 01

6 OPERABLE UNIT 3

6.1 OU3 Background

OU3 was the first Fort Wainwright OU to reach a final-action ROD. That ROD was signed inJanuary 1996 and initially addressed four source areas:

• Remedial Area 1a: Lead-contaminated soils near AST’s within Birch HillTank Farm

• Remedial Area 1b: Area below Birch Hill Tank Farm and around the TruckFill Stand

• Remedial Area 2: Valve Pit A, Valve Pit B, Valve Pit C, and the RailcarOff-loading Facility (ROLF)

• Remedial Area 3: Milepost 2.7, 3.0, and 15.75 of the Fairbanks-EielsonPipeline

Remedial Area 1a was transferred to OU5. The RPMs agreed to defer selection of a final remedybecause additional time was required to select an appropriate cleanup level and remediation goalfor lead in soils.

6.2 Remedial Area 1b – Below Birch Hill Tank Farm, and Truck Fill Stand

6.2.1 Overview

Remedial Area 1b (Figure 6-1) was divided into the following sub-areas based on geographiclocation and differing physical characteristics:

• Lazelle Road Sub-Area

• Building 1173 Sub-Area

• Truck Fill Stand Sub-Area

• Shannon Park Subdivision Sub-Area

• CANOL Road Sub-Area

• Birch Hill Tank Farm Product Recovery System

The Birch Hill Tank Farm dates back to the early 1940’s. Sampling and monitoring atthis source area, also referred to as the “Fairbanks Fuel Terminal”, covers an areaapproximately 250 acres in the northwest corner of Fort Wainwright. Post-rod studiesindicate a substantial increase in the areal extent of contamination at the site to includefree product within bedrock on Birch Hill. Results of FY98 field season sampling events


6-2 REV. 01

indicated elevated concentrations of EDB and 1,2 DCA in the groundwater in the fractured bedrockon Birch Hill. Further investigation during 1999-2000 indicate that groundwater contaminantsmeasured off-post are likely migrating from the free product identified in the fractured bedrockaquifer on the hill directly under the Tank Farm. The ESD will address product recoveryimplementation in the bedrock aquifer and increased costs for remediating this site. The ESD isanticipated to be completed in FY02. A product recovery system was installed on Birch Hill in 2000and modified in 2001 to capture product. Draft Operations, Maintenance and Monitoring reportshave been completed for adoption for all systems at OU3. Bottled water has been provided tobordering churches since 1995; contamination still remains in their wells at levels below the MCL.Wells were monitored semi-annually until 2000, when the Right of Entry expired. A memorandum ofagreement is being developed to continue monitoring.

6.2.2 Background

Contamination was initially discovered at this site during a soil-gas survey conducted in 1988. Fivemonitoring wells were installed along the western boundary of the Post as part of the base-widegroundwater monitoring program. Initial sampling events found BTEX and petroleum hydrocarbonsat levels above MCLs. Monitoring wells were installed in 1992 near the TFS and in the areabetween the Tank Farm and the Chena River along the post boundary. These wells, served a downgradient monitoring wells and were part of the original FFA. These wells were known as “picketwells” and were monitored twice annually until 1995 when they became part of the closest OU.

Periods of use and dates related to the history of the Birch Hill Tank Farm contamination andremediation include the following1:

EVENT DATE

Soil-gas survey conducted 1988


FFA signed 1992

TPA signed 1992

Picket wells installed 1992

RI fieldwork conducted September andOctober 1994

RI and Risk Assessment Reports submitted to EPA October 1994

FS submitted to EPA April 1995

ROD signed January 1996

1 Information obtained from the OU 3 ROD; Groundwater Extraction and Treatment Effectiveness Review (Oct. 2000); OU 3, 1999Monitoring Report; and the OU 3 Draft ESD.


6-3 REV. 01

AS/SVE system installed at Building 1173 and Lazelle Road 1996

Lazelle Road system relocated to the Truck Fill Stand and the Building 1173system expanded to cover Lazelle Road source area. 1997

Product recovery treatability studies initiated at the Birch Hill Tank Farm. 1998

Thaw Channel treatment system installed 1999

ESD submitted to document installation and operation of existing AS/SVEtreatment systems; operation of the duel phase product recovery system onBirch Hill; continuation of groundwater modeling; and concomitant changesin remedial costs.

September 2001


Remedial Area 1b extends south from the base of Birch Hill to the Truck Fill Stand (TFS) andextends west toward Lazelle Road and east toward the CANOL service road. This area is locatedin the Chena River floodplain and is characterized by flat topography that gently slopes southward.The subsurface is typified by discontinuous permafrost and poorly drained soils covered by thickorganic mats. Surface water ponding is common throughout the area from spring breakup untilearly to mid-summer. Wetlands are scattered throughout the area and shrub and forested wetlandsborder the southern portion. The Tank Farm Source Area has two distinct hydrogeologic areas: 1)the Birch Creek schist bedrock aquifer located from the top of the hill to the base of the hill, whichincludes the area beneath the aboveground storage tanks (ASTs) on Birch Hill; and the alluvialaquifer with discontinuous permafrost located south and west of the TFS, which includes privateproperty, the Bentley Trust Property and Church property.

Birch Hill consists of loess overlaying Birch Creek schist and other bedrock units. Groundwater flowin the bedrock aquifer at the Tank Farm is expected to occur mainly in fractures and to flow to thesouthwest.

The presence, location, and extent of permafrost from the base of Birch Hill southward to theChena River significantly affect the groundwater flow direction in this part of the Tank Farm sourcearea. Groundwater occurs in two zones above and below the permafrost in the alluvial aquifer. Thesuprapermafrost groundwater zone is the saturated zone above permafrost. The subpermafrostgroundwater zone is the saturated zone beneath the permafrost. Groundwater occurs atapproximately 20 to 22 feet bgs in the TFS area at the base of Birch Hill in the suprapermafrostgroundwater zone. Groundwater in this area flows to the west. Shallow discontinuous permafrost inthis area may channel groundwater into thawed corridors that occur in meander scars, and ahydraulic connection may exist between the suprapermafrost groundwater zone in the thawedareas and the subpermafrost groundwater zone.

The closest drinking water wells to the Tank Farm Source Area are located at the Shannon ParkBaptist Church and Mormon Chapel on Lazelle Road approximately 0.25 miles west of the TankFarm.


6-4 REV. 01


The current land use is considered light industrial in the immediate Remedial Area and lightindustrial, recreational, and residential in the surrounding areas. The groundwater below RemedialArea 1b is not currently a source of drinking water. For purposes of planning remedial action, futureland use is considered to be industrial, recreational, and residential, and future groundwater use isconsidered to be residential.


The Tank Farm and associated TFS was originally constructed as part of the 1943 CANOL Project.The CANOL Project was the construction of a 3-inch pipeline from Whitehorse to Fairbanks. TheTank Farm originally consisted of fourteen 10,000-barrel-capacity, bolted-steel above ground fueltanks on top of Birch Hill which contained JP-4, mogas, and diesel fuels. The 14 tanks wereconnected by an 8-inch pipeline connected to the Railroad Offloading Facility and the East BirchHill UST Tank Farm. A post ROD historical search indicated that a pump house with a slop tankwas located at the base of Birch Hill. This is believed to be the major source associated with theBuilding 1173 sub-area. The pump house was used until 1955 when the Haines to Fairbankspipeline was built.

In 1955, as part of the new Haines Pipeline, 2-25,000 barrel tanks, the Truck Fill Stand, and a newpump house and manifold building were built. These new facilities were installed on Birch Hill onBirch Creek Schist, with the exception of the Truck Fill Stand that is located in the alluvial area.

A majority of the contamination within the bedrock is from receiving fuels from Haines Terminal,cleaning and dewatering of AST’s and operational spills. At the Truck Fill Stand, the majority ofcontamination was due to spills during truck filling activities and operational spills. USTs located atthe base of the hill are thought to be a source of petroleum contamination through spills andoverfilling or leaking.

The RI for Remedial Area 1b focused mainly on the base of Birch Hill; thus all monitoring wellswere installed in alluvial material. At the time of the RI, no wells or deep borings were installed onBirch Hill, thus missing free product within the bedrock aquifer. Post ROD activities, which identifiedthe free product, have led to the addition of a sub-area known as the Birch Hill Product RecoverySystem. This will be documented in the ESD.

Two of the sub-areas investigated during the RI/FS indicated no remedial action was required. TheShannon Park Subdivision sub-area and the CANOL Road sub-area were both recommended forno further action in the OU3 ROD.

Pre-ROD Response

There were no pre-ROD responses for the RA 1b source area.


6-5



The primary sources of contamination at RA 1b are associated with fuel and fuel additives storage,transfer, and handling activities and the Fairbanks Fuel Terminal and the TFS.

Investigations prior to and during the RI characterized contamination associated with RA 1b asfollows:

Groundwater

Benzene, toluene, ethylbenzene, 1,2-dibromethane (EDB), 1,2-dichloroethane (DCA),1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene were detected in groundwater at the base ofBirch Hill and in the downgradient west transport pathway in concentrations exceeding federaldrinking water MCLs and EPA risk based concentrations used for screening potential contaminantsof concern.

Petroleum hydrocarbons in soil are found at Building 1173 and the TFS.


The remedial action objectives are generic for all source areas in OU3.

Groundwater

• Restore groundwater to drinking water quality within a reasonable timeframe

• Reduce further migration of contaminated groundwater

• Prevent use of groundwater with contaminants at levels above SafeDrinking Water Act levels

Soil

• For petroleum-contaminated soil, prevent migration of contaminants fromsoil into groundwater that would result in groundwater contamination andexceedance of Safe Drinking Water Act standards.

ARARs

The OU3 ROD cited the most significant applicable or relevant and appropriate requirements(ARARs) for remedy selection at RA 3 to be:


6-6

• Federal and State of Alaska MCLs – Relevant and appropriate forgroundwater

• Alaska Water Quality Standards -- Applicable

• Alaska Oil Pollution regulations – Applicable

• Alaska regulations for leaking USTs – Relevant and appropriate

Cleanup Goals

Based on the results of the baseline risk assessment for current (at the time of the ROD) andprojected land use at the site, contaminants of concern were identified for establishing numericcleanup goals for OU3. There were no source specific cleanup goals for this source area.

Groundwater

• Federal and State of Alaska drinking water MCLs were adopted asgroundwater cleanup goals for benzene, toluene, ethylbenzene,1,2-dibromoethane, and 1,2-dichloroethane.

• The concentration corresponding to the EPA excess cancer risk (10-4)based cleanup level was adopted as the cleanup goal for1,2,4-trimethylbenzene and 1,3,5-trimethcylbenzene, since there were noMCLs for these contaminants.

Soil

• The remedial action goal for in-situ soil contaminated with volatile organicand petroleum compounds is protection of groundwater. Because the soilsare acting as a continuing source of contamination to the groundwater,active remediation of the soils will continue until Safe Drinking Water Actlevels are consistently met. Natural attenuation will continue AWQSachieved.

• Petroleum contaminated soils that are treated ex-situ will be treated toState of Alaska Matrix Level A standards before they are returned to thesource area.


Selected Remedy

Appropriate technologies were identified and screened for site conditions. The chosen technologiesfor OU3 were combined into media-specific site wide alternatives. For 1b the remedial area isspecifically Petroleum contaminated soil and groundwater found at the area that extends southfrom the base of Birch Hill to the TFS at the southwest corner of the Tank Farm Source Area andthat extends west toward Lazelle Road:


6-7 REV. 01

The selected remedy for 1b includes:

AS/SVE

• Soil vapor extraction of petroleum-contaminated soil;

• Air sparging of petroleum-contaminated groundwater in permafrost-freeareas to achieve Safe Drinking Water Act levels;

• Natural attenuation to meet AWQS

The OU3 ROD specified that due to different site conditions, site specific design information will becollected in a pilot study. In addition, during implementation or operations of systems the remedy isnot effective or contaminant levels cease to decline, the system performance and/or the remedymay be re-evaluated.


• Maintaining institutional controls restricting access to and development atthe site as long as hazardous substances remain onsite at levels thatprecluded unrestricted use.


Status of Selected Remedy by Subarea

Lazelle Road Sub-Area

An AS/SVE treatment system was installed in 1996 to remove VOCs and to prevent contaminatedsoils from acting as an ongoing source of contamination to groundwater. Air sparging wells wereplaced in areas of highest contamination (hot spots). The Lazelle Road treatment system wasremoved in 1997 and the site was incorporated into the 1173 Sub-area system.

Building 1173 Sub-Area

In 1996 at Building 1173 Sub-Area, a AS/VE treatment system was installed to remove VOCs andto prevent contaminated soils from acting as an ongoing source of contamination to groundwater. In1997 this system was expanded in size to treat additional contaminated areas, including the LazelleRoad Sub-area. In addition, oxidizers were installed to reduce atmospheric emissions. To date thetreatment system has removed 72,693 pounds of VOC.

Truck Fill Stand Sub-Area

In 1997 a AS/VE system was installed in the area of the truck fill stand for the removal ofVOCs in groundwater and to prevent contaminated soils from acting as an ongoing source


6-8 REV. 01

of contamination to groundwater. To date the treatment system has removed 4,776 pounds ofVOC.

In 1999, an AS treatment system was installed as part of a treatability study to reduce contaminantsmigrating off-post through a permafrost thaw channel. This system has been effective and wasretained as part of the remedy for this subarea.

Birch Hill Tank Farm Product Recovery System

Floating product was discovered in large amounts during the 1997 field season on Birch Hill. In1998 active and passive skimmers were installed in various wells located on the hill. In 1999 a pilotscale recovery system was installed in newly installed wells. During the summer and fall of 2000 aproduct recovery system was installed on Birch Hill. The system is currently actively recoveringfree-product. This sub-area was not a part of the OU3 ROD but will be established as part of theESD.


The restricted access boundary for the Birch Hill Tank Farm is depicted in Figure 6-2.


Plate 6-I summarizes the results of groundwater monitoring associated with the Building 1173 andTruck Fill Stand source areas (see appendices section of report).

Building 1173

Dissolved contaminant concentrations have also decreased overall since initial system start-up in1996. Benzene and 1,2-DCA were not detected above remediation goals in downgradient probesduring the 2000 field season.

The following summarizes the results of groundwater analytical sampling at the Former Building1173 treatment system:

• Zone 1 – Benzene and 1,2,4- and 1,3,5-TMB were above remediationgoals during the June and August sampling events. 1,2,4- and 1,3,5-TMBwere the only COC detected during the March sampling event. EDB,detected in LAZ-MP2 in 1999, was not detected in this zone in 2000.

• Zone 2 – A slight rebound in benzene concentrations were seen inGWP1173-MP4 in March; however, benzene was below remediation goalsin this probe during the August sampling event.

• Zone 3 – Benzene, EDB, DCA and 1,2,4-TMB and 1,3,5-TMBconcentrations are above the ROD cleanup level in GWP1173-MP1 andconcentrations did not exhibit a decrease during the 2000 field season.Benzene and 1,2,4-TMB and 1,3,5-TMB were


6-9 REV.01

above remediation goals in AP-7597 during the June sampling eventbut fell below remediation goals in August.

• Zone 4 – Monitoring Well AP-5271, the only point included in thegroundwater-monitoring program in Zone 4, did not contain COCabove the ROD cleanup levels. COC have not been detected aboveROD cleanup levels in this well since 1998; however, results of soilsamples collected from a boring drilled in this zone in 2000 indicate soilcontamination remains in the western portion of this zone. AP-5271,located in the eastern portion of this zone may not be influenced bygroundwater impacted by the soil contamination.

• Downgradient – Dissolved contaminant concentrations indowngradient monitoring locations were below remediation goals withthe exception of 1,2,4-TMB and 1,3,5-TMB in AP-6583 and GWP45.DCA fell below the ROD cleanup goal for the first time since systemstart-up at AP-6056. Groundwater results provide strong evidence thatcontaminants are being intrinsically remediate downgradient of theAS/SVE treatment system.

Truck Fill Stand

There has been a steady decrease in dissolved contaminant concentration at the TFS.

The following summarizes the results of groundwater analytical sampling during 2000 at the TruckFill Stand treatment system:

• Zone 2, GWP145 – Benzene concentrations decreased to below theremediation goal during the March sampling event and remained belowthe remediation goal throughout the year. EDB was detected atconcentrations above the ROD cleanup level during the June andAugust monitoring events for the first time since system start-up.

C Zone 1, GWP100 – Benzene concentrations were above theremediation goal throughout the year, ranging from 5.43 mg/L to 9.79mg/L. COC were not detected in AP-7362, a deep monitoring well(screened from 50 to 60 feet bgs) located adjacent to GWP100.

C Zone 3, GWP121 – No COC was detected during the 2000 fieldseason. COC have not been detected in Zone 3 since March 1999.

C Concentrations of 1,2,4-TMB and 1,3,5-TMB were not observed aboveROD cleanup levels at any monitoring location.


6-10 REV.01



RA 1b AS/SVE Systems

All systems in RA 1b are determined to be operational and functional by the Army. A request will beforwarded to EPA to certify these systems.

Groundwater monitoring results indicate that the identified plumes haves not migrated in the alluvialaquifer. Results of the 2000 Comprehensive Monitoring Report indicate significant decreases inconcentrations for the target analytes. There has been little or no change in the analyteconcentrations within the Birch Hill Aquifer.

Plate 6-I summarizes the results of groundwater monitoring associated with this source area.


Institutional controls are in place at RA1b. Excavation in the active area is restricted and requiresauthorization by DPW Environmental. Groundwater intrusion is also restricted, subject toauthorization by DPW Environmental.1 The IC access restriction boundary does not extend to thearea off-post on the Bentley Trust Property where groundwater monitoring and natural attenuationis occurring, however the downgradient property owners are kept informed of the ongoing work,and the Army provides bottled water to the two churches as specified in the ROD. There have beenno instances of violations of the IC policy in this area.

Summary



Restore groundwater to its beneficial use ofdrinking water quality within a reasonable timeframe

Active AS/SVE treatment still ongoing.Contaminant concentration are decreasing sincesinging of the ROD

Reduce further migration of contaminatedgroundwater from the source areas

No additional growth of plume or increase incontaminant concentrations

Prevent use of groundwater containing Institutional controls in effect and no violations of

1 Further details of the Army/Fort Wainwright IC policy can be found in the OU5 ROD, the U.S. Army Alaska Institutional ControlsStandard Operating Procedures [(APVR-RPW [200-1)], and a September 1999 Memorandum on Institutional Controls [(APVR-RPW-EV-(200-1c)] from Major General Dean W. Cash, Fort Richardson, Alaska.


6-11

contaminants at levels above federal MCLs andAlaska Water Quality Standards (AWQS; 18Alaska Administrative Code [AAC] 70)

these controls have been identified

Use natural attenuation to attain AWQS (18 AAC70)

Active AS/SVE treatment still ongoing. Contaminantconcentrations relatively constant or decreasing sincesigning of the ROD



• The MCLs used to establish groundwater cleanup goals have not changedsince the ROD.

• There have been no changes in RBCs used to establish OU3 cleanupgoals.


No other information has arisen that would question the protectiveness of the currentremedy.

Variances

The following variances were identified in the review of OU3 RA 1B Source Areaprotectiveness and remediation process.


Groundwater flow system not fully characterized.Interactions between bedrock aquifer and alluvialaquifer not understood.

No

Fate and transport of DCA not understood. No

Fate and transport of EDB not understood. No


6-12


No AS/SVE design or operational changes are recommended at this time. The following varianceswere identified in the review of OU3 RA 1B Source Area groundwater monitoring program and ICs.

Recommendation/ Follow-upActions

PartyResponsible

OversightAgency

MilestoneDate


(Y/N)

Further characterization of aquiferinteractions

U.S. Army EPA,ADEC

Ongoing N

Gather data on fate and transportof DCA

U.S. Army EPA,ADEC

Ongoing N

Gather data on fate transport ofEDB

U.S. Army EPA,ADEC

Ongoing N

The remedies selected for RA 1B includes groundwater monitoring. Groundwater flow is complexand varied due to the presence of permafrost and interactions between the bedrock and alluvialaquifers. Further delineation of the RA 1B groundwater flow system is required to evaluate theeffectiveness of ongoing treatment to assure no off-site migration of contaminants occurs and toevaluate the progress of natural attenuation. Despite the lack of this information the remedy isprotective because treatment implemented is moving towards achieving RAOs and institutionalcontrols restrict contact with contamination and bottled water is supplied to the two affected off-postgroundwater users.

6.3 Remedial Area 2 –Valve Pits and Railcar Off-Loading Facility

6.3.1 Overview

RA2, which includes the ROLF and three valve pits, is located south of the Tank Farm Facilityacross the Chena River and north of Gaffney Road. Remedial Area 2 was subdivided intosub-areas based on geographic location and differing physical characteristics. The areas shown onFigure 6-3 are Valve Pit A, Valve Pit C, the Central Header, Former Building 1144, and the EightCar Header. Pipes connect the Tank Farm and the Railcar Off-Loading Facility. The facility coversan area of approximately 40 acres. The facility dates back to 1939. The areas associated with thissource area include the off-loading headers and associated UST’s, six valve pits and undergroundpipelines. Floating product was measured in numerous monitoring wells during the summer of1996. The findings indicated subsurface contamination in “hot spots” throughout the area especiallyalong the pipeline system. Petroleum contamination was found in subsurface soils and


6-13

groundwater surrounding Valve Pits A, B and C, along Front Street, and surface and subsurfacesoils and groundwater in the center of the Central ROLF area.

The SVE/AS systems were installed during the summer of 1996. These studies indicated a largerarea of contamination than originally defined. Expansion of the systems was determined necessary.Institutional controls are in place, and informational signs have been installed to inform the public ofrestrictions and activities in this area. Off-gas vapors are being treated in order to meet compliancewith Title V Permit.

6.3.2 Background

A soil-gas survey was conducted at the ROLF and associated valve pits in 1988. Samples collectedrevealed a contaminant plume centered on the railroad spur containing the 16-tank-car unloadingheader (Central Header) and the former USTs. A monitoring well at Valve Pit C was installed in1989 and contained free-floating product in most of the sampling events until commencement of RAactivities.

Periods of use and dates related to the history of the Remedial Area 2 contamination andremediation include the following1:

EVENT DATESoil-gas survey conducted 1988

Monitoring wells installed 1989


FFA signed 1992

TPA signed 1992


RI and Risk Assessment Reports submitted to EPA October 1994

FS submitted to EPA April 1995

ROD signed January 1996

AS/SVE treatments installed at Valve Pits A, B, & C; Central Header; andFormer Building 1144 source areas July and August 1996

AS/SVE system expanded 1997

AS/SVE system installed at the Eight Car Header sub-source area. CentralHeader and Former Building 1144 further expanded. 1998

ESD submitted to expand AS/SVE treatment areas to cover the lateral extent ofcontamination as identified in Post-ROD investigations. Concomitant increase inremedial costs also documented.

September 2201



6-14


Valve Pit A and portions of the ROLF are located directly on the banks of the Chena River. ValvePit A is approximately 0.25 mile east of 801 Housing Subdivision on the north bank of the ChenaRiver. Groundwater near Valve Pit A generally flows away from 801 Housing Subdivision andtoward the Chena River.

The main area of the ROLF is within the Chena River floodplain. The ROLF is located immediatelynorth of the Fort Wainwright airstrip and is bounded on its north and west sides by the Chena Riverand Gaffney Road to the south. A scrub-shrub wetland borders the northeast edge of the ROLF. Noendangered or threatened species reside in the area.

Groundwater in the shallow aquifer zone generally flows west towards the Chena River. Flowdirection and gradient is subject to seasonal variations. Depth to groundwater in the vicinity of theROLF is approximately 10 to 20 feet.


The area around Remedial Area 2 is used heavily by residents and nonresidents involved inrecreational sport fishing, boating and hiking. Groundwater use is residential. Numerous residentialwells are located on the north bank of the Chena River, less than 0.5 mile downstream. The GoldenHeart Utilities and College Utilities wells are located approximately three and five and a half milesfrom the source area respectively. Four Fort Wainwright drinking water supply wells and thePioneer Class A drinking water wells for the Hamilton Subdivision are located approximately onemile from the ROLF. Future land and groundwater use is considered to be residential andrecreational.


The ROLF was built in 1939 to receive fuel from tanks on railcars and to distribute the fuels to theairfield refueling points, quartermaster fuel system, the Birch Hill AST Tank Farm, and East BirchHill UST Tank Farm. As part of this distribution system, there were three valve pits, Valve Pit A onthe west side of the Chena River, Valve Pit B and C located on the east side of the Chena River. Apipeline connects the ROLF to the East Birch Hill UST Tank Farm. Fuel was stored in USTs at thisfacility until they were removed in 1990. Available records indicate that one 20-gallon spill of fueloccurred at the ROLF between 1970 and 1987. However, it is known that the tank car headerswere prone to minor leaks, and at least one major spill of JP-4 occurred at one of the headers.Additionally, the USTs formerly at the ROLF reportedly were overfilled on numerous occasions. In1991, a pipeline from Valve Pit C to the airfield failed a hydrostatic pressure test and was taken outof service. Valve pits on both sides of the Chena River and at the ROLF had leaks.

Pre-ROD Response

There were no pre-ROD responses for the RA 2 source area.


6-15



The primary sources of contamination at RA 2 are associated with fuel and fuel additives storage,transfer, and handling activities at Valve Pit A, Valve Pit C, Central Header, 8-Car Header, andFormer Building 1144 at the ROLF.

Investigations prior to and during the RI characterized contamination associated with RA 2 asfollows:

Groundwater

Benzene, toluene, ethylbenzene, 1,2-dibromethane (EDB), 1,2-dichloroethane (DCA),1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene were detected in groundwater exceedingfederal drinking water MCLs and EPA risk based concentrations used for screening potentialcontaminants of concern.

Soil

Petroleum hydrocarbon (quantified as diesel in surface soil and Jet-A in subsurface soil) at theROLF.


The remedial action objectives are generic for all source areas in OU3.

Groundwater

• Restore groundwater to drinking water quality within a reasonable timeframe;

• Reduce further migration of contaminated groundwater; and


Soil



6-16

ARARs






Cleanup Goals

Based on the results of the baseline risk assessment for current (at the time of the ROD)and projected land use at the site, contaminants of concern were identified for establishing numericcleanup goals for OU3. There were no source specific cleanup goals for RA 2.

Groundwater


• The concentration corresponding to the EPA excess cancer risk (10-4)based cleanup level was adopted as the cleanup goal for1,2,4-trimethylbenzene and 1,3,5-trimethcylbenzene, since there were noMCLs for these contaminants.

Soil

• The remedial action goal for in-situ soil contaminated with volatile organicand petroleum compounds is protection of groundwater. Because the soilsare acting as a continuing source of contamination to the groundwater,active remediation of the soils will continue until Safe Drinking Water Actlevels are consistently met. Natural attenuation will continue AWQSachieved.



Selected Remedy

Appropriate technologies were identified and screened for site conditions. The chosentechnologies for OU3 were combined into media-specific site wide alternatives. For RA2


6-17

the remedial area is specifically petroleum contaminated soil and groundwater found at Valve Pit Aand the ROLF Source Areas.

The selected remedy for RA2 includes:

AS/SVE


• Air sparging of petroleum-contaminated groundwater at knowncontaminant sources and at locations where MCLs are exceeded (i.e. hotspots) to achieve Safe Drinking Water Act levels;


The OU3 ROD specified that due to different site conditions, site specific design information will becollected in a pilot study. In addition, during implementation or operations of systems the remedy isnot effective the performance standards and/or the design information will be collected in a pilotstudy. In addition, during implementation or operations of systems the remedy is not effective orcontaminant levels cease to decline, the system performance and/or the remedy may bere-evaluated.


Maintaining institutional controls restricting access to and development at the site as long ashazardous substances remain onsite at levels that precluded unrestricted use.

Status of Remediation

Valve Pit A

The AS/SVE system was initially installed in 1996 and expanded in 1997 and further expanded toits current size in 2000. The treatment system operates seasonally. To date the treatment systemhas removed 21,829 pounds of VOC.

Groundwater concentrations in all of the wells for benzene and 1,2,4-TMB remain above RAOs.

Valve Pit B

The AS/SVE system was initially installed in 1996 and expanded to its current size in 1997. Thetreatment system operates seasonally. To date the treatment system has removed 29,564 poundsof VOC.

Valve Pit C



6-18

The AS/SVE system was initially installed in 1996 and expanded to its current size in 1997. Thetreatment system operates seasonally. To date the treatment system has removed 10,311 poundsof VOC.

Central Header


The AS/SVE system was initially installed in 1996 and expanded in 1997 and further expanded toits current size in 2000. The treatment system operates year round. Off-gas emissions arecontrolled by the use of a thermal oxidizer. To date the treatment system has removed 234,763pounds of VOC.

Eight Car Header


The AS/SVE system was initially installed in 1997 and expanded to its current size in 1998. Thetreatment system operates year round. Off-gas emissions are controlled by the use of a thermaloxidizer. To date the treatment system has removed 106,688 pounds of VOC.

Former Building 1144


The AS/SVE system was initially installed in 1996 and expanded to its current size in 1997. Thetreatment system operates year round. Off-gas emissions are controlled by the use of a thermaloxidizer. To date the treatment system has removed 214,398 pounds of VOC.


The concentrations of contaminants in RA 2 in the identified groundwater plume have decreasedsince implementation of the AS/SVE systems. The groundwater monitoring results show that theremedy is working. There has been no identified migration of the plume within the site or off of thesite. Groundwater has not been sampled for lead since the signing of the ROD.

Plate 6-II summarizes the results of groundwater monitoring associated with the Valve Pit A, Valve Pit B,and Valve Pit C source areas. Plate 6-III summarizes the results of groundwater monitoring associatedwith the Central Header, Eight Car Header, and Building 1144.

Valve Pit A

Of the nine locations sampled during the August 2000 sampling event three, VPA-MP4, AP-6064,and GWP72S were below ROD cleanup levels for all COC. Six locations plus monitoring pointVPA-MP1 (last sampled in May 2000) exceeded ROD cleanup levels.


6-19

Since 1996, concentrations of COC have decreased significantly (for some contaminants up to theeorders of magnitude) in all but two of the ten groundwater monitoring locations (GWP22 andGWP24). DCA and EDB are non-detectible at all groundwater monitoring locations.

Valve Pit B

As of the August 2000 sampling event, four of the nine groundwater sample locations were belowROD cleanup levels for all COC sampled. All groundwater sample locations have seen significantdecreases in COC levels since installation of the AS/SVE system in 1996. In particular, VPB-MP3has had three COC concentrations decrease by four orders of magnitude. DCA and EDB arenon-detectible at all monitoring points within this source area.

Valve Pit C

All eight of the monitoring locations sampled during 2000 were below ROD cleanup levels for allsource area COC. Three monitoring locations last sampled during 1999 were also below RODcleanup levels for all source area COC. All groundwater sample locations have seen significant tomoderate decreases in contaminant levels since installation of the AS/SVE treatment system in1996. Contaminant rebound was evident during the last monitoring event of 1998 and the first threemonitoring events of 1999. However, during the last monitoring event of 1999, all COC were belowthe ROD cleanup levels at those locations sampled. Three groundwater sample locationsexperienced benzene rebound in the first sampling event of 2000, however all COC were belowROD cleanup levels as of the last monitoring event. Neither DCA nor EDB was detected in any ofthe groundwater sample locations.

Central Header

Decreasing trends are observed in all Central Header Zones except Zone 5. Contaminant levels atgroundwater probe, GWP48 and GWP150, have fluctuated since installation in 1996 and 1999respectively. All other zones as well as two upgradient and two downgradient groundwater samplelocations have seen moderate to significant decreases in levels of COC. Benzene and toluenelevels have decreased at some locations by four orders of magnitude since installation of theAS/SVE treatment system in 1996.

Free-phase product was not observed during the 1999 sampling season either within orimmediately downgradient of the Central Header treatment area for the first time since thetreatment system began operating in 1996. As of the August 2000 sampling event COC levels attwo groundwater probe and one monitoring well locations were below ROD cleanup levels for allCOC. Eight other locations sampled in 2000 (upgradient, within, and downgradient of the CentralHeader treatment area) were above ROD cleanup levels. EDB was above ROD cleanup levels attwo of these locations, GWP80 and CH-MP2, as of the August 2000 sampling event. Groundwatermonitoring probe GWP79 was last sampled in 1998 and was also above ROD cleanup levels atthat time. Two other monitoring probes were last sampled in 1999 and at that time were below RODcleanup levels for all COC.


6-20

Eight Car Header

ROD COC concentrations have generally decreased at all monitoring locations associated with theEight Car Header since sampling began in 1996. In 1999 no free-phase product was observed atthe Eight Car Header subarea for the first time since installation of the treatment system in 1996.During the August 2000 sampling event five of nine monitoring locations were below ROD cleanuplevels for all COC. 1,2,4-TMB and 1,3,5-TMB were still above ROD cleanup levels at four samplelocations, while benzene exceeded ROD cleanup levels at two of those locations. Neither DCA norEDB was detected in any of the groundwater sample locations.

Building 1144

Groundwater COC levels have generally decreased within the Building 1144 source area. Twogroundwater monitoring probes, GWP109 and GWP147, have seen increasing concentrationssince installation in 1998 and 1999 respectively. In 1999 free-phase product was not observed forthe first time since installation of the treatment system. Three of the ten monitoring locationssampled in 2000 were below ROD cleanup levels for all COC. 1,2,4-TMB and 1,3,5-TMB werefound in seven while three of those contained benzene above ROD cleanup levels. Groundwaterprobe GWP83 was last sampled for 1,2,4-TMB, 1,3,5-TMB, benzene, toluene, and EBZ in Octoberof 1999 and was below ROD cleanup levels for all analytes.


ICs for RA 2 are in effect and policies to limit excavation or well Installation in potentiallycontaminated sites. Figure 6-4 depicts the restricted use boundary.

Fort Wainwright has established a post wide IC policy for all known or suspected contaminatedsites. 1 There have been no violations of the IC policy to date.




• No soil excavation can take place without prior briefings on potentialconcerns at the source area, knowledge of the procedures for handlingcontaminated soils on Fort Wainwright, and possession of a validsite-specific Fort Wainwright Excavation Permit.

USARAK DPW maintains a Geographic Information System (GIS) database with information on allof the contaminated sites on post. The DPW is responsible for ensuring ICs on Fort Wainwright.ICs will remain in place as long as hazardous substances remain


6-21

on site at levels that preclude unrestricted use. Excavation and groundwater intrusion at this sourcearea is restricted subject to approval by DPW Environmental.



AS/SVE Systems

The RA 2 AS/SVE systems were installed beginning in 1996 and have been operational sinceinstallation and have removed a total of 617,553 pounds of VOCs from the soil and groundwater.Results of the 2000 Comprehensive Monitoring Report indicate decreases in soil and groundwaterconcentrations of chemicals of concern. Plate 6-II summarizes groundwater concentrations inmonitoring wells over time. All systems in R2 are determined to be operational and functional by theArmy. A request will be forwarded to EPA to certify these systems.

Implementation of Institutional controls;

Institutional controls for RA 2 are in place. Excavation on this site is restricted and can only beauthorized by DPW Environmental. Groundwater intrusion is restricted and can only be authorizedby DPW Environmental.

Base-wide IC policy is outlined in greater detail in the OU5 ROD, the U.S. Army Alaska InstitutionalControls Standard Operating Procedures [(APVR-RPW [200-1)], and a September 1999Memorandum on Institutional Controls [(APVR-RPW-EV-(200-1c)] from Major General Dean W.Cash – Fort Richardson, Alaska.



Restore groundwater to its beneficial use of drinkingwater quality within a reasonable time frame

Contaminant concentrations decreasing.


No growth plume or increase in contaminantconcentrations

Prevent use of groundwater containing contaminantsat levels above federal MCLs and Alaska WaterQuality Standards (AWQS; 18 Alaska AdministrativeCode [AAC] 70)

Institutional controls in effect

Use natural attenuation to attain AWQS (18 AAC 70)

Source Areas are actively treated with AS/SVE.


6-22



• The MCLs used to establish groundwater cleanup goals for RA 2 have not changedsince the ROD.



Site Inspection

This site was inspected on April 27, 2001. Photographs taken at the time of the site inspection areincluded in the appendices section of this report.

Variances

The following variances were identified in the review of OU3 RA 2 Source Area protectiveness andremediation process.


Lead in groundwater sampling has not beenperformed. Potential


The following variances were identified in the review of OU3 RA 2 Source Area groundwatermonitoring program and ICs.

Recommendations/ Follow-upActions

PartyResponsible

OversightAgency

MilestoneDate


(Y/N)

Groundwater monitoring for lead. U.S. Army EPA,ADEC

6/30/2002 N

Lead needs to be added to the groundwater monitoring program per the OU 3 ROD.


6-23

6.4 Remedial Area 3 – Mileposts 2.7, 3.0, and 15.75

6.4.1 Overview

The Fairbanks to Haines Pipeline was put into service in 1955. Three source areas have beenidentified along the pipeline. The source areas Mileposts 2.7 and 3.0 (Figure 6-5) were discoveredas part of a 1989 soil gas survey. Sampling locations were spaced ¼ mile apart, and theinvestigation spanned 27 miles from the Fairbanks Terminal to Eielson AFB. Elevated levels ofBTEX were noted at MP 2.6 and MP15.75. At the time of the RI and ROD, it was unknown theexact cause of the contamination at MP 2.7 and 3.0. The Proposed Plan and ROD listed potentialsources as potentially from pipeline breaks of the Haines Pipeline, and truck fill stands, waterseparator pits, valve pits, and pipelines associated with the abandoned East Birch Hill UndergroundTank Facility.

A record search to document the source of contamination is being conducted and will bedocumented in the ESD. The contamination at source area Milepost 15.75 (the intersection ofLaurance Road and Robyn Drive) was the result of a spill that occurred in August 1989, when aportion of the Fairbanks-Eielson Pipeline was ruptured during road construction. An SVE/ASsystem was installed and operated, and has accomplished remediation of this site. This systemwas removed and relocated to RA1b. Long-term monitoring continues at Milepost 15.75.

6.4.2 Background

Remedial Area 3 consists of three locations along the Fairbanks-Eielson Pipeline: Milepost 2.7,Milepost 3.0, and Milepost 15.75. A treatability study initiated at Mileposts 2.7 and 3.0, whichincluded SVE/AS and oxygen releasing compounds, was not effective due to low permeability ofthe soils in the area. A new treatability study was completed to determine the effectiveness ofaboveground SVE/AS with soils removed from the Mileposts. This treatment has been highlyeffective, and soils at the Mileposts have been removed for ex situ treatment. In situ long-termmonitoring continues at the actual milepost sites. The OU3 ESD will document changes intreatment for petroleum contaminated soil and associated increased costs.


Milepost 2.7 and Milepost 3.0 Source Areas are similar in physical characteristics. Both have amoderate to steep south-facing slope to the north and a shallow, south-facing slope to the south.They are located downgradient of East Birch Hill UST facility. Soils are poorly drained and pondedsurface water is common from spring breakup until mid-summer. Discontinuous permafrost istypical in the areas’ subsurface soil. A black spruce-scrub-shrub wetland borders the south side ofthe source areas while the rest of the surrounding area is densely vegetated. Groundwater isencountered at depths from 3 to 12 feet bgs and groundwater flows to the southwest.


6-24

The Milepost 15.75 Source Area is located on an off-post military fuel pipeline right-of-way within aresidential area approximately 1 mile south of North Pole. The Chena River is to the north and eastand the Tanana River is to the west. The site is flat except for drainage ditches that parallelLaurance Road. The drainage ditch on the south side of Laurance Road usually contains water.Soils in the area are sandy with little gravel and generally are moderately well-drained. Thesurrounding area is forested with trees and shrubs. Groundwater is encountered at depths from 3to 7 feet bgs and groundwater flows to the north.


The Milepost 2.7 and 3.0 Source Areas are located within a military training area across the ChenaRiver and approximately one mile from the nearest residential development. Both areas are usedrecreationally. The nearest well to both source areas is located approximately one mile away at theBirch Hill Ski area. The well is not hydraulically connected to the alluvial aquifer below both sourceareas. The Milepost 15.75 source area is located within a residential area and wetlands occurwithin 0.25 miles. Future land and groundwater use at all three source areas are residential andrecreational.


The Haines Pipeline was put into service in 1955 to transport fuel from Haines to Fairbanks. Thesection of the pipeline between Fort Wainwright and the Mapco refinery in the city of North Pole,was decommissioned in 1992. Milepost 2.7 and 3.0 are located downgradient of a the former EastBirch Hill UST Facility. This facility was built as part of the CANOL pipeline and stored high-octaneaviation fuel and aviation fuel in 34 50,000 gallon tanks. There were three truck fill standsassociated with this tank farm, two adjacent to the contamination at Milepost 2.7 and 3.0.Numerous investigations were conducted to close out the UST’s under the State of Alaska USTregulations. The state of Alaska closed the UST’s, but due to severe groundwater contaminationassociated with this operation, the groundwater was added to OU3. The RI listed potential sourcesfor MP 2.7 and 3.0 as the Fairbanks Eielson Pipeline, and leaks that could have originated from theformer East Birch Hill UST’s, associated piping, valve pits and truck fill stands. A record search isbeing conducted to determine the source of contamination. The former UST’s were locatedtopographically upslope of the reported pipeline spill locations.

In August 1989, the Fairbanks-Eielson pipeline was ruptured while a contractor was upgradingLaurance road and establishing a subgrade level for Robyn Drive, near Milepost 15.75. Thepipeline was closed at nearby valves and an earthen berm was constructed to contain the spill.Approximately 2,400 gallons of the estimated 4,200 gallons of spilled fuel was recovered.Contaminated soils were removed from the spill area immediately following the recovery of liquidfuel. Elevated benzene concentrations were detected at this source area in 1992 and subsequentinstallation of a monitoring wells revealed elevated levels of petroleum products at this area.


6-25

Pre-ROD Response

There were no pre-ROD responses for the RA3 source areas.



The primary sources of contamination at RA 3 are associated with fuel storage, transfer, andhandling activities at the East Birch Hill Underground Storage Tank Facility and theFairbanks-Eielson Pipeline.

Investigations prior to and during the RI and post-ROD sampling characterized contaminationassociated with RA 3 as follows:

Groundwater

Benzene, toluene, ethylbenzene, 1,2-dibromethane (EDB), 1,2-dichloroethane (DCA),1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene were detected in groundwater exceedingfederal drinking water MCLs and EPA risk based concentrations used for screening potentialcontaminants of concern.

Soil

GRO, DRO and Benzene are the contaminants in soil found at the RA 3 source areas.


The remedial action objectives are the same for all source areas in OU3.

Groundwater

• Restore groundwater to drinking water quality within a reasonable timeframe;

• Reduce further migration of contaminated groundwater; and



6-26

Soil


ARARs






Cleanup Goals

Based on the results of the baseline risk assessment for current (at the time of the ROD) andprojected land use at the site, contaminants of concern were identified for establishing numericcleanup goals for OU3. There were no source specific cleanup goals for RA 3. The ROD describedthe point of compliance for achieving the RAOs as wells downgradient of RA 3.

Groundwater


• The concentration corresponding to the EPA excess cancer risk (10-4)based cleanup level was adopted as the cleanup goal for1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene, since there were noMCLs for these contaminants.

Soil

• The remedial action goal for in-situ soil contaminated with volatile organicand petroleum compounds is protection of groundwater. Because the soilsare acting as a continuing source of contamination to the groundwater,active remediation of the soils will continue until Safe Drinking Water Actlevels are consistently met. Natural attenuation will continue until AWQSare achieved.


6-27


Numeric values for the cleanup goals established in the RODs are summarized in Table6-1.

Selected Remedy

Appropriate technologies were identified and screened for site conditions. The chosen technologiesfor OU3 were combined into media-specific site wide alternatives. For RA3 the remedial area isspecifically Petroleum contaminated soil and groundwater found at 2.7 and 3.0, including TFS-1and TFS-2, and Milepost 15.75 along the Fairbanks-Eielson Pipeline.

The selected remedy for RA3 includes:

AS/SVE


• Air sparging of petroleum-contaminated groundwater in permafrost-free areas toachieve Safe Drinking Water Act levels;


The OU3 ROD specified that due to different site conditions, site specific design informationwill be collected in a pilot study. In addition, during implementation or operations ofsystems the remedy is not effective the performance standards and/or the remedy will bere-evaluated.


• Maintaining institutional controls restricting access to and development at the site aslong as hazardous substances remain onsite at levels that precluded unrestricteduse.


MP 2.7

An air sparging treatability study was conducted at MP 2.7 in 1996. The same year, astudy involving ORC injected into the groundwater was evaluated. Both of these in situtechnologies were considered not viable for the site due to low soil permeability and lack ofelectrical power. 1A treatability study was performed during 1998 to evaluate the feasibility

1Source: HartCrowser 1999 OU3 Monitoring Report


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of excavation and ex situ soil treatment. The RPMs agreed that removing the soil would assist inachieving the RAOs. This involved the excavation of approximately 1,500 cubic yards ofcontaminated soil. These soils were placed in a treatment cell constructed adjacent to the Truck FillStand at the remedial area 1b. The Truck Fill Stand AS/VE blowers were utilized to treat thepetroleum contaminated soil ex-situ. This system is still operational and the results of the 2000 fieldseason indicate that only DRO remain. This action and its basis will be documented in an ESD.

Groundwater monitoring at MP2.7 has been conducted bi-annually to evaluate the progresstowards achieving RAOs. The 2000 monitoring events indicate that there has been no change inbenzene concentrations. All other COC’s remain below RAOs with the exception of DCA. DCA wasdetected in one well in September 2000.

MP 3.0

A pilot study was conducted at MP 3.0 in 1996 involving the use of oxygen-releasing compoundinjected as a slurry below the water table. Analytical results of groundwater samples indicatedinjection of the oxygen releasing compound slurry was not effective.

Since the soils at MP3.0 are similar to MP2.7, ex-situ treatment of the soils was determinedfeasible. In April 2000 at MP 3.0 excavation and ex situ soil treatment was performed. This involvedthe excavation of approximately 6,000 cubic yards of petroleum contaminated soil. These soilswere placed in a treatment cell constructed at the base of Birch Hill. This action and its basis will bedocumented in an ESD. The 1173 Treatment System AS/VE blowers are utilized to treat thepetroleum contaminated soil ex-situ. This system has operated one field season, with the maincontaminants being DRO, GRO and benzene.

Groundwater monitoring has been conducted bi-annually to evaluate the progress towardsachieving RAOs. The 2000 monitoring events indicate that there has been little change in benzene,EDB, GRO and DRO concentrations. All other COC’s remain below RAOs.

MP 15.75

An AS/SVE treatment system was installed at Milepost 15.75 site in November 1996. This site islocated in a residential area in North Pole, Alaska. The treatment system operated continuouslyuntil May 1997, after initial cleanup goals had been achieved. During July 1997, the EPA andADEC agreed to discontinue treatment and remove aboveground portions of the treatment system.

During August 1997, the treatment system connex was moved back to Fort Wainwright to allow foruse at another OU3 site and the underground piping and treatment system probes were removed inOctober 2000. Quarterly groundwater sampling was conducted until 1998, when an annualgroundwater sampling program was implemented. Results of the 1998 and 1999 groundwatersampling have shown contaminant concentrations below ROD


6-29 REV. 01

objectives indicating a lack of significant contaminant rebound. In the 2000 sampling event,benzene was detected in one groundwater sample collected from AP-7915 (37.5 :g/L) during theOctober 2000 sampling event. No other COC were detected above ROD cleanup levels during theOctober sampling event.


No significant changes in contaminant concentration at the monitoring wells associated with MP 2.7and 3.0 have been observed to date. All groundwater wells at Milepost 2.7 are above ROD cleanuplevels as of 2000. 1,3,5-TMB has increased in two wells AP-5651 and AP-6034 between the Marchand September of that year. 1,2,4-TMB rebound in AP-6035 during this same period and increasedin two others. Benzene levels have also increased in AP-6034 during the last four sampling events.In addition, one well detected DCA in the September 2000 monitoring event.

Milepost 3.0, eight of the nine monitoring wells have COC above the ROD cleanup levels as of the2000 sampling events. EDB increased in five wells EBZ has increased in three wells withexceedances above ROD cleanup levels in two of those between 1999 and 2000...

The concentrations of contaminants in the identified plume at MP 15.75 are generally stable withrebound of benzene in one monitoring well AP-7915. There has been no identified migration of theplume within the site or off of the site.

Plate 6-IV summarizes the results of groundwater monitoring associated with this source area.


ICs for the MP 2.7 and MP 3.0 are in effect at RA2 and include policies to limit excavation or wellinstallation in potentially contaminated sites. There have been no violations of the ICs to date.1

Fort Wainwright has established a post wide IC policy for all known or suspectedcontaminated sites.2




1 Further details of the Army/Fort Wainwright IC policy can be found in the OU5 ROD, the U.S. Army Alaska Institutional ControlsStandard Operating Procedures [(APVR-RPW [200-1)], and a September 1999 Memorandum on Institutional Controls[(APVR-RPW-EV-(200-1c)], from Major General Dean W. Cash, Fort Richardson, Alaska.


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• No soil excavation can take place without prior briefings on potential concerns at thesource area, knowledge of the procedures for handling contaminated soils on FortWainwright, and possession of a valid site-specific Fort Wainwright ExcavationPermit.


Site Inspection

This site was inspected on April 28, 2001. Photographs taken at the time of the site inspection areincluded in the appendices section of this report.



MP 2.7

A treatability study conducted at the Milepost 2.7 source area during 1996 showed that air spargingwas not a viable alternative for this source area. A second treatability study initiated in 1998 atMilepost 2.7 showed that it was feasible to use ex situ soil treatment to achieve remedial objectivesin petroleum soils.

Results of the 2000 Comprehensive Monitoring Report indicate no significant changes ingroundwater concentrations for the COC’s at this source area. Based on this trend it is unclear ifgroundwater cleanup goals can be achieved for this area within a reasonable period of time.

MP 3.0

A treatability study conducted at the Milepost 2.7 source area during 1996 showed that air spargingwas not a viable alternative for the MP2.7 source area. Since the soils at MP 3.0 are similar tothose at MP2.7, in situ air sparging was determined to be ineffective at the MP3.0 site as well. Asecond treatability study initiated in 1998 at Milepost 2.7 showed that it was feasible to use ex-situsoil treatment to achieve remedial objectives (HartCrowser 2000a). Results of the 2000Comprehensive Monitoring Report indicate no significant changes in groundwater concentrationsfor the COC’s at this source area. Based on this trend it is unclear if groundwater cleanup goalscan be achieved for this area within a reasonable period of time.


6-31 REV. 01

MP 15.75

Benzene was detected in one groundwater sample collected from AP-7915 (37.5 :g/L) during theOctober 2000 sampling event. No other COCs were detected above ROD cleanup levels during thecurrent sampling event. Benzene is the only COC that has been historically identified above RODremediation goals or AWQS at Milepost 15.75 site. Benzene concentrations were highest in theupgradient probe GWP42. However, benzene has exhibited a decreasing trend from 1996, when itwas detected at 300 :g/L, to 1999 when it was detected at 2.5 :g/L. This decrease wasapproximately three orders of magnitude. Benzene was also below ROD cleanup goals during twosampling events in 1998 and 1999, and were only slightly above the remediation goal during the fall2000 sampling event, when groundwater levels were higher compared to other months. The lack ofsignificant contaminant rebound above ROD cleanup goals following treatment system shutdown in1997 supported the decision to decommission the treatment system. Monitoring of the groundwateris continuing.


Institutional controls for RA 3 are in place. Excavation in the active area is restricted and requiresauthorization by DPW Environmental. Groundwater intrusion is restricted, subject to authorizationby DPW Environmental.




Contaminant concentrations relatively constant atMP 2.7 & 3.0. Concentrations are decreasing at15.75


No growth of plume or increase in containmentconcentrations

Prevent use of groundwater containingcontaiminants at levels above federal MCLs andAlaska Water Quality Standards (AWQS; 18 AlaskaAdministrative Code [AAC] 70)

Institutional controls in effect. No violations ofinstitutional controls.


Contaminant concentrations relatively constant atMP 2.7 & 3.0. Concentrations are decreasing at 15.


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• The MCLs and RBCs used to establish groundwater cleanup goals for RA3 have not substantively changed since the ROD.

• In situ AS/SVE not feasible at MP 2.7 and 3.0

The ESD will address the need for an modification to in situ treatment of petroleum contaminatedsoil at Milepost 2.7 and Milepost 3.0. Contaminated soil was excavated and treated ex-situ byAS/SVE treatment. This is a modification to the remedy of in-situ soil remediation as outlined in theoriginal ROD.

Based on current ground water trends at MP 2.7 and 3.0 it is unclear if groundwater cleanup goalscan be met within a reasonable period of time.



Variances

No variances were identified in the review of OU3 RA 3 Source Area protectiveness andremediation process.


No operational changes are recommended at this time.

6.5 OU3 Explanation of Significant Differences (ESD)

An Explanation of Significant Differences (ESD) for the Record of Decision (ROD) for Operable Unit3 (OU3) is being prepared. This ESD is being prepared in accordance with Section 117(c) ofCERCLA and 40 CFR 300.435(c)(2)(I), and documents significant differences to the selectedremedies in the ROD. This ESD will document, increase in extent and volume of contamination,increase in remedial cost, discovery of additional contaminants and remedial areas, and changes insome components of the selected remedy described in the OU3 ROD. This does not fundamentallyalter the overall remedial approach.

Remedial activities have been operational at all areas described in the ROD.

Extensive historical research about the source areas has lead to a greater understandingof the source areas. In many cases, the understanding of the source of contamination,movement of groundwater, type of contamination and geology has changed or altered the


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remedial option selected. The aerial extent of contamination was estimated in the ROD from alimited number of wells installed, not actual extent. The volume was an underestimate of the totalcontamination due to the fact that limited wells were installed as part of the original RI/FS. A moreaccurate assessment of the contamination was developed during post-ROD remedial investigationsand activities. This ESD will document the installation of systems and their changes and additionsto the remedial actions that were described in the ROD.


No operational changes are recommended at this time.


7-1

7 OPERABLE UNIT 4

7.1 OU4 Background

Operable Unit 4 (OU4) was the second Fort Wainwright OU to reach a final-action ROD. That RODwas signed in August 1996 and initially addressed three source areas: the Landfill, the CoalStorage Yard (CSY) and the Fire Training Pits (FTPs). The ROD specified remedial actions subjectto Five-Year Review at two of these areas: the Landfill and the CSY.

7.2 Fire Training Pits

The OU4 ROD found that removal of contaminated soils at the FTPs would adequately protecthuman health and the environment from potential risk associated with those source areas.Contamination of concern at the FTPs was limited to localized petroleum hydrocarbon “hot spots” insurface and shallow subsurface soils, and there was no reported contamination above action levelsin groundwater at the FTPs. The ROD anticipated that the soil removal action would constitute finalaction for the FTPs. As such, no analysis of remedial alternatives was included in the OU4 ROD,and no additional remedial actions were indicated. The Army decision document for soil removal atthe FTPs was included in the ROD as Appendix A and stated “Because this remedy will not resultin hazardous substances remaining on-site above levels that allow for unlimited use andunrestricted exposure, the Five-Year Review will not apply to this action.”

The Army completed soil removal at the FTPs in September 1996.1

7.3 Landfill

7.3.1 Overview

The Landfill source area covers approximately 14 acres and is located immediately to the south ofFort Wainwright’s active landfill, north of River Road (Figure 7-1). Gravel excavation began in thisarea as early as 1944, and landfill operations reportedly began in the 1950s.2 Unsegregated wastewas disposed in the gravel pits and then burned. After the pits were filled with burned debris, theywere covered. The OU4 ROD, signed in September 1996, specified a phased approach toremediation of the Landfill source area: 1) capping the inactive portion of the Landfill -- completed inSeptember 1997—along with natural attenuation, monitoring of groundwater, and institutionalcontrols; and 2) evaluation of potential groundwater treatment, if levels of contamination ingroundwater were found to increase (which has not been shown to date). The landfill cap ininspected for integrity at least once a year.

1 Site Assessment Report, Remove Soil at Burn Pits, Fort Wainwright, Alaska, Rockwell Environmental Services, January 21, 1997. 2 There are no historical records documenting the starting date of landfill operations.


7-2

7.3.2 Background

Early site investigations confirmed groundwater contamination at the Landfill, which was one of twocontaminated sites that resulted in Fort Wainwright’s being placed on the NPL.

Periods of use and dates related to the history of the Landfill contamination and remediation includethe following1:

EVENT DATESoil and groundwater study conducted 1990


Groundwater monitoring performed 1991 and 1992

FFA signed 1992

TPA signed 1992

RI conducted 1993 and 1994

ROD signed August 1996

Landfill Project Site Plan completed July 1997

Landfill cap constructed 1997

RAR finalized March 1999

OM&M issued January 2001


The Landfill is located north of the Chena River at the base of Birch Hill. It encompasses 60 acres,approximately 40 acres north of River Road and a 20-acre area immediately south of River Road(the former trench area). Wetlands border the Landfill to the north and east, and black spruce forestborders the remainder of the source area except in areas cleared for access to the Landfill alongRiver Road. The source area is in a 500-year floodplain. No endangered or threatened speciesreside in the area.

The Landfill is surrounded by discontinuous permafrost and is a part of a complex hydraulic regime.In the vicinity of the Landfill, groundwater in the shallow aquifer zone generally flows southwesttowards the Chena River, while groundwater in the deep aquifer zone generally flows in thenorth-northwesterly direction of the regional gradient. However, flow direction and gradient issubject to seasonal variations and may be interrupted or redirected by permafrost in somelocations. Depth to groundwater in the vicinity of the landfill is approximately 15 to 20 feet.

The Landfill itself is believed to be in a permafrost-free “thaw bulb”, with thaw channels that havebeen identified as important pathways for contaminant transport from the Landfill towards

1 Information compiled from the OU 4 ROD; OU 4 landfill OM&M; and the Five-Year Review Report Document Log.


7-3

the Chena River. Post-RI monitoring data supports the premise that the southwest thaw channel isthe primary contaminant migration route from the Landfill to downgradient groundwater.


The older southwest portion of the Landfill and the former trench area are inactive. The remainingportion in the cleared area north of River Road is currently an active inert waste landfill, acceptingconstruction and demolition debris. The previous landfill permit allowed the disposal of domesticand commercial refuse, ash, asbestos, incinerator residue, bagged human waste, and constructionor demolition waste. A permit application for the current landfill operation has been submitted toADEC.

It is anticipated that the active portion of the Landfill will be closed within the next five years. Thismay be accomplished in stages with additional areas closed and capped in a manner similar to theportion capped as part of the OU4 ROD.

At the time of the ROD signature, there was concern that groundwater contaminated by the landfillcould enter the Chena River or threaten downgradient users, including residents of the City ofFairbanks. However, sampling to date does not indicate off site migration of groundwatercontaminants from the landfill source area. Future land use is industrial. Groundwater use isconsidered residential because water supply wells for the City of Fairbanks are located in the sameunconfined aquifer as groundwater contamination downgradient of the source area.


Landfill activities began in the early 1950’s. Based on historical aerial photographs, waste wasinitially dumped into gravel pits, burned, and covered. The Landfill began receiving most wastesgenerated at the post in the 1950s. In the early 1960s, trenching and burning ceased and wasteswere spread, compacted by bulldozer, and covered with coal ash generated from the FortWainwright power plant. Wastes that may have been disposed of at the Landfill in the 1950sinclude human waste; household refuse; waste POLs; hazardous waste; solvents; pesticides;asbestos; construction debris; and inert munitions. Historically, the quantity and type of wastedisposed of at the Landfill are not documented.

Previous investigations have identified other suspected wastes as: dry-cleaning waste and filters(reportedly redistilled prior to disposal to remove perchloroethylene); vehicular paint; asbestos;small arms and explosives disposal; triple-rinsed punctured and crushed pesticide cans, rags andsoil from small pesticide spills of less than one gallon; empty drums; and paint debris.

Pre-ROD Response

A well-defined area of petroleum hydrocarbon and lead contaminated surface soil in the inactiveportion of the Landfill was permanently covered prior to the OU4 ROD.


7-4



The primary sources of contamination at the Landfill are wastes that were placed in the Landfill andcoal ash from the power plant that was used as a cover material at the landfill. Initial investigationsconfirmed that transport of Landfill contaminants, including coal ash, through surface runoff fromthe Landfill to downgradient surface water was insignificant. Creation of leachate, throughpercolation and infiltration of surface water (i.e., rainwater or snowmelt) through Landfill waste, isbelieved to have caused groundwater contamination.

Investigations prior to and during the RI characterized contamination associated with the Landfill.

Groundwater

Volatile and semivolatile organic compounds were detected in groundwater under the Landfill andin the downgradient southwest transport pathway in concentrations exceeding federal drinkingwater MCLs and EPA risk based concentrations used for screening potential contaminants ofconcern.

Concentrations of two metals (lead and chromium) exceeded MCLs or Risk Based Concentrations(RBCs) but were less than background levels. Concentrations of two other metals exceeded MCLsor RBCs and background levels for the site but were judged to fall within the range of naturallyoccurring concentrations for the area.

Soil

Petroleum hydrocarbons and lead, from a spill, were reported at one surface soil location of theinactive landfill. That area was permanently covered prior to the ROD.


All of the RAOs for the Landfill source area pertain to groundwater quality:

Groundwater

• Restore groundwater to its beneficial use of drinking water quality within a reasonable time frame

• Reduce further migration of contaminated groundwater from the sourceareas

• Prevent use of groundwater containing contaminants at levels abovefederal MCLs and Alaska Water Quality Standards (18 AAC 70)

• Use natural attenuation to attain Alaska Water Quality Standards (18 AAC70)


7-5

ARARs

The OU4 ROD cited the most significant applicable or relevant and appropriate requirements(ARARs) for remedy selection at both the Landfill and the Coal Storage Yard to be:





Cleanup Goals

Based on the results of the baseline risk assessment for current (at the time of the ROD) andprojected land use at the site, contaminants of concern were identified for establishing numericcleanup goals for the Landfill as follows:

Groundwater

Federal and State of Alaska drinking water MCLs were adopted as groundwater cleanup goals forcis-1,2-dichloroethene, 1,1,2-trichloroethane, trichloroethene, vinyl chloride, and bis(2-ethylhexyl)phthalate.

The concentration corresponding to the EPA excess cancer risk (10-4) based cleanup level wasadopted as the cleanup goal for 1,1,2,2-tetrachloroethane, since there was no MCL for thiscontaminant.


Soil

No numeric cleanup levels were established for Landfill soil in Table 5-1 of the ROD.

Selected Remedy

The goal of this remedial action is to restore groundwater to its beneficial use as a drinking wateraquifer. The ROD described the point of compliance for achieving the RAOs as wells downgradientof the Landfill.

Landfill Cap

• Cap the approximately 8 acre inactive portion of the landfill with aminimum of 2 feet of native soil, compacting to achieve a permeability nogreater than 10-5 cm/sec

• Vegetate the cap with native plants


7-6

• Promote drainage to prevent ponding and erosion


• Achieve the RAOs for this source area through natural attenuation. Sitemodeling estimated that natural attenuation would take 70 years in orderto achieve RAOs.

• Monitor groundwater downgradient of the Landfill and evaluate results todetermine the effectiveness of the capping and natural attenuation withrespect to cleanup goals.

Contingent Remedy

• A methane gas collection system was not anticipated, but the RODspecified that the need for a gas collection system would be consideredduring remedial design. The landfill cap remedial design did not include amethane gas collection system.

• The ROD specified that if natural attenuation of groundwater did notprogress as projected, or did not result in a significant reduction inleachate, an active groundwater treatment system would be considered.


• Maintaining institutional controls restricting access to and development atthe site as long as hazardous substances remain onsite at levels thatprecluded unrestricted use.


Landfill Cap

In 1996, the U.S. Army Corps of Engineers contracted design of the cap system for the inactiveportion of the Landfill. The cap was constructed in 1997. The landfill cap was constructed over theinactive portion of the landfill north of River Road. This area encompasses approximately 14 acres.The trench area south of River Road was not included in the capping project because nocontaminants were found at levels that posed an unacceptable risk to human health or theenvironment in this location. It should be noted that during the design phase of the project the areato be capped was determined to be 14 acres which is greater than the 8 acres initially determinedat the time of the ROD.

The landfill cap is an earthen cap design that includes multiple layers of soil. The layers within thecap include:

• Unclassified subgrade material (6-inches thick) which provided a uniformbase for the remainder of the cap. Unclassified material is defined as any


7-7

inorganic soil, free of trash, peat, debris, or frozen clods which is capableof being compacted as required by the design plans.

• Low permeability soil layer (18-inches thick) which limits infiltration throughthe cap. The low permeability material is defined as a silt or clay (100percent passing the No. 4 screen and 80 percent passing the No. 200screen) which can be compacted to achieve a maximum permeability of5x10-5 cm/sec.

• Drainage layer (6-inches thick) intended to minimize ponding of water onthe surface of the low permeability soil layer. The drainage layer materialis a sand (1000 percent passing the No. 4 screen and 5 percent passingthe No. 200 screen).

• A woven geotextile between the topsoil and drainage layer to minimizemigration of fines between the two layers.

• Top soil (6-inches thick)

• Surface vegetation -- The cap was seeded with a mixture of grass andwildflower.

The landfill cap is a passive remedial alternative intended to reduce surface water infiltration to themass of the landfill and consequently reduce leachate migration to groundwater. The system hasno active operational requirements per se.

Monitoring and maintenance of the landfill cap includes:

• Twice yearly groundwater monitoring

• Annual inspection of the cap


No significant changes in contaminant concentration at the monitoring wells have beenobserved to date. The concentrations of contaminants in the identified plume are generally stablewith some minor variation over the monitoring period from 1996 through 2000. Chlorinated volatilecompounds continue to be detected in concentrations exceeding RAOs in two wells west andsouthwest of the capped portion of the landfill (AP-5588 and AP-6137). Onlybis(2-ethylhexyl)phthalate continues to be detected in concentrations exceeding RAOs in wellssouth of the landfill. Bis(2-ethylhexyl)phthalate analytical results have tended to be variable andhave often been qualified by the laboratory as being estimated and/or questionable due to analytehaving been detected in the blank as well as in the sample. However, there continue to beunqualified groundwater sampling results for this compound (a common landfill contaminant) inconcentrations exceeding the RAO in several of the wells south of the landfill. There has been noidentified migration of the plume within the site or off of the site. Plate 7-I summarizes analyticalresults for each monitoring well pre- and post-ROD (see appendices section of this report).


7-8


ICs for the Landfill are in effect and include fencing and signage to limit access to the site, andpolicies to limit excavation or well installation in potentially contaminated sites. Figure 7-2 depictsthe restricted areas.1

Fort Wainwright has established a post wide IC policy for all known or suspected contaminatedsites.




• No soil excavation can take place without prior briefings on potentialconcerns at the source area, knowledge of the procedures for handlingcontaminated soils on Fort Wainwright, and possession of a valid site-specific Fort Wainwright Excavation Permit.


Site Inspection

This site was inspected on April 27, 2001. The landfill cap and fence were observed to be in goodcondition with no evidence of drainage problems or loss of integrity of the landfill cap. Photographstaken at the time of the site inspection are included in the appendices section of this report.



Landfill Cap

The Landfill cap has been constructed and is being maintained. Groundwater monitoring resultsindicate that the identified plume has not migrated from the site area. Results of the 2000 and theMarch 2001 sampling events indicate no significant increases in concentrations for the targetanalytes. During ROD preparation, the possibility was anticipated that capping the landfill may notsignificantly decrease contaminant concentrations in groundwater and capping the



7-9

entire landfill might be necessary. However, the cap on the inactive portion of the landfill has onlybeen in place since 1997, and a longer period of groundwater monitoring is appropriate beforedetermining the cap’s effectiveness. Contaminants are not migrating off site at this time, andinstitutional controls remain protective of human health and the environment.

Plate 7-I summarizes the results of groundwater monitoring associated with this source area.


Institutional controls for the Landfill are in place. Excavation in the active area is restricted andrequires authorization by DPW Environmental. Absolutely no excavations are allowed in theinactive landfill area. Groundwater intrusion is restricted, subject to authorization by DPWEnvironmental. The ICs do not extend to the area downgradient of the Landfill where groundwatermonitoring and natural attenuation is occurring. Enlarging the zone of IC coverage to include thedowngradient area would preclude any possibility of groundwater in this area accidentally beingused as a source of drinking water.

System Operations/O&M

Since the initial construction of the landfill cap two additional re-vegetation efforts have beenundertaken to fill in areas of poor grass growth. In 1999, a large section of geotextile fabric wasvisible near the surface in the northwest part of the cap and was found to be torn. It is unknownhow this damage occurred, but is suspected to have been caused by vehicle traffic on the cap. Thearea has since been repaired and vehicular traffic is no longer allowed on the cap.




Contaminant concentrations relatively constant 3years after cap constructed


No growth of plume or increase in contaminantconcentrations

Prevent use of groundwater containingcontaminants at levels above federal MCLs andAWQS (18 AAC 70)

Institutional controls in effect


Contaminant concentrations relatively constant 3years after cap constructed


• The understanding of the permafrost distribution has been revised since thedate of the ROD. This has caused a re-evaluation of groundwater flowdirections and locations of downgradient monitoring wells.


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• It was assumed that the active portion of the Landfill may effect downgradientconcentrations of contaminants and that significant decreases in contaminantconcentrations may not occur until the entire Landfill is closed and capped.Groundwater monitoring data to date support this assumption.


• The MCLs used to establish groundwater cleanup goals for the Landfill havenot substantively changed since the ROD.

• The Alaska MCL for 1,1,2-trichloroethane is now 5 ug/L, the same as thecurrent federal MCL, and identical to the cleanup goal in the ROD. (There wasno Alaska MCL noted for this contaminant in Table 5-1 of the ROD.)



Variances

The following variances were identified in the review of OU4 Landfill Source Area protectivenessand remediation process.


Institutional controls do not extend to areadowngradient of Landfill where groundwatermonitoring and natural attenuation is occurring.

N


No landfill cap design or operational changes are recommended at this time. The followingvariances were identified in the review of OU4 Landfill Source Area groundwater monitoringprogram and ICs.


PartyResponsible

OversightAgency

MilestoneDate

Affects Protectiveness

(Y/N)

Change IC boundary to coverarea where groundwater plumefrom landfill leachate affectsdowngradient aquifers.

U.S. Army EPA,ADEC 3/02 N


7-11

The remedy selected for the Landfill includes groundwater monitoring. In order to be protective, themonitoring wells must be located downgradient of the Landfill. Groundwater flow is complex andvaried due to the presence of permafrost in the Landfill area. The groundwater flow system in theLandfill area may be sensitive to changes in the hydrologic system. Changes can be caused bynatural occurrences such as increases or decreases in average annual precipitation or by humandisturbances such as capping of the Landfill. It is important to evaluate the groundwater monitoringdata while keeping these potential effects in mind especially while assessing wells that are locateddowngradient of the source area. It is recommended that the groundwater contours be plotted andevaluated during each monitoring event to ensure that the assumptions used in assessing thegroundwater monitoring data reflect well placement relative to the source area. This will enablechanges in flow patterns to be recognized and appropriate actions taken. Data from thegroundwater monitoring program should be evaluated as it is reported to assure no off-sitemigration of contaminants occurs and to evaluate the progress of natural attenuation.

The area where ICs are implemented at the Landfill source area does not extend far enough westto encompass the downgradient monitoring wells where RAOs have not been met. It isrecommended that the IC boundaries be expanded to include this larger area.

7.4 OU4 -- Coal storage yard

7.4.1 Overview

The CSY is located south of the Fort Wainwright power plant and east of the power plant coolingpond (Figure 7-3). The area of concern is located within an area approximately 800’ by 300’between the cooling pond and an embankment. Historically, coal was stored directly on the groundwithout a liner, and waste petroleum products and solvents were sprayed over the coal pile toincrease the heat content (BTUs) and energy output of the plant, a practice which has beendiscontinued. Two 10, 000-gallon USTs were installed in the 1980s to contain waste oil for thepractice of spraying to increase BTUs. Before these tanks were installed, waste oil was placed indrums adjacent to the coal pile. Two 10, 000-gallon USTs were removed in July of 1995. Thechosen alternative in the ROD, signed September 1996, was in situ treatment of soils andgroundwater by enhanced soil vapor extraction/air sparging. The treatment system was installedand began operation summer 1997. Air vapors are being treated through a vapor phase activatedcarbon absorption system. Additional sampling has been conducted to ensure contaminants are notmigrating, and no expansion of the system is required. Results from calendar year 2000 are beingevaluated to determine future operation and cost efficiencies.

7.4.2 Background

Periods of use and dates related to the history of CSY contamination and remediation include thethose presented in the following table1.

1 Information compiled from the OU 4 ROD; Final 1999 CSY System Monitoring Report; OU 4 CSY OM&M; and the Five-Year ReviewReport Document Log.


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EVENT DATE

Active coal pile sprayed with waste petroleum fuel products 1950s to 1993

Soil borings and installation of 9 monitoring wells 1986


Re-sampling of monitoring wells. Soil sampling conducted at the active coal pileand along road adjacent to cooling pond. 1991

FFA signed 1992

TPA signed 1992

Release investigation conducted at location of UST 295 (formerly located with thefenced area) and groundwater survey conducted beneath the active coal pile. 1993

OU 4 RI conducted 1993

Two USTs removed from fenced storage area adjacent to CSY 1995

ROD signed August 1996

VAS/SVE treatment system and nested groundwater monitoring wells installed Summer 1997

RAR finalized April 1999

OM&M available to public January 2001


The areas north and east of the CSY are industrial areas, while the areas to the south and westhave mixed hardwood forests. A man-made unlined cooling pond is located immediately to the westand is used solely for industrial purposes to cool circulated water from the power plant. The sourcearea is in a 500-year floodplain. No endangered or threatened species reside in the area.


The CSY is used to stockpile supplies of coal prior to burning at Fort Wainwright’s coal-firedcogeneration power plant. This power plant is the sole source of heat and electricity for FortWainwright. The coal is transported to the CSY vial rail and off-loaded through hopper and along aconveyor which deposits the coal on the south side of the power plant. Coal is stored in the yarddirectly on the ground without the use of a liner.

Water supply wells for Fort Wainwright are located downgradient of the CSY source area and areapproximately 900 feet northwest of the active coal pile. Flow velocities based on measuredgradients were estimated to range widely from 243 ft/year to 2,917 ft/year. The cooling pond ishydrologically connected to the groundwater aquifer and may affect groundwater flow locally.Groundwater flows generally north to northwest and varies due to water supply well pumpingpatterns.


7-13

Groundwater use is considered residential because water supply wells for the City of Fairbanks arelocated in the same unconfined aquifer as groundwater contamination downgradient of the sourcearea.


Activities at the CSY began in the 1950s with the industrial operation of the Post power plant.Based on historical documents, the CSY’s active coal pile was sprayed with waste petroleum fuelproducts to increase the British thermal unit content of the coal. This practice was discontinued in1993. As the active coal pile was consumed, the active pile area was graded to include the toplayer of soil and intermixed coal, and then burned in the power plant. New coal supplies were thenadded to the storage yard.

A fenced area existed within the CSY and contained a staging or storage area for drums. Surfacespills of materials were common and associated leakage or spillage of material from the drums maybe another source of contamination.

Pre-ROD Response

Application of POLs and solvents to the coal pile was discontinued in 1993.



Original contaminant sources at the CSY include diesel, fuel oil, solvents, and lubricants sprayedon the active coal pile and waste oil spills and leaks from tanks and drums. VOCs and petroleumcontaminated subsurface soils were identified during RI activities in 1994. Soils contaminated withthese chemicals were considered sources of groundwater contamination at the CSY. Contaminantshave been transported by overland flow of surface water (i.e., rain or snowmelt), vertical migrationthrough soils to the groundwater aquifer, and volatilization. VOC contamination at the groundwaterinterface and at depth was found to be limited laterally to the area under the active coal pile andfenced storage yard.

Chemicals of concern identified in the ROD for the CSY source area include benzene, bis(2-ethylhexyl)phthalate, trichloroethene, and toluene in the groundwater.


Groundwater

• Restore groundwater to its beneficial use of drinking water quality within areasonable time frame

• Reduce further migration of contaminated groundwater from the source areas


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• Prevent use of groundwater containing contaminants at levels above federalMCLs and Alaska Water Quality Standards (18 AAC 70)

• Use natural attenuation to attain Alaska Water Quality Standards (18 AAC 70)

Soil

• Prevent migration of soil contaminants to groundwater that could result ingroundwater contamination and exceedances of federal MCLs and AlaskaWater Quality Standards (18 AAC 70)

ARARs

The OU4 ROD cited the most significant applicable or relevant and appropriate requirements(ARARs) for remedy selection at both the Landfill and the Coal Storage Yard to be:





Cleanup Goal

Groundwater

Federal and State of Alaska drinking water MCLs were adopted as groundwater cleanup goals forbenzene, bis(2-ethylhexyl)phthalate, trichloroethene, and toluene at the Coal Storage Yard. Therewere no risk based cleanup levels established for groundwater at the CSY.

Soil

Petroleum hydrocarbon soil cleanup goals for the Coal Storage Yard were indicated on page 2 ofTable 5-2 of the ROD. At the time of the ROD, these goals set concentration limits for DRO, GRO,benzene, and BTEX. There were no risk based cleanup levels established for soil at the CSY.


Selected Remedy



7-15

To achieve the RAOs for the CSY, in situ treatment of groundwater by air sparging was selected toremove VOCs and to prevent contaminated soils from acting as an ongoing source ofcontamination to groundwater. Air sparging wells were placed in areas of highest contamination. Insitu treatment of soils by soil vapor extraction was also recommended, with extraction wells placedin areas of highest contamination and operated until groundwater MCLs were achieved. Thetreatment system was to be evaluated and modified as necessary to optimize effectiveness inachieving RAOs. Nine years of operation of the AS/SVE system was estimated to achieve soil andgroundwater RAOs and remediate groundwater to federal MCLs and soil to ADEC goals forpetroleum contamination.


After active treatment achieved MCLs, natural attenuation would be relied on to achieve AlaskaWater Quality Standards. Monitoring of the nested downgradient wells was also recommended toensure protection of post drinking water supply wells during remedial action. Institutional controls,including restricted access and well development restrictions, were to be adopted as long ashazardous substances remained on site at levels that precluded unrestricted use. Restrictions ongroundwater were also implemented until contaminant levels fell below federal MCLs and AlaskaWater Quality Standards.


In the summer of 1997, an AS/SVE treatment system was installed. The system consists of 27 airsparge points and 14 SVE wells. Due to steam plant operational considerations, the system doesnot cover the entire area suspected to be contributing to groundwater contamination aboveremedial action objectives. The treatment system is designed to operate only during summermonths (May through October).

CSY Groundwater Monitoring

Groundwater monitoring is performed on a semiannual basis. The concentrations of contaminantsin the identified plume have decreased and are generally stable with some minor variation over themonitoring period with the exception of bis(2-ethylhexyl)phthalate. Bis(2-ethylhexyl)phthalateconcentrations appear to fluctuate widely and it is not understood whether the source ofbis(2-ethylhexyl)phthalate is a sampling or analytical laboratory artifact or an actual groundwatercontaminant. Results of groundwater sampling in April 2001 indicated no contaminant levelsexceeding cleanup goals for this source area.

Plate 7-II presents groundwater concentrations over time since the ROD. There has been noidentified migration of the plume within the site or off of the site.


ICs are in effect at the CSY. Figure 7-4 depicts the areas where the ICs apply.1

1 Further details of the Army/Fort Wainwright IC policy can be found in the OU5 ROD, the U.S. Army Alaska InstitutionalControls Standard Operating Procedures [(APVR-RPW [200-1)], and a September 1999 Memorandum on Institutional Controls[(APVR-RPW-EV-(200-1c)] from Major General Dean W. Cash, Fort Richardson, Alaska.


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Fort Wainwright has established a post wide IC policy for all known or suspected contaminatedsites.






Site Inspection

The CSY was inspected on April 27, 2001. No variances were observed. Photographs taken duringthe site inspection are included as appendices to this report.




The AS/SVE system has been operational since installation, removing VOCs from the soil andgroundwater. The treatment system operates seasonally and has operated for 418 days sincesystem startup in 1997. The ROD assumed a treatment period of nine years or 3, 287 days. Thesystem has averaged 131 days of operation over the last three treatment seasons. Assuming 131days of operation per treatment season it will take 22 treatment seasons to equal the nine years oftreatment.

Continuous operation of the treatment system has been impeded by coal dust. Measures havebeen taken to add filters to the air intake of the blowers.


AS/SVE treatment is on going at the CSY. Groundwater monitoring is an on going aspect of theremedy. Natural attenuation is expected to help achieve RAOs at the CSY.

Plate 7-II summarizes the results of groundwater monitoring associated with this source area.



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Institutional controls for the CSY are in place. Excavation on this site is restricted and shall beauthorized by DPW Environmental. Groundwater intrusion is restricted and shall be authorized byDPW Environmental.



Restore groundwater to its beneficial use ofdrinking water quality within a reasonable time frame

No plume growth or increase in contaminant concentrations to date; decrease incontamination


No plume growth or increase in contaminantconcentrations to date

Prevent use of groundwater containingcontaminants at levels above federal MCLs andAlaska Water Quality Standards

ICs in effect

Use natural attenuation to attain Alaska WaterQuality Standards (AWQS) (18 AAC 70)

No plume growth or increase in contaminantconcentrations to date

Prevent migration of soil contamination togroundwater that could result in groundwatercontamination exceedances of federal MCLs andAWQS (18 AAC 70)

AS/SVE in place and operational (thoughlimited); no plume growth or increase incontaminant concentrations to date



• The MCLs used to establish groundwater cleanup goals for the Coal StorageYard have not changed since the ROD.

• No cleanup goals for the Coal Storage Yard were based on risk calculationsor standard scenario RBCs.

• The 18 AAC 75 and 18 AAC 78 limit for benzene in soil is now 0.02 mg/kg,compared to 0.1 mg/kg at the time of the ROD.




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Variances

The following variances were identified in the review of OU4 CSY Source Area protectiveness andremediation process.


Treatment system does not extend to areasidentified in Remedial Investigation as soil hot spotdue to presence of active coal pile.

N

Institutional controls do not extent to areadowngradient of CSY where groundwatermonitoring and natural attenuation is occurring.

N


The following variances were identified in the review of the OU4 CSY Source Area groundwatermonitoring program and ICs.


PartyResponsible

OversightAgency

MilestoneDate


(Y/N)

Evaluate need for treatmentsystem extension to under coalpile.

U. S. Army EPA,ADEC 9/02 N

Relocate institutional controls tocover area where groundwaterplume from CSY affectsdowngradient aquifer.

U. S. Army EPA, ADEC 3/02 N

The remedy selected for the CSY includes groundwater monitoring. In order to be protective themonitoring wells must be located downgradient of the CSY source area hot spots and upgradient ofthe potential receptors (water supply wells). Because of the proximity of the source area to anumber of water supply wells the groundwater flow does not follow the regional gradient and canvary according to the pumping schedules of the various wells. The groundwater monitoring dataneeds to be evaluated with this in mind.

It is recommended that the downgradient groundwater contours be plotted and evaluated duringeach monitoring event to ensure that the assumptions used in assessing the groundwatermonitoring data reflects where the monitoring wells are located relative to the source area. Thiswill enable changes in flow patterns to be recognized and appropriate actions taken. Data from


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the groundwater monitoring program should be evaluated as it is reported to assure no off-sitemigration of contaminants and to evaluate progress of natural attenuation.

The area where ICs are implemented at the CSY source area does not extent far enough west andnorthwest to encompass the downgradient monitoring wells where RAOs have not been met. It isrecommended the IC boundaries be expanded to include this larger area.


8-1 REV.01

8 OPERABLE UNIT 5

8.1 OU5 Background

OU5 is identified as the final operable unit in the FFA and includes three source areas deferredfrom previously investigated operable units as well as three source areas identified for inclusion inOU5 (Figure 8-1). Four source areas were identified for action: (1) three subareas of the WestQuartermaster’s Fueling System (WQFS); (2) East Quartermaster’s Fueling System (EQFS); (3)Remedial Area 1A (also called the Birch Hill Tank Farm Product Recovery System); (4) OpenBurning/Open Detonation (OB/OD) area. Two source areas were recommended for no furtheraction under the Comprehensive Environmental Response, Compensation, and Liability Act of1980 (CERCLA): (1) Former Explosive Ordnance Disposal (EOD) Range and (2) Motor PoolBuildings. In addition, several petroleum-contaminated sites, including one WQFS subarea, havebeen and are being addressed in accordance with an agreement between the U.S. Army (Army)and the State of Alaska.

The OB/OD area and former EOD range were determined to require no further action underCERCLA. The OB/OD RCRA closure plan has been submitted to EPA for review. Upon agreementof this language, a closure plan for the former EOD range will be drafted as well.

The ROD, then, addresses remediation of WQFS areas 1 through 3 and the EQFS, and RA1A(Figure 6-1). In addition, the OU5 ROD describes the Army’s commitments to the Chena RiverAquatic Assessment Program and to institutional controls (ICs) at all five OUs and commits to an ICprogram that includes a standard operating procedure (SOP) for ensuring compliance with the ICs.The OU5 Five-Year Review is thus organized into the following sections: WQFS, EQFS, RA1A,Chena River, and Institutional Controls.

8.2 West Quartermaster’s Fueling System

8.2.1 Overview

The WQFS area covers approximately 50 acres. The WQFS was divided into four subareas for soil:WQFS1, WQFS 2, WQFS3, and WQFS4 (Figure 8-1). Soils within WQFS4 are being addressedunder the TPA so were not included in remedial actions under OU5, however the groundwaterbeneath WQFS4 is being addressed in OU5.

The west section of the former Quartermaster’s fueling system (WQFS) is located between FrontStreet and Gaffney Road. The area runs from near the southeast boundary of the taxiway to theChena River on the north boundary. Groundwater samples collected indicate diesel range organic,gasoline range organic, solvents and benzene contamination. Soil investigations in 1994 identifiedseveral fuels and a solvents. A remedial investigation (RI) was completed in 1995.

At the WQFS, a treatability study conducted from 1996 to 1998 attempted to use oxygenreleasing compounds to enhance the rate of reduction of VOCs, but had limited success. Anadditional treatability study, using radio frequency and six phase heating to heat soil and


8-2

enhance biodegradation and volatilization has been completed with mixed successes. Bench scaletracer and biodegradation studies were conducted to better understand the persistence of thecontamination. Removal of the retaining structure in the WQFS2 was completed in 1998 prior toinstallation of the air sparging curtain.

On-going active remediation at the WQFS includes horizontal air sparging/soil vapor extractionwells; source strength AS/SVE, and an air sparging/SVE curtain to protect the Chena River.Groundwater modeling is on-going to determine groundwater movement and contaminant transportand remedial action effects on the Chena River. Augmentation of the existing air sparging/SVEsystem and source strength system was constructed in 2001 to better protect the River and attackthe hot spots. A small scale system was installed in the WQFS3 to treat contamination close to theRiver; this system was integrated into the curtain system.

The OU5 ROD, signed in April 1999, identified the remedial actions for the WQFS as soil vaporextraction/air sparging, potential in situ soil heating in hot spots, potential operation of adowngradient air sparging trench, groundwater monitoring, monitored natural attenuation, andlong-term monitoring.

Institutional controls are in place in the entire QFS; an informational sign has been installed toinform the public of activities in this area. Operation, Maintenance and Monitoring reports are beingdrafted. It is anticipated that all components of the remedy will be operational and function by theend of 2002. The LTM plan and exit strategy, as well as the interim Remedial Action Report will becompleted at that time. Off-gas vapors are currently being treated through oxidizers.

8.2.2 Background

Periods of use and dates related to the history of WQFS contamination and remediation include thefollowing1

EVENT DATEIndustrial use including maintenance activities involving the use of solvents,POLs, pesticides, and other hazardous materials 1930s to 1960s

Leak of approximately 30,000 gallons of diesel fuel 197116,000 gallons of gasoline spilled 1971Fuel leak of unknown origin into the Chena River 1980Fort Wainwright NPL listed August 1990FFA signed 1992TPA signed 1992North Airfield groundwater investigation 1994RI completed 1996Initiation of WQFS1 Horizontal Well AS/SVE with Treatability Study Spring 1997

1 Information compiled from the OU 5 ROD; Draft OU 5 PDRAR; and the Five-Year Review Report Document Log.


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FS completed 1998

Proposed Plan for Remedial Action at OU 5 finalized June 1998

OU 5 bench-scale column study initiated January 1998

Initiation of soil heating AS/SVE Treatability Study at WQFS1 Spring 1998

Initiation of WQFS2 AS Curtain Treatability Study Summer 1998

Initiation of WQFS1 source area AS/SVE Treatability Study Aug and Sept 1998

WQFS2 AS curtain Treatability Study initiated August 1998

WQFS3 AS/SVE Treatability Study initiated August 2000

Draft 2000 PDRAR finalized April 2001


The WQFS is bordered to the north by a south trending meander of the Chena River, to the west bythe ROLF and to the south by Taxiway 18. The terrain is open tussock flats as the buildings haveall been removed from the site. The WQFS is located within the 500 year floodplain of the ChenaRiver.


Activities within the WQFS included vehicle and aircraft maintenance operations and the associateduse and disposal of solvents and other cleaning and maintenance compounds. The WQFS alsoincluded underground and aboveground storage tanks, a pump house and fueling islands. Drainswithin the WQFS were connected to a wooden pipe that drained to the river. The underground fuelpipelines and a network of aboveground and buried fuel piping were abandoned in place. Cleaning,pumping and capping of the underground piping is an ongoing project. The primary sources ofcontaminants in groundwater at WQFS are from surface disposals of solvents, petroleum spills andleaks, and other past disposal practices.


Groundwater

Groundwater contamination extends approximately 70 feet BGS or 60 feet below the watertable and the approximate extent of groundwater contamination is 43 acres. Initial investigationsconducted at the WQFS revealed four groundwater plumes. Two free-product plumes (mostlyjet fuel and diesel fuel) exist within the source area. The larger plume extends about 4-1/2 acres and encompasses the area where the predominance of fuel pumps, dispenser islands,and storage tanks were located. The smaller free-product plume extends about 600 feetsouthwest of Building 1599 and coincides with a bermed area around a possible fuel containment structure. A benzene plume covers about 25 acres and with dissolved contaminants to 25 feet thick. A plume of 1,2-dichloroethane extends from the north of Front Street to the Chena River, overlapping the free-product and benzene plumes and extends to a depth of approximately 20 feet. DRO and GRO organics were also detected but their extent


8-4

was not defined. Groundwater contaminants originating in the WQFS source area have beendetected in the Chena River.

Free liquid products exist on the water table in the area influenced by releases from the WQFS.Contaminants reported in the groundwater at the WQFS to contain benzene, 1,2-DCA, toluene,and trichloroethene (TCE) in concentrations exceeding MCLs, and total aromatic hydrocarbon(TAH) and total aqueous hydrocarbon (TAqH) in concentrations exceeding Alaska Water QualityStandards.

Ethylene dibromide (EDB) has recently been detected in concentrations exceeding RAOs ingroundwater samples from two locations in WQFS-1. EDB had not been reported in the WQFS atthe time of the ROD.

Soil

Contaminants of concern at WQFS affect approximately 150, 600 cubic yards of soil. Soilcontamination in WQFS subareas is thought to be due to the following historical practices: inWQFS1 vehicle maintenance at former Building 1599 and leaks from former fuel storage andhandling; in WQFS2 former aboveground storage tanks (ASTs) and an eight-inch fuel pipeline thatparallels Gaffney Road; and in WQFS3 a 6-inch wood-stave pipe through which diesel and gasolinewere channeled during fuel releases in 1971 as well as possible drum storage or road-maintenanceactivities.

Soils in the WQFS contain BTEX, semivolatile organic compounds (SVOCs), and petroleumhydrocarbons in concentrations greater than ADEC cleanup guidelines.


Current land use for the WQFS is light industrial; current and future groundwater use is consideredresidential because water supply wells for the City of Fairbanks are located in the same unconfinedaquifer as groundwater contamination downgradient of the WQFS. The closest residences toWQFS are about one mile west. Each residential area includes a school. Currently access toWQFS is unrestricted, and the area is used for recreational purposes and includes a bicycle trail.Access to the Chena River is unrestricted.



The ROD identified the following objectives for remediation of OU5:

Groundwater

• Restore groundwater to its beneficial uses within a reasonable time frame. Reduce orprevent further migration of contaminated groundwater from the source areas to thedowngradient aquifer or surface water bodies that are closely hydrologically connected byachieving MCLs (where there are no nonzero maximum contaminant level goals [MCLGs])and Alaska Water Quality Standards. For groundwater that is hydrologically connected tosurface water, Alaska Water Quality Standards will apply for the following


8-5

Fresh Water Uses: (I)(A) Water Supply; (I)(B) Water Recreation; and (I)(C) Growth andPropagation of Fish, Shellfish, Other Aquatic Life, and Wildlife.

• Ensure there is no risk to aquatic receptors through control of contaminant movementthrough the groundwater into the Chena River

• Remove free liquid product to the extent practicable to eliminate film or sheen fromgroundwater

• Prevent use of groundwater containing contaminants at levels above Safe Drinking WaterAct MCLs, nonzero MCLGs, or the following Alaska Water Quality Standards for FreshWater Uses: (I)(A) Water Supply; (I)(B) Water Recreation; and (I)(C) Growth andPropagation of Fish, Shellfish, Other Aquatic Life, and Wildlife.

Soil

• Prevent the migration to groundwater of soil contaminants that could result in groundwatercontamination and exceedances of federal MCLs and nonzero maximum contaminant levelgoals (MCLGs) and to groundwater that is closely hydrogeologically connected to surfacewater (such as the Chena River) that could result in exceedances of Alaska Water QualityStandards in surface water (EQFS and WQFS).

Chena River Sediments

• Reduce sources of contaminant releases to the Chena River

Chena River Surface Water

• Meet Alaska Water Quality Standards for the following Fresh Water Uses: (1)(A) Water “JSupply; (1)(B) Water Recreation; and (1)(C) Growth and Propagation of Fish, Shellfish,Other Aquatic Life, and Wildlife

• Continue aquatic assessment

ARARs

The OU5 ROD cited the most significant applicable or relevant and applicable requirements(ARARs) for remedy selection at this site to be:

• Federal and state MCLs are relevant and appropriate for groundwater that is a potentialdrinking water source (40 CFR 141 and 18 AAC 80). These ARARs set the activeremediation goals for groundwater. Alaska Water Quality Standards (18 AAC 70) are alsoapplicable to surface water, sediment, and groundwater that is closely hydrologicallyconnected to surface water.

• Alaska oil pollution regulations (18 AAC 75) are applicable and require the cleanup of oil orhazardous material releases.


8-6

Cleanup Goals

Based on the baseline risk assessment for projected land and resource use at the WQFS, the RODadopted the following cleanup goals:

Groundwater

• Federal and state MCLs for 1,2-DCA, benzene, and toluene, and State of Alaska (18AAC 75) cleanup levels for residual range organics (RRO), DRO, and GRO wereadopted as numeric cleanup goals for the WQFS. In addition, the ROD identifiedelimination of any sheen caused by floating petroleum product as a cleanup goal.

Soil

• The cleanup goal for soil in the WQFS is active remediation of soils until contaminantlevels in groundwater are consistently below state and federal MCLs.


• No concentrations of toxic substances or petroleum hydrocarbons and othercontaminants in bottom sediments that cause deleterious effects to aquatic life, to bedetermined by benthic macroinvertebrate assessment.

• Benthic macroinvertebrate assessment to establish baseline and to monitor aquaticbiotic integrity through time


• 10 :g/L TAH

• 15 :g/L TAqH

• Eliminate petroleum hydrocarbon sheen

• Benthic macroinvertebrate assessment to establish baseline and to monitor aquaticbiotic integrity over time

• Groundwater monitoring to assess reduction of contaminant releases to the Chena River


Pre-ROD Response

Removal or treatability studies taken prior to the ROD include the following:


8-7

• In WQFS3 several leaking drums of tarry substance exposed along the Chena River wereremoved in 1995; nine nearby buried drums and approximately 3 cubic yards ofcontaminated soil were excavated in 1996.

• In 1998 approximately 700 cubic yards of contaminated soil and a sheet metal retainingstructure was removed from WQFS2. An air sparging curtain was installed in this area tominimize contaminate movement into the Chena River.

• Several treatability studies were initiated in the WQFS prior to the signing of the ROD forOU5, with the intent that effective technologies would be considered for incorporation intoWQFS and EQFS remediation:

• SVE and AS with Horizontal Wells-WQFS1

• Source Area AS/VE –WQFS1

• In Situ Soil Heating-WQFS1

• In Situ Oxygen Release Compound (ORC)-WQFS2

• Bench-Scale Column Study of Factors Limiting Bioremediation Rate-Laboratory

Selected Remedy

The ROD identified different remedial actions for the different subareas of the WQFS as describedbelow.

WQFS1

• Operating an SVE/AS system to address solvent and petroleumcontamination in the source-area soil and groundwater and the floating-product contamination. The source area SVE/AS system can be tailored tostrip VOCs from groundwater and soil and to enhance biological degradationof contaminants in saturated- and vadose-zone soils while minimizingvadose-zone desiccation. An existing system, used for a treatability study, willbe expanded to address the source area. The SVE system will include offgastreatment. Before operation of the SVE/AS system begins, abandoned buriedfuel pipelines within the subarea will be purged of residual fuel to eliminate thepotential for the lines to act as ongoing contaminant sources.

• Potential in situ heating at hot spots is proposed as a method to increase therate of remediation in comparison to source-area treatment without heating. Inthe event that AS is ineffective in achieving progressive reduction of the VOCand petroleum hydrocarbon concentrations in soils, in situ soil heating isproposed as a means to increase the movement of VOCs and make themeasier to extract. Treatability studies involving radio-frequency soil heatingand six-phase soil heating have been initiated


8-8

in WQFS1 to evaluate the potential to enhance performance of AS and SVE.

• Potentially supplementing the AS and SVE with the operation of adowngradient groundwater AS trench, if necessary, to intercept and treatdissolved contaminants migrating from source areas downgradient toward theChena River.

• Establishing and maintaining institutional controls to ensure that until federaland state MCLs are attained, the groundwater will not be used as a potablewater source. Institutional controls include restrictions governing site access,onsite construction, and well development or placement. They will benecessary as long as hazardous substances remain onsite at levels thatpreclude unrestricted use. Current and future land use is industrial; currentand future groundwater use is designated for residential use. Groundwater-and land-use restrictions will be incorporated into the Fort Wainwright masterplan.

• Monitoring of the natural attenuation of COCs in groundwater to trackdecreases in concentrations to below ARARs and achievement of RAOs. Thepossible rebound of contaminant concentrations after operation of remediationtechnologies has ceased also will be monitored.

• Monitoring the performance of remedial treatment systems, as describedabove, to optimize treatment system effectiveness and efficiency throughsystem modifications and/or enhancements as appropriate.

• Monitoring and evaluation of the selected remedy, including naturalattenuation, to determine achievement of RAOs.

• Monitored natural attenuation for deep groundwater and areas not beingactively treated within WQFS1.

WQFS2

• Installing an SVE/AS system to address solvent- and petroleum-contaminatedhot spots in the soil and groundwater and floating-product contamination. Thehot-spot SVE/AS system can be tailored to strip VOCs from groundwater andsoil and to enhance biological degradation of contaminants in saturated- andvadose-zone soils. The SVE system will include offgas treatment. Beforeoperation of the AS and SVE system begins, abandoned buried fuel pipelineswithin the subarea will be purged of residual fuel to eliminate the potential forthe lines to act as ongoing contaminant sources.

• Continuing to operate a downgradient AS curtain to intercept and removedissolved-phase contaminants from the groundwater, thus minimizingpotential impacts to the Chena River.


8-9

• Conducting groundwater monitoring to determine whether cleanup levels areachieved and maintained downgradient of the AS curtain.

• Establishing and maintaining institutional controls to ensure that until federaland state MCLs are attained, the groundwater will not be used, except foractivities undertaken to initiate the selected remedies detailed in this ROD.Institutional controls include restrictions governing site access, onsiteconstruction, and well development or placement. They will be necessary aslong as hazardous substances remain onsite at levels that precludeunrestricted use. Current and future land use is industrial; current and futuregroundwater use is designated for residential use. Groundwater- and land-userestrictions will be incorporated into the Fort Wainwright master plan.


• Monitoring performance of remedial treatment systems, as described above,to optimize treatment system effectiveness and efficiency through systemmodifications and/or enhancements as appropriate.



WQFS3

• Installing AS and SVE wells to address solvent- and petroleum-contaminatedhot spots in the soil and groundwater and floating-product contamination. Thehot-spot SVE/AS system can be tailored to strip VOCs from groundwater andsoil and to enhance biological degradation of contaminants in saturated- andvadose-zone soils. The SVE system will include offgas treatment. AS andSVE wells are located in the contaminant hot spot. Before operation of theSVE/AS system begins, abandoned buried fuel pipelines within the subareawill be purged of residual fuel to eliminate the potential for the lines to act asongoing contaminant sources.

• Establishing and maintaining institutional controls to ensure that until federaland state MCLs are attained, the groundwater will not be used, except foractivities undertaken to initiate the selected remedies detailed in this ROD.Institutional controls include restrictions governing site access, onsiteconstruction, and well development or placement. They will be necessary aslong as hazardous substances remain onsite at levels that precludeunrestricted use. Current and future land use is industrial; current and futuregroundwater use is designated for residential use.


8-10

Groundwater- and land-use restrictions will be incorporated into the FortWainwright master plan.


• Monitoring the performance of remedial treatment systems as describedabove, to optimize treatment system effectiveness and efficiency throughsystem modifications and/or enhancements as appropriate.




The following description of the status of the WQFS remediation systems is primarily based on thedraft Preliminary Draft Remedial Action Report, Operable Unit 51 (PDRAR), which is the mostrecent report of the status of remediation systems at the EQFS and WQFS.

All WQFS Subareas

These requirements are applicable to all WQFS sub areas:

Purge Abandoned Fuel Lines

Abandoned buried fuel lines in the WQFS were pigged and capped in 2000.


Groundwater modeling has been applied to the WQFS and has been used to compare the effectsof treatment to what would be projected from natural attenuation and to estimate contaminantloading to the Chena River. This modeling has assisted in development of a Time to CleanupEstimate and in placement and sizing of “hot spot” treatment systems.


Land and water use restrictions are in place for the WQFS. Figure 8-2 depicts the OU5 institutionalcontrol boundary as it exists in the Fort Wainwright GIS. This boundary appears to adequatelyencompass the areas of soil and groundwater contamination that could pose risk of

1 CH2M Hill, April 2001.


8-11

exposure to personnel during intrusive operations in WQFS subareas. No IC violations haveoccurred at these source areas to date.

WQFS1

Horizontal well SVE/AS System -- The horizontal well SVE/AS system, including a thermal/catalyticheater for off-gas treatment, was installed in the spring of 1997 as a treatability study and wasexpanded by installing vertical AS probes and SVE probes in the summer of 1998. This treatabilitystudy was chosen as the remedy for this source area and has operated from the time of installation.This system removed over 227, 000 pounds of VOCs in 2000, with an oxidizer efficiency of 99.5percent. Groundwater sampling indicates a decreasing trend in concentrations.

Source area SVE/AS – The source area treatability SVE/AS was selected as a remedial action. Thetreatment system has removed 43, 000 pounds of VOC in the first two years of operation.Groundwater contaminant concentrations in the treatment zone indicate a decreasing trend. Thissystem is being augmented during the 2001 construction season to improve system performanceand expand the area of treatment. Soil heating to enhance SVE/AS was evaluated in 1999 andfound not to be cost-effective for relatively volatile contaminants such as those subject to OU5cleanup goals. At the time of this review, the Army does not intend to heat soil as part of SVE/AStreatment at any of the Fort Wainwright OUs.

Site Inspection -- This source area was inspected in April 2001. Photographs taken at the time ofthe site inspection are presented in the appendices section of this report.

WQFS2

The AS curtain system was installed in June 1998 and became operational that Fall. This curtainintercepts and treats groundwater contaminants prior to migration into the Chena River. A harborboom was installed in 1998 downgradient of the AS curtain to control contaminant releases into theChena. This boom will be maintained until RAOs are met. It was chosen as a component for thisremedial action for this sub-area. The AS curtain system operated continuously since startup in2000, with some minor down times for system maintenance. This system is being augmentedduring the 2001 construction season to improve system performance and expand the area oftreatment. Two rebound evaluations were performed in 1999 to determine the best mode of systemoperation. It was found that without treatment benzene rebounded to greater than RAOs, indicatingthat the WQFS2 area is a long term source of contamination to groundwater and requires activetreatment. ORC treatability study was evaluated and determined not to be effective for this sourcearea. The ORC wells are scheduled to be decommissioned in 2001.

WQFS3

An SVE/AS system was installed at WQFS3 in the latter half of 2000 and operation begun inJanuary 2001. The wells were connected to the WQFS2 blowers and off-gas treatment system,which was modified to operate in the catalytic mode prior to WQFS3 system start-up.

As of October 2000, benzene was the only contaminant of concern present in concentrationsgreater than the RAO.


8-12



Based on the status of remedial actions at the WQFS as reported in the draft PDRAR, thetreatment systems appear to be effectively removing VOC from soil hot spots and contaminatedgroundwater at the WQFS.

Plate 8-I (appendices section) summarizes the results of groundwater monitoring associated withthis source area.



• Ethylene dibromide (EDB)1, reported in groundwater in the EQFS but not in the WQFS atthe time of the ROD, has now been detected in groundwater in the WQFS inconcentrations exceeding RAOs and being monitoring.

• The MCLs used to establish groundwater cleanup goals for the WQFS have not changedsince the ROD2.

Has Any other Information Come to Light that Could Call into Question the Protectivenessof the Remedy?

Variance from ROD Currently Affects Protectiveness (Y/N)

EDB in WQFS above RAOs N

Recommendations and Follow-Up Actions

Recommendations/ Follow-upActions

PartyResponsible

OversightAgency

MilestoneDate


(Y/N)

Incorporate appropriate samplingof area downgradient of AS U.S. Army EPA, ADEC Sept 2002 N

1 Chemical synonym: 1, 2-dibromoethane 2 The EDB MCL has also not changed.


8-13

Curtain along the Chena River(seep area) into the LTM Plan ofOU51

Incorporate appropriate samplingof EDB in WQFS groundwater, inthe LTM Plan of OU5.

U. S. Army EPA, ADEC Sept 2002 N

8.3 East Quartermaster’s Fueling System (EQFS)

8.3.1 Overview

The east section of the former Quartermaster’s fueling system (EQFS) is located between FrontStreet and Gaffney Road (Figure 8-2). A benzene plume covers approximately 40 acres and mayhave extended under the Chena River in the past. The fueling system was supplied by the 8 inchpipeline that connected the Birch Hill Tank Farm and the ROLF. During an UST ReleaseInvestigation, gasoline and diesel groundwater contamination were encountered. Monitoring wellsand microwells were installed surrounding this plume. In 1989 and in 1992, an investigation showedboth petroleum and solvent contamination in the soil and groundwater. In 1994, a comprehensiveevaluation of the EQFS was conducted, which included installing groundwater probes, soil borings,and monitoring wells. The groundwater data identified several plumes (fuels and solvents), and thesoil data identified solvent contamination, believed to have originated from surface disposal andundocumented spills. The remedial investigation was conducted in 1995 and issued in 1996. An airsparging/soil vapor extraction system was installed and operated at East Building 1060. Thissystem, shut down since contaminant concentrations achieved cleanup goals, has beenrefurbished and has been relocated to the west side of Building 1060 to reduce solventcontamination in that area. It will become operational at Building 1060 West upon installation of anelectrical oxidizer. Natural attenuation and intrinsic remediation treatability studies are on-going atthe EQFS. Chosen alternatives for remedial action at the EQFS include continued operation of thesoil vapor extraction/air sparging at Bldg 1060, groundwater monitoring, and monitored naturalattenuation. As stated for the WQFS, institutional controls are in place in the entire QFS. Operation,Maintenance and Monitoring reports are being drafted, construction complete is anticipated at theend of 2001 (replace as done in WQFS), and the LTM plan and exit strategy, as well as the interimRemedial Action Report will be completed at that time.

8.3.2 Background

Periods of use and dates related to the history of EQFS contamination and remediation include thefollowing2:

EVENT DATE

1 PDRAR recommended routine monitoring in conjunction with Aquatic Assessment.. Routine monitoring recommended here is notcontingent on Chena River assessment.2 Information compiled from the OU 5 ROD; Draft OU 5 PDRAR; and the Five-Year Review Report Document Log.


8-14

Area used for vehicle storage and maintenance, dry cleaning, fuels testing,refueling, pesticide storage and mixing, and waste storage.

FFA signed 1992

TPA signed 1992

Building 1054 referred from OU 1 to EQFS area of OU 5 June 1994

Natural attentuation Treatability Study initiated September 1997

AS/SVE Treatability Study initiated at Building 1060 June 1994

AS/SVE Treatability Study at Building 1060 completed September 2000

AS/SVE system installed at Building 1060 West site August to December2000

Final Intrinsic Remediation Evaluation report submitted November 2000

Draft 2000 PDRAR finalized April 2001


The EQFS area covers approximately 40 acres between Taxiway 18 and the Chena River, andbetween Building 1579 to the southwest and Building 1054 to the northwest. The terrain is opentussock flats as the buildings have all been removed from the site. The EQFS is located within the500 year floodplain of the Chena River.


The EQFS has been used for vehicle storage and maintenance, dry cleaning, fuels testing,refueling, pesticide storage and mixing, and waste storage (for example, polychlorinated biphenyl(PCB) transformers, chemicals, paints, oils, brake fluid, and solvents). The EQFS included USTs,ASTs, a pump house, fueling islands, and an eight-inch diameter fuel pipeline which is abandoned,but still in place. In addition, drains were connected to a wooden pipe that drained to the river.Solvents, pesticides, and petroleum contamination were found in EQFS groundwater. Suspectedsources include spills and leaks from pipelines, fueling stations and undocumented spills.



Groundwater

The remedial investigation identified two groundwater contaminant plumes, one upgradient and onedowngradient of Building 1565 containing benzene, 1,2-ethylene dibromide, 1,1,1-TCA, and TCE inconcentrations exceeding MCLs; TAH and TAqH in concentrations exceeding AlaskaWater Quality Standards (AWQS); and bis(2-chloroethyl)ether in concentrations exceeding theconcentration limit corresponding to 10-6 risk for residential use.


8-15

Floating petroleum hydrocarbon product was been observed on the water table in the areainfluenced by releases from the EQFS.

Soil

Soils contamination in this area has extended to the groundwater table and GRO is found in alocalized area of smear zone soil. Free product, likely to be weathered gasoline, is also found inEQFS south of Building 1060.

Remedial investigations found DRO, GRO, and xylenes exceeding ADEC cleanup guidelines insoils in the EQFS.


Current land use for EQFS is light industrial and the groundwater use is considered residentialbecause water supply wells for the City of Fairbanks are located in the same unconfined aquifer asgroundwater contamination downgradient of the WQFS. The closest residences to EQFS areapproximately ¼-mile northeast. Each residential area includes a school. Currently access to EQFSis unrestricted, and the area is used for recreational purposes and includes a bicycle trail. Accessto the Chena River is unrestricted.


The ROD identified the following objectives for remediation of OU5:

Groundwater

• Restore groundwater to its beneficial uses within a reasonable time frame. Reduce orprevent further migration of contaminated groundwater from the source areas to thedowngradient aquifer or surface water bodies that are closely hydrologically connected byachieving MCLs (where there are no nonzero MCLGs) and Alaska Water Quality Standards.For groundwater that is hydrologically connected to surface water, Alaska Water QualityStandards will apply for the following Fresh Water Uses: (I)(A) Water Supply; (I)(B) WaterRecreation; and (I)(C) Growth and Propagation of Fish, Shellfish, Other Aquatic Life, andWildlife.

• Ensure there is no risk to aquatic receptors through control of contaminant movementthrough the groundwater into the Chena River

• Remove free liquid product to the extent practicable to eliminate film or sheen fromgroundwater

• Prevent use of groundwater containing contaminants at levels above Safe Drinking WaterAct MCLs, nonzero MCLGs, or the following Alaska Water Quality Standards for FreshWater Uses: (I)(A) Water Supply; (I)(B) Water Recreation; and (I)(C) Growth andPropagation of Fish, Shellfish, Other Aquatic Life, and Wildlife.

Soil


8-16

• Prevent the migration to groundwater of soil contaminants that could result in groundwatercontamination and exceedances of federal MCLs and nonzero maximum contaminant levelgoals (MCLGs) and to groundwater that is closely hydrogeologically connected to surfacewater (such as the Chena River) that could result in exceedances of Alaska Water QualityStandards in surface water (EQFS and WQFS).


• Reduce sources of contaminant releases to the Chena River


• Meet Alaska Water Quality Standards for the following Fresh Water Uses: (1)(A) Water “JSupply; (1)(B) Water Recreation; and (1)(C) Growth and Propagation of Fish, Shellfish,Other Aquatic Life, and Wildlife

• Continue aquatic assessment

ARARs

The OU5 ROD cited the most significant applicable or relevant and applicable requirements(ARARs) for remedy selection at this site to be:

• Federal and state MCLs are relevant and appropriate for groundwater that is a potentialdrinking water source (40 CFR 141 and 18 AAC 80). These ARARs set the activeremediation goals for groundwater. Alaska Water Quality Standards (18 AAC 70) are alsoapplicable to surface water, sediment, and groundwater that is closely hydrologicallyconnected to surface water.

Alaska oil pollution regulations (18 AAC 75) are applicable and require the cleanup of oil orhazardous material releases.


8-17

Cleanup Goals

Groundwater

Federal and state MCLs for 1,2-DCA toluene, TCE, ethylene dibromide (EDB)1; the 10-6 residentialrisk value for bis(2-chloroethyl)ether; and State of Alaska (18 AAC 75) cleanup levels for RRO,DRO, GRO, and total xylenes were adopted as numeric cleanup goals for the EQFS. In addition,the ROD identified elimination of any sheen caused by floating petroleum product as a cleanup goalfor EQFS groundwater.

Soil

The cleanup goal for soil in the EQFS is active remediation until contaminant levels in groundwaterare consistently below state and federal MCLs.


• No concentrations of toxic substances or petroleum hydrocarbons and othercontaminants in bottom sediments that cause deleterious effects to aquatic life, to bedetermined by benthic macroinvertebrate assessment.

• Benthic macroinvertebrate assessment to establish baseline and to monitor aquaticbiotic integrity through time


• 10 :g/L TAH

• 15 :g/L TAqH

• Eliminate petroleum hydrocarbon sheen

• Benthic macroinvertebrate assessment to establish baseline and to monitor aquaticbiotic integrity over time

• Groundwater monitoring to assess reduction of contaminant releases to the Chena River


1 Chemical synonym: 1,2-Dibromoethane


8-18

Pre-ROD Response

Two treatability studies were initiated at the EQFS prior to the signing of the ROD for OU5, with theintent that effective technologies would be considered for incorporation into remedial actions:

• SVE and AS at Building 1060

• Natural Attenuation Study

Selected Remedy

• Continuing to operate the AS and SVE wells of the Building 1060 SVE/AStreatability study system to address solvent- and petroleum-contaminated hotspots in the soil and groundwater and floating-product contamination. TheSVE system includes offgas treatment.

• Establishing and maintaining institutional controls to ensure that until federaland state MCLs are attained, the groundwater will not be used, except foractivities undertaken to initiate the selected remedies detailed in this ROD.Institutional controls include restrictions governing site access, onsiteconstruction, and well development or placement. They will be necessary aslong as hazardous substances remain onsite at levels that precludeunrestricted use. Current and future land use is industrial; current and futuregroundwater use is designated for residential use. Land-use restrictionsinclude limiting future land use to operations currently being conducted at thesource area. Groundwater and land-use restrictions will be incorporated intothe Fort Wainwright master plan.


• Monitoring the performance of remedial treatment systems, as describedabove, to optimize treatment system effectiveness and efficiency throughsystem modifications and/or enhancements as appropriate

• Monitoring and evaluation of the selected remedy, including naturalattenuation, to determine achievement of RAOs

• Monitored natural attenuation for deep groundwater and areas not beingactively treated within EQFS


A natural attenuation treatability study for remediation of hot spots was started in September 1997.Sampling results found groundwater contaminant concentrations to be below RAOs at


8-19

the Building 1565 fueling operations hot spot and the trichloroethane (TCA) spill area west ofBuilding 1565, and greater than RAOs at the Avgas Pipeline hot spot.

An SVE/AS system operated on the east side of Building 1060 from 1994 to 1999, and groundwaterRAOs have been achieved.

A small TCE hot spot at the northeast corner of Building 1060 was treated by AS/SVE during thesame time frame, also achieving RAOs.

SVE/AS was discontinued at the east side of Building 1060 as of September 2000.

Groundwater contamination on the west side of Building 1060 was initially treated by naturalattenuation. An SVE/AS system with granular activated carbon (GAC) off-gas treatment wasinstalled to treat this source area from August through December 2000 and operation begun inDecember 2000. Contaminant concentrations exceed RAOs for benzene, EDB, GRO, and DRO ingroundwater at this source area.

Two monitoring wells have been installed to monitor groundwater contamination at the Apple Streetsource area. Groundwater in this area exceeds the RAO for DRO.

Plates 8-II, III, and IV depict the results of groundwater monitoring associated with this source area.


The IC use restriction boundary appears to adequately encompass the areas of soil andgroundwater contamination that could pose risk of exposure to personnel during intrusiveoperations in the EQFS. Figure 8-3 depicts the EQFS area subject to use restrictions.



Remedies are generally functioning as intended.



• The MCLs used to establish groundwater cleanup goals for the EQFS have not changedsince the ROD.


There is no other information calling the protectiveness of the remedy into question at this time.


8-20

Variances

No significant variances from the ROD have been noted to date.



PartyResponsible

Oversight Agency

MilestoneDate


(Y/N)

Long term natural attenuationand monitoring plan for Building1060 West plume

U.S. Army EPA, ADEC 9/30/02 N

Include sampling at AppleStreet in the long-termmonitoring plan

U.S. Army EPA, ADEC 9/30/2001 N


8-21

8.4 Remedial Area 1A -- Birch Hill Above Ground Storage Tanks

8.4.1 Overview

This source area, referred to as RA1A, is located on Birch Hill in the northwest corner of FortWainwright(Figure 6-1). Lead-contaminated soil surrounding the ASTs at the Birch Hill Tank Farmwas deferred from OU3 to OU5, while petroleum hydrocarbon contamination is being managedunder the Two Party Agreement. RA1A covers an area of approximately 110 acres. There aresixteen ASTs on Birch Hill and the associated underground pipeline system. The chosen alternativein the ROD, signed in April 1999, consists of institutional controls. The entire area is fenced, andsigns are in place; the fence is inspected annually to ensure its integrity.

8.4.2 Background

Contamination was initially discovered at the Tank Farm site during a soil-gas survey conducted in1988. Five monitoring wells were installed along the western boundary of the Post as part of thebase-wide groundwater monitoring program. Initial sampling events found BTEX and petroleumhydrocarbons at levels above MCLs. Additional monitoring wells were installed in 1992 near theTFS and in the area between the Tank Farm and the Chena River. These “picket wells” weremonitored twice annually.

Periods of use and dates related to the history of the Birch Hill Tank Farm contamination andremediation include the following1:

EVENT DATESoil-gas survey conducted 1988Fort Wainwright NPL listed August 1990FFA signed 1992TPA signed 1992Picket wells installed 1992


RI and Risk Assessment Reports submitted to EPA October 1994FS submitted to EPA April 1995ROD signed January 1996AS/SVE systems installed at Building 1173 and Lazelle Road 1996Lazelle Road system relocated to the Truck Fill Stand and the Building1173 system expanded to cover Lazelle Road source area. 1997

Product recovery treatability studies initiated at the Birch Hill Tank Farm. 1998



8-22

Thaw Channel treatment system installed 1999

ESD submitted to document installation and operation of existing AS/SVEtreatment systems; operation of the dual phase product recovery systemon Birch Hill; continuation of groundwater modeling; and concomitantchanges in remedial costs.

September 2001

The Tank Farm and associated Truck Fill Stand (TFS) are part of the Fairbanks Fuel Terminal,which was constructed in 1943 beginning with the installation of the fourteen 10, 000-barrel-capacity, bolted-steel tanks on Birch Hill. The mission of the Fairbanks Fuel Terminal was toprovide backup fuel support for Eielson Air Force Base. Fuel was transported via the Canadian OilLine (CANOL) pipeline and the Haines-Fairbanks pipeline. At Fort Wainwright, the CANOL pipelineconnected the Birch Hill UST facility to the ROLF and ran west to the Tank Farm. The portion of thepipeline between the ROLF and the Tank Farm remains in place. The Haines-Fairbanks pipelinewas constructed from 1954 to 1955. The only active portion of this pipeline, now called theFairbanks-Eielson Pipeline, runs between Eielson Air Force Base and the Mapco refinery in NorthPole.

The Tank Farm consisted of fourteen 10, 000-barrel-capacity, bolted-steel fuel tanks on top of BirchHill which contained arctic grade diesel fuel, aviation-grade leaded gasoline, aircraft turbine and jetengine fuel (JP-4), leaded vehicle motor gasoline, and unleaded and regular motor fuel. All tankshave been emptied and cleaned.


Remedial Area 1A is roughly defined by the area of the tank farm located on Birch Hill, north of themain cantonment area. The elevation of Birch Hill ranges from 441 feet to 748 feet above mean sealevel. No permanent surface water bodies are located on Birch Hill, but snow and ice melt wateraccumulate in the depressions and in the diked areas around the ASTs.


Surface soil lead contamination may be the result of several historical tank maintenance activities.These activities included tank bolt removal and replacement, cleaning sludge from tank bottoms,and tank painting and stripping. Historically, bolts removed from the tanks during routinemaintenance were cleaned with solvent to remove red lead pipe dope. The solvent, whichcontained lead from the threaded bolt pipe dope, was spread on the ground in the areassurrounding the tanks. Because these tanks were built as bolted (rather than welded) tanks, a verylarge number of bolts are present on each tank.

Spills occurred around the tanks throughout the fuel terminal’s history as the bolted-steel tankswere subject to minor leaks. Sludge removed from the bottoms of the fuel tanks was buried orspread in the areas surrounding the tanks and may have contributed lead to surface area soil. Inaddition, releases of lead-containing fuels may have contributed to the elevated lead concentrationsnear the ASTs. Surface and subsurface soils at the Fairbanks Fuel Terminal also are contaminatedwith petroleum.


8-23


Soil

Remedial investigations in this area found petroleum hydrocarbons in surface and subsurface soils,with the most significant levels within the bermed areas around the ASTs, decreasing with depthand distance from the tanks. At the ASTs with less than 15 feet of underlying silt, soil contaminationwas generally highest at the interface between silt and schist bedrock. Petroleum hydrocarbons(quantified as Jet A fuel) were detected in surface and subsurface soil at a maximum concentrationof 5, 500 milligrams per kilogram (mg/kg). Low levels of VOCs also were detected. The maximumtotal lead concentration reported in surface soil samples was 7, 840 mg/kg, while the maximumleachable lead (TCLP) concentrations was 5.4 milligrams per liter (mg/L).

Lead contamination of surface soil was found to be most significant directly adjacent to each tank,with lead levels decreasing with lateral distance from each AST. In addition, lead concentrations insubsurface soils were found to decrease to background levels at depths of one to two feet. Leadwas the only inorganic analyte above screening levels and was determined to be the onlycontaminant of concern for Remedial Area 1A under OU5.


Land use at Remedial Area 1A is light industrial. The site is fenced to prevent entry and subsequentexposure to soils within the source area. Groundwater use is considered residential because watersupply wells for the City of Fairbanks are located in the same unconfined aquifer as groundwatercontamination downgradient of the source area. Remedy Selection

Remedial Action Objectives (RAOs)

The RAOs for RA1A are the same as those for the WQFS plus an additional objective for soil:

• Limit human health and terrestrial receptor exposure to lead-contaminated soil.

ARARs

• There are no specific ARARs for the RA1A.

• To Be Considered (TBC) information for RA1A addressing interim lead soilguidance and preliminary remediation goals is included in the ROD on Page111.

Cleanup Goals

Soil

• No direct contact for total lead concentration greater than 1,000 mg/kg



8-24

Pre-ROD Response

Selected Remedy


Land use restrictions, signage, and maintaining the existing fence.


Institutional controls are in place and there have been no violations to date. Annual inspectionshave been completed since 1999.


The OU5 ROD specified that sites that have waste left in place are subject to additionalrequirements under the 5-year review. These requirements were identified as specifically applicableto Remedial Area 1A where natural attenuation is not projected to occur. These requirements areas follows:

• Collection and evaluation of all new lead-risk information and risk-assessmentapproaches for evaluating lead risks recommended by the state, EPA, orArmy. This new information may result in a human health risk assessment forlead exposure being conducted for Remedial Area 1A.

• Collection and evaluation of current Army, EPA, and state regulations andpolicies on remediation of lead in soils, keeping in mind that total lead valuesat Remedial Area 1A reflect commingling of releases from numerous leadsources

• Any other new information, draft or otherwise, or considerations relevant to anassessment of protectiveness for Remedial Area 1A

The Army has collected and evaluated information, regulations and policies regarding lead inindustrial soils published since the OU5 ROD signature. No new information that would affecthuman health or ecological decisions for RA1A has been identified.


Institutional Controls are effectively preventing access to the contaminated soil areas.




8-25


Variances

There are no known variances affecting the protectiveness of the remedy at this location.


No changes in the remedial management of RA1A are recommended at this time.

8.5 Other OU5 ROD Requirements

8.5.1 OB/OD Evaluation

The ROD specified that no less often than during the CERCLA 5-year reviews, the Army willevaluate the OB/OD area. This evaluation will include review of the active range and anyunexploded ordnance (UXO) within the OB/OD area and range, to determine whether institutionalcontrols to restrict land use and protect human health and the environment are sufficient. The Armyalso will evaluate the status of RCRA rules and regulations for military munitions ranges and UXOto determine whether additional RCRA requirements must be met.

The Army's evaluation indicates that ICs for the OB/OD area remain protective. No new RCRA ormunition rules have been promulgated specific to post-closure procedures for former OB/OD areas.The Army has evaluated whether delay of closure affects the OB/OD area and has determined ithas not, because the range has not been closed and Fort Wainwright remains an active installation.Therefore the selected remedy remains protective.

8.5.2 Chena River Surface Water and Sediments

The Chena River Aquatic Assessment is a component of the selected remedies for Operable Unit 5source areas, and is not considered a source area in and of itself. As such, general responseactions were not included in the OU 5 ROD for Chena River sediment or surface water. Throughthe source area remedial investigation process, the Chena River was identified as the area mostlikely to be affected by multiple source area releases at Fort Wainwright, with the greatest potentialfor impact from the WQFS and EQFS.

The Chena River Assessment was established to determine if impacts to the river had occurredfrom Fort Wainwright releases and to measure anticipated improvements in water and sedimentquality over time, based on the effectiveness of selected remedies for the QFS areas. This programalso provides information for optimizing treatment system design and operation. The program todate has consisted of sampling and analysis of surface water, sediments, and detritus; benthicmacroinvertebrate toxicological studies and bioassays; and calculating reductions in contaminantload into the Chena River.

Major components of the assessment program were described as:


8-26

• Spring and fall collection of water, sediment, and detritus (organic leaf litter) samples andanalysis for contaminants of concern and water chemistry

• Benthic macroinvertebrate study, including bioassay and toxicological analysis

• Baseline data collection (water quality, contaminant concentrations, contaminant loadingand ecological conditions) and study of changes in aquatic organisms as a function ofreduction in contaminant load into the river

During the first full-term 5-year review from the signature date of the OU5 ROD, if the data or otherinformation not considered in the development of this ROD indicates significant impacts to theChena River, other remedial alternatives or assessment measures will be evaluated by the Armyand presented to the regulatory agencies through a technical memorandum generated within 6months of the 5-year review date.

• Consider possible remedial actions if further evaluation of impacts to the river showsunacceptable risks to aquatic organisms.

8.5.3 Status of Aquatic Assessment Program

Pre-ROD

To determine whether actual impacts had occurred, assess their significance, and measurechanges over time, the Chena River Aquatic Assessment Program was initiated in 1998. Theassessment included collecting water, sediment, and detritus (organic leaf litter) samples during thespring and fall and analyzing them for COCs and water chemistry. A second year of study wascompleted, with results reported during the first quarter of 1999. The ROD, signed in May 1999,noted ongoing aquatic assessment efforts and committed to continuation of the assessment,including benthic macroinvertebrate studies.

Post-ROD

The ROD included commitments to a post wide sampling program and the Chena River AquaticAssessment Program. The Aquatic Assessment Program found evidence that contamination fromthe Fort Wainwright source areas was potentially adversely influencing biotic health in the ChenaRiver ecosystem but did not prove that sediment toxicities caused changes in the benthicinvertebrate communities of the Chena River.

Observations of sheens on the river or in sediment and detritus samples identified one of the seepareas (Seep Area in Segment D) as being “the most conspicuous” contaminant outfall to the ChenaRiver in the study area. Other, less conspicuous, sheens were observed downstream of the primaryseep in the same study segment.

During summer 2000, polycyclic aromatic hydrocarbon (PAH) studies were conducted along theChena River adjacent to the QFS in the vicinity of the AS curtain and former retaining structure.These studies confirmed the presence of PAHs in the seeps.


8-27 REV. 01



PartyResponsible

OversightAgency

Milestone Date


(Y/N)

Develop work plan for continued Chena RiverAquatic Assessmentmonitoring

U.S. Army EPA, ADEC 6/02 No

8.6 Institutional Controls

Institutional controls (ICs) are a component of the selected remedy for WQFS, EQFS, andRemedial Area 1A. In addition, the OU5 ROD established a comprehensive site wide approach toICs at the Fort Wainwright NPL site for all source areas where the respective RODS specifiedinstitutional controls as an element of remediation.

8.6.1 IC Commitments in OU5 ROD

Major OU5 commitments to a site wide IC program included the following:

• Develop standard operating procedures (SOPs) to identify the objectives to bemet by the restrictions, to identify all land areas under restriction, and tospecify the particular restrictions, controls, and mechanisms to be used.

• Create and maintain a database and tracking mechanism to identify restrictedland areas, objectives to be met by the restrictions, and the specificrestrictions, controls, and mechanisms.

• Monitoring of SOP compliance annually (or some other monitoring frequencyto be agreed upon by EPA, ADEC, and the USARAK).

• As part of the O&M report for each OU, assess the condition of areas at FortWainwright subject to institutional controls. These inspections will determinethe effectiveness and protectiveness of all institutional controls anddesignated land uses, and will ascertain whether the current land andgroundwater uses in the area are consistent with the institutional controls andall RAOs outlined in the relevant decision document governing that site or OU.Results of any field inspection will be documented in the annual O&M reportsubmitted for the OU pursuant to the remedial action report.

• USARAK will notify the EPA and ADEC immediately on discovery of anyunauthorized activity that is inconsistent with the institutional-control SOPs.The USARAK will issue a stop work or stop activity notice on discovery of anyunauthorized work. The stop work or stop activity notice


8-28 REV. 01

will remain effective until the EPA, ADEC, and USARAK determine a plan ofaction to resolve the unauthorized change.

• USARAK will notify the EPA and ADEC at least 6 months in advance aboutany transfer, by sale or lease, of areas of Fort Wainwright that are subject toinstitutional controls, to ensure adoption of such additional measures as maybe needed to assure continued compliance with institutional controls on suchtransferred property. Before actual transfer of land managementresponsibilities to the Bureau of Land Management or another federal agencyor department or to a private party, the Army will provide such transferee awritten copy of installation master-planning documentation that identifies allinstitutional controls remaining in force.

• SOPs will be a component of the 5-year review process.

8.6.2 Status of IC Program

The Army has established an SOP and a GIS-based tracking system to ensure the land and userestrictions are enforced. The IC system has been incorporated into the post wide Master Plan, andcompliance with ICs is reported in the Annual Monitoring Reports for each OU. The IC policyapplies to all USARAK units and activities, Military and Civilian Support Activities, TenantsOrganizations and agencies and Government and Civilian Contractors. In the fall of 2001, theInstitutional Control Memorandum signed by Major General Cash dated February 1999, will beupdated to require a Work Authorization Permit for all groundwater and soils on USARAK lands.This revised memorandum, signed by the Commanding General, will include a section on areaswith IC mandated by a Record of Decision and a section on areas where contamination is notsuspected. Currently, all contracts that include intrusive activities require a Work AuthorizationPermit. The Permit will be updated to clearly alert the user on procedures to follow when potentialcontamination is encountered. The Standard Operating Procedure (SOP) for IC will include a moredetailed section on the procedures and responsibilities for incidents where potential contaminationis found.

During the past few years, there have been numerous instances confirming the effectiveness of theInstitutional Control policy at Fort Wainwright. One example is the Post Signal Battalion's project toinstall fiber optic lines throughout the installation (project name: OSCAR). Since the project'sinception in 1998, signal personnel have coordinated their locates with Fort Wainwrightenvironmental personnel. Environmental personnel have walked the proposed lines with theOSCAR personnel and negotiated relocation of the lines away from areas of highest contaminationand/or active treatment systems. Environmental project work was coordinated with OSCAR workschedules to minimize disruptions to either project. Environmental staff met nearly weekly basisduring the highest periods of OSCAR activities to expedite the dig permit signing processes and toensure all parties understood what action would be taken if contamination was encountered.

Other examples demonstrating that the IC program is working include:

• DPW Environmental has been included as part of the planning team for thepre-construction and pre-design of housing units in the Fort


8-29

Wainwright North Post area to ensure that potential areas of contamination beavoided to extent possible. Planning stage discussion has also resulted inagreement on the handling of contamination while continuing construction.

• The Federal Aviation Administration (FAA) is planning to construct a radartower on Fort Wainwright, and chose the N4 site, a “No Further Action” site,as its desired location. Even though the site has been identified as needing nofurther action, the potential to encounter contamination still exists. FAA hasmet with the Environmental personnel and has been provided copies of theas-builts of former activities in the area and all known information on the N4site. FAA will therefore be able to include provisions in the constructioncontract related to the potential to encounter contamination and steps to betaken by the contractor.

• When sitting the new hospital to be built on Fort Wainwright, the originalpreferred site was listed in the environmental GIS data base as requiring nofurther action, but indicated that construction debris tar remained in fairly largeconcentrations in this area. Rather than reopening the issue and attempting tobuild around the tar, another site was selected.

• Other requests for use of areas under institutional controls include the BirchHill Tank Farm (OU3) and the inactive, fenced portion of the landfill (OU4).Requested uses have ranged from a horse stable to a skeet range. Review ofeach of these requests identified the pertinent IC restrictions and resulted inrelocating the proposed activities to other sites while still in the planningstages.



PartyResponsible

OversightAgency

Milestone Date


(Y/N)

Perform post-wide ICinspection and evaluateprotectiveness. Update restricted use boundaries inGIS as new informationbecomes available.

U. S. Army EPA, ADEC

Inspection –3/02[E1]

Update GIS -Ongoing

No

Make SOP coverage moreinclusive (i.e., apply tenants) U.S. Army EPA, ADEC 2002[srg2] No

Update IC Policy U.S. Army EPA, ADEC 2002 No


9-1

9 PHYTOREMEDIATION OF PESTICIDE CONTAMINATEDSOIL

Based on findings from a storm drain construction project, Preliminary Site Evaluation studies,Remedial Investigations and other site investigations, drum removal actions at the 801 Drum BurialSite (OU2) took place in several episodes. Drum removal was completed in 1996. Approximately850 cubic yards of pesticide and DRO contaminated soil was removed and stockpiled following the1996 drum removal and relocated to the south side of River Road across from the landfill fortreatability studies.

Treatability Studies

A treatability study was designed and implemented to evaluate the performance ofphytoremediation for reducing concentrations of pesticides (aldrin and dieldrin) in the soil removedfrom the 801 Drum Burial Site. Several vegetation types were evaluated and both drained andsaturated conditions were maintained. After 4 years of monitoring, overall results show that thealdrin concentrations decreased significantly whereas dieldrin concentrations increased slightly.Results vary due to sample variability and different conditions such as in saturated (slightlyanaerobic) conditions where dieldrin decreased significantly and aldrin decreased only slightly.

Additional studies were conducted by University of Alaska Fairbanks and Anchorage to evaluatethe rhizosphere-enhancements, vegetation variations, chemical movement with radio-labeledcompounds, and leachability of the chemicals.

Regulatory Status

EPA, in a Memo to the Army dated July 26, 2000, concurred with the conclusion that the soil fromthe treatability studies is not a RCRA regulated hazardous waste. The soil from the treatabilitystudies is still considered part of the CERCLA action for Fort Wainwright although no longerassociated with OU1 for regulatory or management purposes.

Disposal Options

Following evaluation of the available disposal options, the Army's current plan is to transfer the soilto the Fort Wainwright solid waste landfill sometime in 2001 in compliance with the State of AlaskaSolid Waste Permit. The plan proposes that the soil will be placed in a lined and cappedcontainment cell following ADEC guidance.


10-1

10 SITE-WIDE SUMMARY AND RECOMMENDATIONS

10.1 General

10.1.1 ROD Commitments are Being Met

Management of Fort Wainwright NPL site remediation under the FFA has been very effective. Thiseffectiveness translates into a good rate of progress implementing the remedial actions specified inthe RODs and is in the best interest of the public and the environment. This effectiveness alsotranslates into best use of public resources, i.e. a greater proportion of funding for RD/RA/LTM isfocused on remediation (as opposed to transactional costs) than has been the case at many otherNPL sites.

10.1.2 Public Information Repositories

A status memorandum on five-year review site visits to the Fort Wainwright public informationrepositories is included in the appendices section of this report. The visits found the repositories tobe generally meeting CERCLA requirements and public needs. The repository site visit reportincludes several specific recommendations for enhancing the repositories and potentiallysimplifying maintenance of the administrative record at these locations.

Recommendation

• Decide which recommendations to adopt as action items for maintenance of the FortWainwright administrative record at the public repositories and add to scope ofadministrative management for the site.

10.1.3 Institutional Controls

All five Fort Wainwright RODs specify institutional controls to ensure protection of human healthand the environment. As of February 1999, Fort Wainwright formally established standard operatingprocedures to fully comply with the commitments made in the RODs and to ensure the integrity ofinstitutional controls specified in the RODs.

Implementation of institutional controls involving access and use limitations requires maintaininginstitutional boundaries in the USARAK GIS database. These boundaries are not specified in theRODs and are subject to routine review and revision to ensure continued protectiveness of theinstitutional controls.

Recommendations to update institutional control boundaries appear in the OU- and sourcearea-specific recommendations summarized in this section.


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10.1.4 Groundwater Monitoring

Consider which source areas are amenable to plotting isocontours in light of complexities posed bydiscontinuous permafrost, thaw trenches, and thaw bulbs. Where appropriate, it is recommendedthat the downgradient groundwater contours be plotted and evaluated during each monitoring eventto ensure that the assumptions used in assessing the groundwater monitoring data reflects wherethe monitoring wells are located relative to the source area. This will enable changes in flowpatterns to be recognized and appropriate actions taken. Data from the groundwater monitoringprogram should be evaluated as it is reported to assure no off-site migration of contaminants and toevaluate progress of natural attenuation. An example of a source area amenable to such analysisand interpretation is the OU4 Landfill.

10.2 Operable Unit and Source Area Specific

The following table (Table 10-1) summarizes recommendations and follow-up actions from OU andsource area sections of this report.


10-3

Table 10-1 Recommendations and Follow-up ActionsOU

Source Area Recommendations/ Follow-Up Actions PartyResponsible

OversightAgency Milestone Date


(Y/N)

1 801 Drum Storage Area Redraw IC boundaries to more closely coincide with thecontaminated area. U.S. Army EPA, ADEC March 02 N

2

Building 1168 LeachWell

Redraw the IC boundary around the entire source area(CERCLA and TPA). U.S. Army EPA, ADEC March 02 N

DRMO Yard Redraw the IC boundary to extend to the north toencompass the groundwater plume. U.S. Army EPA, ADEC March 02 N

3

RA1b -- Birch Hill TankFarm & Truck Fill Stand

Further characterization of aquifer interactions U.S. Army EPA, ADEC Ongoing NGather data on fate and transport of DCA. U.S. Army EPA, ADEC Ongoing NGather data on fate and transport of EDB. U.S. Army EPA, ADEC Ongoing N

RA2 -- Valve Pits A, B,& C, & ROLF Groundwater monitoring for lead U.S. Army EPA, ADEC June 02 N

RA3 -- Mileposts 2.7,3.0, & 15.75 No operational changes are recommended at this time.

4

Landfill Change IC boundary to cover area where groundwaterplume from landfill leachate affects downgradient aquifers. U.S. Army EPA, ADEC March 02 N

Coal Storage Yard

Evaluate need for treatment system extension to under coalpile. U.S. Army EPA, ADEC September 02 N

Relocate institutional controls to cover area wheregroundwater plume from CSY affects downgradient aquifer. U.S. Army EPA, ADEC March 02 N

5

WQFS

Incorporate appropriate sampling of area of downgradient ofAS Curtain along the Chena River (seep area) into the LTMPlan of OU5

U.S. Army EPA, ADEC September 02 N

Incorporate appropriate sampling for EDB in WQFSgroundwater into the OU5 LTM plan. U.S. Army EPA, ADEC September 02 N

EQFS

Long Term natural attenuation and monitoring plan forBuilding 1060 West plume U.S. Army EPA, ADEC September 02 N

Include Sampling at Apple Street in the long-term monitoringplan. U.S. Army EPA, ADEC September 02 N

RA1a -- Birch Hill ASTs No changes in the remedial management of RA1A are recommended at this time.

Chena River SurfaceWater & Sediments

Develop work plan for continued Chena River AquaticAssessment monitoring` U.S. Army EPA, ADEC June 02 N


FINAL 11-111-1

11 PROTECTIVENESS STATEMENTSTable 11-I, on the following page, summarizes OU and source area information from the precedingsections, used to formulate protectiveness statements1.

OU1 -- 801 Drum Burial Site

The remedy at OU1 is expected to be protective of human health and the environment uponcompletion, and in the interim, exposure pathways that could result in unacceptable risks are beingcontrolled.

OU2 – Building 1168 Leach Well and DRMO Yard


OU3 -- Birch Hill Tank Farm (RA 1B); Railcar Off Loading Facility (ROLF) (RA 2); andFairbanks-Eielson Pipeline Mileposts 2.7, 3.0, and 15.75


OU4 – Landfill and Coal Storage Yard


OU5 – Quartermaster Fueling System, Birch Hill Tank Farm (RA 1A), Chena River, andInstitutional Controls Program


1 Comprehensive Five-Year Review Guidance, EPA Office of Emergency and Remedial Response, June 2001.


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Table 11-1. Protectiveness Statement Basis

OU Source AreaQuestion A: Is the remedy functioning

as intended in the decisiondocuments?

Question B: Are the exposureassumptions, toxicity data,

cleanup levels, and remedial action objectives still valid?

Question C: Has any other information come to light that

could call into question the protectiveness of the

remedy?

Is the remedy protective in

the short term?

Is the remedyprotective in the

long term?

1 801 Drum Burial Site

Yes -- though too early to measuredecreases in groundwater contaminantconcentrations.

Yes No Yes Yes

2 Building 1168Leach Well Yes Yes No Yes Yes

DRMO Yard Yes Yes No Yes Yes

3 Birch Hill TankFarm (RA 1B)

Yes. Further, early operating reportsindicate dual phase product recoverysystem (added pursuant to newunderstanding of nature & extent ofcontamination) is functioning as intended.

Yes No Yes Yes

Railcar OffLoading Facility(ROLF) (RA 2)

Yes. Further, Expanded AS/SVE system(added pursuant to new understanding ofnature and extent of contamination) isfunctioning as intended.

Yes No Yes Yes

Fairbanks-EielsonPipeline Mileposts

2.7, 3.0, and15.75

Yes. Further, ex situ treatment of POLcontaminated soil (added pursuant to newunderstanding of nature and extend ofcontamination) is functioning as intended.

Yes No Yes Yes

4 LandfillYes -- though too early to measuredecreases in groundwater contaminantconcentrations.

Yes No Yes Yes

Coal StorageYard Yes Yes No Yes Yes

5 WQFS Yes

Yes, however EDB has beendetected in WQFS groundwater inconcentrations exceeding RAOssubsequent to the ROD.

No Yes Yes

EQFS Yes Yes No Yes Yes

RA 1A Yes Yes No Yes Yes


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12 NEXT REVIEWThe next Fort Wainwright Five-Review will be conducted in 2006.

Recommendations for that review include:

Some contaminants with risk based cleanup goals are candidates for MCLs. The next five-yearreview should follow up on the status of these contaminants:

• Aldrin and dieldrin have been placed on the Safe Drinking Water Act (SWDA)) drinkingwater Contaminant Candidate List (CCL), and MCLs may be established for thesecontaminants in the future.

• The contaminant 1,1,2,2-tetrachloroethane is now on the federal drinking water CCL,and an MCL may be established for this contaminant in the future.

The next review should include assessment of the status follow-up actions identified in this report.

The next five-year review will be the first full-term review for the OU5 ROD. As such, the followingOU5 requirement will apply to that review:

During the first full-term 5-year review from the signature date of theOU5 ROD, if the data or other information not considered in thedevelopment of this ROD indicates significant impacts to the ChenaRiver, other remedial alternatives or assessment measures will beevaluated by the Army and presented to the regulatory agenciesthrough a technical memorandum generated within 6 months of the 5-year review date.


13-1

13 REFERENCESThis five-year review focused on understanding commitments made in the RODs, the status ofremedial actions undertaken in response to the RODs, and the continued protectiveness of theremedial actions specified in the RODs. The individual RODs were the starting points for thereviews of compliance with the RODs, remediation progress to date, and protectiveness. To theextent possible, the review made use of the most recent summary documents available,augmenting the information in those summaries with information from earlier reports and, in somecases, with knowledge or information not yet included in reports. Much of the review focused onpost-ROD reports, though pre-ROD documents were also consulted as needed to understand thehistory of contamination and remediation at the source areas. Table 2-1 is a listing of the RODs andrelated documents and post-ROD reports available at the time of this five-year review. Keyreferences used by reviewers are indicated in the table.