FINAL

FIVE-YEAR REVIEW

ELLSWORTH AFB, SOUTH DAKOTA

UNITED STATES AIR FORCE

AIR COMBAT COMMAND

SEPTEMBER 23, 2005

FXBM 20047001

3057 001
EPA CONCURRENCE

with the

ELLSWORTH AIR FORCE BASE

FIVE-YEAR REVIEW

SEPTEMBER 2005

In accordance with Section 12t of the Comprehensive Environmental Response, Compensation, and

Li,'lbility Act (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986

(SARA); and the Federal Facilities Agreement (FFA) signed January., 1992. Ellsworth Air Force Base

(EAFB) is required to conduct a five year review of al), remedial actions which result in any hazardous

substances, pollutants, or contaminants remaining at the site, to assure that human health and the

enYironment are being protected by the remedial actions being implemented. On September 27, EAFB

suhmitted its five year review to the US EPA Region 8 office and the South Dakota Department of

Environment and Natural Resources (SDDENR).

In consultation with the SDDENR, EPA has reviewed this five year review and concurs with the findings

made herein.

CONCURRENCE:

Max H. Dodson

Assistant Regional Administrator Date

Ofl]ce of Ecosysiems Protection

and Remediation

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Final Five-Year Review

TABLE OF CONTENTS

Section Pa_e

EPA CONCURRENCE

1.0 INTRODUCTION .............................................................................................. ..................... 1

1.1 PURPOSE OF THE REVIEW ...................................................................................... 1

1.2 REVIEW PROCESS ..................................................................................................... 1

1.3 BASE CLOSURE CONSIDERATIONS ...................................................................... 2

2.1) SITE CHRONOLOGY ........................................................................................................... 3

3.t) BACKGROUND ...................................................................................................................... 8

3.1 BASEWIDE ................................................................................................................... 8

3.2 OPERABLE UNIT 1 FIRE PROTECTION TRAINING AREA (FPTA) .................. 10

3.2.1 Physical Setting ............................................................................................. 10

3.2.2 Land and Resource Use ................................................................................. 11

3.2.3 History of Contammatlon .............................................................................. 12

3.2.4 Initial Response ............................................................................................. 13

3.3 OPERABLE UNIT 2 LANDFILL 1 AND LANDFILL 6 .......................................... 13

3.3.1 Physical Setting ............................................................................................. 13

3.3.2 Land and Resource Use ................................................................................. 14

3.3.3 History of Contamination .............................................................................. 15

3.3.4 Initial Response ............................................................................................. 17

3.4 OPERABLE UNIT 3 LANDFILL 2............................................................................ 17

3.4.1 Physical Setting ............................................................................................. 17

3.4.2 Land and Resource use .................................................................................. 17

3.4.3 History of Contamination .............................................................................. 17

3.4.4 Initial Response ............................................................................................. 19

3.5 OPERABLE UNIT 4 LANDFILL 3............................................................................ 19

3.5.1 Physical Setting ............................................................................................. 19

3.5.2 Land and Resource Use ................................................................................. 20

3.5.3 History of Contamination .............................................................................. 20

3.5.4 Initial Response ............................................................................................. 23

3.6 OPERABLE UNIT 5 LANDFILL 4............................................................................ 23

3.6.1 Physical Setting ............................................................................................. 23

3.6.2 Land and Resource Use ................................................................................. 23

3.6.3 History of Contaminahon .......................................................................... .... 24

3.6.4 Initial Response ............................................................................................. 25

3.7. OPERABLE UNIT 6 LANDFILL 5............................................................................ 25

3.7.1 Physical Setting ............................................................................................. 25

3.7.2 Land and Resource Use ................................................................................. 25

3.7.3 History of Contamination .............................................................................. 26

3.7.4 Initial Response ............................................................................................. 26

3.8 OPERABLE UNIT 7 WEAPONS STORAGE AREA ................................................ 27

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TABLE OF CONTENTS

(continued)

Section Pa_e

3.8.1 Physical Setting ............................................................................................. 27

3.8.2 Land and Resource Use ................................................................................. 27

3.8.3 History of Contamination .............................................................................. 27

3.8.4 Initial Response ............................................................................................. 28

3.9 OPERABLE UNIT 8 EXPLOSIVE ORDNANCE DISPOSAL AREA ..................... 28

3.9.1 Physical Setting ............................................................................................. 28

3.9.2 Land and Resource Use ................................................................................. 29

3.9.3 History of Contamination .............................................................................. 29

3.9.4 Initial Response ............................................................................................. 30

3.10 OPERABLE UNIT 9 ................................................................................................... 31

3.10.I Physical Setting ............................................................................................. 31

3.10.2 Land and Resource Use ................................................................................. 31

3.10.3 History of Contarmnatlon .............................................................................. 32

3.10.4 Initial Response ............................................................................................. 33

3.11 OPERABLE UNIT 10 NORTH HANGER COMPLEX ............................................. 33

3.11.1 Physical Setting ............................................................................................. 33

3.11.2 Land and Resource Use ................................................................................. 33

3.11.3 History of Contamination .............................................................................. 33

3.11.4 Initial Response ............................................................................................. 34

3.12 OPERABLE UNIT 11 BASEWIDE GROUND WATER .......................................... 34

3.12.1 Physical Setting ............................................................................................. 34

3.12.2 Land and Resource Use ................................................................................. 35

3.12.3 History of Contamination .............................................................................. 35

3.12.4 Initial Response ............................................................................................. 37

3.13 OPERABLE UNIT 12 HARDFILL 1 ......................................................................... 37

3.13.1 Physical Setting ............................................................................................. 37

3.13.2 Land and Resource Use ................................................................................. 38

3.13.3 History of Contamination .............................................................................. 38

3.13.4 Initial Response ............................................................................................. 39

3.14 FLIGHTLINE REFUELING AREA ........................................................................... 39

3.14.1 Physical Setting ............................................................................................. 40

3.14.2 Land and Resource Use ................................................................................. 40

3.14.3 History of Contamination .............................................................................. 40

3.14.4 Initial Response ............................................................................................. 41

3.15 OFF-BASE JP-4 SOUTH OF OPERABLE UNIT 2 ................................................... 41

3.15.1 Physical Setting ............................................................................................. 41

3.15.2 Land and Resource Use ................................................................................. 42

3.15.3 History of Contamination .............................................................................. 42

3.15.4 Initial Response ............................................................................................. 42

4.0 REMEDIAL ACTIONS ........................................................................................................ 43

4.1 REMEDY SELECTION .............................................................................................. 43

4.1.1 Operable Unit 1 ............................................................................................. 43

4.1.2 Operable Unit 2 ............................................................................................. 48

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TABLE OF CONTENTS

(continued)

Section Pa_e

4.1.3 Operable Unit 3 ............................................................................................. 48

4.1.4 Operable Unit 4 ............................................................................................. 49

4.1.5 Operable Unit 5 ............................................................................................. 49

4.1.6 Operable Unit 6 ............................................................................................. 50

4.1.7 Operable Unit 7 ............................................................................................. 50

4.1.8 Operable Unit 8 ............................................................................................. 51

4.1.9 Operable Unit 9 ............................................................................................. 52

4.1.10 Operable Unit 10 ........................................................................................... 52

4.1.11 Operable Unit 11 ........................................................................................... 52

4.1.12 Operable Unit 12 ........................................................................................... 53

4.1.13 Flightline Refueling Area .............................................................................. 54

4.1.14 Off-Base JP-4 South of Operable Unit 2 ....................................................... 54

4.1.5 North Docks .................................................................................................. 54

4.2 REMEDIAL ACTION IMPLEMENTATION ............................................................ 54

4.3 OPERATION AND MAINTENANCE ACTIVITIES ................................................ 55

4.3.1 Operation and Maintenance Procedures ........................................................ 55

4.3.2 Summary of System Downtime and Operation and Maintenance Issues ...... 63

4.4 SYSTEM OPTIMIZATION ........................................................................................ 63

4.4.1 Operable Unit 1............................................................................................. 63

4.4.2 Operable Unit 4 ............................................................................................. 64

4.4.3 Operable Unit 11 ........................................................................................... 64

4.4.4 JP-4 ................................................................................................................ 65

4.4.5 Flightline Refueling Area .............................................................................. 65

4.4.6 North Docks .................................................................................................. 65

5.t) FIVE-YEAR REVIEW PROCESS ...................................................................................... 70

5.1 TEAM MEMBERS ..................................................................................................... 70

5.2 DOCUMENT REVIEW .............................................................................................. 70

5.3 FIVE-YEAR REVIEW TASKS .................................................................................. 73

6.0 FIVE-YEAR REVIEW FINDINGS ..................................................................................... 74

6.1 CHANGES IN STANDARDS AND TO BE CONSIDERED CRITERIA ................. 74

6.2 CHANGES IN EXPOSURE PATHWAYS ................................................................ 74

6.3 TOXICITY AND OTHER CONTAMINANT CHARACTERISTICS ...................... 75

7.(t ASSESSMENT ...................................................................................................................... 91

7.1 REMEDY OPERATION ............................................................................................. 91

7.1.1 HASP and Contingency Plan ........................................................................ 91

7.1 2 Institutional Controls and Other Measures .................................................... 91

7.1.3 Remedial Action Performance ...................................................................... 91

7.1.4 Operation and Maintenance ........................................................................... 94

7.1.5 Operation and Maintenance Costs ................................................................. 94

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TABLE OF CONTENTS

(eontinued)

Section Pa-Eg-e7.1.6 Remedial Action Optimization ...................................................................... 95

7.1.7 Indicators of Potential Failures ...................................................................... 95

7.2 VALIDITY OF ASSUMPTIONS ............................................................................... 96

7.2.1 Changes in TBC Criteria ............................................................................... 96

7.2.2 Changes in Exposure Pathways ..................................................................... 96

7.2.3 Changes in Toxicity and Contaminant Characteristics ................................. 96

7.2.4 Changes in Risk Assessment Method ........................................................... 97

8.0 DEFICIENCIES AND MODIFICATIONS ........................................................................ 99

9.0 RECOMMENDATIONS AND FOLLOW-UP ACTIONS .............................................. 100

9.1 RECOMMENDATIONS FROM 2000 FIVE-YEAR REVIEW ............................... 100

9.2 2005 FIVE-YEAR REVIEW RECOMMENDATIONS ........................................... 102

9.2.1 OU-1 ............................................................................................................ 102

9.2.2 OU-2 ............................................................................................................ 102

9.2.3 OU-3, OU-5, OU-6, OU-8, and OU-12 ....................................................... 103

9.2.4 OU-4 ............................................................................................................ 103

9.2.5 OU-7 ............................................................................................................ 103

9.2.6 OU-9 ............................................................................................................ 104

9.2.7 OU-10 .......................................................................................................... 104

9.2.8 OU-11 .......................................................................................................... 104

9.2.9 Flightline Refueling Area (SS-08, ST-10, ST-14) ....................................... I06

9.2.10 JP-4 Jet Fuel Release ................................................................................... 106

9.2.11 North Docks ................................................................................................ 106

10.0 PROTECTIVENESS STATEMENTS .............................................................................. 107

10.1 OU-1 .......................................................................................................................... 107

10.2 OU-2 .......................................................................................................................... 107

10.3 OU-3 .......................................................................................................................... 107

10.4 OU-4 .......................................................................................................................... 107

10.5 OU-5 .......................................................................................................................... 108

10.6 OU-6 .......................................................................................................................... 108

10.7 OU-7 .......................................................................................................................... 108

10.8 OU-8 .......................................................................................................................... 108

10.9 OU-9 .......................................................................................................................... 109

10.10 OU-10 ......................................................................................................................... 109

10.11 OU-11 ........................................................................................................................ 109

10.12 OU-12 ........................................................................................................................ 109

11.0 NEXT REVIEW .................................................................................................................. 110

12.0 MISCELLANEOUS COMMENTS ................................................................................... 111

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LIST OF TABLES

TaMe Pa_e

2-1 History of Installation Operations at EAFB .............................................................................. 4

2-2 Key Regulatory Actions Impacting EAFB ................................................................................ 6

2-3 Site Closure Status ..................................................................................................................... 7

4-1 Summary of Applied Remedial Alternatives for EAFB .......................................................... 44

4-2 OU-1 Clean-Up Goals, Soils (ug/kg) ...................................................................................... 46

4-3 OU-1 Clean-Up Goals, Ground Water (ug/L) ......................................................................... 47

4-4 Remedy Implementation ......................................................................................................... 57

4-5 Summary of Operational Downtime and Operations and Maintenance Issues ....................... 66

5-1 Documents Reviewed During the EAFB Five-Year Review Process ..................................... 71

6-1 Federal and State ARARS Applied to Ellsworth AFB, South Dakota .................................... 76

6-2 Changes in Chemical-Specific Standards ................................................................................ 80

6-3 Changes in Action-Specific Standards .................................................................................... 83

6-4 Changes in Location-Specific Standards ................................................................................. 83

6-5 Summary of Exposure Pathways Evaluated for the Human Health Risk Assessment for

Current On-Site Land Uses at Ellsworth AFB ........................................................................ 84

6-6 Summary of Exposure Pathways Evaluated for Human Health Risk Assessment for

Current Off-Site Land Uses at Ellsworth AFB ........................................................................ 85

6-7 Summary of Exposure Pathways Evaluated for Human Health Risk Assessment for

Future On-Site Land Use at Ellsworth AFB ............................................................................ 86

6-8 Summary of Exposure Pathways Evaluated for Human Health Risk Assessment for

Future Off-Site Land Uses at Ellsworth AFB ......................................................................... 87

6-9 Chemicals of Concern at EAFB that Resulted in the Application of a Remedial Action ....... 88

6-10 Toxicity Values for Chemicals of Concern at EAFB .............................................................. 89

LIST OF FIGURES

Fi_[gure

3-1 Base Area Map

3-2 OU Location Map

3-3 Surface Water Flow

3-4 OU-1 Area

3-5 OU-1 Soil

3-6 OU-1 Ground Water

3-7 OU-2 Area Map

3-8 OU-2 Soil Concentrations

3-9 OU-3 Site Map

3-10 OU-3 Soil

3-11 OU-4 Soil

3-12 OU-4 Ground Water

3-13 OU-5 Site Map

3-14 OU-5 Soil

3-15 OU-5 Ground Water

3-16 OU-6 Soil
Ellsworth Air Force Base

Final Five-Year Review

LIST OF FIGURES

(continued)

F_._ure

3--17 OU-6 Ground Water

3-18 OU-7 Area

3-19 OU-8 Ground Water

3--20 OU-8 Soil

3--21 OU-9 Soil

3--22 OU-9 Ground Water

3--23 OU-10 Soil

3-.24 OU- 10 Ground Water

3--25 OU-11 Area

3-.26 OU-11 Ground Water

3-.27 OU-11 Ground Water

3-.28 OU-11 Ground Water

3-.29 OU-11 Ground Water

3-.30 OU-11 Ground Water

3-.31 OU-12 Soil

3-.32 OU-12 Ground Water

3-.33 Flightline Refueling Area (FRA)

3-.34 FRA TPH in Ground Water

3-35 Current FRA Contaminant Concentrations

3-.36 JP-4 Site Contaminant Concentrations

4-.1 OU-1 Soil Area of Attainment

4-2 OU-1 Ground Water area of Attainment

4-,3 OU-2 Area of Attainment

4-4 OU-3 Area of Attainment

4- 5 OU-4 Area of Attainment

4-6 OU-5 Area of Attainment

4-7 OU-6 Area of Attainment

4-8 OU-7 Area of Attainment

4-9 OU-8 Area of Attainment

4-10 OU-I 1Area of Attainment-1

4-11 OU- 11 Area of Attainment-2

4-12 OU- 12 Area of Attainment

LIST OF APPENDICES

Appendix

A Public Notice of Five-Year Review

B Copy of Base Continuing Order

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Final Five- Year Review

1.0 INTRODUCTION

The United States Air Force has completed the second five-year review of the remedial actions at

Ellsworth Air Force Base (EAFB), located in Meade and Pennington Counties, South Dakota. This

review was conducted from April 2005 through August 2005. This report documents the results of the

review. The purpose of the five-year review is to determine whether the remedy at a site is protective of

human health and the environment. The methods, findings, and conclusions of reviews are documented

in the five-year review report. In addition, the report identifies deficiencies found during the review, if

any, and makes recommendations to address them. Finally, the report makes recommendations for future

optimization and management of the environmental restoration program.

1.1 PURPOSE OF THE REVIEW

This review is required by statute. Five-year reviews must be implemented in accordance with the

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the

National Oil and Hazardous Substances Pollution Contingency Plan (NCP). CERCLA §i21 (c), as

amended, states:

"If the President selects a remedial action that results in any hazardous substances, pollutants,

or contaminants remaining at the site, the President shall review such remedial action no less

often than each five years after the initiation of such remedial action to assure that human

health and the environment are being protected by the remedial action being implemented. "

The NCP part 300.430(f)(4)(ii) of the Code of Federal Regulations (CFR) states:

"'Ira remedial action is selected that results in hazardous substances, pollutants, or

contaminants remaining at the site above levels that allow for unlimited use and unrestricted

exposure, the lead agency shall review such action no less often than every five years after the

initiation of the selected remedial action. "

1.2 REVIEW PROCESS

Contractors prepared portions of this review for the Air Force. The Air Force, using its contractual

arrangements via the Omaha District Corps of Engineers Environmental Restoration Services Contract

(ERS), contracted with Earth Tech, Inc., to provide information for all or part of report sections 4, 5, 6, 7,

8, 9, 10, and 12. In addition, RD Todd & Associates was contracted to Earth Tech, Inc., to assist in the

development of all or portions of report sections l, 2, 3, 4, 6, and 7.

This is the second statutory five-year review for EAFB. The first five-year review was completed in

September 2000. Because hazardous substances, pollutants, or contaminants remain at the site above

levels that allow for unrestricted use and limited exposure, a five-year review was required.

The review covers remedial actions taken at 12 operable units (OUs) at EAFB. In addition, reviews were

conducted for two non-CERCLA sites undergoing remedial action under State of South Dakota programs.

The sites reviewed include:

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Final Five- Year Review

CERCLA Sites:

OU- 1 Fire Protection Training Area

OU-2 Landfills Nos. 1 and 6

OU-3 Landfill No. 2

OU-4 Landfill No. 3

OU-5 Landfill No. 4

OU-6 Landfill No. 5

OU-7 Weapons Storage Area

OU-8 Explosive Ordnance Disposal Area (Pramitol Spill)

OU-9 Old Auto Hobby Shop Area

OU- 10 North Hangar Complex

OU- 11 Base-wide Ground Water (Including AOC-24)

OU-12 Hardfill No. !

Non-CERCLA Sites:

JP-4 Release south of Operable Unit 2

JP-4 Release Flightline Refueling Area

1.3 BASE CLOSURE CONSIDERATIONS

The Department of Defense issued its recommendations on base realignment and closure on

May 13, 2005. Ellsworth AFB was proposed for closure on that list. Subsequently, the Base Realignment

and Closure Commission reviewed the DoD recommendations and removed Ellsworth AFB from the

closure list. The closure list was submitted to the President on September 8 and was approved by the

President in September. Congressional action on the closure list is pending.

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2.0 SITE CHRONOLOGY

Ellsworth AFB was officially activated in July 1942 as the Rapid City Army Air Base. It became a

permanent facility in 1948, with the 28 tt_strategic Reconnaissance Wing as its,host unit. Throughout its

history, EAFB has been the base of operations tbr a number of types of aircraft and missile systems.

Presently, the 28_hBombardment Wing (BI-B bombers) is the host unit. The following three tables

provide a summary of the History of Installation Operations at EAFB (Table 2-1), Key Regulatory

Actions Impacting EAFB (Table 2-2), and Site Closure Status (Table 2-3).

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TABLE 2-1

HISTORY OF INSTALLATION OPERATIONS AT EAFB

(from Management Action Plan EAFB, South Dakota-2004)

Period I Types Of Operations Weapon System [ Waste Generating Activities

Pre- 1939 Rangeland None None

1939-1941 Rapid City Airport None Fuel/oil storage

1941-1942 EAFB construction None Construction/demolition

B- 17 Bomber

1942-1945 Bomber Training Wing crew training, EAFB landfills, airplane and automotive weapons storage fuel storage, hangars, machine shops

for bombers (solvents, oils, metals).

1945-1946 Weather Reconnaissance Reconnaissance Weapon storage areas, landfills, water

Squadron training treatment facility, fuel/oil storage.

1946-1947 Inactive None None

Weapons storage area, low-level nuclear

waste storage area, explosive ordnance

1947-1957 Bomber Wing B-36 Bombers disposal area, fire protection training areas,

machine shops, fuel/oil storage, fuel pump

houses, sludge burial, landfills.

Weapons storage area, landfills, low-level

nuclear waste storage area, explosive

ordnance disposal area, fire protection 1957-1959 Bomber Wing B-52 Bombers

training areas, machine shops, fuel/oil

storage, fuel pump houses, sludge burial,

buried tanks.

B-52 Bombers Weapons storage area, low-level nuclear

waste storage area, landfills, explosive Titan I missiles

Bomber Wing KC-135 Tankers ordnance disposal area, fire protection

1960-1965 Missile Wing EC-135 training areas, machine shops, fuel/oil

Reconnaissance storage, fuel pump houses, sludge burial,

T-38 Trainers various dumping areas, buried tanks, low- level nuclear waste.

Minutemen Oil/water separators, landfills, buried

Missiles fuel/oil tanks, fire protection training areas,

B-52 Bombers burn pits, weapons storage area, wastewater

1962-1992 44 thStrategic Wing B-1 Bombers treatment facility, drum storage areas,

KC-135 Tankers machine shops, fuel/oil storage, fuel pump

UH-1 Helicopters houses, explosive ordnance disposal area,

T-38 Trainers low-level nuclear waste.

Oil/water separators, landfills, buried

B-1 Bombers fuel/oil tanks, fire protection training areas,

KC-135 Tankers weapons storage area, wastewater treatment 1993-1994 28 th Bombardment Wing

UH-1 Helicopters facility, drum storage areas, machine shop,

T-38 Trainers fuel/oil storage, fuel pump houses,

explosive ordnance disposal area.

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TABLE 2-1

HISTORY OF INSTALLATION OPERATIONS AT EAFB

(from Management Action Plan EAFB, South Dakota-2004)

Period Types Of Operations Weapon System [ Waste Generating Activities

Oil/water separators, landfills, buried

fuel/oil tanks, fire protection training areas,

weapons storage area, wastewater treatment

1994-mid 28 th Bombardment Wing B-I Bombers facility, drum storage areas, machine shop, 1995 T-38 Trainers

fuel/oil storage, fuel pump houses,

explosive ordnance disposal area, low-level

nuclear waste.

Oil/water separators, landfills, buried

fuel/oil tanks, fire protection training areas,

Mid-1995 28th Bombardment Wing B-1 Bombers weapons storage area, wastewater treatment

to present facility, drum storage areas, machine shop,

fuel/oil storage, fuel pump houses,

explosive ordnance disposal area.

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TABLE 2-2

KEY REGULATORY ACTIONS IMPACTING EAFB

(from Management Action Plan EAFB, South Dakota-2004)

Date Action Details

September 1985 PA/SI Records Search Completion of PA/Records Search by EAFB

June 1988 Phase II, Stage I Report became final

December 1989 Phase II, Stage II Report became final

October 26, 1989 Proposed NPL EAFB proposed for National Priority List

August 30, 1990 NPL EAFB Final Listed on NPL with 12 operable units

January 24, 1992 FFA USAF, EPA, South Dakota complete FFA

April 1, 1992 RI/FS Initiated in accordance with FFA

July - August 1995 Public Comment Public Comment Period, OU-6 Proposed Plan.

Public meeting held July 25, 1995.

October 1995 OU-6 ROD ROD Execution by USAF, EPA and SDDENR

September - October 1995 Public Comment Public Comment Period for OU- 1, 2, and 4

Proposed Plans. Public meeting held

January 11, 1996.

December 1995 - January Public Comment Public Comment Period for OU-3, 5, 7, 8, 9, 10,

1996 and 12 Proposed Plan. Public meeting held

January 11, 1996.

May 1996 RODs, OU- ROD Execution by USAF, EPA and SDDENR

1,2,4,9,10,12

June 1996 RODs, OU-3,5,7,8 ROD Execution by USAF, EPA and SDDENR

September 1996 RA Report, OU-6 RA Report approved by EPA

February - March 1997 Public Comment Public Comment Period for OU-11 Proposed Plan.

Public meeting held February 19, 1997.

April 1997 ROD, OU-I 1 ROD Execution by USAF, EPA and SDDENR

September 1997 RA Reports Approval by EPA of RA Reports for OU-1, 2, 3, 4

(IRA and Final Action), 5, 7, 8 and 12.

1999 WP-22 Close-out Site Closeout, approval by SDDENR

September, 1999 PCOR Preliminary Closeout Report for OUs, approval by

HQ EPA

September, 2000 5 Year Review Report consisting of review of all OUs. Approval

by EPA.

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TABLE 2-3

SITE CLOSURE STATUS

(from Management Action Plan EAFB, South Dakota-1999)

Final Final

Draft RA Final RA RA Report Site No. Construction Regulatory

Report Inspection Inspection Report Approval

CERCLA SITES

IRA (OU- l) 7/12/96 7/96 7/2/96 8/22/96 9/30/96

IRA (OU-4) 9/23/96 8/8/96 2/20/97 5/9/97 9/8/97

OU- 1 11/1/96 6/6/97 7/17/97 7/25/97 9/25/97

Rad Removal (OU-2) 11/5/97 12/2/97 NA 12/22/97 NA

OU-2 9/23/96 5/1/97 11/6/96 5/9/97 9/8/97

OU-3 11/1/96 5/1/97 2/20/97 5/9/97 9/8/97

OU -4 I ! / 1/96 4/15/97 2/20/97 6/11/97 9/25/97

OU-5 11/1/96 5/1/97 2/20/97 5/9/97 9/8/97

OU-6 6/96 7/2/96 7/2/96 7/31/96 9/30/96

OU-7 9/5/97 12/2/97 9/23/97 9/26/97 9/29/97

OU-8 11/1/96 6/6/97 2/20/97 6/11/97 9/8/97

OU-9 l NA NA NA NA

OU- 10 t NA NA NA NA

OU-! 1 9/8/97 12/18/97 1/14/98 12/10/99 2/10/00

OU- 12 11/1/96 5/1/97 11/6/96 5/9/97 9/8/97

Draft Final Final Final

Completion Construction Regulatory Completion Approval

Report Inspection Inspection Report

NON-CERCLA SITES

SS- 082 NA NA NA

ST- l 0 s 6/19/97 12/19/97 12/29/97

ST- 144 12/19/97 12/29/97

WP-225 5/8/97 5/7/97 6/I 7/97 9/16/97

ST-236 NA NA NA NA NA

JP-4 (OU-2) 7 NA 3/25/97 6/19/97 12/19/97 12/29/97

IST-178 NA NA NA 6/18/97 4/30/98

OT-189 NA NA NA NA NA

OT-16 I° NA NA NA NA NA

I No-Action OU; Complction occurred when ROD was signcd in May 1996.

2 Spill Sitc Jet Fuel Pump Housc 7.

3 Jet Fuel Line Leak Pump House Hydrant.

4 Jet Fucl Spill Sitc Pump House 6.

5 Abandoned Industrial Wastc Water Treatment Plant.

6 Abandoned WWII Petroleum Oil Lubricant (POL) Systcm ST 23 is being addressed as part of the OU I I South Docks Ground Water

Rcmcdial Action.

7 JP-4 Pipclinc puncture Icak south of OU 2.

8 Bascwide UST locations.

9 Badlands Bombing Range Impact Area. Administratively closed; work proceeding under Federal Facilities Compliance Act.

10 Jct Fucl Spill 70 Row Hanger Complcx. Pump house 7 and UST havc bccn removed; DENR Closcout Pcnding.

L WORKERS ' ,8461OWP , IEAFB5-_EAR RE17EW2005DOC 7 S¢'ptet nher 2005

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3.0 BACKGROUND

3.1 BASEWIDE

Ellsworth AFB is located 12 miles east of Rapid City, South Dakota, and adjacent to the City of

Box Elder. Thc installation covers 4,858 acres within Meade and Pennington Counties and includes

runways, airfield operations, industrial areas, housing and recreational facilities. Open land, containing

individual residences, lies to the north, south, and west of EAFB, while residential and commercial areas

lie to the east (Figure 3-1).

On August 30, 1990 (55 FR 35509), EAFB was listed on the U.S. Environmental Protection Agency's

(EPA's) National Priorities List. A Federal Facility Agreement signed in January 1992 went into effect

on April 1, 1992. The FFA identified 11 potential source area Operable Units as well as a Basewide

ground water Operable Unit (Figure 3-2). In addition, the South Dakota Department of Environment and

Natural Resources (SDDENR) provides oversight for several petroleum release sites, which are

mentioned in this report but are not addressed under CERCLA. Ground water extraction systems have

been constructed to address ground water contamination associated with the JP-4 plume and the

Flightline Refueling Area (FRA).

Rapid City, located approximately 6 miles west of EAFB, is the second largest city in South Dakota with

a population of more than 54,000 (U.S. Department of Commerce, 1992). Access to national rail lines,

Interstate Highway 90, commercial airlines, and state highways has created a transportation hub in

Rapid City. The economy of the Rapid City area is composed of light industry, tourism, agriculture, and

a variety of service industries.

EAFB is located on the border of Pennington and Meade Counties, and the southernmost property line is

approximately 4,800 ft north of the Box Elder corporate limits. The estimated population within a

four-mile radius of the Base was 16,000 in 2005. The Base employs slightly more than 5,500 people.

This consists of about 4,100 active-duty military and the remainder composed of civilian personnel.

There are approximately 5,800 individuals living in the base-owned or base-leased military family

housing units and dormitory rooms provided for members and their families (EAFB, Public Affairs

Office, 2005).

Land use on and around EAFB is a mixture of industrial (primarily on-Base), commercial, residential, and

agricultural uses. EAFB is an active military installation, comprised of runways and airfield operations,

industrial areas, housing, and recreational facilities. The on-Base residential areas are located along the

eastern boundary of EAFB. Ranches lie to the north and west of the Base, and residential and commercial

areas lie to the east. Residences and ranches lie south of EAFB. Private residences are located within a

few thousand feet of the EAFB southwestern boundary. The closest residence to EAFB is approximately

300 feet southwest of Operable Unit 4 (Landfill 3). There are other residences in the same vicinity. The

nearest residence to OU-1 is approximately 1,500 feet south of the southern edge of the FPTA, and

600 feet west of OU-2.

Shallow ground water in the area is used for domestic water supplies and for livestock watering.

According to the Ellsworth Air Force Base Public Health Assessment report prepared by the Agency for

Toxic Substance and Disease Registry (ATSDR), (U.S. Department of Health and Human Services,

1993), some nearby off-Base residents use shallow (less than 70 ft below grade) private wells for both

household and livestock water supplies. The Air Force has completed a detailed investigation of off-site
Ellsworth Air Force Base

Final l'_ive - Y_,ar Review

ground water to obtain data pertaining to water quality of oftZsite residential wells in support of the

OU-I 1 RI.

Ground water resources provide most of the water supplies required by municipal, industrial, domestic

and agricultural consumers in the study area. The Rapid City municipal distribution system obtains its

water supplies from several deep high-capacity wells finished into the bottom of the

Pennsylvanian Minnelusa Formation and the upper Mississippian Madison Group (Pahasapa Limestone),

three infiltration galleries finished along Rapid Creek and from a surface water intake on Rapid Creek that

is more than five miles west of EAFB (USAF, 1985). EAFB obtains its potable water from thc

Rapid City Municipal Distribution System. In past years, EAFB obtained its water supplies from its own

wclls. A total of five wells had been installed into deep bedrock aquifers at the Base. These wells were

taken out of service by the Air Force and have been abandoned following State of South Dakota

requirements. The City of Box Elder's municipal distribution system receives water from four wells more

than 2 miles south of EAFB. Three of the wells are finished into the lnyan Kara Group (Cretaceous Fall

River and Lakota Formations) at depths of 2,000 feet or more, and one well has been completed into the

Madison Group (Pahasapa Limestone) at a depth of 4,180 feet below grade (USAF, 1985). Other than the

shallow wells outside the southwest corner of the Base, it is reportcd that ranches and rural homes in the

area depend on wells completed into the Inyan Kara Group at depths of at least 1,700 t_ct below land

surface for water supplies (U.S. Department of Health and Human Services, 1993). Five oft-Base private

domestic wells are situated within 2,500 feet of the western and southern boundaries of EAFB near OU-1.

The closest well, PW05, is approximately 300 feet west of OU-I. The closcst down-gradient private

domestic supply well from OU-1 (PW01) is approximately 1,300 feet down-gradient (southeast) of the

OU.

The major streams near EAFB are Box Elder Creek, Elk Creek, and Rapid Creck, all of which are located

in the Missouri River Basin. Box Elder Creek is an ephemeral stream, while Elk Creek and Rapid Creek

are perennial streams that support a permanent fish population.

Surface water runoff at EAFB discharges from the Base property through eight outfalls (Figurc 3-3).

Outfalls 007, 008, and 009 flow north to the Elk Creek drainage. Outfalls 001,002, 003, and 006 flow

south to the Box Elder Creek drainage. An additional Outfall (005) is located at the Base Waste Water

Treatment Plant (WWTP) and discharges from the Base through Outfall 006. The outfalls carrying water

north to the Elk Creek drainage have low to no flows and therefore arc not routinely monitored. The

remaining outfalls are monitored on a specific schedule as specified m applicable National Pollutant

Discharge Elimination System (NPDES) Permit requirements.

Flow to the south into the Box Elder drainage is more significant and comprises the majority of runoff

from the Base. The flows leave the Base to the south from Outfalls 001,002, 003, and 006. The water

leaving the Base flows through drainageways into the Box Elder Creek segment between $22, T2N, R8E,

and Haines Avenue in Rapid City. Surface water in the area is used to water livestock and it also supports

limited aquatic populations. Fishing is allowed in on-Base lakes.

EAFB experiences temperature variations that are typical of semi-arid continental climates. The

Black Hills to the west of EAFB exert a pronounced influence on the climate in this area

(National Climatic Data Center, 1992). Summer days are warm, with cool comfortable nights. The

average summer temperature is 68°F, and the daily high average is 81°F. July is the hottest month, and

the highest recorded temperature was I I0°F in July 1989. Winters are relatively mild, due to the

protection of the Black Hills and the frequent occurrence of Chinook winds. The average winter

temperature is 26°F, with an average daily minimum of 14.9°F. The coldest month, on the average is

9 3057 017 s`v''''be':°°>
Ellsworth Air Force Base

Final Five- Year Review

January, and the lowest recorded temperature was -30°F in December 1990. Snowfall is normally light,

with the greatest monthly average of about 8 inches occurring in March.

Average annual precipitation is t6.3 inches. Most precipitation falls during the spring and early summer

months. April through July average 2.5 in. per month of precipitation, and June has the highest monthly

average with 3.3 inches. The average relative humidity is 71 percent at dawn, and 50 percent in the late

afternoon. Prevailing winds are from the north and northwest at a mean speed of 11.3 mph (U.S. National

Weather Service, Asheville, North Carolina).

Remedial Investigations (RI) completed at EAFB at the 12 operable units resulted in the collection of

media samples from soil, sediment, ground water and surface water. The primary list of analytes

collected at each operable unit and at the background locations were identical. Analysis of additional

site-specific analytes was conducted at OU-7 (radiological), OU-8 (explosives, dioxins and Pramitol), and

OU-I (dioxins). The primary analytes included:

SOIL SAMPLES STREAM SEDIMENT

TCL VOC (8240) TCL VOC (8240)

TCL SVOC (8270) TCL SVOC (8270)

TCL Pesticides/PCBs (8080) TCL Pesticides/PCBs (8080)

TAL Metals TAL Metals

Dioxin/Furan ( 1613) Dioxin/Furan ( 1613)

Cyanide (9012) Cyanide (9012)

TRPH (8015) TRPH (8015)

SURFACE WATER GROUND WATER

TCL VOC (8240) TCL VOC (8240)

Vinyl Chloride (80 i0) Vinyl Chloride (8010)

TCL SVOC (8270) TCL SVOC (8270)

Polycyclic Aromatic Hydrocarbons (8100) Polycyclic Aromatic Hydrocarbons (8100)

Pentachlorophenol (8150) Pentachlorophenol (8150)

TCL Pesticides/PCBs (8080) TCL Pesticides/PCBs (8080)

TAL Metals (total & dissolved) TAL Metals (total and dissolved)

Cyanide (9012) Cyanide (9012)

TRPH (8015) TRPH (8015)

3.2 OPERABLE UNIT 1 FIRE PROTECTION TRAINING AREA (FPTA)

3.2.1 Physical Setting

The topography of OU-I is characterized by a local topographic high, especially in the area where the fire

training was conducted, which is bounded on the southwest and southeast by drainages that converge to

from a southerly pointing apex. Surface water, which flows onto and through OU-I, originates from

several separate sources. These source areas, from upstream to downstream, are discussed below and

illustrated on Figure 3-3.

The main drainage channel at OU-I flows from north to south along the eastern perimeter of OU-l. The

main channel drains a portion of the southern area of EAFB including some of the hangar complex,

runways, and OU-12. The main channel is approximately 12-15 ft across and 3-4 ft deep. The channel is

considered to be ephemeral; however, standing water was observed in the channel throughout the

L.IWORK_ERSI846101WPIEAFB 5-YEAR REVIEW 2005 DOC , ]0 September2005

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Ellsworth Air Force Base

Final Five- Year Revww

1993 RI field investigation. The main drainage channel eventually empties into the upstream end of

Pond 001. Flow in the drainage ditch along the southeast boundary of OU-I originates as surface water

run-off from the landfill area (OU-12) to the northeast of OU-I and from drainage pipes that discharge

storm water run-off from the South Docks area of the flight line and from portions of the adjoining

taxiways and flight lines. Flow was measured at approximately 1 cubic foot per second (cfs) above

Pond 001 during the OU-1 field investigation.

A secondary shallow drainage ditch delivers surface runoff from the eastern portion of the FPTA to the

main drainage channel. This secondary drainage ditch is generally dry. Two drainage culverts extend

beneath the alert apron and discharge surface water from the east into the main drainage channel. The

source of the discharge from these two culverts is presumed to be runoff from the alert apron.

Surface water runoff from the above sources is temporarily held in Pond 001 (Figure 3-4). Pond 001 is

located at the southern extreme of the Operable Unit. At the downstream end of the pond is an oil

skimmer and earthen dam. On the downstream side of the skimmer, flow passes through piping beneath

Kenney Road and discharges into an open drainage ditch on the west end of OU-2. The skimmer consists

of a fixed overflow weir and two discharge pipes. The skimmer is designed to allow water to exit

Pond 001 without allowing light non-aqueous phase liquids (LNAPL) or floating debris to discharge. In

addition, a floating aerator is used in the pond to help oxygenate water.

A secondary unnamed ephemeral drainage channel is located along the southwestern edge of OU-i and

receives surface water runoff from off-Base west of OU-I and from runoff from the western edge of the

FPTA. This ancillary drainage channel empties into Pond 001 beneath the main channel approximately

200 ft downstream of the main drainage channel. The flow in the drainage along the southwest boundary

of OU-1 originates as sheet flow and surface run-off from fields to the northwest of OU-1. There was no

measurable discharge in this drainage ditch during the OU-I field investigation although there was

standing water.

The slope break into the unnamed ephemeral drainage to the southwest is gentle, whereas the slope break

into the unnamed mare drainage, to the southeast, is much steeper. Wetlands were found along both

drainageways and along Pond 001. The relief from the topographic high of OU-1 to the pond is

approximately 40 ft.

3.2.2 Land and Resource Use

OU- l contained the Former Fire Protection Training Area (FPTA) and is located on the southwest portion

of EAFB northwest of the alert apron and east of Kenny Road. OU-1 covers approximately ten acres and

consisted of a centrally located, unlined, bermed burn pit, a steel aircraft mockup and surrounding land.

The burn pit area was the source area of contamination.

This OU is currently being remediated and is closed to access, except for Base personnel and contractors

responsible of the operation of the remedial systems. Undisturbed grass areas on the OU may be used by

local wildlife for foraging, loafing, and nesting. No specific future use has been determined for this OU.

Operable Unit 1 has several habitat features, most of which are heavily influenced by human activities

such as past burn usage and current maintenance. In spite of this disturbance, some natural habitat still

exists in the form of grassland, weedy areas, and a small portion of wetlands, that would attract animal

species that would be potential contaminant receptors. The U.S. Fish and Wildlife Service

L _WORK ERS 846 I0 It[" E4 FB _ }'£4R REI'I£ _l 2005 DOC I ] ._;eptember 2005

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National Wetland Inventory Map (NWI) classifies the wetland community type present on OU-I as

Palustrine Emergent Seasonally Flooded (PEMC).

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

3.2.3 History of Contamination

The FPTA was operated by the EAFB Fire Department from 1942 to 1990 at this location. The location

of the burn area within the former FPTA has changed several times over the years. Aerial photographs of

EAFB dated May 28,1952, October 8, 1954, August 25,1962, and June 19,1968, show numerous areas of

staining presumed to be a result of fire training activities within the former FPTA. The training exercises

conducted at the FPTA involved simulation of aircraft fires and spills. Various types of fuels, oils, and

solvents were dispersed within the burn-pit area and subsequently ignited and then extinguished.

Soils at OU-I contained JP-4 (jet fuel); benzene, toluene, ethylbenzene, xylenes (BTEX); and, chlorinated

volatile organic compounds (VOCs). JP-4 concentrations were much higher than other compounds

(Figure 3-5). Ground water at OU-I contained chlorinated VOCs, BTEX, and JP-4. LNAPLS were

present in the northern and southern end of the FPTA. Dense non-aqueous phase liquids (DNAPLS) were

not present at OU-1. Ground water contamination in this area did not extend beyond the Base boundary

(Figure 3-6).

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-I. Carcinogenic risks were estimated as the incremental probability of an individual developing

cancer over a lifetime as a result of exposure to a potential cancer-causing chemical. The acceptable risk

range expressed as a probability is one cancer incidence in ten thousand people to one cancer incident in a

million people. This level of risk is also denoted by 1 × 104 to 1 × 10 -6. Risks within the acceptable risk

range may or may not warrant remedial action depending upon site-specific circumstances. Risks below

this range cannot be differentiated from the background occurrence of cancer in human populations.

Risks calculated in a risk assessment are excess (i.e., over background) cancer risks due to exposure from

contaminants.

Non-carcinogenic health risks are evaluated using a hazard index (HI). If the hazard index is less than or

equal to one, the contaminant concentration is considered an acceptable level and generally assumes that

the human population may be exposed to it during a 30-year period without adverse health effects.

The risk assessment for OU-1 indicated unacceptable risk in the shallow ground water for the future

residential exposure scenarios. The chemicals, which contributed the majority of the risk in shallow

ground water, were VOCs. Of the VOCs, benzene, 1,2-dichloroethane, (1,2-DCA) l,l-dichloroethylene

(I,I-DCE), 1,2-dichloroethylene (1,2-DCE), l, l,l-trichloroethane, perchloroethylene (PCE),

trichloroethylene (TCE), and vinyl chloride were identified as being above their respective maximum

contaminant levels (MCLs).

The risk assessment indicated that unacceptable future risk exists in the soils of the burn-pit area,

primarily from the potential for contaminating the underlying ground water. In order to prevent future

contamination of the ground water, four VOCs were identified for remediation in soils: benzene,

1,2-DCE, PCE, and TCE. These chemicals were selected for remediation on the basis of a contaminant

transport model. Remediation of jet fuel in the soil at OU-1 is also required because concentrations of jet

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Final Five Year Review

fuel (and related components) exceed State of South Dakota regulations. Risks from exposure to

pesticides and dioxins/furans in surface and subsurface soils at OU-1 were well below the acceptable

range and do not warrant remediation.

The current and future risk from the contaminants in the sediments and surface water at OU-1 is within

the acceptable risk range. Several compounds were detected in surface water at above the

Federal Ambient Water Quality Criteria (FAWQC), but the risk to human health from these contaminants

is within the acceptable risk range of l x 10 4 (one in 10,000) to 1 × 10 6 (l in 1,000,000) increased

incidents of cancer above background. Risks within the acceptable risk range may or may not warrant

remedial action depending upon site-specific circumstances. Risks below this range cannot be

differentiated from the background occurrence of cancer in human populations. Risks calculated in a risk

assessment are excess, i.e., over background, cancer risks due to exposure from contaminants. Because of

the risk being within the acceptable risk range, remediation of these chemicals in surface water and

sediment is not warranted.

Remediation of the ground water is warranted based on the risk to human health from ingesting and

contacting contaminated ground water. Remediation of soil is warranted based on the potential for

contaminants in the soil to be transported to the underlying ground water. Actual or threatened releases of

hazardous substances from OU-1, if not addressed by implementing the response action selected in this

Record of Decision (ROD), may present an imminent and substantial endangerment to public health,

welfare, and the environment.

An ecological risk evaluation of OU-I was based on a combination of data and literature reviews, field

and laboratory analyses, analyte evaluation and screening, and preliminary risk screening. A variety of

animal species may live, forage, or nest in OU-I habitats. These species include various types of

invertebrates, amphibians, birds, and mammals. Terrestrial vegetation and soil faunal communities do not

reveal characteristics that indicate chemical-related impacts. This finding is consistent with the relatively

low levels of contaminants in the soil.

Because of the altered natural environment at OU-I, rare, threatened, or endangered species are unlikely

to utilize the area for more than briel, periodic habitat. Due to the low levels of contaminant

concentrations and the identified exposure pathways, the contaminants do not pose an unacceptable risk

to these species. In addition, the limited contact these species would have with the OU-! area ensures

unacceptable risk to a single individual will not occur.

3.2.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were completed at this OU. A new FPTA

was constructed to the northeast of the OU in 1994. However, this new FPTA construction was not done

as a remedial response action.

3.3 OPERABLE UNIT 2 LANDFILL 1 AND LANDFILL 6

3.3.1 Physical Setting

Surface topography at Landfill No. I generally slopes in a southerly direction from Kenney Road to the

southern boundary of EAFB (Figure 3-7). Some hummocky topography and small surface depressions

are visible across the area. A series of east-west trending depressions are clearly visible in aerial

photographs of the area and are assumed to be the surface reflection of historical trench and fill

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Final Five- Year Review

operations. The topography of Landfill 1 reflects minimal relief with a gentle southeast slope

(approximately 5 to 10 degrees) toward the small southeastward flowing stream. An elongated, flat-top

mound is present near the western boundary of the landfill. This mound is oriented in a north-south

direction and is about 18 feet wide, 243 feet long, and stands about 1.5 to 2.0 feet above the surrounding

topography. Parallel to the east edge is a ditch-like depression extending the full length of the mound.

Surface water that flows adjacent to and through Landfill 1 originates from Pond 001. Pond 001 is

located upstream immediately northwest of Landfill No. 1, across Kenney Road. Pond 001 is elongated

in shape, approximately 720 feet long and 180 feet wide at the widest point on the south end of the Pond.

It collects surface water drainage from north and west of the alert apron. Precipitation that falls on the

edge of the alert apron is also discharged to Pond 001. Outflow from the pond empties to a small

unnamed, southeasterly flowing stream located along the western boundary of the landfill. The stream

follows a ditch that is approximately 20 feet wide and 15 feet deep. The ditch channels the stream along

the western boundary of Landfill l and eventually off-Base through a pasture south of OU-2. Stream

flow measurements were conducted on July 21, 1993, at OU-2 surface water sample locations on this

stream. The stream flow measurements indicate that this unnamed stream had an average discharge of

approximately 1.14 cubic feet per second (CFS). The OU-2 stream flow measurements were measured

during peak flow of a rain event. This stream ultimately discharges into Box Elder Creek.

Landfill No. 6 is situated on a hillside that slopes to the east and is located just west of Pool 002 and

northeast of Landfill No. 1 (Figure 3-7). The landfill boundary presented in Figure 3-7 is based upon fill

material encountered in borings drilled during the 1993/1994 RI. No landfill material was encountered

under the asphalt parking lot at the top of the hillside. Therefore, the approximate boundary of

Landfill No. 6 identified during the RI is east of the boundary depicted in Installation Restoration

Program (IRP) reports as presented in Figure 3-7.

Surface drainage from Landfill No. 6 is toward the east to a small surface water body designated

Pond 002. Pond 002 is semi-circular in shape, approximately 120 feet long, and 100 feet wide. This

pond also collects surface water runoff from the western one-half of the runway and adjacent operations

areas, and from storm water drains located within the alert apron. Outflow from Pond 002 empties to a

small, ephemeral stream that drains to the south and ultimately to Box Elder Creek. Stream flow

measurements were conducted on July 21, 1993, at OU-2 surface water sample locations on this stream.

The stream flow measurements indicated that this small ephemeral stream had a discharge of approximately 0.24 cfs.

3.3.2 Land and Resource Use

There is very little natural undisturbed surface soil across OU-2, since the area has been used for landfill

operations. Landfill No. l covers a large portion of the central and southern parts of OU-2 and the

surface material in this area is predominantly comprised of cover soil. Construction debris (concrete,

reinforcing bar, brick) is visible in small areas in the northwest corner of the landfill. Along the western

landfill edge, adjacent to the ephemeral stream, twisted metal rods and pipes, concrete with reinforcing

bars, flattened drums, and other debris are exposed.

The western edge of Landfill No. 6 is covered by an asphalt parking lot, while toward the east,

Landfill No. 6 has been covered with soil. A gravel road runs from Kenney Drive to the small dam at

Pond 002 and winds through the eastern edge of Landfill No. 6.

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During the RI a variety of habitat features were observed at OU-2, many of which had been altered by

human activities such as past landfill operation, maintenance, and grazing. In spite of these activities,

habitat still existed that would attract animal species that would be potential chemical receptors. Since

the landfill has had a soil cover placed and reseeded as part of the remedial action, these grass habitats

have been improved.

Wetlands consisting of a retention pond and drainageway are located in the west part of OU-2. These

wetlands offer shelter, foraging and nesting habitat for a variety of species. The U.S. Fish and Wildlife

Service National Wetland Inventory Map (NW1) classifies the wetland community types present on OU-2

as Palustrine Emergent Temporarily Flooded (PEMA) and Palustrine Aquatic Bed Semipermanently

Flooded (PABF).

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered m South Dakota were observed on EAFB.

The construction of the landfill covers for this OU is complete. Access is restricted to Base personnel and

contractors responsible of the maintenance of the cover and operation of the remedial systems.

Undisturbed grass areas on the OU may be used by local wildlife for foraging, loafing, and nesting. No

specific future use has been determined for this OU.

3.3.3 History of Contamination

Landfill No. 1 was active from the early 1940s to 1964 and was used to dispose of a variety of wastes

including Base refuse, incinerator ash, sludge, oil, possibly liquid industrial wastes, and hardfill debris.

Aerial photo analysis conducted by the EPA from historical photos (1938 to 1990) indicated the types of

disposal practices at Landfill No. I. Through interpretation of these photographs, landfill materials

appear to have been placed in trenches in the eastern two-thirds of the landfill. The western third of the

landfill appears to have been used to dispose of primarily hardfill materials. This is evidenced by the

presence of exposed rubble piles in this area. Hardfill has been placed along the embankment of the

drainage channel in the western portion of the landfill. Other disposal practices at Landfill No. I include

open burning of refuse and debris.

Landfill No. 6 was used from 1962 to 1965 and primarily received general Base refuse. Waste oil, thel,

and solvents may also have been disposed of at this location. No direct physical evidence of these

chemicals was found at Landfill No. 6 during the 1993/1994 remedial investigation (R1) field activities.

Within OU-2, soils contained chlorinated VOCs, BTEX, and polynuclear aromatic hydrocarbons (PAHs),

(Figure 3-8). The reported VOCs and BTEX chemicals represent the residual of fuels and solvents used

for aircraft and vehicle operation and maintenance at EAFB. The PAHs are the residual of incomplete

combustion of motor fuels and were not a specific chemical used at EAFB. All but one of the reported

concentrations in soil was below the 10-_' risk based level calculated for excess carcinogenic risks.

Samples from monitor wells installed in the interior of Landfill No. 1 indicated the presence of TCE and

DCE in five samples at maximum concentrations of 14 ug/L and 19 ug/L, respectively.

JP-4 contamination caused by a leak in a fuel line was identified along the southern boundary of OU-2.

This JP-4 contamination has been remediated under State of South Dakota petroleum release regulations.

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Final Five- Year Review

OU-2 is bounded on the west by a surface water drainage channel. This channel contains areas of

wetlands. Remedial construction activities at the OU resulted in some reworking of soil and drainage

channel relocation in the wetland areas. Since 2000, this portion of the channel has been graded and

erosion protection (in the form of rip rap and rock-filled gabions) has been installed. Replacement

wetlands were constructed near other Base lakes located near the center of EAFB.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-2.

The risk assessment for OU-2 indicated that the future carcinogenic risk slightly exceeded the acceptable

range only from ingestion of ground water containing arsenic and beryllium. Arsenic and beryllium are

considered naturally occurring at OU-2. All other current and future quantified carcinogenic risks were

within the acceptable risk range.

Part of the remaining site risk includes risks from exposure to surface soil contaminants. The chemicals,

which contributed the majority of risk in the soil, were PAHs. Benzo(a)pyrene, a PAH, is the primary

contaminant identified in the risk assessment as contributing to risk from soils. However, only one

surface soil and two subsurface soil samples actually contained concentrations of benzo(a)pyrene that are

of concern. Due to the heterogeneity of the landfill contents, uncertainty is associated with the calculated

risk values for the surface soil.

Benzo(a)pyrene was also the primary chemical contributing to carcinogenic risk in the sediments at

OU-2. Five of seven sediment samples contained benzo(a)pyrene at concentrations that are of concern.

[towever, the results of the risk assessment indicate that risk due to exposure to contaminants in

sediments at OU-2 is within the acceptable risk range. It is typical for compounds in the surface soil to

wash into adjacent drainages and to settle or become trapped in the drainage areas. Remedial action for

the drainage areas outside of the landfill boundaries is not warranted.

The risk assessment for OU-2 indicated that the only non-carcinogenic risk resulting in an HI above

1.0 was from ingestion of ground water containing arsenic. Arsenic detected in samples throughout the

Base is considered to be naturally occurring.

Results of the risk assessment indicated that surface water was not a media of current concern. Chemicals

detected in the ground water which contributed to excess risk are considered to be naturally occurring.

Therefore, remedial action is not warranted for the ground water and surface water at this time.

Remedial action was considered warranted for the landfills based on the potential risk to human health

from future releases of hazardous substances from the landfills. Contaminants in the landfills may leach

downward to contaminate the underlying ground water. Off-Base residents may then ingest or come in

contact with the contaminated ground water. Also, the surface of the landfills may erode, thus exposing

Base personnel doing maintenance work to disposed hazardous substances.

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

In terms of ecological value OU-2 represents a highly disturbed environment dominated by the adjacent

runway and alert apron. Some habitats do exist in the area including grass fields, weedy old fields, trees

and wetlands interspersed among the disturbed areas. The tiered ecological assessment did not identify

any chemical related impacts and a Tier III assessment was considered unwarranted.

L.',WORK_ERS'.84610!WP,EAFB_-YEARREVIEW2005DOC 16 3057 0 2 _ptember2005
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3.3.4 Initial Response

Two removal actions were completed at this OU. A site in the southwest comer of Landfill l identified

during RI geophysical investigations was excavated in 1997. This location contained remnants of

chemical weapons training materials and low-level radioactive waste material The identified material

was excavated and moved off Base for disposal at a licensed waste disposal facility.

3.4 OPERABLE UNIT 3 LANDFILL 2

3.4.1 Physical Setting

The area west of Landfill 2 slopes very gently to the south, whereas the area east of Landfill 2 slopes to

the east where a dendritic pattern of ephemeral drainages has dissected the area. The southern drainage

leads to Box Elder Creek. The eastward drainage at OU-3 is part of an overall northern-sloping dendritic

pattern that drains toward ephemeral drainages that lead to Elk Creek. OU-3 is currently undeveloped

and is dominated by relatively undisturbed grassland. Some exposed rubble was evident in full trenches

in the northern portion of the OU at the time of the RI.

Water uses designated for the streams include irrigation, wildlife propagation, and livestock. In addition,

the Elk Creek designation includes limited contact recreation.

The available habitat on OU-3 is dominated by relatively undisturbed grassland. OU-3 differs from most

of the other operable units in that none of the site is developed. There are no buildings, parking areas, or

paved roads within the OU. Trench-and-fill activities have physically altered the vegetation on a small

portion of OU-3, but the majority of the OU is relatively undisturbed grassland that remains attractive to

animal species that would be potential chemical receptors.

No wetlands were identified on the OU. No standing or flowing water existed, and dominant plant

species were not hydrophytic in any part of the OU.

3.4.2 Land and Resource use

OU-3, located in the northeast portion of EAFB, consists of Landfill 2. It is approximatcly a one-acre

site, the four identified trenches to the north and two disturbed soil areas in the southeast and southwest

comers (Figure 3-9). It is currently undeveloped and is dominated by relatively undisturbed grassland.

The placement of the landfill cover is complete at this OU. The OU is closed to access, except for Base

personnel and contractors responsible for the operation of the remedial systems. Undisturbed grass areas

on the OU may be used by local wildlife for foraging, loafing and nesting. No specific future use has

been determined for this OU.

3.4.3 History of Contamination

The landfill was active for approximately one year (1964-1965) until operational concerns with trash

containment ended its use. Methods used to dispose of the refuse included surface filling of a low-lying

area (fill area) and trench and fill operations. Combustible trash, described as shop wastes, was burned

daily in a bum pit. Four trenches located north of the fill area were used for the disposal of metal and

industrial and household refuse. Possible burial sites were identified in the August 24, 1971, aerial photo,

L _WORKERS£46I#IIPE4I_B _ }'E4RRLI'IEJt 2OO_DO(" I7 Sept n " ) 5 3o57
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Final kTve- Year Review

but the trench origination dates are not known. Some metal debris was exposed at OU-3 and may have

been the result of surface disposal of metal waste. Areas of disturbed soil in the southwestern and

southeastern corner of OU-3, which may have been dump areas, were also identified in historical aerial

photographs of EAFB.

A sign had been located within the boundary of OU-3 indicating a missile disposal/burial site

(USAF, 1988). The missile disposal site is basically scrap metal salvaged from a test flight and is not a

source of chemical release to the environment. According to the USAF, the missile dates from a test

firing in the mid-1960s. Information on the missile is still classified at this time.

Soil and soil vapor samples from OU-3 indicated the presence of VOCs, BTEX, methane (soil vapor

only), and semi-volatile organic compounds (SVOCs) (soil only). See Figure 3-10. The calculated

carcinogenic risk level for surface soil was 1 × 10 -6, due to the presence of SVOCs. This was considered

within the acceptable range. The reported VOCs and BTEX compounds are residual from fuels used at

EAFB and from solvents used in maintenance and repair of aircraft and other vehicles.

The most commonly reported compound, in soil vapor samples, in the trench-area samples was

tetrachloroethylene (PCE) with a maximum concentration of 0.192 parts per million (ppm) near the

middle part of the western trench. Toluene and xylenes were also reported in soil vapor samples, at

concentrations up to 38.23 ppm, total reported benzene, toluene, ethylbenzene, and xylenes (BTEX)

concentrations up to 99.53 ppm, and trichloroethylene (TCE) at concentrations up to 0.297 ppm.

Methane was reported at concentrations up to 50,722 ppm, primarily in samples for which other

compounds were also reported. The lower explosive limit for methane is 50,000 ppm, with an upper

explosive limit of 150,000 ppm. The PCE and TCE identified at this OU are the residual from equipment

maintenance and de-greasing operations related to aircraft and vehicle repair and maintenance.

Toluene was reported in two soil vapor samples collected from the burn-pit area at concentrations of

0.53 ppm and 1.21 ppm, respectively. Xylene, methylene chloride, Dichloroethene (DCE), and TCE were

reported in samples at concentrations of 1.10 ppm, 0.57 ppm, 1.14 ppm, and 0.003 ppm, respectively.

TCE was also reported in a sample at a concentration of 0.014 ppm.

TCE was reported in six soil vapor samples collected from the southwest corner of OU-3 at a maximum

concentration of 0.169 ppm. One sample had a reported total DCE concentration of 0.264 ppm.

Soil samples contained acetone, acetonitrile, VOCs (total 1,2-dichloroethene was reported as high as 12.0

ug/kg), jet fuel concentrations as high as 170 mg/kg, SVOCs, and pesticides.

Ground water samples indicated the presence of chlorinated VOCs and petroleum constituents. In the

trench area, nine VOCs were reported above quantitation limits for ground water samples. Vinyl chloride

was reported in two of the samples (tl.0micrograms per liter [ug/L] and 4.2ug/L), and 1,2-

dichloroethane was reported in one sample at 17.0 ug/L. Downgradient from the fill area, VOC samples

were obtained from three monitoring wells, but because of insufficient water, no other constituents were

analyzed in one of the wells. A total of six VOCs were reported: PCE, TCE, total 1,2-dichloroethene,

benzene, ethylbenzene, and xylenes.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-3.

l WORK',ERS_84610_WPIEAFB5-YEAR REVIEW2005 DOC 18

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Fina/ Fiw'- Year Review

The risk assessment for OU-3 indicated that the current and future total carcinogenic site risk, calculated

using average exposure assumptions, is within the acceptable risk range for the residential scenario. Total

current and future carcinogenic risk calculated using the RME exposure assumptions is greater than

! × 10-4. The majority of the total carcinogenic site risk for the residential scenario is from exposure to

VOC and arsenic in the ground water. The current and future non-carcinogenic risk is due to naturally

occurring selenium in ground water. However, due to the heterogeneity of the landfill contents, great

uncertainty is associated with the calculated risk values.

Based on the OU-3 risk assessment, the calculated carcinogenic and non-carcinogenic risks for ground

water is 2 x I0 -a and 4.8, respectively. The calculated carcinogenic risk level for surface soil is I × IO 5,

due to the presence of SVOCs. This is within the acceptable risk range. Based on this calculated

acceptable risk, and the low concentrations of contaminants detected in surface soil samples, remediation

was not warranted for surface soil as part of OU-3.

Remedial action was warranted for the landfill based on the uncertainty associated with the calculated risk

values. Based on the OU-3 risk assessment, the calculated carcinogenic and non-carcinogenic risks for

ground water exceed the acceptable carcinogenic and non-carcinogenic risk ranges. However,

remediation is not warranted for ground water at OU-3. The sporadic reported concentrations and lack of

localizations of contaminants detected in ground water at OU-3 result in the risk assessment model

estimates developed for this site being highly conservative and therefore present uncertainty for

interpretation of risks for these contaminants within an OU-wide context. The data do not support the

existence of plumes of these contaminants, therefore monitoring of the ground water will provide for the

protection of the environment and human receptors as degradation of the COC (vinyl chloride) is

monitored overtime.

The potential sources for the chemical COCs at OU-3 are the landfill and trenches, which cover about

one acre. The Tier I and I1 ecological risk evaluations determined that this area was too small to present a

significant ecological risk and the site was not recommended for a Tier Ili assessment.

3.4.4 Initial Response

No CERCLA removal actions or other initial cleanup actions wcre performed at this OU.

3.5 OPERABLE UNIT 4 LANDFILL 3

3.5.1 Physical Setting

OU-4 consists of Landfill No. 3, which is approximately 35-40 acrcs in size and is located in the

southwestern corner of EAFB. The topography at OU-4 is fairly level, with a slight slope toward the

south and east, and a few broad, shallow depressions. The western portion of the OU slopes gently

toward the west. A series of east-west trending depressions are visiblc on aerial photographs, and are

assumed to be the surface reflection of historical trench and fill operations.

A shallow aquifer has been identified at depths of 10 feet to 50 feet beneath the ground surface at EAFB.

The top of the shallow aquifer at OU-4 varies seasonally, but is generally 14 ft to 32 fl below the ground

surface. This ground water is classified as having a beneficial use as a drinking water supply suitable for

human consumption (ARSD 74:54:01, Groundwater Quality Standards). The shallow aquifer may also

discharge to the surface. However, no known seeps or springs were identified at OU-4.

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3.5.2 Land and Resource Use

Field surveys were conducted at EAFB in 1993 tbr threatened and endangered species. No sensitive plant

or fauna species, classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

OU-4 is predominately grassland habitat, much of which has been disturbed by human activities, such as

past landfill operation and current maintenance. Despite the disturbance, habitat still exists that would

attract animal species that would be potential contaminant receptors. Introduced grasses dominate

existing vegetation on OU-4. Crested wheatgrass (Agropyron cristatum) covers most of the OU-4

investigative area, including the area over the former landfill. The landfill covers approximately half of

the OU, but the only remaining visual evidence of the landfill is the rough and uneven terrain resulting

from trench and fill activities. Small patches of other grasses, such as smooth brome (Bromus inermis)

and Kentucky bluegrass (Poa pratensis), are also present within the crested wheatgrass field. A number

of forb species, such as yellow sweet clover (Melilotus officinalis), skeletonweed (Lygodesmiajuncea),

purple coneflower (Echinacea angustifolia), scurfy pea (Psoralea tenuiflora), and cowboy's delight

(Spharalcea coccinea), are present as well.

Construction of the landfill cover at this OU is complete. Access to the OU is restricted to Base personnel

and contractors responsible for the maintenance of the cover and tbr the completion of long term ground

water monitoring and operation of the remedial systems. Undisturbed grass areas on the OU may be used

by local wildlife for foraging, loafing and nesting. No specific future use has been determined for

this OU.

3.5.3 History of Contamination

The landfill was primarily active between 1965 and 1976 as a trench and fill operation. Disposal trenches

were approximately 13 to 15 ft deep. A recent examination of 1946 and 1952 aerial photographs of

EAFB indicated that some landfill activity may have occurred prior to 1965. Also records indicate that

one open trench was used for disposal of construction demolition debris during the mid-1980s. Digested

wastewater treatment plant biosolids was also added to the landfill at this time. Solid waste generated

on-Base has been disposed of by contract at an off-Base sanitary landfill since 1976.

Shop wastes (liquids and paints), industrial sewer sludge and oils, and miscellaneous refuse were placed

in Landfill No. 3. During the mid-1970s, a gravel-filled waste-oil pit was operated in the southwest

comer of the OU for about one year. These wastes are thought to be the source of the VOCs and SVOCs

identified during the RI. The contents of approximately 100 55-gallon drums containing waste oil and

fuel were placed in the waste-oil pit. Prior to 1982, the southwest corner of OU-4 was also used as a

staging area for 55-gallon drums containing waste oil and fuel. The southwest corner of OU-4 was used

to stage asphalt rubble. The asphalt rubble was removed in the fall of 1993. The exact locations of the

waste pit and drum staging area are not known, but are presumably in the vicinity of the former asphalt

waste pile area. During 1982 and 1983, OU-4 was used as a disposal site for soil containing Pramitol, a

herbicide, and sodium chromate, a launch facility coolant.

Soil at OU-4 contained elevated VOCs, semi volatile organic compounds (SVOCs), and pesticides within

the EAFB boundary (Figure 3-11). Ground water contained chlorinated VOCs, SVOCs, and pesticides

(Figure 3-12). Contaminated ground water within this OU moved from the landfill, located within the

original Base boundaries, to an adjacent area within the OU, which is now owned by the Air Force. The

VOCs and SVOCs were residuals from shop wastes disposed at the OU. The pesticides residuals are the

result of normal ground keeping use on EAFB.
Ellsworth Air Force Base

Final Five- Year Review

Sixteen separate VOCs were reported in soil samples from OU-4. Toluene was the only reported VOC in

surface soil samples. Acetone, toluene, ethylbenzene, xylenes, octamethylcyclotetrasiloxane,

trichloroethene (TCE), and 1,2-total-dichloroethene were the most commonly reported VOCs m

subsurface soil samples. Four soil samples taken from locations within Landfill No. 3 contained PAH,

o-cresol and p-cresol. Benzo(a)pyrene was reported in three surface soil samples.

Twenty different pesticides and two PCBs were reported in soil samples. The highest frequency of

reported pesticides was from surface soil samples collected within Landfill No. 3. Reported pesticides are

believed to be a result of normal pesticide application practices on the surface, rather than disposal of

waste product. No specific source was identified in Base records for the PCBs.

Eight inorganic compounds were reported above background in OU-4 surface soil samples. Calcium and

magnesium were the inorganic analytes most frequently reported above background concentration.

Sixteen inorganic analytes were reported above background levels in OU-4 subsurface soil

samples. Lead, silver, and zinc were reported at 4, 250, and 18 times, respectively, above the background

range in one subsurface sample. These inorganic elements are from naturally-occurring materials

contained in the Black Hills Soil Complex and base rock materials.

Reported dioxin/furan included: 2,3,7,8-tetrachlorodibenzofuran; i,2,3,4,6,7,8-heptachlorodibenzo-pdioxin and furan; and octachlorodibenzo-p-dioxin and furan. The international toxic equivalents were

below the !,000 picograms per gram (pg/g) level of concern for residential soil.

One sediment sample was taken during the 1993 RI. This sample was taken from an off-Base ephemeral

stream channel down-gradient of OU-4. Reported analytes included acetone in the duplicate analysis

only, eight separate PAH compounds, three pesticide compounds, and inorganic compounds.

TCE and total dichloroethene (DCE) were the most frequently reported VOCs in ground water samples.

TCE, vinyl chloride, and 1,2-dichloropropane were reported in samples taken from the shallow aquifer at

or above the Maximum Contaminant Level (MCL). Sample results from OU-4 monitoring wells indicate

chlorinated hydrocarbons were reported in ground water samples from four general areas. The first area

extends from the center of Landfill No. 3 south past the Base boundary a distance of approximately 2,600

feet. The second area is in the southwestern corner of the landfill, and extends off-Base to the south and

southwest. There is some indication that these two areas may be interconnected. The third area is an

isolated occurrence in the northeast corner of the OU. A fourth area is in the vicinity of the control tower.

Nineteen different SVOCs analytes were reported in ground water samples from OU-4.

Bis(2-chloroethyl)ether and 1,4-dichlorobenzene were the most frequently reported SVOCs in ground

water samples. 1,2,4-trichlorobenzene was reported once above the MCL of 70 ug/L. Pentachlorophenol

was reported once at 1 ug/L, equal to the MCL.

Fourteen different pesticides were reported in eight ground water samples. Aldrin, alpha-BHC,

beta-BHC, heptachlor, and heptachlor epoxide were the most frequently reported pesticides in OU-4

ground water samples. The highest reported pesticide value was for prometon, which was reported once

at a concentration of 0.95 ug/k.

Seventeen inorganic compounds exceeded background ranges in ground water samples. Antimony,

cadmium, manganese, lead, nickel, and selenium were reported at values that exceeded the MCL in at

L 'WORK,ERS84610tl)°E,4k-B _ }E4R REVII.W 200_ DO( 21 September 2005

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least one sample. However, antimony, manganese, and selenium were also reported in background

samples above the MCL, and are believed to naturally occur at higher concentrations in the area.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-4.

The risk assessment for OU-4 indicated that the chemical, which contributed the majority of the risk in

the soil, was benzo(a)pyrene, a polynuclear aromatic hydrocarbon (PAH). However, only three of

five samples had reported benzo(a)pyrene concentrations in excess of the reasonable maximum exposure

(R_IVIE) 10 -6 risk range. None of the sample concentrations exceeded the central tendency/average risk

range. However, due to the heterogeneity of the landfill contents, uncertainty is associated with the

calculated risk values for the surface soil.

The following compounds were identified in the risk assessment as contributing to unacceptable current

and future risk (risk drivers) in ground water on-Base: vinyl chloride, I,I-DCE, TCE,

n-nitroso-di-n-propylamine, bis(2-chloroethyl)ether, 1,4-dichlorobenzene, aldrin, alpha-BHC, and

heptachlor. In addition, 1,2,4-trichlorobenzene, cadmium, and lead were reported above the MCL in onBase ground water samples. Total-l,2-DCE was reported above the MCL for cis-l,2-DCE in on-Base

ground water samples.

Vinyl chloride, I,I-DCE, TCE, 1,2-DCA, and alpha-BHC were identified as current and future risk

drivers in off-Base ground water. In addition, lead and total-l,2-DCE were reported above the MCL in

off-Base ground water samples.

Remediation of the ground water was warranted based on the risk to human health from ingesting and

contacting contaminated ground water. Remedial action also was warranted for the landfill based on

potential risk to human health from future releases of hazardous substances. If not remediated,

contaminants in the landfill could leach downward to contaminate the underlying ground water. Off-Base

residents could then ingest or come in contact with the contaminated ground water. Due to the potential

heterogeneity of the waste materials present within the landfills, a complete characterization of waste

materials present was not possible during the RI. This adds a degree of uncertainty to the risk assessment

for the landfill contents. Rather than attempting to fully characterize landfill contents and gain more

certainty in the risk assessment, the Air Force utilized guidance developed by EPA titled

Presumptive Remedy for CERCLA Municipal Landfill Sites (OSWER Directive 9355.0-49FS). The

presumptive remedy for landfills is containment (capping) of landfill contents. Using the presumptive

remedy strategy, a quantitative risk assessment is not necessary to evaluate whether the containment

remedy addresses all exposure pathways and contaminants potentially associated with a landfill. Rather,

all potential exposure pathways can be identified using the conceptual site model and compared to the

pathways addressed by the presumptive remedy. Containment of the landfill contents addresses exposure

pathways and risks normally associated with landfills. The contaminant exposure pathways for the

potential risks associated with the landfill contents at OU-4 include (1) direct physical contact with the

landfill contents, and (2) consumption or contact with ground water that may become contaminated.

In terms of ecological value OU-4 represents area that has been highly disturbed. The area has overgrown

with a wide variety of grasses and herbaceous plants. The Tier I and II ecological risk assessment

identified a number of invertebrates, small mammals, birds, larger mammals, and reptiles that may forage,

live, or nest in the area. Terrestrial vegetation and soil faunal communities did not reveal patterns

indicating chemical-related impacts. Therefore, a Tier III investigation was not considered warranted.

L:IWORK!ERS_84610!WP_EAFB5-lr'EARRE|TEW 2005 DOC 22

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Final t'7_v- Year Review

3.5.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.6 OPERABLE UNIT 5 LANDFILL 4

3.6.1 Physical Setting

OU-5 consists of Landfill 4 and approximately 50 adjacent acres near the northern perimeter of EAFB.

Landfill No. 4 is approximately a 10-acre area located at the northern end of Scott Drive.

Topographically, the southern portion of the landfill slopes slightly to the north (Figure 3-13). The

northern portion of Landfill No. 4 slopes steeply to the north-northeast and the western portion of the OU

slopes toward the west. Several incised valleys exist to the north and west of Landfill No. 4. These

valleys carry storm water runoff off-Base, north and northwest of OU-5 into several unnamed ephemeral

tributaries of Elk Creek. Two ephemeral ponds along an erosional gully were identified during the field

survey. The "ponded" areas are within the natural drainage way where the water source is surface runoff.

The erosional gully originates on the steep face of Landfill No. 4. It collects surface runoff from the

surrounding hilly terrain and carries it to the north, off the OU and the Base. Southwest of the landfill,

the topography is fairly level with a slight rise associated with a Base perimeter service road.

Landfill No. 4 had exposed fill areas throughout most of the former disposal areas.

3.6.2 Land and Resource Use

Crested wheatgrass fields and mixed grass prairie dominated the habitat on OU-5 during the RI. OU-5

differs from the majority of the operable units in that none of the site is developed. There are no

buildings, parking areas, or paved roads within the OU. Because of the lack of development, over half the

OU contained grassland that was attractive to animal species that would be potential receptors.

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

The only wetlands identified on OU-5 are part of an isolated drainage system associated with the

erosional gully. They consist of two small ephemeral ponds located in depressions along the erosional

gully. The ponds are highly degraded and are unlikely to provide any wildlife habitat. Both ponds were

heavily used by cattle; compacted soils and trampled vegetation were common around the ponds. In

addition, both ponds were scattered with debris from the landfill, such as tires, rubble, and scrap metal.

Remedial construction activities at this OU have been completed. Accessed to the site is restricted to

Base personnel and contractors responsible for the maintenance of the landfill cover and long term

monitoring of ground water. Undisturbed grass areas on the OU may be used by local wildlife for

foraging, loafing and nesting. No specific future use has been determined for this OU.

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3.6.3 History of Contamination

Waste was disposed of at OU-5 from the 1940s through 1990. This landfill was used primarily for the

disposal of construction demolition and hardfill materials; however, reports and visual observations from

Installation Restoration Program (IRP) studies noted that this site was also used for general refuse and

drum disposal. The Base Commander terminated waste disposal activities at this landfill after 1990.

Polynuclear aromatic hydrocarbons (PAHs) at estimated values below the sample quantitation limit

(48 ug/kg to 250 ug/kg) and JP-4 jet fuel, in one surface soil sample (SB930502) at 190 mg/kg, were

reported in soil samples collected from OU-5 (Figure 3-14). Jet fuel was also reported at a concentration

of 100ug/L in one ground water sample collected during the investigation (Figure 3-15). The

PAH compounds are attributed to the incomplete combustion of jet and motor vehicle fuels.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-5.

Part of the site risk present at OU-5 includes risk from exposure to surface soil contaminants from within

the landfll. In addition, due to the heterogeneity of the landfill contents, there is some uncertainty

associated with the calculated risk values for the surface soil. The risk assessment for OU-5 indicated that

the carcinogenic current and future risk was within the acceptable risk range of 1 × 10.4 to 1 × 10 -6, and

there were no non-carcinogenic risks resulting in an HI above 1.0.

Results of the risk assessment indicated shallow ground water and surface water were not media of

current concern. Therefore, remedial action is not warranted for the ground water and surface water at

this time. The ground water at OU-5 will still he retained as part of the Base-wide ground water

evaluation for OU- 11.

Remedial action is warranted for the landfill based on the potential risk to human health from future

releases of unidentified hazardous substances in the landfill. Contaminants in the landfill may leach

downward to contaminate the underlying ground water. Off-Base residents may then ingest or come in

contact with the contaminated ground water. Also, the surface of the landfills may erode, thus exposing

off-Base residents to contaminants in both surface water and air. Due to the potential heterogeneity of the

waste materials present within the landfill, uncertainty is associated with the calculated risk values for

surface soil.

The ecological evaluation of OU-5 was based on a combination of data and literature reviews, field and

laboratory analyses, analyte evaluation and screening, and preliminary risk screening.

A variety of potential receptors were identified that could nest and/or forage in OU-5 habitats. These

range from the soil fauna identified with pitfall traps to aquatic invertebrates in the ephemeral ponds to

birds and mammals. Those species preferring grassland and tolerant of disturbed, weedy areas would be

expected to be more common. Rare, threatened, or endangered species are unlikely to utilize OU-5 for

more than very transitory habitat.

Terrestrial vegetation and soil fauna communities at OU-5 were statistically different from those at an

off-Base reference area. While not confirming effects of elevated chemicals (differences may in fact have

L _WORKIERS!846101WP_EAFB5-YEAR REVIE V 2005.DOC 24 ao57 oa'
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Final l"zve- Ycar Review

been due to differences in physical disturbance), thc differences were sufficient to conduct a Ticr II

evaluation (based on terrestrial vegetation) and then a preliminary risk screen (based on soil fauna data).

The preliminary risk screen identified the tbllowing analytes as chemicals of concern at OU-5: silver,

endrin, heptachlor epoxide, arsenic, beryllium, and mercury. The metals are considered naturally

occurring elements in the Black Hill Area soil complex; the pesticides are thought to be residuals from

on-Base pest control practices.

The landfill that is a potential source of the COCs at OU-5 covers an area of about ten acres. This is

considered too small to present significant ecological risk, and an OU-specific Tier III assessment was not

completed. However, the identified COCs were carried over ['or evaluation in a Basewide ecological risk

assessment.

3.6.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.7. OPERABLE UNIT 6 LANDFILL 5

3.7.1 Physical Setting

OU-6 consists of Landfill No. 5, which is approximately seven acres in size and is located in the

southeastern comer of EAFB. The topography of OU-6 is characterized by an cast-west drainageway and

a north-south stream. The east-west drainageway is located m the southern portion of OU-6, and drains

surface water off OU-6 to the southeast. It also includes a storm sewer discharge. The stream along the

eastern boundary of OU-6 drains surface water off site to the south. This drainage is fed by

Gateway Lake, located approximately 1,000 ft up-gradient of OU-6, and by discharge from the

Base WWTP. This drainage collects approximately two-thirds of tile storm water runoff from the Base.

One of the more important wildlife habitat features on OU-6 is the wetlands vegetation associated with

these drainages.

3.7.2 Land and Resource Use

Two distinct types and areas of fill material were tbund at OU-6. The first type of fill material was clean

fill used on the eastern portion of the OU, probably during construction of the golf course, and consists of

re-worked soil and organic material. The organic material was described in the field as black organic

humus type material resembling WWTP sludge material and plastic, and may have been used as a soil

amendment when the golf course was built. The second type of fill material is landfill material, which

consists of construction debris and demolition debris. Construction and/or demolition debris consists of

broken concrete, broken brick, asphalt, and wood.

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered m South Dakota were observed on EAFB.

Remedial actions at this OU have been completed. Access to the area is restricted to Base personnel and

contractors responsible for the maintenance of the landfill cover and for long term monitoring activities.

Undisturbed grass areas on the OU may be used by local wildlife for foraging, loafing and nesting. No

specific future use has been determined for this OU.

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3.7.3 History of Contamination

The landfill at OU-6 (Landfill No. 5) was active from 1960 to 1980 and primarily used to dispose of

construction and demolition debris. Hardfill (i.e., concrete, asphalt) was placed along the rail line to

stabilize erosion. In addition, reports state digested sewage sludge, miscellaneous refuse, and possibly

shop wastes may have been disposed of at this landfill (USAF, 1985). However, no direct physical

evidence of miscellaneous refuse or industrial/shop waste has been found at OU-6.

Polynuclear aromatic hydrocarbons and pesticides were reported in soil samples collected from OU-6

(Figure 3-16). Levels of VOCs and metals contaminants observed in the ground water at the site were

below Maximum Contaminant Levels (MCLs) or considered to be representative of background levels

(Figure 3-17). PAHs are the residuals of incomplete motor and jet fuel combustion. The pesticides are

residual from normal grounds keeping use on Base.

Acetone, pentane, styrene, benzene, toluene, xylene, naphthalene, bis (2-ethylhexyl) phthalate, and

heptachlor epoxide were reported in at least one sample collected from surface water locations during the

RI investigation.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-6.

The human health risk assessment evaluated potential effects on human health posed by exposure to

sources and/or releases associated with Landfill No. 5. The assessment considered the possibility of

multi-media sources including ground water, soil, surface water, sediment, and air. Results of the

baseline risk assessment indicated shallow ground water and surface water were not media of concern.

Identified risk driver chemicals of concern for OU-6 included: PAH in surface soil, manganese in soil,

and arsenic in sediment. The calculated current and future carcinogenic risks for OU-6 were within

EPA's acceptable range of 10-4to 10 -6.

A variety of potential receptors that may live, forage or nest in OU-6 habitats was identified. These range

from benthic invertebrates and amphibians in the drainage channels to birds and mammals. Terrestrial

vegetation and fauna communities did not show patterns indicating elevated chemical exposure-related

impacts. This finding was considered consistent with the relatively low levels and limited distribution of

elevated chemical concentrations in soil, and the active and disturbed nature of the site observed during

the RI. Tier III investigations were not completed at this site but the COCs were carried over to the

Basewide Tier llI assessment.

OU-6 is bounded on the east and south sides by surface water drainage channels. These channels contain

areas of wetlands. Remedial construction activities at the OU resulted in some reworking of soil and

drainage channel relocation in the wetland areas. Replacement wetlands were constructed near other

Base lakes located near the center of EAFB.

3.7.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

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3.8 OPERABLE UNIT 7 WEAPONS STORAGE AREA

3.8.1 Physical Setting

The Weapons Storage Area, now known as the Munitions Storage Area, covers approximately 65 acres at

the northwest corner of EAFB. The topography at OU-7 gently slopes toward the west and southwest

away from the high plateau located in the northeastern corner of the WSA. Surface-water drainage from

OU-7 generally flows into drainages directed to Box Elder Creek. Some surface water flows oft-Base to

the east, northeast, and southeast of the OU.

OU-7 surface geology generally consists of a surface layer of silty clay, approximately 3 to 6 feet thick,

underlain by a layer of silty sandy gravel to clayey gravel, 4 to 27 feet thick. These layers overlie the

Pierre Shale Formation. Depth to shallow ground water at OU-7 ranges from approximately 10 to 31 feet.

The shallow aquifer at EAFB is considered a potential drinking water source and possibly discharges to

the surface. The ground water is classified as having a beneficial use as a drinking water supply suitable

for human consumption (ARSD 74:54:01, Groundwater Quality Standards).

3.8.2 Land and Resource Use

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

Remedial actions implemented at the OU consisted of the application of institutional controls and ground

water monitoring. A removal action was completed to remove low level radiological waste materials

buried at this OU. The material was removed and disposed of according to current EPA and

Nuclear Regulatory Commission requirements.

3.8.3 History of Contamination

OU-7 includes the Low-Level Radioactive Waste Burial (LLRWB) site located in the Munitions Storage

Area (MSA) at the northern end of the Base. The MSA is currently active. The complex included two

storage buildings with vaults, a maintenance building, three other assembly/maintenance buildings,

several storage igloos, two waste burial pit areas, five wastewater underground storage tanks (USTs), and

16 heating fuel USTs (Figure 3-18). The wastewater USTs were used to store water from the wash-down

and cleaning of nuclear weapons that drained through the floor drains into the USTs.

Radioactive wastes were generated at EAFB between 1952 and 1962. The five wastewater USTs and

16 heating fuel USTs were removed in 1993 as part of a Base tank removal program. Although historical

records indicate that there were two waste burial pits, the exact locations are not known. No available

information has indicated that any ordnance or explosive radioactive wastes were disposed of at OU-7.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants

from OU-7.

Scattered detections of VOCs were reported in surface soil samples at OU-7; concentrations were below

10 -6 risk based concentrations for Human Health Risks. Radionuclides were determined to be present

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within the normal background range due to natural variations in soil types and geological characteristics.

The residual VOCs at the OU were attributed to the use of these chemicals in the maintenance of weapon

system components and equipment.

Some surface soil samples had concentrations of gross alpha and gross beta radioactivity exceeding the

soil background range. However, the risks associated with ingestion and inhalation of, and dermal

contact with, these contaminants by potential future residents and construction workers are very small and

within the acceptable range (1 x 10.4 to 1 x 10-6 or less). Risks associated with construction worker

exposure to gross alpha and gross beta and several inorganic analytes (especially manganese) in UST pit

soils are also minimal and within the acceptable range. Although VOCs, inorganics, and radionuclides

were detected in sediment, the risks to potential future residents and construction workers from ingestion,

inhalation, and/or dermal contact are within the acceptable range. There are no unacceptable risks to

potential future residents and construction workers from ingestion and inhalation of, or dermal contact

with, contaminants in surface water or ground water. Based on the minimal risks associated with

contaminants in soils and ground water at the site, limited institutional controls for these media are

warranted.

Results of the Tier I and II ecological risk assessment indicated that OU-7 does not exhibit significant

ecological value due to its highly disturbed environment (OU-7 primarily consists of buildings, roads, and

paved areas). There are small areas of potential grassland and wetland habitats at the OU. Several animal

species may live, forage, or nest in OU-7 habitats. These species include various types of invertebrates,

amphibians, birds, and mammals. Terrestrial vegetation and soil faunal communities do not reveal

characteristics that indicate chemical-related impacts.

3.8.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.9 OPERABLE UNIT 8 EXPLOSIVE ORDNANCE DISPOSAL AREA

3.9.1 Physical Setting

OU-8 is the current designation for the area surrounding and including the explosive ordnance disposal

(EOD) Area. OU-8 was divided into two distinct areas of investigation. Area 1 is the actual EOD Area.

Area 2 consists of the Debris Burial Area where waste from the EOD Area was buried. Sediments in

drainages within and adjacent to the EOD Area are also included in OU-8, which is located in the extreme

northeast comer of EAFB.

The EOD Area was approximately 600 ft by 1,350 ft and located in sloped rugged terrain. Service roads

parallel the two north-south trending ridges located along the eastern and western edges of this site. The

area within the confines of these service roads is where explosive ordnance demolition was formerly

conducted. In addition, it is reported that an herbicide spill occurred in May 1982. Terrain in this area

slopes predominantly toward the north. An unnamed ephemeral drainageway exists along the east and

west edges and in the central portion of this area. This drainageway conducts surface flow off the site in a

northerly direction.

The Debris Burial Area was approximately 300 ft by 150 ft and located on a ridge south of the EOD Area,

in a less rugged area. Spent shell casings (from small arms) were visible at the surface in this area. The

terrain surrounding the ordnance burial area slopes gently toward the east.

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The wetlands on OU-8 consist of ditch wetlands along portions of the two drainages, and three small

impoundments created by the construction of the earth berms. The wetlands along the westernmost

drainage begin north of the first berm; a narrow ditch wetland, approximately 2 feet wide, widens into a

cattail slough created by the construction of the second earth berm. The vegetation in the ditch is visibly

different from the surrounding vegetation and is dominated by hydrophytic species such as saltgrass

(D&tichlis spicata), foxtail barley, and curly dock (Rumex crispus). Vegetation in the slough is also

dominated by hydrophytic species such as cattail (Typha sp.), saltgrass, foxtail barley and curly dock.

Farther north, just south of the third berm, is a second slough.

3.9.2 Land and Resource Use

The habitat on OU-8 is dominated by mixed grass prairie. OU-8 is not developed; there are no buildings,

parking areas, or paved roads within the OU. Base activities, such as the detonation of active explosives

and the burial of debris created by explosives detonation, had visibly altered only a small portion of the

OU-8 habitat. The most disturbed area on OU-8 is the EOD Area, which collectively refers to a burn pit

area, bum furnace area, and a detonation area. The majority of the EOD Area is characterized by native

black surface soil and very little vegetation.

Field surveys were conducted at EAFB in 1993 for threatened and endangcred species. No sensitive plant

species or fauna species classified as rare, threatened, or endangered in South Dakota were observed on

EAFB.

This OU has had the selected remedy completed. Access is restricted to Base personnel and contractors

responsible for the operation of the remedial systems. Undisturbed grass areas on the OU may be used by

local wildlife for foraging, loafing and nesting. No specific future use has been determined for this OU.

3.9.3 History of Contamination

The three processes were used to destroy munitions at EAFB: (1) open detonation; (2) open burning; or

(3) detonation within a burn furnace. In open detonation, an explosive charge was used as a donor chargc

to detonate a particular explosive ordnance item at ground surface or in a shallow pit. In open burning,

munitions were placed on top of a combustible material (such as wood) within a 4 ft. deep burn pit.

Approximately 20 to 40 gallons of diesel fuel was poured on the munitions and combustible material in

order to promote combustion. A burn furnace was considered the safer and more expeditious method of

burning such items as small arms ammunition, delay elements, or primer detonators. The burn furnace

consists of a diesel-fired furnace mounted on a concrete structure. Munitions were led into the furnace

through a feed chute. A smokestack and vent allow smoke and vapors to leave the furnace. If munitions

were treated in the burn furnace, personnel would start a diesel fuel fire in the combustion chamber of the

furnace. When operating temperature was reached, personnel slowly fed munitions into the feed chute.

All burn furnace, burn pit, and detonation site residue has been transferred to the debris burial area just

south of the explosive ordnance disposal area. Off-spec munitions are currently shipped off-Base as

hazardous waste.

Product charactcristics from the treatment processes, i.e., open burning, and open detonation, are also an

environmental concern. Literature research indicated that the bulk of open burning and open detonation

treatment residuals are evolved in gaseous or airborne particulate form. The gaseous components include

CO, NO_, N2, SO2, and CO2. Particulates may include MgO, H20, and HCL. In addition, trace quantities

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of primer compounds could result in the evolution of PbO. Solid residuals remaining after treatment are

primarily metal casings, soot and a residual ash.

Approximately 100 gallons of prometon (Pramitol 25E) was reportedly released at the EOD area in

May 1982. In June 1982, approximately 200 cubic yards of prometon-impacted soil was excavated from

this site and transported to Landfill No. 3 (OU-4). Earthen dams were constructed of native soil in 1983

in order to prevent off-Base movement of residual prometon. Approximately one year later, Base

personnel visually observed what they considered to be prometon leaching from OU-8 into ephemeral,

surface-water drainageways (USAF, 1989). Sampling was not performed to verify the existence of

pramitol leachate. During a site inspection in May 1992 it was observed that the earthen dams had been

breached and were no longer impounding surface water flow. These dams were rebuilt as part of the

remedial actions at OU-8.

Volatile organic chemicals and SVOCs were detected in ground water during the remedial investigation

(RI). The reported concentrations of these contaminants were less than or equal to 2 ug/L. Antimony and

selenium were reported above the MCL in one or more ground water samples (Figure 3-19). Toluene was

the only VOC detected in soil samples collected in the EOD area during the RI. PAHs and phthalates

were also detected in the soil. PAHs typically result from incomplete combustion of organic materials.

Dioxins in the soil correlated with combustion activities in the EOD area. Dioxin concentrations were

well below action levels of 1,000 picograms/kg (gg/kg) for residential soils (Figure 3-20). The risk

assessment for OU-8 indicated that there are no unacceptable non-carcinogenic or carcinogenic risks at

the OU under current land use conditions resulting from activities conducted at OU-8.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-8.

The risk assessment for OU-8 indicated that there are no unacceptable non-carcinogenic or carcinogenic

risks at the OU under current land use conditions resulting from activities conducted at OU-8. Dioxins in

surface soil were the only chemicals identified in the RI present at concentrations greater than 10 -6. Risk

associated with the dioxins in the surface soil is in the 10-5 range. Non-carcinogenic and carcinogenic

risks were also identified for the OU from naturally-occurring inorganic chemicals in the soil and ground

water; however, risks from naturally-occurring chemicals are not considered for remediation.

Chemicals detected in the ground water that contributed to excess risk are considered to be naturally

occurring. Therefore, remedial action is not warranted for the ground water at this time. The ground

water at OU-8 is included as part of the Base-wide ground water evaluation for OU-I 1.

An ecological risk evaluation of OU-8 was based on a combination of data and literature reviews, field

and laboratory analyses, analyte evaluation and screening, and preliminary risk screening. Due to the low

levels of contaminant concentrations, the contaminants do not pose an unacceptable risk to these species.

In addition, the limited contact these species would have with the OU-8 area ensures unacceptable risk to

a single individual will not occur.

3.9.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

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3.10 OPERABLE UN|T 9

3.10.1 Physical Setting

The OU-9 study area consists of the Old Auto Hobby Shop and the surrounding area. OU-9 is

approximately 90 acres in size and is located in the south-central section of the base, southwest of

Heritage Lake. Surface topography is relatively fiat in the western portion of the study area, sloping

gently to the east at a gradient of approximately one percent. In the vicinity of the unnamed ephemeral

stream, which is present along the east boundary of OU-9, topography is much steeper, sloping 5-20

degrees inward towards the stream on either side. Runoff in the OU-9 study area flows along drainage

ditches and underground storm sewer lines, eastward to the ephemeral stream and then south to Gateway

Lake. The stream and Gateway Lake are part of a drainage system that collects storm water runoff from

the center of the Base and directs it southward through a series of retention lakes (Bandit Lake, Heritage

Lake, Gateway Lake) and interconnecting ephemeral streams (Figure 3-2).

3.10.2 Land and Resource Use

OU-9 is located in the south-central portion of EAFB in one of the older and more developed sections of

the Base. Buildings and surface streets along the western part of the study area and asphalt lots and

undeveloped grassy areas along the eastern and northeastern portion of the site generally characterize the

area. Vegetation in the developed parts of the site is primarily limited to grassy areas alongside roads and

buildings. The operable unit has traditionally been associated with the Old Auto Hobby Shop, located in

the center of the study area on the southeast corner of Ryan Street and George Drive. The Auto Hobby

Shop was razed in 1985. Another razed building in the area was the former location of a jet engine test

stand located approximately 150 fl northwest of the Auto Hobby Shop. Buildings and surface structures

surrounding the Auto Ilobby Shop include Building 601 (jet engine repair) to the west, Building 605

(former hangar) to the southwest, Building 805 (warehouse storage) to the south, the present jet enginc

test facility to the east, and a one million-gallon water storage tank to the north.

Field surveys were conductcd at EAFB in 1993 tbr threatened and endangered species. No sensitive plant

or fauna species classified as rare, threatened, or endangered in South Dakota were observed on EAFB.

The U.S. Fish and Wildlife Service National Wetland Inventory Map (NWI) that includes Ellsworth

Air Force Base classifies the wetland community type present on OU-9 as Palustrine Emergent

Seasonally Flooded (PEMC). Gatcway Lake and a portion of the drainage just south of OU-9 are

classified as Palustrine Aquatic Bed Semipcrmanently Flooded (PABF). Aquatic Bed wetlands are

dominated by plants growing primarily on or below the surface of the water in most years. Two wetland

areas arc located on OU-9. The first is a drainage that enters the OU via a culvert under George Drive in

the northeast portion of the investigative area. The drainage flows to the southeast through the eastern

portion of the OU and eventually passes through a culvert under Ellsworth Drive, to exit OU-9. The

second wetland present on OU-9 is a small kidney-shaped depression wetland located south of where the

drainage passes under Ellsworth Drive. Two wetlands located off OU-9, a drainageway just south of the

OU investigative area, and a fringe wetland around Gateway Lake are also characterized with OU-9

because they are adjacent to the OU and receive runoff from it.

This OU is currently undergoing remediation under the OU-I 1 remedial action, and remains a functional

portion of the Base. Access is available to Base personnel working at the various shops or buildings in

thc OU, and to Base personnel and contractors responsible for the operation of the remedial systems.

Limited undisturbed grass areas on the OU are available to local wildlife for foraging, loafing, and

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nesting. No specific use changes have been directed for this area as a result of the selected remedial

actions.

3.10.3 History of Contamination

A number of different contaminant sources are present within and upgradient of the OU-9 study area

which have the potential to impact environmental media at the operable unit. OU-9 consists of roughly

equal portions of industrialized and undeveloped areas. Gateway Lake is also included as part of OU-9

and is located in the extreme southeast corner of the OU.

The types of potential contaminant source areas at OU-9 include: Building Operations, underground

storage tanks (USTs), the former Quartermaster Gasoline Dispensing Area, the former fuel transfer line,

industrial waste lines, jet engine test facilities, and upgradient source areas. There is no known

documentation of major spills or releases at OU-9. Srnail volumes of fuels, oils, and solvents may have

been released to the environment over time through incidental spills, leaks, and/or poor waste handling and disposal practices.

Low concentrations of VOCs, primarily BTEX, were found in soils (Figure 3-21). BTEX and chlorinated

VOCs were detected in ground water (Figure 3-22). Because an upgradient source was suspected, ground

water cleanup was addressed in OU- 11 (the Basewide ground water Operable Unit).

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-9.

The risk assessment for OU-9 indicated that the risk for the future industrial land-use scenario, which is

similar to the current land-use, is within the acceptable risk range. For non-carcinogenic risk, the HI was

0.4, which is acceptable. For carcinogenic risk, the calculated risk value was 5 × 10-8,which indicates

that there is no unacceptable current or future risk due to carcinogenic compounds. Using reasonable

maximum exposure (RME) values, the risk for the residential land use scenario is within the acceptable

risk range. The risk for this scenario using average exposure values is also well within the acceptable risk

range. The future industrial land-use and residential land-use risks do not warrant remediation,

particularly given the most likely future land use will be industrial, and the soils are being remediated

under State of South Dakota petroleum release regulations.

Potential risks posed by exposure to shallow ground water and ingestion of fish in Gateway Lake are

being addressed as part of OU-II and are not being addressed as part of OU-9. Because of these

conclusions, remediation is not warranted for surface water, sediment, and soil at OU-9.

The ecological risk evaluation of OU-9 was based on a combination of data and literature reviews, field

and laboratory analyses, analyte evaluation and screening, and preliminary risk screening. Results of the

evaluation indicate that most of OU-9, other than Gateway Lake, does not present significant ecological

value due to its highly disturbed environment (OU-9 consists primarily of buildings, roads, and paved

areas). There is a small area of grassland and wetland habitat (including Gateway Lake) near the eastern

boundary of OU-9. A variety of species was identified that could use OU-9 habitats, from snails and

frogs inhabiting the wetland areas to birds and mammals. These species, along with terrestrial vegetation

and soil faunal communities, do not reveal characteristics that indicate chemical-related impacts.

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Final _Tve-Year Re_'iew

3.10.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU

3.11 OPERABLE UNIT 10 NORTH HANGER COMPLEX

3.11.1 Physical Setting

OU-10 is the North Hangar Complex, a 75-acre site located in the central portion of the Base, northeast of

the primary instrument runway. The land surface is relatively flat at the North Hangar Complex and

slopes gently toward the southeast at a gradient of approximately 1 percent. The gradient in the

surrounding area slopes to the south. The majority of OU-10 is paved, although grassy areas are present

southwest and northeast of the site and between the hangar rows.

No surface water bodies are present at OU-10. Storm water runoff within the hangar area is collected in

underground storm-water drains. Storm-water lines at Rows 60 and 70 drain to the south beneath the

runway, eventually emptying into an unlined drainageway that runs through the center of OU-12. This

drainageway ultimately drains to an oil/water separator at Pond 001 adjacent to OU-I. Storm-water lines

at Rows 80 and 90 drain to the west, beneath the runway and ultimately to an oil/water separation pond

adjacent to the west property boundary.

3.11.2 Land and Resource Use

There are no permanent surface waters or wetlands on OU-10. There is virtually no natural habitat on the

OU to support breeding, foraging, or sheltering of wildli[?. The vegetation on OU-10 was not compared

statistically to a reference area, but based on simple observation, the small grass median strips on OU-10

are entirely different from any reference area evaluated because they are mowed and managed.

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

species nor thuna species classified as rare, threatened, or endangered in South Dakota were observed on

EAFB.

3.11.3 History of Contamination

The North Hangar Complex was constructed in the 1950s and is composed of five rows of aircraft repair

and maintenance hangars. Most of OU-10 is paved with concrete with some grassy areas between the

hanger rows. No surface water is present at OU-10. The area contains a system of underground jet-fuel

hydrant lines that deliver fuel to docking aircraft. The primary source of contamination at OU-10 is the

fuel distribution system. Additional contaminant source areas include the aircraft maintenance areas and

underground industrial waste lines. It was reported that waste products used for aircraft maintenance may

have been washed down floor drains in the maintenance buildings. The remedial investigation focused on

determining if these waste products were then discharged into the soil beneath the maintenance area and

to determine if contaminants had leaked from the underground industrial waste lines.

OU-10 contains a system of underground jet-fuel hydrant lines that deliver fuel to docking aircraft and

underground industrial waste lines associated with aircraft maintenance. Organics reported in soil

samples included VOCs, SVOCs and jet fuel (Figure 3-23). The predominant VOCs were BTEX

compounds. Ground water contamination associated with OU-10 was addressed within OU-11 (the

Basewide ground water Operable Unit) for remediation (Figure 3-24).

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A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-10.

The risk assessment for OU-l0 indicated that the risk for the future industrial land-use, which is similar to

its current use, is within the acceptable risk range. For non-carcinogenic risk, the HI was 0.006, which is

acceptable. For carcinogenic risk, the calculated risk value was 2 × 10 -6, which indicates the risk is within

the acceptable risk range. Potential risks posed by exposure to shallow ground water are being addressed

as part of OU-I1 and are not being addressed as part of OU-10. Because of these conclusions,

remediation is not warranted under CERCLA for soil at OU-10.

An ecologicaI risk evaluation of OU-10 was based on a combination of data and literature reviews, field

and laboratory analyses, analyte evaluation and screening, and preliminary risk screening. Various types

of invertebrates, amphibians, birds, and mammals may live, forage, or nest in OU-10 habitats. These

species, along with terrestrial vegetation and soil faunal communities, do not reveal characteristics that

indicate chemical-related impacts. This finding is consistent with the relatively low levels of contaminants

in the soil.

Because of the altered natural environment at OU-10, rare, threatened, or endangered species are unlikely

to utilize the area for more than brief, periodic habitat. Due to the low levels of contaminant

concentrations, the contaminants do not pose an unacceptable risk to these species. In addition, the

limited contact these species would have with the OU-10 area ensures unacceptable risk to a single

individual will not occur.

Findings of the RI indicate that the contaminants at OU-IO are not altering the ecology to noticeable

levels. A Base-wide ecological risk assessment will be conducted as part of OU-11, and OU-IO will be

included in this Base-wide evaluation.

3.11.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.12 OPERABLE UNIT 11 BASEWIDE GROUND WATER

3.12.1 Physical Setting

OU-II is the Basewide Ground Water Operable Unit. The physical characteristics of this OU are

consistent with those described for the Base as a whole in the introduction to Section 3.1 above, and as

described in specific OU sections. Investigations completed at OU-11 were designed to fill in data gaps

at specific locations across the Base that had been included in specific OU investigations. The OU-I 1

areas of investigation are shown on Figure 3-25, and are defined as:

• A Basewide ground water study.

• A Basewide ecological evaluation.

• The area surrounding well MW93BG04 (This included AOC-24).

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* The area surrounding well MW93BG05 (This included AOC-24).

• Up-gradient of OU-6, near MW930602.

• The South Docks Area.

• The northern edge of OU-12.

• Additional investigations at OU-7.

• The Pond 003 Area.

3.12.2 Land and Resource Use

Land uses in this OU range from open grassed areas to industrial areas covered with roads, buildings, and

pavement. Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No

sensitive plant or animal species classified as rare, threatened, or endangered in South Dakota were

observed on EAFB.

3.12.3 History of Contamination

Based on the risk assessment and an evaluation of the data collected as part of the Basewide

Ground Water Study and the studied of the additional areas listed above, it was determined during the

RI process that three areas warranted remediation as follows: the area surrounding well BGO4, the area

surrounding well BGO5, and the South Docks Area. In addition, long-term monitoring was

recommended for ground water at OU-8. The other areas investigated (upgradient OU-6, northern edge

of OU-12, OU-7 [additional investigation], and the Pond 003 area) did not warrant remediation and were

not included or discussed in the OU- 11 ROD.

To facilitate project planning, OU-II was divided into two parts, Area l and Area 2. Area 1 is the

South Docks Study Area. This includes the South Docks and areas of ground water contamination in

OU-9 that were deferred to OU-I 1. Ground water contamination at OU-10 was also deferred to OU-I 1

for remediation; however, ground water contamination at OU-10 is the result of petroleum product

releases and is being addressed through the State of South Dakota petroleum release regulations.

Contaminated ground water in Area 1 lies entirely on-Base. Remedial alternatives developed for this area

are referred to collectively as the "South Docks" alternatives since the South Docks is the primary area of

contamination in Area I. Area 2 is the area around BG04 and BGO5, which includes areas where ground

water contamination was found to leave the Base along the eastern boundary.

Area 1

The South Docks is located in the central part of the Base between OU-9, OU-10, and the flightline.

Major buildings in the area include the Pride Hangar and hangars in Rows 20, 30, 40, and 50, Figure 3-2.

Historical aerial photographs indicate that the Pride Hangar and the hangars in the South Docks Area have

been in place since the late 1940s to early 1950s. Historically, the hangars have been used for the

docking and maintenance of aircraft. The Pride Hangar was most recently used for storage, maintenance

of missile-support equipment, for offices, and meeting rooms, in 1992, several underground storage tanks

(USTs) were removed from the Pride Hangar. Hangars in the South Docks are now used for storage and

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maintenance of various support equipment, including aircraft refueling vehicles, fire-fighting vehicles,

grounds-keeping equipment, and periodic parking of aircraft.

Other potential sources in the area include industrial waste lines, equipment wash racks, and historical

chemical handling disposal practices. However, no specific incidents of hazardous material spills have

been documented.

Contaminated ground water in Area 1 is located entirely on-Base, Figure 3-26 to 3-30.

Area 2

The BG04 Study Area is located in an open grass area at the northeast edge of EAFB, approximately

1,500 ft south of the explosive ordnance disposal (EOD) debris burial area perimeter (OU-8). A firing

range is located approximately 1,200 ft to the northwest and a housing tract is located approximately

800 ft to the east of monitoring well MW93BG04. Area 2 includes the areas where ground water

contamination has moved off-Base along the eastern boundary. Off-site contamination associated with

these areas has also been referred to as Area Of Concern 24 (AOC-24). The contaminant of concern

associated with Area 2 is TCE and its associated breakdown products. The contaminant plume has been

defined and currently extends approximately 5 miles to the east-southeast of the Base boundary.

Twenty-five private water supply wells in the plume area have shown TCE levels in excess of the

5 ug/L MCL. The Base has installed a water line to properties within the plume area to provide an

alternate water supply until the TCE plume is remediated. See Figure 3-30.

The BG-05 Study Area is located in a housing area in the east-central portion of EAFB, approximately

300 ft east of LeMay Boulevard and continues off-Base to the east. There are no known sources in the

immediate vicinity of well BG05.

Ground Water at OU-8

Ground water at OU-8 was evaluated as part of the OU-I 1 remedial investigations. Detailed descriptions

of the OU-8 area are described earlier in this document. It was determined that remediation of ground

water at OU-8 was not warranted; therefore a detailed analysis of alternatives was not completed for

ground water media at this OU. However, to comply with State landfill closure requirements, compliance

monitoring was implemented to verify that chemical concentrations in the ground water do not pose

unacceptable risk.

Volatile organic compounds, SVOCs, and petroleum hydrocarbons were detected in ground water

samples from the South Docks Area. Trichloroethene (TCE) was the most frequently reported compound

in the ground water samples along with its breakdown products.

The ground water at OU-I 1 also is impacted by petroleum releases associated with refueling of airplanes

at the flightline refueling area (FRA). No commingling of hazardous substances occurred at this site;

therefore, remediation activities associated with the FRA are being addressed under the State of South

Dakota petroleum release regulations.

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-I 1.

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At Area 1, the total carcinogenic risk to potential future residents from ingestion, inhalation, and dermal

contact with contaminated ground water was estimated at 1.77 × 10-4. This risk level exceeds thc

acceptable risk range of 1 x 10 4 to 1 x 10 _'. At Area 2, the total carcinogenic risk to potential future

residents from ingestion, inhalation, and dermal contact with contaminated ground water was estimated at

2.27 x 10-5. This risk level is within the acceptable risk range. However, the ground water in Area 2

contains contaminants at concentrations greater than the MCL and contaminants have moved beyond the

Base boundary. Remediation of ground water in Areas 1 and 2 was considered warranted because of the

unacceptable risk to human health for exposure to contaminated ground water and to prevent further

offsite movement of ground water containing contaminants at concentrations greater than the State of

South Dakota Groundwater Quality Standards or Federal Drinking Water MCLs.

An ecological risk assessment was not conducted for OU-I 1 specifically since this was a ground water

OU. However a Tier III ecological assessment was conducted as a Basewide evaluation using data from

the Tier I and 1I evaluation completed at other OUs.

The result of this Basewide ecological assessment indicated that there was little to limited risk to

ecological communities evaluated at EAFB from the site-specific exposures at individual OUs. No

remedial actions were recommended as a result of the estimated ecological risks fbr an individual OU or

for the Base as a whole.

3.12.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.13 OPERABLE UNIT 12 HARDFILL 1

3.13.1 Physical Setting

OU-12 is located in the southern half of EAFB, immediately north of the Alert Apron and southwest of

the runway. OU-12 is designated as Hardfill No. 1, which is approximately 14 acres in size. Surface

topography at OU-12 generally slopes inward toward an ephemeral stream that flows in a southerly

direction from the Primary Instrument Runway to the northern boundary of the alert apron. The

drainageway through OU-12 is unlined. Hardfill areas on the east bank of the stream encroach into the

drainageway and also serve as rip-rap in some places. The drainageway has undergone extensive

channelization in order to divert water from the alert apron. The primary drainage is part of a stormwater

drainage system that originates in the north part of OU-12. The source of water is stormwater runoff from

the runways and surrounding areas, which collects in a french drain north of OU-12 and drains into

OU-12 via a culvert. The drainage runs through the center of OU-12 and is ponded toward the south end.

The drainage is channelized around the alert apron, and continues south through OU-1 and OU-2 before

exiting the Base. It is less than 10 feet wide along much of its length and typically contains 6 to 18 inches

of slowly moving water. The pond is approximately 80 ft wide at its widest point and over 700 ft long. A

small, tributary drainage originates to the west of the primary drainage and joins with it north of the pond.

This smaller drainage is fed by runoffffom the west. At the south end of OU-12, the ephemeral strcam is

more characteristic of a pond, which may contain water year round. There is minimal observable water

flow within the ponded portion of the drainageway.

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3.13.2 Land and Resource Use

Operable Unit 12 contains a variety of habitat features, some of which have been heavily influenced by

human activities such as landfill operations and aircraft usage. In spite of this disturbance, some habitat

still exists that could attract animal species that would be potential contaminant receptors.

The most disturbed areas on the OU are the hardfill areas, used to dispose of construction debris and

concrete rubble. The largest hardfill area is located just west of the pond (widened drainageway) in the

south part of OU-12. Another smaller hardfill area is located just to the east of the pond, and a

third hardfill area is found farther north along the primary drainage. The hardfill areas are sparsely

vegetated by weedy species such as annual sunflower (Helianthus annuus), summer cypress

(Kochia scoparia), and bindweed. The only developed area on OU-12 consists of two small buildings

and a circular gravel drive located in the southwest corner of the OU. A few dirt and grass field access

roads are also located in the OU. Operable Unit 12 is bordered on three sides by a formerly used runway,

the current runway, and the alert apron. Although not on the OU, these features may affect the

accessibility and attractiveness of wildlife habitat on OU-12.

Field surveys were conducted at EAFB in 1993 for threatened and endangered species. No sensitive plant

species nor fauna species classified as rare, threatened, or endangered in South Dakota were observed on

EAFB.

This OU is closed to access, except for Base personnel and designated contractors. Undisturbed grass

areas on the OU may be used by local wildlife for foraging, loafing and nesting. No specific future use

has been determined for this OU.

3.13.3 History of Contamination

Historical aerial photographs indicate the area has been used for dumping of construction debris such as

wood, metal, concrete, and asphalt since the 1940s. Construction debris was visible over portions of

OU-12, although much of the former disposal area is covered by vegetation. Disposal of hazardous

materials has not been documented at OU-12; however, the area was designated as an operable unit based

on historical disposal practices at the Base.

This landfill received building and road demolition rubble from maintenance and repair activities on the

Base. Historical records indicated that the landfill was used for disposal of this demolition rubble only,

and did not receive hazardous wastes. The investigation showed the presence of VOCs, SVOCs, jet fuel,

and pesticides, but through site characterization it was found that these contaminants were related to

flightline runoff rather than landfill disposal practices (Figure 3-31). Levels of contaminants observed in

the ground water at the site were below Maximum Contaminant Levels. A single up-gradient well

reported TCE in a ground water sample at a concentration of 7 ug/L (Figure 3-32).

A quantitative risk assessment was performed for the ground water, surface water, soil, sediment, and air.

The risk assessment evaluated potential effects on human health posed by exposure to contaminants from

OU-12.

The risk assessment for OU-12 indicated that the total carcinogenic site risk is within the acceptable risk

range for the residential (future) scenario and is less than 1 x 10 -6 for industrial (current) scenario. The

majority of the total carcinogenic site risk for the residential scenario is from exposure to surface soil

contaminants from within the hardfill. The non-carcinogenic His are below the reasonable maximum

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exposures (RME) of 9 x 10 5 for current industrial land use and I × 10 J tbr future residential land use.

The average His for both current industrial land use and future residential land use were 3 × 10 6 and

5 × 10 2, respectively. However, due to the heterogeneity of the hardfill contents, great uncertainty is

associated with the calculated risk values.

Arsenic and benzo(a)pyrene in the sediment of the drainage areas also contributed to the total site risk.

Based on the risk assessment (risk calculated for sediment is 3 x 10-6), and other factors such as maximum

concentrations, distribution, detection frequency, etc., remediation is not warranted for sediment at

OU-12.

The risk to human health from the ingestion and use of the shallow ground water is 2 x 10 6. This is on

the lower end of the acceptable risk range. Based on this calculated acceptable risk and low

concentrations of contaminants detected in ground water samples, remediation is not warranted for

ground water.

The calculated risk level for the surthce water at OU-12 is 8 × I0 -s, which is below the acceptable risk

range. Remediation is not warranted for surface water as part of OU- 12.

A variety of potential receptors were identified that may live, forage or nest in OU-12 habitats. These

range from benthic invertebrates and amphibians in the drainage channels to birds and mammals.

Terrestrial vegetation and fauna communities did not show patterns indicating elevated chemical

exposure-related impacts. This finding was considered consistent with the relatively low levels and

limited distribution of elevated chemical concentrations in soil, and the active and disturbed nature of thc

site observed during the RI. Tier Ill investigations were not completed at this site but the COCs wcre

carried over to the Basewide Tier 111assessment.

A surface water drainage channel runs through and along the southern boundary of OU- i 2. This channel

contains areas of wetlands. Remedial construction activities at OU-12 resulted in some reworking of soil

and drainage channel relocation in the wetland areas. Replacement wetlands werc constructed near other

Base lakes located in the center of EAFB.

Remedial action was warranted for the hardfill based on the potential risk to human health from future

releases of hazardous substances from the hardfill. Contaminants in the hardfill may leach downward to

contaminate the underlying ground water. Off-Base residents may then ingest or come in contact with the

contaminated ground water. Also, the surface of the hardfill may erode, thus exposing off-Base residents

to contaminants in both surface water and air.

3.13.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were performed at this OU.

3.14 FLIGHTLINE REFUELING AREA

The Flightline Refueling Area consists of three adjacent sites (originally designated SS-08, ST-10, and

ST-14) surrounding seven jet fuel pump houses. The study area is located between the operable apron

and the primary instrument runway in the central part of the Base (Figure 3-33).

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3.14.1 Physical Setting

Soils at the site are described as typically consisting of tan, hard silty clay from 3 to 12 ft below ground

surface, underlain by loose to dense clayey sands and gravels to sandy gravels ranging in thickness from

approximately 5 to 15 ft. These sediments are typical of the relic channel deposits, which are present over

portions of EAFB. Unconsolidated sediments are underlain by hard, gray to black weathered shale, which

is typically present at depths ranging from 18 to 24 ft below ground surface. At an abandoned soil boring

drilled approximately 50 feet northwest of Pump House No. 5, sands and gravels were not observed and

weathered shale bedrock was encountered 8 ft below ground surface, suggesting a localized pinching-out

of unconsolidated channel deposits in this area. Overall, the shale bedrock surface appears to slope to the

southeast.

Depth to ground water typically ranges from 13 to 20 fi below ground surface. Ground water elevations

in the wells indicate a gradient to the southeast, similar to the slope of surface topography. Ground water

is present within the sand and gravel sediments approximately 2-5 ft above the weathered shale bedrock

interface.

3.14.2 Land and Resource Use

This area consists of a grassed field with three pump houses located east of the runway (Pumphouses 4,

5, 6, and 7 and their associated USTs have been removed). The area has been graded flat and matches the

grade of the flightline. The only above-grade structures are the pump houses and adjacent piping controls

associated with each pump house. The pump houses dispense JP-4 for aircraft refueling from

underground storage tanks adjacent to each pump house. Previous fuel release incidents which occurred

at all of the pump houses between 1972 and 1984 were reported in the IRP Phase I Records Search

(1985), and sampling was performed during the IRP Phase II investigations (Stage 1-1987 and

Stage 2 - 1989) which identified petroleum hydrocarbons in the soil and ground water samples.

3,14.3 History of Contamination

The most commonly reported VOCs were benzene, ethylbenzene, and xylenes, with isolated occurrences

of non-JP-4 related compounds (chloroform, methylene chloride, TCE, 1,1,1-trichloroethane,

tetrachloroethylene, and l,l,2,2-tetrachloroethane). (Note that because some samples contained elevated

petroleum hydrocarbon concentrations, which required sample dilution for analysis, the chlorinated VOC

detection limits for some samples were greater than regulatory MCL.)

TPH JP-4 (extractable and purgeable fractions) was reported in samples from 14 of the wells. The

distribution of extractable TPH JP-4 in ground water samples at the time of the Corrective Action Plan

investigation is shown in Figure 3-34. A summary of reported petroleum hydrocarbon compounds in

ground water samples relative to the pump house locations is provided below:

• Pump House No. 1 - Benzene (12 ug/L), ethylbenzene (16 ug/L), xylenes (1.3 ug/L), and

purgeable TPH JP-4 (280 ug/L) were reported in the sample from well MW87CP01.

Ethylbenzene (140 ug/L) and purgeable TPH JP-4 (1,300 ug/L) were reported in the sample

from MW93CP 14.

• Pump House No. 2 - Benzene (27 ug/L), ethylebenzene (270 ug/L), xylenes (210 ug/L), and

extractable and purgeable fractions of TPH JP-4 (9,400 and 5,700 ug/L, respectively) were

reported in the sample from well MW87CP02. Ethylbenzene (300 ug/L), xylenes (830 ug/L),
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Final Five- Year Review

and extractable and purgeable fractions of TPH JP-4 (16,000 and 1t,000 ug/L, respectively)

were reported in the sample from welt MW89CPI2. Purgeable TPH JP-4 (180 ug/L) was

reported in the sample from well MW93CPI0.

• Pump ttouse No. 3 - Benzene (26 ug/L), ethylbenzene (220 ug/L), xylenes (190 ug/L), and

extractable and purgeable fractions of TPH JP-4 (5,300 and 2,600 ug/L, respectively) were

reported in the sample from well MW87CP03. Benzene (620 ug/L), ethylbenzene (130 ug/L),

xylenes (120 ug/L), and extractable and purgeable fractions of TPH JP-4 (30,000 and

12,000 ug/L, respectively) were reported in the sample from well MW89CP09. A concentration

of I I0 ug/L purgeable TPH JP-4 was reported in the sample from well MW93CPI8.

• Pump House No. 4 - Benzene (66 ug/L) and purgeable TPH JP-4 (180 ug/L) were detected in

the sample from well MW87CP04. Ethylbenzene (6 ug/L), xylenes (14 ug/L), and extractable

and purgeable fractions of TPH JP-4 (5,900 and 2,000 ug/L, respectively) were reported in the

sample from well MW93CP20. Wells MW89CPI0 and MW93CP07 were not sampled due to

the presence of LNAPL.

• Pump House No. 5 - Benzene (190 ug/L), ethylbenzene (130 ug/L), xylenes (120 ug/L), and

extractable and purgeable TPH JP-4 fractions (13,000 and 3,600 ug/L, respectively) were

reported in the sample from well MW87CP05. Benzene (1,900 ug/L), ethylbenzene (140 ug/L),

xylenes (500 ug/L), and extractable and purgeable fractions of TP[I JP-4 (9,200 and

10,000ug/L, respectively) were reported in the sample from well MW89CPII. Benzene

(24 ug/L) and purgeable TPH JP-4 (540 ug/L) were reported in the sample from well

MW93CP 1I.

• Pump House No. 6 - The purgeable fraction ofTPH JP-4 was reported in the sample from well

MW93CP06 at a concentration of 600 ug/L.

• Pump House No. 7 - The purgcable fraction of TPH JP-4 was reported in the sample from well

MW93CP15 at a concentration of 520 ug/L.

Current contaminant concentrations are reported on Figure 3-35.

3.14.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were perfonned at this area.

3.15 OFF-BASE JP-4 SOUTH OF OPERABLE UNIT 2

3.15.1 Physical Setting

Surface topography generally slopes in a southerly direction from the southern boundary of EAFB.

Surface water flows through the off-Base area in a small stream originating from Pond 001. Stream flow

measurements were conducted on July 21, 1993, at OU-2 surface water sample locations on this stream.

The stream flow measurements indicate that this unnamed stream had an average discharge of

approximately I. 14 cfs. The OU-2 stream flow measurements were measured during peak flow of a rain

event. This stream ultimately discharges into Box Elder Creek.

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3.15.2 Land and Resource Use

The off-Base area is a grass-covered pasture located adjacent to the south boundary of OU-2. The grasses

are primarily crested wheatgrass and smooth brome. Wetlands in the area consist of a retention pond at

OU-1 and its drainageway, which flows off-Base along the western edge of this study area.

3.15.3 History of Contamination

JP-4 contamination caused by a leak in a fuel line was identified along the southern boundary of OU-2

in 1989. The fuel line was punctured during the Stage 2 IRP field investigations at OU-2. The 12-inch

fuel line was shut off within 30 minutes and a trench was excavated to repair the line. Base records

indicated fuel was recovered with buckets and rags. No record of the fuel volume leaked was reported.

This JP-4 contamination is being remediated under the State of South Dakota petroleum release

regulations.

Total petroleum hydrocarbon, as jet fuel, was reported in soil samples at concentrations ranging from

170 to 2,000,000 ug/kg. The results indicated that the highest concentrations were in samples collected

from moist sand and gravel deposits south of the landfill perimeter. Total BTEX in ground water samples

was reported at concentrations ranging from below detection limits to 9 ug/L. Ground water samples

were not analyzed for oil and grease or TPH during the RI investigations. However, data collected during

the IRP Phase II investigation indicated that ground water samples had reported concentrations of 1 mg/L

to 49 mg/L ofoil and grease. Plume concentrations are shown on Figure 3-36

3.15.4 Initial Response

No CERCLA removal actions or other initial cleanup actions were completed at this OU.

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4.0 REMEDIAL ACTIONS

4.1 REMEDY SELECTION

This section describes the remedies selected at each of the 12 operable units. The remedies are

summarized in "Fable 4-I.

4.1.1 Operable Unit !

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

" in consultation with EPA and the State, the Air Force determined that source area soil treatment and

ground water treatment was the appropriate remedial action. This alternative includes institutional

controls in conjunction with physical modification of the OU to reduce potential risk. Major components

of the remedy specified in the record of decision (ROD) were:

• Continued operation of the remedial system installed as part of the IRA which consists of

(1) eight SVE wells to remediate a portion of the source area soils, and (2) four dual-phase

ground water wells and all existing collection trench to remove contaminated ground water near

the source area

• Installation and operation of four additional SVE wells, seven dual phase ground water wells,

nine ground water extraction wells, and a dual phase extraction trench.

• Treatment of soil gas and contaminated ground water at the IRA treatment plant. Discharge of

plant effluent to surface water, underground injection, or the Base wastewater treatment plant.

• Implementation of institutional controls (deed and land use restrictions) to restrict the future use

of the area while tile remedy is being implemented.

• Long-term ground water monitoring to identify development of future risks associated with the

OU. Long-term maintenance of the remedial actions.

The objective of this alternative is to decrease soil contaminant concentrations within the burn-pit to the

levels listed in Table 4-2 and to remediate the shallow aquifer to levels listed in Table 4-3.

The area targeted for SVE is the burn-pit area (Figure 4-1). Additional SVE wells were placed in the

bum-pit area to remove soil contamination that was not addressed in the IRA.

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TABLE 4-1

SUMMARY OF APPLIED REMEDIAL ALTERNATIVES FOR EAFB

Remedial Action OU-1 OU-2 OU-3 ] OU-4 OU-5 I OU-6 [ OU-7 OU-8 OU-9 OU-10 t OU-11 [ OU-12

INSTALLED REMEDY

No Action X5 X5

Soil Vapor Extraction X

Ground Water Extraction Wells X X X X _ X

Ground Water Extraction Trench X

Monitored natural attenuation X

Alternative water supply X

Earthen Cover X X X X X X X

Realignment of Storm-water channel X X

Pre-Design study ,for landfill gas X X

INSTITUTIONAL CONTROLS

Deed Restrictions 2 X X X X X X X X X X

Continuing Order 3 X X X X X X X X X X

Wetland loss mitigation X X

Records Search/removal action 4 X

Fencing X X X X X X x x x

OPERATION/MAINTENANCE

Long Term Operation/Maintenance X X X X X X X X NA NA X X

Program

Long Term Monitoring Program X X X X X X X X NA NA X X

Notes:

Extraction of ground water containing low levels of TCE was done as a voluntary removal and not a ROD requirement.

z Deed restrictions would be placed on any property transferred from Air Force ownership-this has not occurred at any of the areas listed above.

3 The continuing order is a Base Commander level directive specifying access and use restrictions on the OU areas.

4 This records search/removal action was related specifically to low-level radiological waste material disposal areas within the OU.

Ground water extraction and monitoring at this site was deferred to OU 11 the Basewide ground water OU.

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Final l:ive- Year Revtew

Ground water wells and a collection trench were installed to remcdiate the contaminated shallow aquifer

at OU-1 to the levels listed in Table 4-3. The number and placement of wells and/or trenches was

evaluated during system design. The ground water wells and the trench collect and remove contaminated

ground water at OU-I (Figure 4-2). At the time of remedial design, the aquifer was expected to be

remediated in 10-15 years.

Extracted soil gas, condensate from the SVE wells, and ground water removed by wells and trenches

contain VOCs and petroleum hydrocarbons. These contaminants are treated at the treatment plant built

for the IRA. Treatment of the contaminated ground water consists of oil-water separation, filtration, air

stripping, and liquid phase granular activated carbon. Soil vapor was originally treated in a thermal

oxidizer, but concentrations decreased to a point where the soil gas could be discharged to the atmosphere

without treatment. The thermal oxidizer has been removed from the system.

The treatment plant effluent is discharged into a drainage, which flows into Pond 001, or back to ground

water via one of two re-injection trenches. The effluent is monitored prior to discharge to determine the

effectiveness of the treatment system. Effluent discharge standards and monitoring were determined

during the design phase and are subject to State and EPA reviews and approvals.

Institutional controls were implemented to prevent human exposure to contaminated soil and ground

water. These controls include: (1) issuing a continuing order (see Appendix C) to restrict on-site worker

access to contaminated soil, and to restrict or control temporary construction activities unless proper

protective equipment is worn; (2) filing a notice with the State to recommend denial of water

appropriation permit applications to install ground water wells within the area of contamination and any

area which may be effected by potential contaminants; (3) filing a notice to the deed detailing the

restrictions of the continuing order and ground water well restrictions; and (4) a covenant to the deed m

the event of property transfer.

Continuing Order requirements will be in effect as long as the property is owned by Ellsworth AFB and

the remedial action has not reached remediation goals. In the case of the sale or transfer of property

within OU-! by the United States to any other person or entity, the Air Force will place covenants in the

deed which will restrict access and prohibit disturbance of contaminated soils or the remedial action

without approval of the United States. These covenants will be in effect until removed upon agreement of

the State of South Dakota, the U.S. Environmental Protection Agency, and the U.S. Air Force or their

successors in interest. The Air Force will also include in the deed the covenants required by section

120(h)(3) of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA),

which include (1) a warranty that the United States will conduct any remedial action found to be required

by law after the date of the transfer; (2) a right of access on behalf of EPA and the Air Force or their

successors in interest to the property to participate in any response or corrective action that might be

required after the date of transfer. The right of access referenced in the preceding sentence shall include

the State of South Dakota for purposes of conducting or participating in any response or corrective action

that might be required after the date of transfer.

A maintenance program was established to ensure the long-term integrity of the removal and treatment

system. The maintenance program includes development of standard operating procedures (SOPs) to

provide for inspections, repairs, and leak response actions.

A long-term monitoring program was developed and implemented during remedial action and is subject to

approval of both EPA and SDDENR. Contaminant concentrations from the treatment plant vapor stream

I,"tWORK'ERS',84610,WP',E4FBS)EdRRLF/EW200SDO(" 45 3057 0 _1_3''200j
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Final Five- Year Review

and treated ground water are monitored to evaluate the effectiveness of the system in removing VOCs

from the contaminated media. Contaminant concentrations in the burn-pit area and in the ground water

are also monitored. Continued analysis and monitoring of the ground water remedial action system

performance is conducted to determine if the remediation system is reaching the established clean up

goals, is approaching an asymptotic level due to physical limitations of the site, or the benefits of the

remedial action no longer justify long-term operation of the system.

TABLE 4-2

OU-I CLEAN-UP GOALS

Soils (ug/kg)

Analyte Clean-up Model Goal Estimates (° Basis

1,2-Dichloroethylene (1,2-DCE) 41 41.4 Ground water protection

Benzene 10(2) 2.5 Ground water protection

Tctrachloroethylene (PCE) 10 10.5 Ground water protection

Trichloroethylene (TCE) 10(2) 3.3 Ground water protection

JP-4 500,000 (3) - State Regulation

Toluene 15,000 (3) - State Regulation

Ethylbenzene 10,000 (3) - State Regulation

Xylene 300,00013) - State Regulation

Naphthalene 25,000 (3) - State Regulation

Notes:

(I) Based on SUMMERS Model (Summers, 1980).

_2) When the model estimates are less than standard detection limits, remediation clean-up goals will be based on standard detection limits.

(3) State of South Dakota Remediation Criteria for Petroleum Contaminated Soil, Tier 1 action levels at

petroleum release sites, which would require a corrective action plan or Tier 2 analysis (ARSD

Chapter 74:56:05)

L',,'ORh',ERS!_46,0_.t-,,PYEAiEAREVRFBieW:0ODO5 C 46 3057 0 5September 2005
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TABLE 4-3

OU-I CLEAN-UP GOALS

Ground Water (ug/L)

Analyte Clean-up Goal Basis

1,2-Dichloroethane (1,2-DCA) 5.0 MCL

1, l-Dichloroethylene ( 1, I-DCE) 7.0 MCL

1,2-Dichloroethylene (1,2-DCE) 70.0 MCL

1,1,1 -Trichloroethane 5.0 MC L

Benzene 5.0 MCL

Tetrachloroethylene (PCE) 5.0 MCL

Trichloroethylene (TCE) 5.0 MCL

Vinyl Chloride 2.0 MCL

TPH 10,000 State Regulation

Ethylbenzene 700 MCL and State Regulation

Toluene 1,000 MCL and State Regulation

Xylene 10,000 MCL and State Regulation

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4.1.2 Operable Unit 2

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedial action for

Landfill 1 was the placement of a soil cover and institutional controls. The selected remedial action for

Landfill 6 was institutional controls. This alternative uses access restrictions, monitoring, and other

controls to reduce potential risk. See Figure 4-3.

For Landfill l, major components of selected remedy are:

• Installing an earth cover over the area of attainment at Landfill No 1.

,, Institutional controls to restrict future use of the operable unit.

• Realignment and lining of the storm-water channel.

• Providing for long-term monitoring to identify development of future risks associated with the

operable unit. Providing long-term maintenance for the remedial actions taken at the operable

unit.

For Landfill 6, major components of Alternative 2 are:

• Institutional controls to restrict future use of the operable unit.

• Providing for long-term monitoring to identify development of future risks associated with the

operable unit. Providing long-term maintenance for the remedial actions taken at the operable

unit.

4.1.3 Operable Unit 3

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedial action was

the placement of a vegetative soil cover. This alternative includes institutional controls in conjunction

with physical modification of the OU to reduce potential risk. Major components of remedy are:

• Placing a soil cover, capable of sustaining perennial vegetation, over the landfill area.

• A pre-design study to examine the need for landfill gas control measures.

• Institutional controls for the landfill area.

• Long-term ground water monitoring, and long-term maintenance of the soil cover.

The final Remedial Action for OU-3 consisted of landfill covers and the installation of ground water

monitoring wells. Four existing monitoring wells are sampled and analyzed for VOCs, PAtts, metals,

and indicator parameters (Figure 4-4).

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kVnal Five-Year Review

4.1.4 Operable Unit 4

The selected alternative for the landfill, soil cover, includes the tbllowing major components:

• Institutional controls for the landfill area.

• Placing a soil cover capable of sustaining perennial vegetation over the landfill area.

• Landfill gas monitoring and passive collection system, as necessary.

• Long-term monitoring and maintenance.

The selected alternative for the ground water, pump and treat, includes the following major components:

• Continued operation of the ground water extraction wells installed as part of the interim

remedial action (IRA), and treatment of contaminated ground water.

• Installation of recovery trenches and/or additional extraction wells to be added to the existing

IRA ground water recovery system.

• Treatment of removed ground water at the treatment plant built for the IRA.

• Discharge of treated ground water to a surface water drainage, to the Base wastewater treatment

plant, or by underground injection.

The OU-4 system includes ground water extraction wells that were installed as a part of a 1995 IRA

project and additional wells installed as part of the final RA in 1996. Since the completion of the

RA construction, two additional ground water extraction wells have been constructed to optimize the

system's effectiveness. The total system consists of 28 ground water extraction wells. It also includes the

ground water treatment system in Building 6908, which was built as a part of the 1995 IRA project, and

12 monitoring wells (Figure 4-5). In-situ methods of ground water remediation are being evaluated at this

site as described in Section 4.4.2.

4.1.5 Operable Unit 5

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force has determined that the selected alternative is

Alternative 3, Vegetative Soil Covering. This alternative includes institutional controls in conjunction

with physical modification of the OU to reduce potential risk. Five-year reviews of the remedy will be

required because potential contaminants will remain at OU-5 following completion of remedial action.

The selected alternative, Covering, includes the following major components:

• Placing a soil cover capable of sustaining perennial vegetation over the landfill area.

• Institutional controls for the landfill area.

• Long-term ground water monitoring; and, long-term maintenance of soil cover.

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The final Remedial Action for OU-5 consisted of landfill covers and the installation of ground water

monitoring wells. A total of four monitoring wells are sampled and analyzed for VOCs, metals, and

indicator parameters (Figure 4-6).

4.1.6 Operable Unit 6

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedy was the

placement of a vegetative soil covering. This alternative included institutional controls in conjunction

with physical modification of the OU to reduce potential risk.

The selected alternative, landfill cover construction, included the following major components:

• Installation of fencing to control physical access to the landfill area. Posting the area to indicate

the landfill is closed to further use.

• Implementation of institutional controls (deed and land use restrictions) to prevent future use of

the area for residential use and/or limiting its use to industrial uses.

• Providing a minimum of one foot of sustainable earthen cover over the area of attainment

(approximately seven acres).

• Grading and contouring the area to maintain stability and route surface water precipitation away

from previously active fill areas and prevent ponding of the water.

• Extending an existing stormwater drain to the south and east of the landfill area to prevent the

erosion of fill material and future potential contact with contaminated sediment.

• Providing and maintaining suitable vegetation to enhance evapotranspitration and reduce infiltration and soil erosion.

• Mitigating any wetlands affected by placement of the cap.

• Providing for long-term ground water, surface-water, and sediment monitoring at the OU to

identify development for future risks associated with the OU. Providing long-term maintenance

of the remedial actions taken at the OU.

The final RA for OU-6 consisted of landfill cover construction and the sampling and analysis of four

monitoring wells. The landfill cover construction was completed in 1996, and sampling of the monitoring

wells began in July 1996. Two wells were installed in July 1998 to better monitor downgradient areas of

the landfill (Figure 4-7).

4.1.7 Operable Unit 7

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

consultation with EPA and the State, the Air Force determined that the appropriate remedy was a

combination of institutional controls for soil and institutional controls for ground water with additional

L _WORKERS84610 WP EAFB 5-YEAR REI"IEW2005. DO( 50 3057 05 _eptember2005
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monitoring. This alternative includes institutional controls in conjunction with comprehensive ground

water monitoring and monitored natural attenuation to evaluate and reduce potential future risk.

The following major components comprise the soil remedy:

• Institutional controls for furore land use.

• An cxtensive records search will be performed that may provide additional intbrmation relating

to the burial trenches. A removal action might be used to address waste within the trenches if

the weight of evidence from this records search combined with previous information identifies

and warrants this type of remedial activity.

The ground water remedy includes the following major components:

• Institutional controls for ground water use.

• Implementing a long-term ground water monitoring and maintenance program.

The OU-7 remedial action consisted of a voluntary action to pump and treat

trichloroethylene-contaminated ground water from an existing monitoring well at the northeast corner of

the Weapons Storage Area. The RA includes sampling and analysis of 4 monitoring wclls for VOCs

(Figure 4-8).

4.1.8 Operable Unit 8

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedy for the

EOD Area was the construction of a vegetative soil cover and application of institutional controls. Thc

selected remedy for the Debris Burial Area was also placement of a vegetative soil cover and application

of institutional controls.

For the EOD Area, components of the selected remedy are:

• Constructing an earth cover over the EOD Area.

• Institutional controls for the EOD Area.

• Long-term sediment sampling.

• Long-term maintenance of the earth cover.

For the Debris Burial Area, components of selected remedy arc:

• Constructing an earth cover over the Debris Burial Area.

• Institutional controls for the Debris Burial Area; and

• Long-term maintenance of the earth cover.

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The OU-8 remedial action consisted of the placement of cover soils over two areas and the construction

of one new monitoring well. In addition, drainage facilities in the area were re-constructed to form runoff

retention basins to retain any contaminated soils that may be carried offthe OU by runoff(Figure 4-9). A

total of one monitoring wells will be sampled and analyzed for VOCs, explosives, and TPH-extractables

to perform long-term monitoring of ground water. Sediment is sampled and analyzed at two locations for

dioxins.

4.1.9 Operable Unit 9

Based on the requirements of CERCLA, public comments, and in consultation with EPA and the State, the

Air Force determined that the appropriate remedy for ground water and the fish-ingestion pathway at OU9 would be better addressed under OU-I l, the Basewide ground water OU. Ground water contamination

originates upgradient and extends beyond the boundaries of OU-9 and would be more efficiently

addressed concurrently with other areas of the Base as part of OU-1 I.

The "No Action" alternative was selected as the appropriate remedy for the remaining media of concern:

surface water, soil, and sediment. No action is warranted when a site poses no unacceptable current or

future threat to people or the environment, when CERCLA does not provide cleanup authority, or when a

previous cleanup activity eliminates the need for future cleanup. Unacceptable risk to human health or

the environment from the contaminants related to OU-9 does not exist. Cleanup of petroleum-type

chemicals will be addressed under State of South Dakota petroleum release regulations. Based on the

above conclusions, no action was warranted for soil, surface water, and sediment at OU-9.

4.1.10 Operable Unit 10

Based on the requirements of CERCLA, public comments, and in consultation with EPA and the State, the

Air Force determined that the appropriate remedy for ground water at OU-10 would be better addressed

under OU-11, the Basewide ground water OU. Ground water contamination extends beyond the

boundaries of OU-10 and would be more efficiently addressed concurrently with other areas of the Base

as part ofOU-11.

The "No Action" alternative was selected as the appropriate remedy for the remaining media of concern,

soil. No action is warranted when a site poses no unacceptable current or future threat to people or the

environment, when CERCLA does not provide cleanup authority, or when a previous cleanup activity

eliminates the need for future cleanup. The low levels of contamination in the soil at OU-10 do not pose

an unacceptable risk to human health or the environment. Cleanup of petroleum-type chemicals will be

addressed under State of South Dakota petroleum release regulations. Based on the above conclusions,

no action was warranted for soil at OU-10.

4.1.11 Operable Unit 11

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedy for ground

water at OU-11 would be ground water extraction and treatment with containment. OU-II remedial

alternatives were developed for Area 1 and Area 2.

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The selected alternative for Area 1 is ground water extraction and treatment with containment, including

the following major components:

• Removal and containment of ground water containing contaminants at concentrations above

MCLs.

• Ground water treatment and discharge.

• Institutional controls and long-term monitoring.

The selected alternative for Area 2, ground water containment/extraction and treatment, includes the

following major components:

• Ground water removal along the northeast Base boundary and at areas of high concentration onBase.

• Ground water treatment and discharge.

• Monitored natural attenuation of off-base ground water.

• Alternative water supply to off-base residents affected by contamination coming from the Base.

• Additional investigation to determine the eastern extent of off-Base ground water

contamination.

• Institutional controls and long-term monitoring.

Area 1 includes vacuum dewatering well points, ground water extraction wells and dual extraction wells

to serve the Pride Hangar, Building 102, 30 Row, 50 Row, and the south end of the South Docks. Area 1

is served by the stand-alone treatment facility at FRA-PHI. This project includes daily operation of the

Area 1 systems and quarterly sampling and analysis of 6 monitoring wells for TCE (Figure 4-10). Area 2

consists of the BG-04/BG-04 West/BG-05 area at the northeast comer of the base, where a TCE plume

has moved east off the base (Figure 4-11). The BG-04/BG-04 West/BG-05 area includes 12 ground water

extraction wells, with carbon or air stripping treatment. Effluent is re-injected into the ground water at

BG-04 and BG-05; at BG-04 West, effluent is disposed via irrigation or discharge to the base sanitary

sewer system. The project provides for the daily operation of the ground water extraction wells for

containment at the base boundary in the BG-04/BG-05 areas. Project also includes quarterly sampling

and analysis of 10 monitor wells for TCE. The OU-I 1 system is expected to operate daily for a period of

twenty years.

4.1.12 Operable Unit 12

Based on the requirements of CERCLA, comparative analysis of the nine criteria, public comments, and

in consultation with EPA and the State, the Air Force determined that the appropriate remedy for OU-12

was capping. This alternative includes institutional controls in conjunction with physical modification of

the OU to reduce potential risk. Major components of the selected remedy are:

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• Install an earth cover over the area of attainment at Hardfill No i.

• Institutional controls to prevent future use of the area for residential use and/or limiting its use to industrial uses.

• Developing a long-term monitoring and maintenance plan for the hardfill.

The OU-12 remedial action included landfill cover soil construction at three separate areas within the OU

(Figure 4-I 2). In addition, three monitoring wells are sampled and analyzed annually for VOCS, PAHs,

and indicators.

4.1.13 Flightline Refueling Area

The remedial action selected for the flightline area is based on the need to meet the State of South Dakota

petroleum release regulations. Remedial actions at the flightline refueling area consist of one ground

water extraction trench at Pump House No. 1, which discharges to the FRA Pumphouse No. 1 treatment

system. It also includes two ground water extraction wells at Pump House No. 4 and ground water

collection sumps at Pumphouses 4, 5 and 6, which discharge to the treatment facilities at Building 6908.

4.1.14 Off-Base JP-4 South of Operable Unit 2

The remedial action selected for the JP-4 plume was based on the need to meet State of South Dakota

petroleum release regulations. The JP-4 extraction system consists of eleven dual phase (water/vapor)

extraction wells. Ten of the wells were installed in 1996 and one in 1999. Also, three soil vapor

extraction wells were installed in 1999. The remedial strategy is to contain the plume and address hot

spots within the plume. The dual-phase extraction wells were installed to recover free-phase product,

impacted ground water and soil vapor. Recovered ground water is pumped to the central treatment

facility in Building 6908. This system achieved cleanup goals in 2002 and has been shut down since that

time.

4.1.15 North Docks

The remedial action selected for free-phase product in the 80 Row, behind Dock 74, was total fluids

extraction to remove the product. Two dual-phase recovery wells were placed and a portable extraction

and treatment system was operated in 2001.

4.2 REMEDIAL ACTION IMPLEMENTATION

Information on the implementation of the remedies at each operable unit is summarized in Table 4-4.

A LTM Quality Assurance Project Plan (QAPP) has been implemented for the purpose of monitoring

ground water quality at Ellsworth Air Force Base. The plan outlines monitoring wells, sampling points,

analytical parameters, and sampling schedules for all the Operable Units at Elisworth Air Force Base.

Landfill cover inspections are also covered in this plan. Results of the ground water sampling and landfill

cover inspections are summarized in Long Term Monitoring Reports submitted to the USACE, Air Force,

SDDENR, and EPA on a quarterly basis or as outlined in the SAP.

The LTM QAPP for Ellsworth Air Force Base is periodically reviewed by the Remedial Project Manager

Group. Changes are periodically made in the SAP based on results from previous sampling events or due

L-IWORK!ERSI84610_WP',EAFB5_YEARREI/IEW 2005 DOC 54

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to changing conditions. In particular, sampling frequency and analytical parameters have been revised

regularly.

4.3 OPERATION AND MAINTENANCE ACTIVITIES

Operation and maintenance activities and down time are summarized in Sections 4.3.1, 4.3.2, and 4.3.3.

In addition to operation of pumping and extraction systems, implementation and/or modification of

institutional controls is a part of the Base operation and maintenance program.

4.3.1 Operation and Maintenance Procedures

A System Operation and Maintenance (O&M) Plan is in place at Ellsworth Air Force Base which covers

all operable units that contam active remediation systems. The following tasks are covered in the plans:

• Operating and maintaining the facilities within effluent limitations.

• Maintaining accurate O&M records.

• Completing and submitting required reports.

• Ordering supplies, chemicals, replacement parts, and other materials required for facility

operation.

• Making regular rounds of facilities to ensure proper functioning of equipment.

• Operating and adjusting facilities equipment and making required process adjustments.

• Monitoring chemical storage tank levels.

• Performing preventive maintenance and cleaning duties on facility process equipment, buildings,

and grounds.

• Performing preventive maintenance and cleaning duties on the ground water collection system

(pumps, controls, and pipes), and the discharge system (controls and pipes).

• Drawing samples for laboratory analysis and performing limited process control testing.

• Maintaining and repairing process mechanical, electrical, and control equipment.

• Planning, coordinating, and participating in major equipment overhauls.

• Observing safety practices and being aware of chemical hazards, hazardous areas, and/or

procedures.

• Maintaining good public relations.

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• Maintaining/renewing proper treatment plant operator certification.

• Preparing budgets and annual reports.

Four positions are staffed in order to perform these tasks. The position titles are Site Manager,

Lead Operator, Operations Manager/Chemist, and Operating and Maintenance Technician. All operators

have completed the 40-hour health and safety training required by OSHA 29 CFR 1910.120 and annual

health and safety refresher courses as needed. Additional training, including additional safety training, is

provided to O&M staff as needed.

A review of the O&M manuals and procedures indicates that all manuals are appropriate for the systems

installed and that all the procedures provide adequate guidance for the O&M of the systems. The O&M

manuals have been updated periodically and will be updated again by October 2005.
Ellsworth Air Force Base

Final Five-Year Review

TABLE 4-4

REMEDY IMPLEMENTATION

Eilsworth Air Force Base, South Dakota

Remedial Design Construction Period Average Ground Mass Removal

Water Pumping Ground Other Comments Date of ROD Remedial System Components Air

Operable Unit Signature Start Completion Start Completed Rates Water

(gpd) (lbs) (Ibs)

OU-I IRA August 1995 January 1995 June 1995 4 DWs j June 1995 August 13, 1996 NAi_I NA_3_ NAi3_

8 SVE 2 Wells

1 SVE Blower

Remodeling of Buiiding 6908 and

conversion of building into a CTF 3

for treatment of contaminated soil

vapor and ground water.

ICs

OU-4 IRA August 1995 January 1995 July 1995 10 EWs 5 June 1995 August 13, 1996 NA(3_ NA_3! NAt31 Offsite EWs (3)were

ICs installed in June 1997.

Six EWs shut down

Febmar'/2003.

FRA Pumphouse NAc, January 1995 July 1995 2 EWs June 1995 August 13, 1996 13,000 NA_ 1221

No. 4-IRA ICs

3 Sumps December 2003 May 2004 NAI__ NA NA(_I

FRA Pumphouse NA/L_ January 1995 July 1995 I EW June 1995 August 13, 1996 8,000 tot trench NA_a_ NA_.,_ EW shut down

No. I-IRA I Ground Water Extraction Trench March 2000.

Ground Water treatment building

for treatment of contaminated

ground water,

Institutional controls

L 14'ORK_ERSXI04(_IVPE.,IFB5-FEARRfzV/EW2005Z)OC 5 7 September 20()_

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TABLE 4-4

REMEDY IMPLEMENTATION

Ellsworth Air Force Base, South Dakota

Remedial Design Construction Period Average Ground Mass Removal

Operable Unit Date of ROD Remedial System Components Water Pumping Ground Other Comments

Signature Start Completion Start Completed Rates Air Water

(gpd) (lbs) (lbs)

OU- 1 Final Remedy May 1996 November 1995 June 1996 12 EWs July 1996 June 6, 1997 11,000 62,000 2,500 Two Ews shut down

(FR) 10 DWs January 2005.

I Dual phase extraction trench

4 SVE wells

Soil vapor extraction building

Modifications to CTF

Fencing to restrict access to OU

ICs

NA NA Biotreatment of soils. August 1997 November 1997 NA<21 NAI2/ NA<2/

NA NA Installation ofPZs_and MWs for August 1998 September 1998 NAI2_ NA_2_ NAt2)

LTM 7.

NA NA Long-term monitoring program. April 1998 Ongoing NA(21 NAI2/ NA/2I

Installation of 2 Ews July 2003 November 2003 NAI31 NAI_/ NAI__

Installation of 3 Ews March 2004 September 2004 NAt31 , NAI31 NAI3/

DU-2 May 1996 November 1995 April 1996 Landfill cap. June 1996 May 1, 1997 NA(2) NA<2) NAI2!

Fencing to restrict access to OU

November 1995 April 1996 Construction of draina_,e channel June 1996 October 1996 NAI21 NAI2/ NAt2/

October 1996 June 1997 LLRW _excavation and disposal July 1997 January 1998 NA(2/ NA<2_ NA/, _

NA NA Chemical Weapons Material August 1997 February 1998 NAI2/ NAt21 NA¢2)

!xcavation and disposal

LTM program. April, 1997 Ongoing NA/2/ NA(2_ NA{2/ IlCs

OU-2 JP-4 NAI]_ November 1995 April 1996 Offsite easement. June 1996 December 1996 Shut Down 23,785 424

10 DWs in JP-4 Area.

SVE blower building

ICs

DW in JP-4 Area February 1998 NAol NAc_ NAI3_

3 SVE wells in JP-4 Area

OU-2 JP-8 NAo_ JP-8 Excavation November 1996 November 1997 NA/_ NA(3, NA_

2 SVE wells in JP-8.
Ellsworth Air Force Base

Final Five. Year Review

TABLE 4-4

REMEDY IMPLEMENTATION

Ellsworth Air Force Base, South Dakota

Remedial Design Construction Period Average Ground Mass Removal

Operable Unit Date of ROD Remedial System Components Water Pumping Ground Other Comments Signature Start Completion Start Completed Rates Air Water (Ibs) (gpd) (Ibs)

OU-3 June 1996 ' Landfill Cap June 1996 May 1997 'NAt2! NA;> NA_:_

LTM Program April 1997 Ongoing

lCs

OU-4 FR May 1996 November 1995 July 1996 Landfill Cap June 1996 December 1996 4,000 NA<> 50 Two wells shut down in

Property Acquisition 2004.

9 Ews

Additional Investigation

Fencing to restrict access to OU

ICs

MWs and PZs for LTM July 1998 September 1998 NA_:/ NA_2/ NAI2)

2 EWs September ]999 December 1999 NAi,} NA!!I NA,_i

MWs and PZ for LTM

LTM program. April 1997 On_oin_ NA/: I NAI21 NAi2/

MWs, TMWs, TIWs for 2003 May 2005

Treatability Study

OU-5 November 1995 June 1996 Landfill Cap June 1996 May 1. 1997 NA/:/ NA¢:! NA<>

Fencing to Restrict Access to OU

LTM Program April 1997 Ongoing

ICs

OU-6 October 1995 January I995 August ]995 Landfill Cap November 1996 July 1996 NAc:I NA _.'i NA_:_

Fencin_ to Restrict Access to OU

MWs to monitor effectiveness of July 1998 August 1998 NA!:/ NAI:_ NAi:>

cap.

LTM program. July 1996 Ongoing NA(2/ NAi:_ NAI:_

iCs

OU-7 June 1996 October 1996 June 1997 Removal of LLRW August 1997 January 1998 NA/2i NAI:_ NA_:_

Monitoring wells for NA

monitoring

Monitored natural attenuation October, 1998 Ongoing

Monitoring

ICs

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TABLE 4-4

REMEDY IMPLEMENTATION

Ellsworth Air Force Base, South Dakota

Remedial Design Construction Period Average Ground Mass Removal

Operable Unit Date of ROD Remedial System Components Water Pumping Ground Other Comments

Signature Start Completion Start Completed Rates Air Water

(gpd) (Ibs) (Ibs)

OU-8 June 1996 November ]995 June 1996 Placement of Soil Cover June ]996 June 1997 NAI: _ NA/2) NAi2/

Long Term Monitoring Program

ICs April 1997 Onl_o!n _

OU-9 May 1996 NA NA No Action ROD NA NA NAI2_ NAI2) NAI2) ICs

OU- I0 May 1996 No Action ROD NA{2) NAI2) NAI2) ICs

DU-II April 1997 July 1998 September 1998 Off-Base water line September 1998 Ongoing NA_2_ NA(2_ NA(2)

!Off-Base Additional investigation (AOC 24) September 1997

LTM program Ongoing

Installation of MWs to monitor

_lume

ICs

OU-11 November 1996 June 1997 Installation of 4 Ews April 1997 January 1998 12,000 NAI2_ 10 Two Ews shut down

BG04 Base Boundary Installation of ground water May 2005, reinjection gallery

Installation of ground water

treatment building

ICs

Installation of MWs and PZs to April 1997 December 1999 NAI2_ NA(2) NA_._

monitor extraction system

performance

OU-I I November 1996 June 1997 Installation of 3 EWs April 1997 January 1998 88,000 NA(2) 22

BG05 Base Boundary Installation of ground water reinjection gallery

Installation of ground water

treatment building

ICs

Installation of MWs and PZs to April 1997 January, 2000 NA/3_ NA_3/ NA(3)

monitor extraction system

_erformance

Installation of 4" EW
Ellsworth Air Force Base

Final Five- Year Review

TABLE 4-4

REMEDY IMPLEMENTATION

Ellsworth Air Force Base, South Dakota

Remedial Design Construction Period Average Ground Mass Removal

Operable Unit Date of ROD Remedial System Components Water Pumping Ground Other Comments Signature Start Completion Start Completed Rates Air Water (Ibs) (gpd) (Ibs)

OU-II April 1997 November I996 March 1997 Installation of 4 EWs April 1997 January.' 1998 16,000 NAi3) 37

BG04 West Installation of ground water

treatment building

ICs

OU-II November I996 March 1997 !Installation of 6 EWs April I997 January 1998 61,000 NA_2) 2,970 SVE portion of DWs

South Docks Main ilnstallation of 4 DWs taken off line. Three

Modification of the Pumphouse DWs shut down July

No. 1 treatment building 2003.

SVE blower

ICs

Installation of 2 EWs July 2003 November 2003 NA(_/ NA?/ NAI_/

OU-I 1 November 1996 March 1997 Installation of 3 EWs April 1997 January 1998 NAi_/ NAIl/ NA_

30 Row ICs

OU-11 November 1996 March 1997 Installation of 3 EWs April 1997 January 1998 NA/3> NAI__ NAI3_ Shut down July 2003.

50 Row ICs

OU-I1 November 1996 March 1997 Installation of 9 WPs April 1997 January 1998 25,000 NA NAi_/ System shut down

Building 102 nstallation of vacuum and transfer August 2002.

pumps in a concrete vault

ICs

OU-11 November 1996 March 1997 Installation of 9 WPs April 1997 January 1998 63,000 NA NAI_! Shut down 3 WPs in

Pride Hangar Installation of vacuum and transfer 2003.

pumps in a concrete vault

ICs

Installation of eight SVE wells June 2004 January 2004 NA 35 NA System shut down November 2004.
Ellsworth Air Force Base

Final Five- Year Review

TABLE 4-4

REMEDY IMPLEMENTATION

Ellsworth Air Force Base, South Dakota

Remedial Design Construction Period .... Average Ground Mass Removal

Operable Unit Date of ROD Remedial System Components Water Pumping Ground Other Comments

Signature Start Completion Start Completed Rates Air Water

(gpd) (lbs) (lbs)

OU-I 1 NAI_I November 1996 June 1997 5 WPs May 1997 November I998 1,200 20 System shut dowr

North Docks 60 ROW Vacuum pump m 1998.

Mobile treatment system

ICs

Pump House I FP September 2001 April 2002 8,000 946 1 System shut down'

in 2003.

OU- 12 May 1996 November 1995 June 1996 Earthen cover over hard fill June 1996 May 1, 1997 NAI21 NAI21 NA(2_

LTM program April t997 Ongoing

ICs

DWs = dual extraction well, w/soil vapor extraction and ground water extraction systems installed.

SVE = soil vapor extraction well.

CTF = central treatment facility.

ICs = institutional controls.

EWs = ground water extraction well.

PZs = piezometer well.

LTM = long term monitoring.

LLRW = low level radiological waste.

WPs =vacuum dewatering well points.

NA = Not Applicable,

NA(ll = Not Applicable - Non CERCLA Action.

NA_2)= Not Applicable - No Soil Vapor/Ground water is extracted,

NA(31= Not Applicable - Components incorporated into existing system,

HA(4)= Not Applicable - IRA incorporated into Final Remedy System,

L'H¥ORKIERSIg46101WPIEAFB5-YEARREVIEW2005 DOC , 62 3057 070 September2005
Ellsworth Air f'orce Bast'

Final Frye- Year Review

4.3.2 Summary of System Downtime and Operation and Maintenance Issues

Table 4-5 summarizes all major system downtime and operation and maintenance issues.

4.4 SYSTEM OPTIMIZATION

The Ellsworth Air Force Base ERP team continually reviews the operational effectiveness of the

remediation systems. Optimization measures are implemented to maintain or improve the systems'

effectiveness. This section summarizes optimization actions at the sites where remedial systems are in

operation.

Optimization actions which have been implemented since the year 2000 and which affect all of the

operating sites included the following:

• Installation of remote monitoring capability for the sites. This allows more economical

monitoring of system operations from a central location.

• An interactive voice response and alarm system was installed at all of the sites, allowing more

rapid response to alarm conditions in mechanical or electrical equipment.

• Ground water extraction wells are evaluated every 1 to 3 months for production and drawdown;

selected wells are re-developed to maximize ground water production and aquifer drawdown.

• The LTM program at each site has been reviewed every one to two years; the programs have

been optimized and reduced in terms of frequency of sampling and number of analytes sampled

and reported.

4.4.1 Operable Unit 1

Two additional ground water extraction wells were constructed in the southeast area of this operable unit

in 2003 to improve capture of the ground water plume and increase the recovery of free product. Selected

ground water extraction wells in this OU have been deactivated when ground water contaminant

concentrations have been reduced below regulatory levels. One of the SVE blowers at this site was shut

down, since SVE performance could be maintained by a single blower at a substantial savings in

electrical consumption and maintenance. Periodic hydrogen peroxide backwashing of the liquid-phase

granular activated carbon filters was initiated, to reduce biofouling of the filters and increase their usable

life and efficiency. Free-product depth is measured quarterly to optimize product recovery and monitor

plume characteristics. Current sensors were installed in the ground water extraction wells to allow

increased recovery of free-phase product in these wells. Re-injection trenches were installed to allow

injection of treatment plant effluent back into the ground water, eliminating a problem with surface

discharge of effluent containing high concentrations of selenium. Quarterly sampling of soil vapor is

performed to allow shutdown of clean SVE wells and concentration of SVE system performance on

contaminated areas. The SVE system is monitored quarterly to detect pipe blockages resulting from

condensate, which is removed as necessary to maintain optimum operation of the system. All of these

measures have been implemented in the period since 2000.

L:!WORK_ERSg4610 WP E4f B 5 ) E 4R REI'IEW200_ DO( 6 _ September 2005

3057 07i
Ellsworth Air Force Base

Final Five- Year Review

4.4.2 Operable Unit 4

Two additional extraction wells were placed in this operable unit to increase capture in the northeast area

of the plume (pre-2000). Seven extraction wells in the northern and western portion of the plume were

shut down when contaminant levels were reduced below regulatory levels. An existing extraction well in

the southern portion of the plume was replaced with a new well in a more favorable geologic location,

which has increased ground water production and enhanced plume containment.

A treatability study is being performed at this site to determine whether an innovative in-situ remediation

method (reductive biodechlorination) can be more cost-effective than ground water pump-and-treat. The

study involves injection of substrates such as vegetable oil and sodium lactate to foster the growth of

anaerobic bacteria that break down chlorinated solvents (such as TCE) into harmless compounds. Initial

work at the source area within the landfill showed positive results. The treatability study has been

expanded to the ground water plume south of the landfill. One of the primary goals of the study in this

area is to determine whether reductive biodechlorination can be achieved in areas where the contaminant

concentration is quite low (<25 ppb) and pump-and-treat technology is limited by a thin aquifer. Column

studies are also being performed in the laboratory at the site, using native soils and ground water to

evaluate the effectiveness ofreductive dechlorination under controlled conditions and low concentrations.

These OU-4 measures have been implemented since the year 2000 except as noted.

4.4.3 Operable Unit 11

Liquid-phase granular activated carbon filters at FRA-PH1 were deactivated after it was demonstrated

that satisfactory treatment could be achieved with air strippers alone. This produced a savings in carbon

costs and in reduced operator labor for regular carbon system backwashing and replacement. An

additional extraction well was placed in the BG-05 system to increase plume capture at the base

boundary. Three wells in the Pride Hangar system were shut down when the contaminant levels decreased

below regulatory levels. The Building 102 system was shut down when the contaminant levels in the area

were reduced below regulatory levels. Three extraction wells in the South Docks Main system, and the

wells in the 50 Row system, were shut down when the contaminant levels were reduced below regulatory

levels. An irrigation system was established at the BG-04 West system to allow productive re-use of

treatment plant effluent, reducing the cost of disposal of this effluent in the base sanitary sewer system.

In-situ reductive biodechlorination, involving injection of vegetable oil or sodium lactate substrates, is

being implemented at a ground water hot spot at the northwest corner of the Pride Hangar. Four

monitoring wells located outside the Pride Hangar are used for monitoring and for substrate injection. On

a weekly basis, approximately 100 gallons of a 1,000-2,000 mg/L sodium lactate solution are injected into

each of the four monitoring-injection wells. Three monitoring wells located inside the Pride Hangar, plus

three monitoring wells outside the hangar, are used for monitoring. The monitoring wells were sampled

prior to the start of injection in May, 2005, and will be sampled every two months for the 12 month

duration of the test. Analytes include VOC, COD, sulfate, pH, conductivity, and oxidation-reduction

potential (ORP). Selected samples are analyzed for dissolved gasses (ethane, ethane, methane, and

acetylene) as well on a four-month schedule. A small SVE system was installed to address soil TCE

contamination in this same area.

These OU-I 1 measures have been implemented since the year 2000.

All ground water issues from the other operable units have been shifted to OU-11 for ongoing long-term

monitoring and remedial action operations

L iWORKIERSI846IOIWPIE.4FB5-YEAR REVIEW2005 DOC 64 September 2005

3057 072
Ellsworth Air f'brce Base

Final Five- Year Review

4.4.4 JP-4

This system was shut down whcn ground water and soil contaminant levels were reduced below

regulatory levels.

4.4.5 Flightline Refueling Area

Free-product removal was pertbrmed at the Pumphouse 1 area in 2002-2003, using a portable system, and

resulted in the elimination of free product in that area. Ground water and free-product removal systems

were installed at former Pumphouses 4, 5, and 6 when tile buildings were demolished and their associated

underground storage tanks were removed in 2003-2004.

4.4.6 North Docks

Ground water and free product recovery was performed at 80 Row (near Dock 74) in 2001 using a

portable system. The site continues to be monitored. An automated free-product recovery system will be

installed at this location in October 2005.

L "IlZgRKIERS'846101WP,EAFB5-_E,4R REllEW 2005 DOC 65 September 2005

3057 073
Ellsworth Air Force Base

Final Five- Year Review

TABLE 4-5

SUMMARY OF OPERATIONAL DOWNTIME AND OPERATIONS AND MAINTENANCE ISSUES

Ellsworth Air Force Base, South Dakota

Operable Unit Problem Description Resolution Date of Date of I

I

• Identification Resolution I NotesComments

OU-1 Wellfield 1. Biosolids from EW and DW wells were 1. Reconditioned two wells with acid in 1998, 1. 6/98 & 2/00 1. 9/98 & 2/00 1. Well field trends are continually being

fouling treatment equipment in CTF redeveloped rest of well field in 1998 and 2. 7/98 2. 9/98 monitored to determine when well

2. Inadequate number placement ofwellfield 2000 3. On-going On-going redevelopment is needed

monitoring points 2. Added monitoring points to monitoring 4. 7/21/99 7/29/99

3. Low flows fromwellfield network 5. 1/27/99 2/5/99

4. Problems with pumps and controllers 3. See above note

5. Potable waterline break repair resulted in 4. Ongoing maintenance/preventative

wellfield shut-down maintenance program

6. Motor starters burned up at extraction wells 5. Repaired waterline and re-started well field

6. Replaced motor starters at 16 wells

6908 CTF 1. Selenium exceedance in plant effluent 1. Increased frequency of plant effluent 1. Plant start-up 1. On-going FRA-PH4, 1/10/99' to 1/19/00 for

2. SVE Blower damaged due to scale build-up in sampling, investigated wellfields, shut down 2. 2/23/98 2. 5/28/98 Honeywell controls change-out

blower housing selected wells intermittently 3. 7/98 3. 6/4/99 2. JP-4, 1/14/00 to 1/21/00 for Honeywell

3. Problem with communication and controls 2. Repaired blower, revised inspection schedule 4. 6/20/99 4. 6/25/99 controls change-out

between 6908 and FRA-PH4 3. Checked cable splices, replaced a section of 5. 1999 5. I/I0/00 3. 6908 CTF, 1/11/99 to 1/25/00 for

4. Problems with air stripper blower motor cable, completed controls changes 6. 1999 6. 5/18/00 AI Winland incident.

5. Problems with controls for OU-1, OU-4, JP-4, 4. Repaired air stripper blower motor 17. 7/18/00 7. 7/28/00 4. Site was down from 5/18,/99 to 6/4/99,

FRA-PH4, and 6908 5. Replaced Allen Bradley controllers with 8, 1/10/02 8. 1/23/02 problem with controls displaying incorrect

6. Cost for injecting Aquamag sequestering Honeywell controllers 9. 2002 9, 2002 site status from 7/98 to 6/4/9

agent, introducing phosphates to surface water 6. Replaced Aquamag with magnetic resonance 10. 2002-2004 i10. 2003-2004 5. Significant LTO cost reduction with

7. Control BUS failing periodically units 1, 2004-2005 11. 11/4/05 similar results

8. Scale accumulation in process piping, caused 7. Replaced comm. Card for JP-4 site and 6. Also cleaned other sections of piping.

pressure backup repaired comm. Line 7. Significant savings in utility costs and gas

9. High utility cost to operate building 8. Replaced section of piping, flushed valve usage for building heat

ventilation system 100% of time while rack 8. USAF personnel replaced with

occupied 9. Modified make-up air unit and reduced USAF equipment

10. Continued selenium exceedance in plant operation of ventilation system during

effluent unoccupied time

1, Periodic problem with modem connections for 10. Construct two reinjection trenches for plant

dial-up sites effluent

1. Replaced modems with hard-wire

connections

OU-I SVE System 1, Blower motor failed 1. Motor repaired 1. 7/2/01 I. 7/26/01 !2. On-going operational issue, system

2. Water in SVE piping 2. Removed water from pipin_ with compressor 2. 1/28/04 2, On-going checked quarterly
£11sworth Hip"Force Base

Final Five-Yeur Review

TABLE 4-5

SUMMARY OF OPERATIONAL DOWNTIME AND OPERATIONS AND MAINTENANCE ISSUES

Ellsworth Air Force Base, South Dakota

I

Operable Unit Problem Description Resolution Date of I Date of Notes/Comments Identification Resolution I

OU-2 Landfill Cap MinorMinorsettlementer°si°nin coVeraboveandwastealongtrenches.Westditch, withEr°si°nalsoilreas repaired. Settling areas re-filled 4 , /99 10/99

Movement of TCE plume across the south base Installation of three extraction wells to contain

boundau. TCE _round water plume,

,lP-4 Site 1. DWJP06 damaged (near free product plume) 1. Used DWJP06 as temporary SVE well 7/97 1. 3/98 2, Site was operated during manned hours

2, Problem with commurucation system between 2. Replace portion of communication cable, 2, 7/9/98 2. 9/23/98 during problem period

6908 CTF and blower building replaced modem at JP-4 site 3, 6/14/00 3. not resolved 3. Transfer pump prime o/ten lost so pump

3. Blower vaporliquid separator frequent high 3, not resolved 4, 5/3 b'0l 4, I 1/12/01 occasionally ti:iled

level 4. Shipped blower for repair and maintemmce

4. Blower failed

JP-8 Spill Site JP-8 spill immediately south of OU-2 landfill Excavated all accessible contaminated soil, Remediation completed and wells were taken

installed _'o SVE wells to cleanup residual soil off line

contamination, connected to JP-4 SVE

OU-3 Landfill Cap Landslide from OU-5 affects north edge of cover Repairs planned 2/00 :Onl_oin_ ....

OU-4 Landfill Cap None noted.

Wellfield I. Low flows from weHfieM I, Redeveloped several extraction wells in 1998 1, 6/98 & 2,/00 I1. 9/98 & 7/00

and 2000 2, 9/99 2. I/5/00

OU-5 Landfill Cap Landfill cover subsidence and landslide Repaired subsidence cracks in cover two times in 10/96 Ongoing

1997 and 1998. Installed underdrains to control

ground water pore pressure in 2001.

OU-6 Landfill Cap None noted

OU-7 Ground Water Plume expanding Continued monitoring Ongoing Edge of Plume is not near base boundary.'

Monitorin_

OU-8 Landfill Cap Soil cover disturbed by Air Force personnel during ISoH cover repaired, new signage, restricted area 9/99 0/99

ordnance disposal activities map developed, training, Base Continuing Order

Prairie dokzsencroachinl_ on Debris Burial Area. Reissued.

OU-9 No action ROD

OU- 10 No action ROD
Ellsworth Air Force Base

Final Five. Year Review

TABLE 4-5

SUMMARY OF OPERATIONAL DOWNTIME AND OPERATIONS AND MAINTENANCE ISSUES

Ellsworth Air Force Base, South Dakota

Operable Unit Problem Description Resolution Date of Date of Notes/Comments

Identification Resolution

OU-I I Pump house No. 1 1. Problem with oil/water separator transfer 1. Converted oil/water separator to a reservoir l. Start-up 1. 12/1/98 1. Hole was cut in the oil/water separator

Treatment Building pump short-cycling which reduced cycle frequency of the transfer 2. 12/97 2. 2/18/99 interior wall to convert it to a reservoir, no

2. Problem with solids from transfer piping pump 3. 1999 3. 1/21/02 free product had been collected from the

passing through process equipment when i2. Placed franc tank in treatment system to drop system since start-up

Pride Hangar system operated with more than out solids from transfer piping, removed bag 2. Frac tank in place from 10/14/98 to

one transfer pump filter system and carbon units from treatment 12/1/98, removed bag filter system and

3. Cost for injecting Aquamag sequestering process carbon units from treatment process on

agent, introducing phosphates to surface water 3. Replaced Aquamag with magnetic resonance 2/18/99

OU-I 1 unit

South Docks Main Problem with SD SVE heater contactor caused Replaced transfer pump and replaced heater 3/I 0/98 4/8/98

building to freeze and transfer pump to crack contactor

30 ROW None noted

50 ROW None noted

Building 102 Vacuum 1. Problem with transfer pumps overheating 1. Inspected motors, serviced pumps 1. 6/25/99 1. 7/5/99 2. Problem with pumps observed to occur

Pump 2. Problem with vacuum pump motor 2. Replaced motor 2. 5/20/00 2. 6/6/00 with high ambient air temperatures

3, Vacuum pump frequently over-heated 3. Routed ventilation to vacuum pump cooling 4. 4/00 4. 4/00 4. Allowed vacuum pump to operate within

4. Continued problem with vacuum pump over- fan 4, 2000 4. 7/11/01 normal operating range for temperature

heating 4. Replaced heat exchanger with system that 5, 9/21/01 5. I 1/7/01

5. Water on floor &vault circulates process water 6. 2/4/02 6. 2/14/03

!6. Scaling of vacuum pump cooling system 5. Placed backflow prevention valve on pump

piping discharge piping and placed solenoid valve in

cooling circulation piping

6. Installed access and drains to allow acid

circulation throul_h coolin_ system pipin_

Building 102 None noted.

Wellfield

LIWORK_ERS_84610IWP_EAFBS-YEARREVlEW2005DOC 68 3057 076 September2005
Ellsworth Air Force Base

Final Five- Year Revww

TABLE 4-5

SUMMARY OF OPERATIONAL DOWNTIME AND OPERATIONS AND MAINTENANCE ISSUES

Ellsworth Air Force Base, South Dakota

Date of" Date of Notes/Comments

Operable Unit Problem Description Resolution Identification Resolution

Pride Hangar Vacuum l. System operated with only one transfer pump 1. Place frac tank in treatment system to drop Start-up 1. 10/14/98 1. Site able to operate with more than one

Pump due to problems at FRA-PH 1 treatment plant out solids from transfer piping to allow Pride 2. 7/6/99 2. 8/31/99 transfer pump after frac tank was placed on

when more than one transfer pump operated Hangar system to operate with more than one 3. 4/00 3. 4/00 I0/I 4/98, the frac tank was removed on

2. Problem with vacuum pump motor transfer pump 4. 2000 4. 6/22/01 12/1/98

3. Vacuum pump frequently over-heated 2. Repaired motor two times 5. 2/'4/02 5, 2/14,/03 2. Site was down from 7/6/99 to 7/29/99 and

4. Continued problem with vacuum pump over- 3. Routed ventilation to vacuum pump cooling 8/4/99 to 8/31/99, intermittent operation

heating fan from 7/'29/99 to 8/4/99

5. Scaling of vacuum pump cooling system 4. Replaced heat exchanger with system that 4. Allowed vacuum pump to operate within

piping circulates proccss water normal operating range for temperature

5. Installed access and drains to allow acM

circulation throu_,h coolin_ system piping

Pride ttangar Weflpoint SDPHWP01 was damaged by' Wellpoint was replaced 1/99 1/99

Wellfield contractor

OU-I I BG04 West Problem with motor for air stripper transfer 1. Replaced electrical components including 3/16/00 4/28/00 Site was down from 4/16/00 to 4/28/00,

Treatment System pump and motor starter for transfer pump motor starter, repaired transfer pump motor 2. 4/8/01 2. I 1/29/02 intermittent operation from 3/16/00 to 4/16.'00

2. Continued problem with transfer pump motor, 2. Electrician replaced motor circuit protection 3. [ 1/29/02 3. 1/20/03

had to replace motor three times 3. Placed tank to reduce pump/motor cycles 4. 9/03 4. 5/05

3. Transfer pump motor 4. Replaced valve with bronze valve

4. Three-way PVC valve for irrigation system

frequently stickin_ in one position

BG04 West Wellfield Chattering of motor starter for extraction ',,','ell I. Electrician replaced transformer in well 2/26/02 5/14/02

control panel

BG04 Base Boundary None noted

Treatment Svstem

BG04 Base Bounda W None noted

Wellfield

BG05 Base BoundarylNone noted

Treatment System

BG05 Base Boundary, 1. Capture of TCE plume on north end 1. Placed fourth ,,,,'ellon north end I999 1/4/00

Wellfield 2. Three pumps not cycling, need to increase 2. Replaced pumps with larger capacits' pumps 2. 2003 2. 2004

radius of influence for these EWs

AOC 24 None noted

OU-12 Landfill Cap Minor soil erosion. Erosion repaired.

69 3057 077 S_7)temher2005
Ellsworth Air Force Base

Final Five-Year Review

5.0 FIVE-YEAR REVIEW PROCESS

5.1 TEAM MEMBERS

Environmental Restoration Program (ERP) team members who prepared the five-year review included the

following:

Dell Petersen, ERP Chief, Ellsworth AFB

Jim Haggins, Program Manager, Headquarters/Air Combat Command

John DeYoe, Ellsworth AFB ERP

Tim Pavek, Ellsworth AFB ERP

Deb Morrissey, Omaha District, US Corps of Engineers

Keith Anderson, Earth Tech/contractor

Joe Odegaard, Earth Tech/contractor

Robert Todd, RD Todd & Associates/contractor

The time period covered by the five-year review was May, 1995 through July 2005.

5.2 DOCUMENT REVIEW

During this five-year review a number of EAFB RI/FS program primary documents were reviewed and

relied upon for information. Table 5-1 lists those documents.

3057 078 September2005
Ellsworth Air I_).'ce Ba_c

Final Frye-Year Review

TABLE 5-1

DOCUMENTS REVIEWED DURING THE EAFB FIVE-YEAR REVIEW PROCESS

Final Remedial Invcstigahon Report Operable Unit 01 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 02 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 03 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigahon Report Operable Unit 04 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 05 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 06 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 07 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 08 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 09 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 10 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 11 at Ellsworth Air Force Base, South Dakota

Final Remedial Investigation Report Operable Unit 12 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 01 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 02 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 03 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 04 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 05 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 06 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 07 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 08 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 09 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 10 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 11 at Ellsworth Air Force Base, South Dakota

Final Feasibility Study Report Operable Unit 12 at Ellsworth Air Force Base, South Dakota

Final Record of Decision for Remedial Action at Operable Unit 01 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 02 at Ellsworth Air Force Base,

South Dakota

L IWORKi[:RS_846101lP_EAFB_ )EAR REI'IEW 200_ DOU 71 September 2005

3057 079
Ellswm'th Air Force Base

Final Five- Year Review

TABLE 5-1

DOCUMENTS REVIEWED DURING THE EAFB FIVE-YEAR REVIEW PROCESS

Final Record of Decision for Remedial Action at Operable Unit 03 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 04 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 05 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 06 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 07 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 08 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 09 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 10 at Ellsworth Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 11 at Ellsworlh Air Force Base,

South Dakota

Final Record of Decision for Remedial Action at Operable Unit 12 at Ellsworth Air Force Base,

South Dakota

U.S. Environmental Protection Agency (USEPA). t989. Risk Assessment Guidance for Superfund,

Volume I: Human Health Evaluation Manual (Part A). Interim Guidance. Office of Emergency and

Remedial Response, Washington, D.C. EPA/540/I-89/022.

U.S. Environmental Protection Agency (USEPA). 1989. Exposure Factors Handbook. Office of Human

Health and Environmental Assessment, Washington, D.C. EPA/600/8-89/043.

U.S. Environmental Protection Agency (USEPA). 1989. Risk Assessment Guidance for Superfund,

Volume II: Environmental Evaluation Manual (Part A). Interim Guidance. Office of Emergency and

Remedial Response, Washington, D.C. EPA/540/I-89/001

U.S. Environmental Protection Agency (USEPA). 1989. Ecological Assessment for hazardous Waste

Sites: A field and Laboratory Reference. EPA/600/3-89/013.

U.S. Environmental Protection Agency (USEPA). 1993. Integrated Risk Information System (IRIS).

U.S. EPA Office of Research and Development, Washinston, D.C.

U.S. Environmental Protection Agency (USEPA). 2005. Integrated Risk Information System (IRIS).

U.S. EPA Office of Research and Development, Washinston, D.C. http://www.epa.gov/iris.

Draft-Final Program Review, Ellsworth AFB Environmental Restoration Program, Ellsworth AFB, South

Dakota. 2005.

L IWORKIERSi84610iWPIE,4FB5-YE,4RREVIEW2OO5 : .DOC _' 72 3057 _e_e_er 2005
Ellsworth Air For_ e Base

Final F_ve- Year Review

5.3 FIVE-YEAR REVIEW TASKS

• Review ROD documents for documentation of the selection of the final remedial action.

• Compare completed remedial actions to those outlined in RODS.

• Refine and incorporate remediation and closeout strategies contained in the EAFB ERP Draft

Program Review Report.

L _WORKiERSL8461O_,WPE4FB_-YEARREI'tEW 20#5 DOC 73 September 2005
Ellsworth Air" Force Base

Final Five-Year Review

6.0 FIVE-YEAR REVIEW FINDINGS

6.1 CHANGES IN ARARS AND TO BE CONSIDERED CRITERIA

The principal standards applied to the remedial action process at EAFB were based on the Applicable or

Relative and Appropriate Requirements (ARAR). Table 6-1 provides a summary of the ARARs reviewed

for applicability to EAFB during the RI process. This list contains chemical, action, and location specific

standards determined to be ARARs for EAFB. Table 6-1 has been updated for the 2005 Five Year

Review. Chemical specific standards or criteria that have changed since the first ROD was signed at

EAFB are summarized in Tables 6-2 through 6-4. Chemical standards for surface water, ground water,

and soil media for a limited number of analytes have changed. These changes are reflected in Table 6-2,

which has been updated for the 2005 Five Year Review. Those changes affect the cleanup criteria for

petroleum-related compounds. The State of South Dakota regulations for remediation of petroleumcontaminated soils changed from cleanup requirements between 10 and 100 ppm TPH to a risk-based

approach. This risk-based approach includes Tier 1 Action Levels for benzene, toluene, ethylbenzene,

xylenes, and naphthalene, and a TPH "trigger level" of 500 ppm. The TPH criterion is not a cleanup

standard, but a screening level to be used to determine whether additional investigation or other action

will be required at a site. OU-I is the only OU where soil cleanup standards are specified in the ROD. The

ROD for OU-I was signed in 1996 and accurately reflects the current regulations for petroleumcontaminated soil. The result of these changes is that generally higher concentrations of some organic

contaminants may be considered as acceptable action or cleanup levels at petroleum release sites at

EAFB. No changes were identified in the location and action specific ARARs.

6.2 CHANGES IN EXPOSURE PATHWAYS

The exposure pathways evaluated for each OU at EAFB are summarized in Tables 6-5 through 6-8. The

evaluations considered on-site and off-site exposures based on current and future land use. These

pathways are still appropriate for use in evaluation of the site, but one additional pathway is under review.

This is the air inhalation pathway for TCE vapor in residences and in work areas, e.g., the Pride Hangar,

that may originate in contaminated ground water. Limited sampling of indoor air in residences has been

completed with inconclusive results. Further sampling and testing is underway in 2005.

The exposure scenarios used are conservative and probably represent a greater potential average

(normally expected) exposure, than actual exposures. As an example, for landfills with earthen covers

that must be mowed as part of routine maintenance, it was assumed that the covers would be mowed six

times per year. In actual practice the covers are mowed at a less frequent rate (once or twice per year),

thus the estimated potential risk is greater than actual risk.

The most significant change in exposure pathways is the evidence of a completed ground water pathway

off-Base at OU-I 1. When the OU-11 human health risk assessment was completed no sampling had been

completed east of the northeastern Base boundary. This area has been referred to as AOC-24 and the

BG-04 area. Subsequent investigations have shown an extensive area where TCE-contaminated ground

water has left the base. This area was investigated and is undergoing remediation as part of the OU-11

Basewide Ground Water Remedial Action.

No completed exposure pathway has been identified for the flightline refueling area or the JP-4 plume

area.

L:IWORKIERSI846101WPIEAFB5-YEAR REVIEW2005 DOC 74 September 2005

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Final Five- }_,ar Review

6.3 TOXICITY AND OTHER CONTAMINANT CHARACTERISTICS

Table 6-9 provides a summary of the chemicals of concern (COCs) that resulted in remedial action being

recommended for various OUs at EAFB. Although risk assessments were done in detail for each OU, the

final remedial actions used applicable MCLs for ground water cleanup levels. With respect to other

potential exposures, since soil covers were installed to eliminate the exposure pathway, risks are not

likely to increase with changes in toxicity values. As noted in Table 6-9 six OUs (3, 5, 6, 7, 10, and 12)

did not have COCs reported in concentrations at a level that would require chemical specific remedial

actions being implemented at the OU. For the most part these OUs received remedial actions based on

action-specific criteria needed to provide for adequate soil cover on previously closed landfill areas. The

soil exposure remedy applied at OUs 2, 3, 4, 5, 6, 8, and 12 was based on the application of EPA's

Presumptive Remedy for Municipal Landfills, and was not specific for a COC.

Five COCs have had toxicity value or limits revisions since the RODs were completed for EAFB. Those

chemicals are summarized in Table 6-10. The change in the standards or chemical toxicity of the organic

analytes in ground water and soil (see note above) is not expected to affect the protectiveness of the

remedial actions applied at specific OUs. The current technologies applied, and possible new

technologies that are under consideration, are expected to remove the COCs to the levels identified as

cleanup goals. One possible exception is tile criteria for gamma chlordane (identified in ground water

samples at OU-I 1), which is now twenty fold lower than the previous criteria. No specific remedial

action was initiated for this COC; additional monitoring may be needed to determine if this chemical

poses an environmental risk. Gamma chlordane is a broad-spectrum insecticide and was used extensively

in agriculture and for termite control in the 1980s. Since that time its use has been restricted and EPA has

issued a no-use restriction on food products.

Chemical toxicity values have changed for COCs at the flightline refueling area and the JP-4 plume area.

For example, the toxicity level for benzene is lower (see Table 6-10); however, we are applying MCLs

and this will result in lower allowable concentrations in ground water than the risk-based approach and

the chemical toxicity values.

L !WORKERS¢_4610;WPEAFB 5 YEAR REVIEW200_ DOU 75 September 2005

; "S L• o -. 7 0S;,,,
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Final Five- Year Review

TABLE 6-1

FEDERAL AND STATE ARARS APPLIED TO ELLSWORTH AFB, SOUTH DAKOTA

A. Potentially Applicable or Relevant and Appropriate Federal Standards, Requirements, Criteria, and Limitations

Standard Requirernent, Criteria, or Limitation Citations Description ARAR Type Applicability to EAFB

Safe Drinking Water Act of 1986 42 USC 300g

National Prirnary Drinking Water 40CFRPam [41.11-12 Specifies maximum chemical contaminant Chemical Relevant and appropriate for Federal

Regulations levels (MCLs) of public water systems. Class [I aquifer.

National Secondary Drinking Water 40 CFR Part 143.03 Establishes secondary maxirnunl Chemical Relevant and appropriate,

Standards contaminant levels (SMCLs) for public

water systems. These are federally nonenforceable standards, which regulate

contaminants in drinking water that

primarily affect the qualities.

Maximum Contaminant Level Goals 40 CFR Part 141.50 & Establishes drinking water quality goals set Chemical Relevant and appropriate.

Pub. L. No. 99-330, I00 Slat. 642 (1986) al levels of unknown or anticipated adverse

health effects, with an adequate margin of

safety,

Clean Water Act of 1977 33 USC 1251-t376

Water Quality Criteria 40 CFR Part 131 Sets criteria for water quality based on Chemical Relevant and appropriate. Aquifer may

toxicity to aquatic organisrns and human be a Federal Class IIA (discharge to

health, surface water),

Criteria and Standards for the National 40 CFR 125.1-3 Establishes criteria and standards for Chemical Applicable for groundwater treated and

Pollutant Discharge Elimination technology-based requirements in pen'nits discharged to EAFB WWTP in future.

under the Sections 30[(b) and 402 of the

CWA.

General Pretreatment Regulations for 40 CFR 403.1-4, 8-I l, IB Establishes responsibilities of federal, state, Action Applicable for groundwater treated and

Existing and New Sources of Pollution and local government and of the POTW in discharged to EAFB WWTP in future.

providing guidelines for and developing,

submitting, approving, and modifying state

pretreatment programs,

40 CFR 403.5-7, 13, 15 Specifies standards for pretreatment.

Guidelines Establishing Test Procedures for 40 CFR 136.1-5 and Appendices A-C Specifies analytical procedures for NPDES Action Applicable for any future treatment and

the Analysis of Pollutants applications and reports discharge of ground water.

L IWORKIERSIg46IOIWPIEAFB5- YEARREVIEW 2005 DOC _6

3057 084 September2005
Ells worth Air Force Base

Final Five- Year Review

Standard Requirement. Criteria, o1"Limitation Citations Description ARAR Type Applicability to EAFB

('lean Air Act of 1983 42 USC 7401

National Primary and Secondary Ambient Air 40 CFR Part 50 I-6, 8,9,11,12, and Establishes national primary andsecondal T Action Applicable,

Quality Standard Appendices A, H, ,I, K ambient air quality standards to protect

public health and welthre.

National Emission Standards for Hazardous Air 40 CFR Part 6I 01 Establishes regulato W standard for specific Action Applicable lbr alternatives that would

F'ollutants air pollutants, discharge to the air following

treatlnen [,

Solid Waste Disposal Act as amended by 42USC6901

Resource Conservation and Recovery Act of 1976

Solid Waste Disposal Facility Criteria 40 C|:R Parts 257 and 258 Sets forth revised ininimum fiederal criteria Action Relevant and appropriate lbr addressing

lbr Municipal Solid Waste Landfills landfill closure performance standards.

{MSWt.Fs) for existing and new units

Land Disposal Restrictions 40 CFR Part 268 Identifies hazardous wastes that are Actiun Relevant and Appropriate, Alternati,,'es

restricted from land disposal and defines may include the disposal of residual

those limded circumstances under which a waste due to treatlnent,

prohibited waste may continue to be land

disposed

Guidelines lbr the Land Disp,._sa[nfgolid Waste 40 CFR PaI'{ 241 100-213 Establishes requirements and procedures tbr Action Relevant and appropriate for meeting

the disposaI of solid waste, landfill closure performance guidelines.

Resource Conser:ation and Recovery Act ol

1976

Hazardous Waste Management S>stem: General 40 CFR Part 260 Establishes defindions as well as Action Applicable lbr identifying hazardous

procedures and criteria for rnodification or waste during soil placement at landfills

revocation of any provision in 40 CFR Parts at EAFB

260-265

[der, tification and Listing of Hazardous Wastes 40 CFR Part 261 Defines those solid wastes which are Action Applicable for identifying hazardous

subject to regulations as hazardous wastes waste during soil placement at landfills

under 40 CFR Parts 262-265 at EAFB.

Standards Applicable to Generators of Hazardous 40 CFR Part 262 Establishes standards ¿br generators of Action Applicable to ahematives relating to _astes hazardous waste removal or offsite transport of a

hazardous material.

Standards Applicable to Transporters of 40 CFR Part 263 Establishes standards which apply to Action Applicable for any transport of Hazardous Wastes persons transporting hazardous waste hazardous materials off'site,

within the U,S, if the transportation requires

a manifest under 40 CFR Par_ 262

Standards for Ow'ners and Operators of 40 CFR Part 264 Establishes standards for acceptable Action Relevant and Appropriate for

Hazardous Waste TSDF's hazardous waste management, performance guidelines for landfill

closure.

L n'ORK'ERS8a61OHPEAFB 5-FE1R REVIEW 2005 DC)C 7 7 September 2005

3057 085
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Final Five- Year Review

Standard Requirement, Criteria, or Limitation Citations Description ARAR Type Applicability to EAFB

Toxic Substances Control Act (TSCA) 40 CFR Part 761.[ Substances regulated under this rule Action Applicable

include, but are not limited to, soils and

other materials contaminated as a result of"

spills

Fish and Wildlife Coordination Act 16 USC 1531-666 Requires consultation when a federal Action Not an ARAR.

40 CFR 6,302(g) department or agency proposes or

authorizes any modification of a stream or

other water body and adequate provision for

protection of fish and wildlife resources

Endangered Species Act 16 USC 1531-1543 Requires that Federal agencies insure that Location/Action Not an ARAR. Ecological Assessment

50 CFR Parts 17, 402 any action authorized, funded, or carried out did not identify EAFB as having

40 CFR 6.302 (g) by the agency is not likely to jeopardize the critical habitat or endangered species.

continued existence of any tbreatened or

endangered species or destroy or adversely

modify critical habitat

Archaeological and Historic Preservation Act 16 USC 469 Establishes procedures to provide for Location Potential ARAR. On-Base property

40 CFR 6.301(c_ preservation of historical and archaeological was used for landfilling activities. No

data, which might be destroyed through known historic or archaeological value,

alteration of terrain as a result of federal although no confirmation study has

construction project for a federal licensed been pertbrmed.

activity or program.

Archaeological Resources Protection Act 93 Star. 721 Requires a pernait for an excavation or Action/Location Not an ARAR.

(1979) 16USC470 removal of archaeological resources from

public or Indian land.

Executive Order 11,958 on Floodplains 42 USC 7401 Requires federal agencies to evaluate the Location Not an ARAR. Area not in lO0-year

Management 40 CFR 6,302 (b) & Appendix A potential effects of actions they may take in floodplain.

a floodplain to avoid, to the extent possible,

the adverse impacts associated with direct

and indirect development of a floodplain

Executive Order on Protection of Wetlands Exec. Order No. 11,990 Requires federal agencies to avoid, to the Action/Location Applicable. EAFB has identified

40 CFR 6.302(a) & Appendix A extent possible, the adverse impacts wetland areas adjacent to sites where

associated with the destruction or loss of Ras were completed.

wetlands and to avoid support of new

construction in wetlands if a practicable

alternative exists

LIWORK_+RS_846IO_,WP'_EAFB5"YLARREVIEIq"2005DOC 7_ 3057 080 eptember2005
Ellsworth Air Force Base

Final Five- Year Review

Standard Requirement, Criteria, or Limitation Citations Description ARAR Type Applicability to EAFB

B. Potentially Applicable or Relevant and Appropriate State Standards, Requirements, Criteria, and Limitations

South Dakota Air Pollution Control 74:36:01-18 Establishes pert'nit requirements for ,Action Applicable

construction, amendment, and operation of

Regulations air discharge services

South Dakota Waste ]Management 74:28:05 Establishes requirements for disposal of Action Relevant and appropriate for landfill

Regulations hazardous waste in sanitary landfills closure performance guidelines.

South Dakota Waste Management 74:27:15:03 Defines requirements for closure of solid Action Relevant and appropriate for landfill

Regulations waste disposal facilities closure performance guidelines,

South Dakota Waste Management 74:27:09:O6 Defines criteria for peranit application for Action Not an ARAR

Regulations otber solid waste TSD facilities

South Dakota Waste Management 74:27:15:09 Establishes standards for landfill closure Acnon Relevant and appropriate

Regulations and postctosure monitoring

South Dakota Waste btanagement 74:28:24:01 Establishes standard for transporters of Action Relcvant andappropriatc

Regulations waste

South Dakota Water Discharge Permit Rules 74:52:02 Establishes surihce water discharge permit Action Applicable for any ground-water

applications requirements treatment discharge.

South Dakota Water Discharge Permit Rules 74:52:03 Establishes surface water permit conditions Action Applicable for any ground-water treatment discharge

South Dakota Water Discharge Permit Rules 74 _3:( ] Establishes requirements [or individual and Action Applicable for any ground-water

small onsite v,,astev,'ater systems treatment discharge

South Dakota Water Qualit) Standards 74:51:03:1 I Defines use of Box Elder Creek and certain Action Applicable for an_ ground-water tributaries treatment discharge

South Dakota Remediation (?riteria for 74:56:05 Establishes requirements for the Chemical Relevant and appropriate for evaluating

Petroleum-Contaminated Soils remediation of soil contaminated v,ith acceptabie levels of pctroleum products

petroleum products, in tile soil

South Dakota Ground Water Standards 74:54:01 Defines ground ",,rater classilqcations by Claentical Rele',,ant and appropriate in evaluating

beneficial use and sets chemical standards the beneficial use of impacted

groundwater.

L Jif)RI< A/¢S;e4,',H)I_I-',LA/-135- YA,4RA'Al'Ik. W 2g)o5DO(' 79 Septeml)er 200f

3057 087
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Final Five-Year Review

TABLE 6-2

CHANGES IN CHEMICAL-SPECIFIC STANDARDS

Contaminant Media II Standard (ug HH/AA/AC /L) Source _ /Year l|

BHC (alpha) (Hexachlorocyclohexane-alpha) Surface Water Previous 0.031 SDSWQC 1996211

New 0.026/--/-- SDSWQC 20053'

Previous 0.063 SDSWQC 1996

BHC (beta) (Hexachlorocyclyhexane-beta) Surface Water New 0.0091/--/-- SDSWQC 2005

Previous 0.096 SDSWQC 1996

BHC (gamma) (Lindane) Surface Water New 0.098/0.095/0.095SDSWQC 2005

Previous 20/134 SDSWQC 1996

Pentachlorophenol Surface Water

New 0.27/19/15 SDSWQC 2005

Previous 82/3.2 SDSWQC 1996 Lead Surface Water

New --/65/2.5 SDSWQC 1998

Previous 2.4/0.012 SDSWQC 1996

Mercury Surface Water New 0.050/1.4/0.92 SDSWQC 2005

Standard (mg/kg)

Contaminant Media (SDDENR Action Source/Year

levels)

Previous NS SDRCPCS 1991

Benzene Soil

New 0.2 SDRCPCS 1995

Previous NS SDRCPCS 1991 Toluene Soil

New 15 SDRCPCS 1995

Previous NS SDRCPCS 1991

Ethylbenzene Soil New 10 SDRCPCS 1995 '

Previous NS SDRCPCS 1991

Xylenes Soil New 300 SDRCPCS 1995

Previous NS SDRCPCS 1991

Naphthalene Soil New 25 SDRCPCS 1995

Previous 10-100 SDRCPCS 1995

Total Petroleum Hydrocarbons Soil New 500 SDRCPCS 1999

Contaminant Media [[ Standard (mg/L) Source/Year

Previous 0.003 SDGWQS: Aldecarb sulfone Ground Water

New 0.002 SDGWQS 7

Previous ND 8 SDGWQS 9

Benzo(a)pyrene Ground Water New 0.0002 SDGWQS 9

Previous ND SDGWQS 7

Dalapon (sodium salt) Ground Water

New 0.2 SDGWQS 9

L. IWORKIERSI84610iWP!EAFB 5-YEAR RE_TEW 2OO5 DO(" 80 September 2005

3057 088
Ellsworth Air t'?_rce Base

Final I'_ve- 'fear Review

Previous ND SDGWQS 7 Di(2-ethylhexyl)adipate Ground Water

New 0.4 SDGWQS _

Previous ND SDGWQS v

Di(2-ethylhexyl)phthalate Ground Water

New 0.006 SDGWQS 9

Dichloromethane (Methylene chloride) Ground Water Previous ND SDGWQS 7

New 0.005 SDGWQS 9

Previous ND SDGWQS 7

Dinoseb Ground Water New 0.007 SDGWQS 9

Diquat Ground Water Previous ND SDGWQS 7

New 0.02 SDGWQS 9

Previous ND SDGWQS 7

Endothall Ground Water New 0. | SDGWQS 9

Previous 0.0002 SDGWQS 7

Endrin Ground Water New 0.002 SDGWQS _

Glyphosate Ground Water Previous ND SDGWQS 7

New 0.7 SDGWQS _

Hexachlorobenzene Ground Water Previous ND SDGWQS 7

New 0.001 SDGWQS 9

Hexachlorocyclopentadiene Ground Water Previous ND SDGWQS v

New 0.05 SDGWQS 9

Total Haloacetic Acids, including: Previous ND SDGWQS 7

Dichloroacetic acid, Monochloroacetic acid, Ground Water New 0.06 SDGWQS _ and Trichloroacetic acid

Previous ND SDGWQS v Oxamyl (Vydate) Ground Water

New 0.2 SDGWQS 9

Previous ND SDGWQS 7 Pichoram Ground Water

New 0.5 SDGWQS ')

Previous 0.00005 SDGWQS 7 Polychlorinated biphenyls (PCBs) Ground Water

New 0.0005 SDGWQS 9

Previous ND SDGWQS 7 Simazine Ground Water

New 0.004 SDGWQS 9

Previous ND SDGWQS7 2,3,7,8-TCDD (Dioxin) Ground Water

New 3.0E-08 SDGWQS 9

Previous ND SDGWQS v 1,2,4-Trichlorobenzene Ground Water

New 0.07 SDGWQS 9

Previous ND SDGWQS v i, 1,2-Trichloroethane Ground Water

New 0.005 SDGWQS 9

Total trihalomethanes, including Previous 0. l SDGWQS 7

bromodichloromethane, bromoform New 0.08 SDGWQS 9

(tribromomethane), chloroform

(trichloromelhane), and Ground Water

dibromochloromethane

(chlorodibromomethane)

L ltORKERS,84510'IVPE4FB 5-YEAR REI'IEW2005 DOC 81 September 2005

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Ellsworth Air Force Base

Final Five-Year Review

Antimony Ground Water Previous NSI SDGWQS 7

New 0.006 SDGWQS9

Arsenic Ground Water Previous 0.05 SDGWQS 7 New 0.01! SDGWQS 9

Previous NS SDGWQS 7

[Asbestos Ground Water New 7MFL (longer SDGWQS 9 than 10

micrometers)

Previous NS i SDGWQS 7

Beryllium Ground Water New 0.004 SDGWQS 9

Bromate Previous NS! SDGWQS 7

Ground Water New 0.011 SDGWQS 9

Chlorite Ground Water Previous NS! SDGWQS 7

New 1 SDGWQS 9

_Copper Ground Water Previous 1.3 _ SDGWQS 7 New 1 SDGWQS 9

_yanide Ground Water Previous ND l SDGWQS 7

New 0.2 SDGWQS 9

Previous 2.41 SDGWQS 7 !Fluoride Ground Water

New 41 SDGWQS 9

Previous NSJ SDGWQS 7 Nitrate + Nitrite (both as N) Ground Water

New 101 SDGWQS 9

Silver Ground Water Previous 0.05 SDGWQS 7 New 0.1 SDGWQS 9

Thallium Ground Water Previous NS SDGWQS 7 New 0.002 SDGWQS 9

Beta particle and photon radioactivity (from Previous NS SDGWQS 7

!man-made radionuclides) Ground Water New 4 mrem/yr SDGWQS 9

Previous 15pCi/L SDGWQS 7

excluding

uranium SDGWQS 9

gross alpha Ground Water New 15pCi/L

excluding'

uranium and

radon

L_ WORKIERSI84610iWPIEAFB5-YEARREVIEW 2005 DOC 82 September 2005

• 3057 090
Ellswortk Air Force Base

Final Five-Year Revww

Radon Previous NS SDGWQS 7

Ground Water New 300 pCi/L SDGWQS '_

Uranium Previous 0.02 SDGWQS 7

Ground Water New 0.03 SDGWQS 9

HH/AA/AC=Human Itealth-Ingestion/Aquatic Acute/Aquatic Chronic.

2 South Dakota Surface Water Quality Criteria 1996.

3 South Dakota Surface Water Quality Criteria 1998.

4 Acute/Chronic ug/L.

5 NS=No Standard.

6 South Dakota Remediation Criteria for Petroleum Contaminated Soils 1995.

7 South Dakota Surface Water Quality Criteria 2004.

ND = Non Detect.

9 South Dakota Surface Water Quality Criteria 2005.

TABLE 6-3

CHANGES IN ACTION-SPECIFIC STANDARDS

Action Requirements Prerequisite Citation/Year

Previous None

New

TABLE 6-4

CHANGES IN LOCATION-SPECIFIC STANDARDS

Location Requirements Prerequisite Citation/Year

Wetland Previous None

New

L _I|T)RK_ERS84610WP E.IFB _ }L.4RREI'IE_4"2005DO(_" _%'3 Septenlber 2005

3057 091
Ellsworth Air Force Base

Final Five- Year Review

TABLE 6-5

SUMMARY OF EXPOSURE PATHWAYS EVALUATED FOR THE HUMAN HEALTH RISK ASSESSMENT FOR

CURRENT ON-SITE LAND USES AT ELLSWORTH AFB

Y=pathway complete NA= pathway not applicable to site not at site

EXPOSURE PATHWAYS OU-1 OU-2 OU-3 OU-4 OU-5 OU-6 OU-7 OU-8 OU-9 OU-10 OU-11 OU-12

CURRENT ON SITE USES Chem./

rad.

Commercial/Industrial Land Use.

GROUND WATER

Ingestion N N N N N N N/Y N N N N N

SURFACE SOIL

Ingestion Y Y N Y Y Y Y/Y Y Y Y N Y

Dermal Contact Y Y N Y N Y Y/N Y Y y N Y

Inhalation N N N N N/N Y Y N N N

External NA NA NA NA NA NA NA/Y NA NA NA NA NA

SUBSURFACE SOIL

Ingestion N N N N N N N/N N Y N N N

Dermal Contact N N N N N N N/N N Y N N N

Inhalation N N N N N N N/N N Y N N N

External NA NA NA NA NA NA NA/N NA NA NA NA NA

SURFACE WATER

Ingestion N N N N N Y N/N N N N N N

Dermal Contact Y N N N N Y N/N N Y N N N

Inhalation Y N N N N Y N/N N N N N Y

External NA NA NA NA NA NA NA/N NA NA NA NA NA

SEDIMENT

Ingestion 'Y N N N N Y N/N N Y N N N

Dermal Contact N N N N N N N/N N N N N N

Inhalation N N N N N N N/N N N N N N

External NA NA NA NA NA NA NA/N NA NA NA NA NA

AIR

Inhalation Y N N N N Y N/N Y Y N N Y

FAUNA

Ingestion of fish/game N N N N N N N/N N Y N N N

L'_WORK_,ERSig461(IIWPiEAl-'BS-YEARREVIEW2005DOC _4 3057 092 September2005
Ells worth Air Force Base

Final Five- Year Review

TABLE 6-6

SUMMARY OF EXPOSURE PATHWAYS EVALUATED FOR HUMAN HEALTH RISK ASSESSMENT FOR

CURRENT OFF-SITE LAND USES AT ELLSWORTH AFB

Y= _lete NA = to site N = not completed at site

EXPOSURE PATHWAYS OU-1 OU-2 OU-3 OU-4 OU-5 OU-6 O'U-7 OU-8 OU-9 OU-10 OU-11 OU-12

CURRENT OFF-SITE USES Chem./Rad,

Residential/Agricultural Land Use. ]

I,, GROUND WATER [

Ingestion N N N Y N N/N N N N N N

Inhalation N N N Y N N N N N N N

SURFACE SOIL

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

External Exposure NA NA NA NA NA NA N NA NA NA NA NA

SUBSURFACE SOIL

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

SURFACE WATER

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

SEDIMENT

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

AIR

Inhalation N N N N N N N N N N N

FAUNA

Ingestion of fish/game N N N N I N N N N N N N

k :JIORKkT?S_g6/()I_,Pk.I?B 5-)k.lJ? ]?EITEI4"20;)5 _r)OC _.5 Se, u/el,ubd_'" 200.5

3057 093
Ellsworth Air Force Base

Final Five-Year Review

TABLE 6-7

SUMMARY OF EXPOSURE PATHWAYS EVALUATED FOR HUMAN HEALTH RISK ASSESSMENT FOR

FUTURE ON-SITE LAND USE AT ELLSWORTH AFB

_lete NA= to site not 91eted at site

EXPOSURE PATHWAYS OU-I OU-2 OU-3 OU-4 OU-5 OU-6 OU-7 OU-8 OU-9 OU-10 OU-11 OU-12

FUTURE ON-SITE USES Chem./Rad

On-Site Residential Land Use.

GROUND WATER

Ingestion y y y y y y y/y y y y y y

Dermal Contact Y Y Y Y Y Y Y/N Y y y y y

Inhalation Y Y Y Y N Y Y/N Y y y y y

External NA NA NA NA NA NA NA/N NA NA NA NA NA

SURFACE SOIL

Ingestion 'Y Y Y Y Y Y Y/Y Y Y Y N Y

Dermal Contact Y Y Y Y N Y Y/N Y N Y N Y

Inhalation Y N N N N N N/N N Y N N N

External NA NA NA NA NA NA NA/N NA NA NA NA NA

Ingestion of homegrown produce NA N N N N N N/N N N N N N

SUBSURFACE SOIL

Ingestion N Y Y y y y y/y y y y N Y

Dermal Contact Y N N N N N N/N N N N N N

Inhalation Y Y Y Y N Y Y/N N Y y N Y

External NA NA NA NA NA NA NA/Y N NA NA NA NA

SURFACE WATER

Ingestion Y Y N N N Y y/Y N Y N N Y

Dermal Contact Y Y N N N Y Y/N N Y N N Y

Inhalation Y Y N N N Y Y/N N N N N Y

External NA NA NA NA NA NA NA/N NA NA NA NA NA

SEDIMENT

Ingestion Y Y N N N Y Y/Y N Y N N Y

Dermal Contact Y Y N N N Y Y/N N Y N N Y

Inhalation Y Y N N N Y Y/N N N N N Y

External NA NA NA NA NA NA/N NA NA NA NA NA 'AIR

Inhalation Y Y Y Y N Y Y/y y y y N Y

FAUNA

Ingestion of fish/l_ame, N N N N N N N/N N Y N N N
Ellsworth Air Force Base

Final Five-Year Revtew

TABLE 6-8

SUMMARY OF EXPOSURE PATHWAYS EVALUATED FOR HUMAN HEALTH RISK ASSESSMENTS FOR

FUTURE OFF-SITE LAND USES AT ELLSWORTH AFB

Y= )lete NA = _licable to not completed at site

EXPOSURE PATHWAYS OU-I' OU-2 OU-3 OU-4 OU-5 OU-6 OU-7 OU-8 OU-9 OU-10' OU-11 OU-12

FUTURE OFF-SITE USES

Residential

GROUND WATER

Ingestion N Y N Y N N N N N Y N

Dermal Contact N Y N Y N N N N N Y N

Inhalation N Y N Y N N N N N Y N

SURFACE SOIL

In_,estion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

SUBSURFACE SOIL

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

SURFACE WATER

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

SEDIMENT

Ingestion N N N N N N N N N N N

Dermal Contact N N N N N N N N N N N

Inhalation N N N N N N N N N N N

AIR

Inhalation N N N N N N N N N N N

FAUNA

Ingestion of fish/game N N N N N N N N N N N
Ellsworth Air Force Base

Final Five- Year Review

TABLE 6-9

CHEMICALS OF CONCERN AT EAFB THAT RESULTED IN TIlE APPLICATION OF A

REMEDIAL ACTION

'Note. Presumptive Remedy Applied at OU-3, OU-5, OU-6, OU-10, and OU-12 therefore No COC listed)

COC Operable Units

1 [ 21314 I 5 [ 6 [ 7 I 8[9110111}12

GROUND WATER

benzene X X .... X

ethylbenzene ..... X

toluene - - _

xylenes - - X

l,l,l-Trichloroethane X

1,2-DCE X X X X

1,2-DCA X X

I,I-DCE X X

PCE X X

1,2,4-- X ._

"Frichlorobenzene

1,4-Dichtorobenzene X

FCE X X X

vinyl chloride X X

benzo[a] pyrene

a-nitroso-di-n- X

_ropyalamine

ibis (2-chloroethyl) X

ether

Aldrin X - _

alpha-BHC X _

Heptachlor X -

Beta BHC - X

bis(2-ethylhexyl) - - X

9hthalate

TPH X - - X

JP-4 X _

gamma chlordane .... X

p,p'-DDT .... X

Cadmium - - - X -

Lead X -

SURFACE SOIL

benzene X

1,2-DCE X

PCE X

rCE X

FPH X

JP-4 X

benzo[a] pyrene X

:lioxins X

SUBSURFACE SOIL

Low level Radiological waste X

SEDIMENT

benzo[a] pyrene I I xl I I I I I I I I I

L-IWORKIERSI846101WP',EAFB _-?EAR REVIEW 2005 DOC 88 September 2005

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TABLE 6-10

TOXICITY VALUES FOR CHEMICALS OF CONCERN AT EAFB

Oral Inhalation Oral Inhalation

RfD RfC Slope Factor Slope Factor

COC (mg/kg-d) (mg/m') (mg/kg-d)" (mg/kg-d)

Value1995 Value2000 Value2005, S Value199512000Value 2001 1995 2000 2005] 1995 2000 I 2005I I Value S Value Value Value S Value Value Value S

Volatile Organic Compounds:

benzene na 3.0E-3 4.0E-3 I na 1.7E-3 3.0E-2 I 2,9E-2 2.9E-2 5.5E-2 1 8.3E-6 2.7E-2 2.7E-2 I'

dichloroethane, 1,2- na 3.0E-2 2.0E-2 P na 1.4E-3 2.5E+0 M 9.1E-2 9,1E-2 9.1E-2 I 9.1E-2 9,1E-2 9.IE-2 I

dichloroethylene, 1,1- 9.0E-3 9.0E-3 5,0E-2 1 na 1.4E-I 2.0E-1 I 6.0E-I 6.0E-1 na na na na

dichloroethylene, 1,2- 2.0E-2 9.0E-3 H2 na 6.0E-2 pl 9,1E-2 na 9.1E-2 na

ethylbenzene 1.0E- 1 1.0E- 1 I 1.0E+0 1.0E+0 I na na na na

naphthalene 4.0E-2 2.0E-2 2.0E-2 1 na 3.0E-3 3.0E-3 I na na na na na na

toluene 2, IE- 1 2.0E- 1 8,0E-2 I na 4.0E- l 5,0E+O I na na na na na na

tetrachloroethytene (PCE) I.OE-2 1.0E-2 I na 4.9E-1 E na 5.4E-1 O na 2,0E-2 O

trichloroethane, 1,1,1- na 3,5E-2 2.8E-1 E na 2,9E-I 2,2E+0 P na na na na na na

trichloroethylene (TCE) na 6,0E-3 3.0E-4 E na 6.0E-3 3.5E-2 E I.tE-2 I.IE-2 4.0E-1 E na 6.0E-3 4.0E- I E

vinyl chloride na 3.0E-3 I na 9.8E-2 I 1.9E+O 1.4E+0 I 3,0E-I 3.0E-2 I

xylenes 2.0E+0 2.0E-I 1 na 1.OE-I I na na na na

Petroleum Compounds:

JP-4 na na na na na na na na na na na na

Semivolatile Organics:

trichlorobenzene, 1,2,4- 1.0E-2 l.OE-2 1 na 3.5E-3 P na na na na

dichlorobenzene, 1,4- na 3.0E-2 E 8.0E-1 8,0E-I I 2.4E-2 2.4E-2 H na 2.2E-2 E

methylnaphthalene, 2- na na 4,0E-3 I na na na na na na na na na

benzo[a]pyrene na na na na 7.3E+0 7.3E+0 I 6.1E+0 3.1E+0 E

bis(2-chloroethyl)ether na na na na 1.IE _0 I. IE+0 1 1.2E+0 1.1E+O I

BEHP 2.0E-2 2,0E-2 1 na na 14E-2 1.4E-2 I na na

NDPA na na na na 7.0E +-0 7.0E+O 1 na na

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Oral Inhalation Oral Inhalation

RfD RfC Slope Factor Slope Factor

COC /mg/kg "d) /mg/m_) (mg/kg-d)" (mg/kg-d),

, Values Va , lueValoe"al, o,s VaIuo"alue ValueIs

Pesticides and PCBs:

aldrin 3.0E-5 3.0E-5 l na na 1.7E+I 1.TE+I I I.TE+l 1.7E+I I

alpha-BHC (alpha-HCH) na na na na 6,3E+0 6.3E+0 l 6.3E+0 6.3E+0 I

beta-BHC (beta-HCH) na na na na 1.BE+0 1.8E+0 I 1.9E-4 1.8E+0 I

chlordane 6.0E-5 5.0E-4 5.0E-4 I na 7.0E-4 7.0E-4 l na 3.5E-1 3.5E-I I na 3.5E-1 3.5E-1 I

chlordane, gamma 6.0E-5 na 5.0E-4 I na na 7.0E-4 l na na 3.5E-1 I na na 3.5E-1 I

DDE na na na na na na na 3.4E- 1 3.4E- 1 I na na na

DDT 5.0E-4 5.0E-4 I na na 3.4E-I 3.4E-1 I 3.4E-I 3.4E-1 I

heptachlor 5.0E-4 5.0E-4 l na na 4.5E+0 4.5E+0 l 4.6E+0 4.6E+0 I

PCBs na na 2.0E-5 13 na na na na 2.0E+0 2.0E+O I na 2.0E+0 2.0E+0 I

Dioxins:

di°xins4 I na [ na na [ I na I na na I na 1.5E+5 1.5E+5 H I na 1.5E+5 1.5E+5 I H

Metals:

arsenic 3.0E-4 3.0E-4 3.0E-4 I na na na 1.8E+0 1.5E+0 1.5E+0 l 1.5E+0 1.5E+l 1.5E+l I

aluminum na 1.0E+0 1.0E+0 p na 1.4E-3 3.5E-3 P na na na na na na

beryllium 5.0E-3 2.0E-3 2.0E-3 I na 2.0E-5 2.0E-5 I 4.3E+0 na na 8.4E+0 ' 8.4E+0 8.4E+0 I

cadmium 5.0E-4 5.0E-4 1S na 2.0E-4 E na na 6.IE+0 6.3E+0 I

chromium _ 1.0E+0 3,0E-3 3.0E-3 I na 8.0E-6 8.0E-6 I na na na na 2.9E-2 4.1 E+ 1 I

cobalt na 6.0E-2 2.0E-2 p na na 2.0E-5 P na na na na na 9.8E+0 P

lead na na na na na na na na na na na na

manganese 5.0E-5 1,4E-4 2.0E-2 I 5.0E-5 5,0E-5 5.0E-5 I na na na na na na

thallium na na 7,0E-5 O na na na na na na na na na

na = No values were found in readily available literature. Sources for 2005 toxicity values:

NPDA = N-nitroso-di-N-propylamine. I = Integrated Risk Information System (IRIS)

BEHP = bis(2-etbylhexyl)phtbalate, P = USEPA Provisional Peer-Reviewed Value (PPRV) (taken from Region 3

RfD = Reference dose. RBC Table, version 04/05)

RfC = Reference concentration. N = USEPA National Center for Environmental Assessment (NCEA) (taken

S = Source from Region 3 RBC Table, version 04/05;,

M = Minimum Risk Level (MRL) from Agency for Toxic Substances and

Value for dichloroethylene, 1,2-trans. Disease Registry (ATSDR) (taken from Region 3 RBC Table, version 04/05.

: Value for total 1,2-dichloroethylene. O = Other unnamed sources (taken from Region 3 RBC Table, version 04/04. Value for Aroclor 1254.

4 For dioxins not otherwise specified, the value for 2,3,7,8-tetrachlorodibenzodioxin is used. Source for 2000 toxicity values: Final Five Year Review, Ellsworth AFB,

5 Cadmium value for water. South Dakota, September 19, 2000.

_' Chromium assumed to be Cr VI. Source for 1995 toxicity values: Final Remedial Investigation Reports at

Ellsworth Air Force Base, South Dakota. 1995.
El/sworth Air Force Base

Final PTve- Year Revww

7.0 ASSESSMENT

7.1 REMEDY OPERATION

7.1.1 HASP and Contingency Plan

All work conducted at the site is completed in compliance with the Base Wide Health and Safety Plan

(HASP) unless an addendum to the HASP is submitted for a particular activity or operable unit. All

workers are required to attend a Health and Safety briefing and site walk over prior to commencing work

at any operable unit.

A Contingency Plan is also in place for all OUs. The Contingency Plan consists of an ongoing process

within the Long Term Monitoring/Long Term Operations (LTM/LTO) program that wilt identify any

failure of the selected remedy or remedies; establish a budget for necessary corrective action; obtain

funding through the Air Force's project programming system; and implement the corrective action. For

Operable Units that included a landfill cap as a part of the final selected remedy, quarterly visual

inspections of the landfill caps are conducted and repairs are performed as needed to maintain the

integrity of the caps to assure compliance with the RODs.

7.1.2 Institutional Controls and Other Measures

Institutional controls and others measures applied at EAFB included a standing order by the

Base commander restricting property use at specific OUs, installation of fencing and posting new signs

identifying areas as restricted to control access to the sites and the development of appropriate deed

restriction language that could be placed on properties should they be sold or transferred from the

Air Force in the future. The deed restrictions have not been filed as no specific properties have been sold

or transferred. Base closure would require restrictions being registered on County property records. Base

maps depicting environmentally-impacted areas are periodically updated. Contaminated ground water

plumes are monitored quarterly or semi-annually and data is presented in LTM reports.

The institutional controls have been effective for controlling access to the OUs, with one noted exception.

At OU-8, out-of-date or unstable ordnance was destroyed (exploded) on one occasion prior to 2000. Prior

to detonation of the ordnance, the site was graded and a shallow burn/blast pit was constructed. This

excavation resulted in breaching of the soil cover placed on this area as part of the selected remedial

action for the OU. This was a violation of the institutional controls established for the protection of

human health and the environment. The Base made immediate evaluations of the action and repaired the

cover. This effort included review of operation directives, providing for additional staff/personal training,

completion of sampling and analysis of surface soil samples to determine if COCs had been released,

installation of new signage, development and distribution of a new Base map showing environmentally

restricted areas, and re-issuance of the Base Commander Continuing Order Policy.

The institutional controls have been effective for controlling access to the flightline refueling area and

JP-4 area.

7.1.3 Remedial Action Performance

The following is a summary of remedial action performance and history at all operable units including

system performance and progress towards cleanup levels. Recommendations for changes in the remedial

actions at each Operable Unit are contained in Chapter 9.

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OU-I

The remedial system in the OU-i area consists of a combined soil vapor/ground water extraction system.

Two ground water extraction wells were added to the system since the 2000 Five Year Review, to

improve containment in the southeast corner of the ground water plume. The system is designed to treat

highly contaminated soils and ground water as well as to contain the ground water contaminant plume onsite. Institutional controls at this site consist of a fenced perimeter with a locked gate and appropriate

signs to restrict access to the OU. It appears from the LTM that the OU-I system is functioning as

designed; however it is unlikely that the system will reach MCLs in the near future. It was estimated in

the original design analysis that it would take 25 years to remediate soil and ground water at this site.

OU-2

The remedy at the OU-2 area consists of a landfill cap to prevent movement of contaminants, creation of

a drainage ditch and a LTM program. It appears that the remedy at this site is functioning as designed.

Institutional controls at this site consist of a fenced perimeter with a locked gate and appropriate signs to

restrict access to the OU. Two removal actions took place in the OU-2 area. Chemical weapons material

training sets and low-level radioactive waste were excavated from this area and disposed off-site. Since

the 2000 Five Year Review, three ground water extraction wells were constructed along the south

boundary of the operable unit, to address TCE contamination in ground water. In addition, settlement has

occurred in the landfill in areas where waste was placed in trenches. Soil fill is being added to restore the

surface grade in these areas.

OU-3

The selected remedy in the OU-3 area consists of a landfill cover and LTM monitoring. Institutional

controls at this site consist of a fenced perimeter with a locked gate and appropriate signs to restrict access

to the OU. One of the monitor wells in this area became unusable due to casing damage. Direct push

borings have been installed to determine whether a new monitor well is required in this area. The landfill

cover remedy is functioning as intended.

OU-4

The remedial system in the OU-4 area consists of a landfill cap and ground water extraction system. The

landfill cover is designed to prevent infiltration through buried waste while the ground water extraction

system is designed to contain the plume and to remediate the plume south of the landfill. Institutional

controls at this site consist of a fenced perimeter with a locked gate and appropriate signs to restrict access

to the OU. The long-term monitoring data indicates that the pump and treat containment system is not

completely effective, due to geologic conditions (heterogeneous soils and impermeable soils) which limit

the effectiveness of this technology.

Additional ground water extraction wells have been installed to enhance the effectiveness of the plume

containment system. The remedial design analysis estimated that 15 years would be required to remediate

the off-Base portion of the plume. Experience is indicating that the required time for remediation with

pump and treat will be longer. Alternative technologies to enhance the ground water remediation are

discussed in Section 4.4 (System Optimization) and in Section 9.

L"WORK'LERS"846101H'PIE,4FBS-YEARREVIEIV2005DOC 92 3057 10 _tember2005
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Final Five-Year Revtew

OU-5

The remedy in OU-5 consists of a landfill cap and LTM monitoring. Institutional controls at this site

consist of a fenced perimeter with a locked gate and appropriate signs to restrict access to the OU. The

remedy's effectiveness was hampered by a landslide in the years following the cover construction. This

caused breaches in the landfill cover soil, allowing surface water to infiltrate into the waste area. A

system of underdrain pipes was installed in the area in 2001 to lower the ground water table at the top of

the Pierre Shale, where tile slope failure occurred. Monitoring of the area has shown a reduction in ground

water levels and the slide movement has been halted.

OU-6

The remedy in the OU-6 area consists of a landfill cap and LTM monitoring. Institutional controls at this

site consist of a fenced perimeter with a locked gate and appropriate signs to restrict access to the OU. It

appears that the remedy is functioning as designed and that ground water has not been impacted by

contamination from waste in the landfill.

North of the landfill an area of incinerator ash was discovered since the 2000 Five Year Review. Limited

testing of the material has been performed to determine its extent and chemical characteristics. The Air

Force is considering removing this material in order to eliminate any future concern about the material

and to free this area for future construction or other land use.

OU-7

The remedy in the OU-7 area consists of institutional controls and monitored natural attenuation.

Institutional controls at this site consist of a fenced perimeter with a locked gate and appropriate signs to

restrict access to the OU. The plume has been delineated in the northeast corner of the MSA and in areas

immediately to the north and the east. The plume is stable. The VOC concentration has been low (<25

ppb) for the past several years and has been declining. In the September 2004 sampling event, the

maximum TCE concentration was 2.9 ppb which is below the MCL. A low-level radioactive waste

(LLRW) removal action also was performed in this OU in 1997. The LLRW was disposed of at an offsite

location. The remedy is functioning as intended.

OU-8

The remedy in the OU-8 area consists of a soil cover and LTM monitoring. Institutional controls at this

site consist of a fenced perimeter with a locked gate and appropriate signs to restrict access to the OU.

The remedy appears to be functioning as designed. No ground water impacts have occurred. Prairie dogs

have been observed moving into the area of the cover over the Debris Burial Area. This could

compromise the cover. The Air Force is considering an action to excavate and remove the buried material

in this area, rendering the prairie dog issue moot.

OU-9

OU-9 had a no-action ROD.

OU-10

OU-l0 had a no-action ROD.

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OU-11

The remedy in the OU-I l area consists of eight ground water extraction systems that are designed to

contain low-level chlorinated hydrocarbon contamination, as well as monitored natural attenuation in the

area east of the installation. It appears that the systems are functioning as designed although, due to the

expanse of the plumes, it is unlikely that contaminant levels will reach MCL's in the near future. A fourth

extraction well was placed in the BG-05 Base Boundary remediation system since the 2000 Five Year

Review. A fifth extraction well is being installed at the BG-05 system in 2005 to enhance containment in

this area.

In-situ remediation is being implemented at the northwest comer of the Pride Hangar, where a localized

area of TCE ground water contamination has been found. The remediation consists of sodium lactate and

vegetable oil injection to achieve reductive biodechlorination in-situ. An Explanation of Significant

Difference (ESD) is being executed to accomplish this in-site remediation.

An off-base water line conveying potable water to land owners impacted by the off-site portion of the

plume in the AOC 24 area has been installed to mitigate any potential risk to the public. An additional

water line was constructed to serve property located south of the Base near OU-4. This water line was

installed to limit the pumping of the ground water in this area as the TCE plume from the OU had moved

south of the Base boundary and had been detected in private domestic wells.

TCE contamination has been detected in ground water flowing from a drain line under the South Docks,

and a pump is being installed to move this water to the FRA-PH l treatment facility. Further monitoring is

planned in this area, identified as ST-23. This area contains UST sites and was the site of the original

Civil Engineer shops in the 1940s. The monitoring is intended to locate sources of the TCE contamination

and to address UST sites in this area.

OU-12

The remedy in the OU-12 area consists of a landfill cover and LTM monitoring. The institutional

controls at this site include a perimeter fence with locked gates and appropriate signs to restrict access to

the OU. The remedy appears to be functioning as designed; however, TCE concentrations in ground water

north of the OU continue to slightly exceed MCLs. Minor erosion has occurred on the landfill cover and

has been repaired.

7.1.4 Operation and Maintenance

Operation and maintenance activities are conducted on a daily basis. Operation and maintenance consists

of trouble shooting any problems that occur at any of the active remediation sites as well as scheduled

preventive maintenance. Operation and maintenance activities are outlined in Chapter 4.

7.1.5 Operation and Maintenance Costs

Operations and maintenance (O&M) costs include costs of operating the remediation systems, long-term

monitoring of ground water, and landfill cap inspections at the operable units.

O&M costs for the operation and monitoring of the remediation systems at OU-I, OU-4, JP-4, OU-11,

and the Flightline Refueling Area were $1,059,000 for the 12-month period ending July 30, 2005. This

L:II_DRKIERSI84610!WP',EAFBg-YEARREVIE V2OOSDOC 94 September 2005

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Final Five- Year Review

includes labor, materials, equipment, and maintenance costs for tile remediation systems and labor,

analytical costs, and reporting costs for the monitoring program at these OUs.

Long-Term monitoring costs for OU-3, OU-5, OU-6, OU-7, OU-8, and OU-12 were approximately

$19,000 for the period ending June 30, 2005. These costs are principally the costs for periodic sampling

and analysis of monitor wells at these sites, as well as related evaluation and reporting of the monitor well

data. LTM costs have been higher in past years when landfill cover problems at OU-5 were being

addressed.

7.1.6 Remedial Action Optimization

The remedial systems are continually monitored and examined for ways to optimize the system and

reduce costs. This includes preventative maintenance, shutting down systems where remediation has

been achieved, optimizing treatment systems (e.g., taking carbon filters off line at Pump House No. 1)

and periodically changing monitoring and sampling plans to account for changes in plumes or system

operations. Remedial actions arc monitored on an ongoing basis to evaluate system effectiveness and to

find ways to optimize system operation. Optimization actions implemented over the past 5 years are

described more fully in Section 4.4.

7.1.7 Indicators of Potential Failures

There have been no chronic recurrent equipment breakdowns that could potentially impact the selected

remedies. When equipment breakdowns occur the onsite O&M staff have the training and resources to

deal with the problem in a timely manner.

Biofouling of ground water extraction wells is a chronic issue. Biofouling drastically decreases flow from

the extraction wells and as a result makes the remedial system less effective. Extraction well pumping

rates are constantly monitored to detect biofoulmg. Affected wells are redeveloped annually.

High selenium in treatment plant effluent has been a recurring problem. Selenium is a naturally-occurring

element in ground water in this area. Occasionally, the selenium concentration will exceed permissible

standards for discharge to a surface water body. Two re-injection trenches have been constructed to allow

re-injection of plant effluent from the Building 6908 facility into the ground. Under high flow conditions,

the capacity of these trenches can be exceeded. When that occurs, the effluent is directed back to the

surface discharge. The re-injection trenches have mitigated the selenium problem at Building 6908. At the

current time, effluent disposal is alternated between the surface discharge and the re-injection trenches.

The effluent from the treatment facility at FRA-PHI is also prone to occasional spikes in selenium levels.

At those times, the situation is controlled by selectively shutting down extraction wells which have high

selenium levels.

The TCE plume at OU-4 has not been completely addressed by the ground water pump and treat system,

due to the ground conditions which include narrow preferential flow paths. An additional extraction well

was placed in this plume since the 2000 Five Year Review to enhance plume capture. In addition, an insitu remediation technique is being implemented on a treatability testing basis. The technique is in-situ

reductivc dechlorination; the test includes injection of vegetable oil or sodium lactate at the source area in

OU-4 and at three locations down-gradient in the TCE plume. The treatability test began in May, 2005

and will extend for 12 months. The test is showing early positive results in the source area. In the downgradient areas, the effectiveness is not yet clear. The effectiveness of this technique in the down-gradient

areas may bc hampered by the low TCE concentrations (<25 ppb) in the ground water in those arcas.

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The cover at OU-5 developed a series of cracks or sinks in the 1990's. The southeast face of the OU

slumped significantly in 1999. The Air Force, along with engineering and soil experts from contractor

firms and the South Dakota School of Mines, investigated the site. This investigation recommended

repairs to the slide area and further monitoring for additional movement. The repair work was completed

in August of 2000. Ground water underdrains were installed in 2001, reducing the ground water level in

this site and arresting the slide movement. The area continues to be monitored for movement of the slide

mass.

7.2 VALIDITY OF ASSUMPTIONS

7.2.1 Changes in ARARS and TBC Criteria

The ARARs and TBC criteria used to develop the remedial action selection process at EAFB were

appropriate at the time of FS and ROD development. No changes in the chemical, action, or location

specific criteria have resulted in the need to reevaluate these ARARs or TBC criteria. South Dakota

Ground Water Quality Standards for a number of contaminants were changed from either a "No standard

available" or a "Non-Detect Level" to a specific concentration in 2004. Of these standards, eight

chemicals now have lower allowable concentrations, 28 have higher allowable concentrations, and nine

have a concentration standard for the first time. The eight chemicals with lower allowable concentrations

and the nine new chemicals were not specifically identified as COCs in the RODs. The criteria selected

were and continue to be protective of human health and the environment.

7.2.2 Changes in Exposure Pathways

The exposure pathways evaluated as part of the human health risk assessment were appropriate for the

conditions existing at the time of the completion of the RI, FS and RODs. Current conditions and

anticipated future conditions on-Base and on off-Base properties are represented appropriately by these

pathways and no revisions are needed. The completed ground water pathway at the BG-04/BG-05 area

off-Base to the east adds a completed pathway that was not specifically addressed in the human health

risk assessment for OU-II. However, the remedial actions applied to this site have taken into

consideration this completed pathway and the application of MCLs as cleanup goals will be protective of

human health and the environment. The indoor air pathway is being investigated further at this time,

based on the possibility of TCE vapor from contaminated ground water entering basements of residences.

However, this does not represent a new pathway in terms of the risk assessment, since the original risk

assessment included the inhalation pathway for those OUs where contaminated ground water would be

used for showering in the future. The levels of exposure would be higher in these risk assessments than

the levels observed from soil vapor moving through foundations or floors, since they result from direct

volatilization into a closed bathroom.

7.2.3 Changes in Toxicity and Contaminant Characteristics

Table 6-10 summarizes changes in toxicity values applicable to specific COCs identified at EAFB. The

changes in the reference doses and slope factors for the organic COCs identified in Table 6-10 are not

expected to affect the overall remedial actions at EAFB. The COCs reported at EAFB are expected to be

removed and/or contained by the remedies selected for EAFB. In those situations where one of the values

decreased, the calculated dose or exposure concentration to receptors, and therefore the risk, would

increase. Whether these changes are significant is specific to the particular chemical and exposure

pathway. The assumptions made in the risk assessments were to evaluate the risk using both average and

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Final t:'ive- Year Review

reasonable maximum exposures (RMEs). This resulted in a conservative risk approach for the site.

Marginally acceptable or unacceptable risks were considered when developing remedial actions. The

design of the remedial systems at EAFB was completed based on the cleanup goals listed in the RODs.

These cleanup goals took into consideration the results of the human health and ecological risk

assessments as well as MCLs and other State standards. For ground water remediation, the MCLs were

the primary consideration during design. Therefore, unless the MCLs change, the changes in the toxicity

values used to estimate risk at the operable units wilt be reviewed while evaluating the protectiveness of

the remedial decision but would not specifically drive the selection or re-design of a remedial action.

7.2.4 Changes in Risk Assessment Method

Human health risk assessments and the risk scenarios applied at EAFB were appropriate for the identified

completed pathways and current and anticipated future land use. No revisions or changes in the

assumptions appear appropriate based on current information. The dermal risk calculations completed in

the R1 reports were based on 1989 EPA Guidance Manuals. Utilization of the current EPA Dermal Risk

Assessment Guidance for Superfund would likely result in lower calculated risks.

The ecological risk assessment completed as part of the RI process at EAFB utilized a three-tiered

assessment approach. The Tier I level included evaluations, observation and assessment of habitat values

at the OUs. Wetland and terrestrial plant communities were evaluated in the field and augmented with

anecdotal and systematic wildlife observations. The Tier I data was used to evaluate the sites in more

detail under Tier lI where either species of concern were identified or significant habitat that could attract

wildlife was present even though Tier I field data did not indicate the presence of the wildlife during the

study. The Tier lI investigations lbcused on the evaluation of benthic invertebrates, fish, and terrestrial

invertebrates. Field observations of birds and other terrestrial fauna were completed. If initial screening

of data under the first two Tiers indicated; either, degraded benthic, fish or soil fauna communities or

elevated concentrations of COCs in sediment, surface water of soils then the site was carried to the

Tier III level of investigation. The Tier III evaluation involved detailed quantitative ecological risk

assessments. This approach was consistent with the USEPA guidance for the selection of assessment and

measurement endpoints in ecological risk assessments. None of the individual OUs were carried over to a

Tier III investigation, however a Basewide evaluation was completed.

The Basewide Ecological Risk Assessment for EAFB was structured according to U.S. EPA guidance,

and consists of four related components (EPA 1992): problem formulation, exposure assessment,

ecological effects assessment, and risk characterization. The relationship of these components is

illustrated in Figure 7-1. This model provided a logical sequence from Problem Formulation

(identification of Chemicals of Concern [COCs], Receptors of Concern [ROCs], exposure pathways [in

the Conceptual Site Model (CSM)], and measurement and assessment endpoints), to Analysis

(characterization of exposure and toxicological effects), to Risk Characterization (the integration of

exposure and ecological [toxicological] effects assessments).

The structure of the Basewide ecological risk assessment evolved throughout the remedial investigation

process. Some of the elements of Problem Formulation, i.e., identification of stressors and ecological

components, were an outgrowth of the preliminary risk screens done at each individual OU. This

information was reviewed and discussed with the EPA Region VIII Ecological Technical Assistance

Group (ETAG). Ultimately, the Problem Formulation phase was formalized as shown in Figure 7-1, and

the components of Analysis and Risk Characterization were added to the framework to support the

Basewide ecological risk assessment.

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In 1998 the USEPA issued updated ecological risk assessment methods and standard guidance that has

changed since this evaluation was done at EAFB. The tiered approach used in the ecological risk

assessments completed for EAFB is still one of the recommended approaches. The completed risk

assessment did not identify excessive risk exposures for the Species of Concern nor were any habitats

identified as needing remedial actions. The assumptions made during the ecological risk assessment were

appropriate and protective of the ecological community at and adjacent to EAFB.

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8.0 DEFICIENCIES AND MODIFICATIONS

Information on past deficiencies and applied modifications was presented in Table 4-5 and was discussed

in section 7.1.3. The following summarizes the deficiencies/problems identified during this five-year

review.

OU-I Continued occasional selenium discharge limit violation at the central treatment facility.

Possible contaminant movement past extraction wells in the southeast area of the OU.

OU-2 Increased concentrations of TCE in some southern boundary monitor wells. Three new ground

water extraction wells were installed to address this issue. Ground water concentrations down

gradient tYom the extraction wells have been reduced below MCLs. Minor settlement has

occurred in the waste trenches. Soil will be used to restore these areas to grade.

OU-3 No identified issues.

OU-4 Increased concentrations of TCE in some boundary monitor wells. Containment of the plume is

incomplete. Additional extraction wells have been installed to address this issue. A treatability

study has been initiated to determine whether in-situ passive techniques may be more effective

than ground water pump and treat.

OU-5 The slope failure along the southeast and north face of the landfill has stabilized satisfactorily.

OU-6 No issues identified. An area of buried incinerator ash is located near, but not within, this OU.

Removal and disposal of the ash is being considered by the Air Force.

OU-7 No issues identified.

OU-8 Possible impacts on the soil cover at the debris burial area due to encroachment of prairie dogs.

OU-9 No issues identified.

OU-10 No issues identified.

OU-II An additional extraction well will be installed in the BG-05 system to increase the capture

efficiency at the site. A drainage pipe in the South Flightline area is discharging water

containing TCE at a concentration between 5 and l0 ppb. A pump will be installed to recover

this contaminated drainage and pump it to the FRA-PHI facility for treatment and discharge.

Additional monitoring is planned north of OU-12 to evaluate consistent TCE concentrations

above 10 ppb in this area. Additional monitoring is planned in the ST-23 area (south end of the

flightline) to address the TCE contamination in the South Flightline drain and several UST sites.

OU-12 No issues identified. Routine repairs have been performed on the landfill cap.

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9.0 RECOMMENDATIONS AND FOLLOW-UP ACTIONS

A Remedial Project Manager (RPM) group is in place to oversee the Environmental Restoration Program

at Ellsworth Air Force Base. The group is comprised of personnel/managers from the Air Force, Corps of

Engineers/Omaha District, South Dakota Department of Environment and Natural Resources,

EPA Region 8, and contractors. The purpose of this group is to monitor the remedies and remedial

actions selected for the 12 Operable units, and to develop revisions to the remedial action program as

necessary in response to changed conditions and new technologies. As deficiencies or opportunities for

optimization are identified, they are addressed by the RPM group. The group is also responsible for

programming and obtaining funding for additional work at the base. This will ensure the remedies will

continue to be protective of human health and the environment or continue or to progress towards being

protective of human health and the environment, i.e., O&M of RA systems and LTM monitoring.

This chapter reviews recommendations made in the first five year review in 2000, and presents new

recommendations for future management of the ERP.

9.1 RECOMMENDATIONS FROM 2000 FIVE-YEAR REVIEW

Based on the results of agency review comments and the evaluations completed as part of the 2000

five-year review at EAFB, a number of recommendations were suggested for evaluation and

consideration prior to the next five-year review. These recommendations and their current status are

summarized below.

I. Conduct a detailed evaluation of the geophysical conditions at OU-5 that have or may have

contributed to the soil slide conditions observed at this OU. This evaluation should recommend

a solution to the problem.

Status - Complete. A corrective action consisting of underdrains to remove ground water was

installed in 2002. The movement of the slide has slowed to a near standstill. Monitoring and

periodic surface repairs continue.

2. Review the available dioxin data from OU-8 and compare the data to the new information

published by the US EPA on dioxins and PCBs. Review the risk implications of these changes

if the data indicates that the dioxin and PCBs concentrations are different than action levels.

Status - Complete. This information was provided in the Long Term Monitoring 2001 Annual

Report for OU-8, Serial Letter No. 1-36-RD-337, dated November 7, 2001. This letter included

a recommendation for additional sampling which was completed. Results were reported in the

Long Term Monitoring 2002 Annual Report for OU-8, Serial Letter No. 1-48-RA-322.

3. Develop a data summary table containing the analytical data from the RI and the LTM

programs. Compare the data set to the risk based screening levels and preliminary remediation

goals levels published by EPA Regions 9 and 3, respectively. This data file should be updated

with new LTM data as it becomes available.

Status - Complete. For sample locations included in the LTM program, the summary table was

included in the April and July 2005 LTM reports. Detected analytical results were compared to

the Federal maximum contaminant levels (MCLs) and the South Dakota Ground Water

Standards. If no MCL or numerical South Dakota Ground Water Standard was established, the

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detected result was compared to EPA Region 3 and 9 risk based screening levels. Note: These

reports are outstanding for OU-3, OU-6, OU-8, OU-11 and the Flightline Refimling Area.

4. Complete an evaluation of the ground water elevations and chemical contaminant

concentrations of the plumes at OU-I, OU-2 and OU-4. The evaluation should be focused on

determining if there is an inter-relationship between the plumes and ground water flow patterns

and evaluate if the remedial actions installed are providing containment of these plumes.

Status - Complete. Preliminary results from a 2005 intrusive investigation indicate that the

OU-1 plume does not reach the OU-2 area or interact with the OU-2 plume. A previous study

established that the OU-I and OU-4 plumes do not mix or interact.

The OU-I plume remediation system has been effective at maintaining plume containment and

removing contaminant mass from the ground water.

The containment system installed on the south boundary of OU-2 has been in operation for

nearly one year and has proven to be effective in containing the TCE ground water plume at this

location.

The OU-4 plume containment has been incomplete, due to geologic conditions which hinder the

effective operation of pump and treat technology. Partly tbr this reason, the Air Force is

initiating a treatability study of in-situ reductive biodechlorination, using sub-surface injection

of substrates such as vegetable oil and/or sodium lactate.

5. Develop a decision tree/process which provides an approach to the close out and finalization of

the remedial action process for operable units as they reach applicable cleanup levels. This

could include recommendations on the duration of operation and monitoring after the systems

meet remediation goals, and/or how to document asymptotic conditions. Development of a list

of documents and or reports necessary to close out a site.

Status This task has begun with the de-listing proposal that is currently being developed. This

initiative is described more fully in Section 9.2 (below).

6. Develop a series of maps that show the changes in contaminant plume size and concentration

levels over time for each OU with an active remediation system.

Status - Complete. These maps are presented in the periodic LTM reports.

7. Develop a statistical evaluation of the removal rates and effectiveness of the each remedial

system. Evaluations should provide estimates of percent of original contamination removed,

estimated remaining contamination mass, and estimates of remaining time needed to remediate

the plume.

Status - Complete. This information will be submitted in a serial letter report in September,

2005.

8. The Air Force will address the issues raised during the community interview process.

Status - In progress.

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9. Evaluate revisions to the Long Term Monitoring Plan.

Status - Complete. The LTM program has been revised periodically.

9.2 2005 FIVE-YEAR REVIEW RECOMMENDATIONS

The Ellsworth AFB RPM group has undertaken an extensive review of the overall management of the

operable units, with a view toward achieving closure or deletion of the OUs where possible. In general

terms, the proposed future management of these OUs involves consolidation of all ground water

contamination issues into a single OU (Operable Unit 11); and deletion, i.e., removal from the National

Priorities List, of most of the other operable units. This section presents detailed recommendations for

each of the 12 operable units.

9.2.1 OU-I

Management and cleanup of contaminated ground water in the OU-1 area was recently shifted to OU-11,

the basewide ground water operable unit. This will consolidate ongoing LTM sampling into OU-I 1.

Institutional controls identified in the ROD should be maintained. Routine inspection of site access

controls could be conducted during long-term ground water monitoring programs.

Alternative technologies were evaluated with a view toward accelerated closeout of this site. These

included wholesale excavation and land farming; excavation and thermal treatment; and in-situ thermal

treatment through electrical resistance heating. The estimated costs of the current RA were compared

with the costs of the "accelerated closeout options"; the accelerated options are estimated to be much

higher in cost. EAFB recommends continued operation of the existing SVE and ground water systems,

with ongoing optimization to continue to maximize contaminant recovery. Consideration should be given

to increasing the number of SVE points and to installing additional ground water extraction wells to

increase the removal of vapor phase, free-phase, and dissolved phase contaminants. This would also

introduce increased levels of oxygen into the subsurface, helping expedite the natural attenuation of the

petroleum compounds.

9.2.2 OU-2

TCE ground water contamination was detected south of OU-2. Three extraction wells were installed to

address the issue. Based on early monitoring results, the plume appears to be been contained and the offbase plume has been remediated. Ground water remediation and monitoring issues were transferred to

OU-I 1. The substantive requirements for site closure for this OU have been met. EAFB will prepare and

submit a recommendation for partial deletion of the EAFB site, including this OU. The partial deletion

documentation will outline any post-closure monitoring/inspections that need to be done to assure

continued compliance with the ROD and statutory compliance, including compliance with applicable

institutional controls. These will include recommendations for annual landfill cover inspections and

limited (once every 5 years) ground water monitoring to provide assurance of continued compliance with

statutory requirements. This site will then be eligible for removal from the NPL through a partial deletion

process, which includes public involvement and approval by EPA and the State of South Dakota.

This site is considered buildable within the restrictions applied by the institutional controls. Construction

at the site will be limited to facilities that can be built slab-on-grade or by other means that will not

compromise the soil cover and which are consistent with the geotechnical limitations of the waste

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trenches.. Use of the site for equipment parking, shops, and other industrial purposes is possible provided

they fall within any Base land-use restrictions for flightline, safety, and noise programs.

9.2.3 OU-3, OU-5, OU-6, OU-8, and OU-12

Based on the risk assessment results from the RI and LTM monitoring results at these OUs it is apparent

that no adverse ground water conditions exist. Ground water management is being transferred to OU-I I.

The substantive requirements for site closure for these OUs have been met. EAFB will prepare and

submit a recommendation for partial deletion of the EAFB site, including this OU. The partial deletion

documentation will outline any post-closure monitoring/inspections that need to be done to assure

continued compliance with the ROD and applicable statutes. These will include recommendations for

annual landfill cover inspections to assure compliance with statutory and ROD requirements. These sites

will then be eligible for removal from the NPL through a partial deletion process, which includes public

involvement and approval by EPA and the State of South Dakota.

9.2.4 OU-4

Management and cleanup of contaminated ground water in the OU-4 area was shifted to Operable Unit

11. OU-II is the basewide ground water operable unit, and it would be most efficient to consolidate

ground water contamination issues into that OU. This change would consolidate ongoing LTM sampling

into OU-11.

The current treatability study for in-situ reductive biodechlorination should be completed. If it is

effective, this technique should be implemented at full-scale to eliminate the source area. If the in-situ

technique is not effective, EAFB recommends a removal action to positively and quickly remove the

source area contamination from the OU-4 landfill.

Institutional controls identified in the ROD should be maintained. Annual inspection of the soil cover

and routine inspection of site access controls will be conducted during mowing operations. Following

site closure, this site is considered buildable within the restrictions applied by the institutional controls.

Construction at the site will be limited to facilities that can be built slab-on-grade or by other means that

will not compromise the soil cover and which are consistent with the geotechnical limitations of the

buried waste. Use of the site for equipment parking, shops and other industrial purposes is possible

provided they fall within any Base land-use restrictions for flightline, safety, and noise programs.

9.2.5 OU-7

No adverse ground water conditions exist with the exception of limited areas east of the OU, where TCE

concentrations historically have exceeded MCLs. That area has low concentrations and is stable. The

ground water portion of OU-7 was transferred to OU-11 (the basewide ground water operable unit) for

continued management or closeout. This consolidates routine monitoring activities into OU-i l.

The substantive requirements for partial deletion for this OU have been met. EAFB will prepare and

submit a recommendation for partial deletion of the EAFB site, including this OU. The partial deletion

documentation will outline any post-closure monitoring/inspections that need to be done to assure

continued compliance with the ROD and applicable statutes. This monitoring is likely to be limited to

annual verification that the institutional controls are in place and effective. Limited ground water

monitoring should be performed. This site will then be eligible for removal from the NPL through a
Ellswortk Air Force Base

Final Five- Year Review

partial deletion process, which includes public involvement and approval by EPA and the State of South Dakota.

9.2.6 OU-9

The preferred alternative for the site was no action, and a Record of Decision incorporating that

alternative was signed in 1996. There is no RA or LTM activity at this site. The Air Force will include

this site in the request for partial deletion of the EAFB site from the NPL.

9.2.7 OU-10

The preferred alternative for this site was no action under CERCLA and treatment of contaminated soil

under the State of South Dakota petroleum release regulations. A no-action ROD was signed for this site

in 1996. Removal activities for petroleum-contaminated soil have been completed. Limited removal of

free product is continuing at the area north of the 80 Row hangars. There are no CERCLA remedial

activities or monitoring activities underway or required at this operable unit. The Air Force will prepare

and submit a request for partial deletion of this site from the NPL.

9.2.8 OU-II

Ground water management for Operable Units l, 2, 3, 4, 5, 6, 7, 8, and 12 and for the Flightline Refueling

Area was recently transferred to Operable Unit 11.

Currently, the first technology of choice for remediation of chlorinated solvent contamination in

ground water is in-situ biodechlorination. This consists of the injection into the subsurface of electron

donors such as proprietary products, emulsions of vegetable oil, sodium lactate, or even waste milk

products. This technology has been developed in the period since the EAFB remedial actions were

developed and the RODs were signed. Generally, in the Ellsworth AFB sites, in-situ biodechlorination is

considered a potentially valuable supplement to the existing ground water pump and treat systems.

Area 1

Operation of the pump and treat system at the Pride Hangar should continue, along with the aggressive

biodechIorination treatment of the TCE source area at the northwest corner of the Pride Hangar. This

source area treatment has been initiated with soy oil and is being evaluated. This operation is expected to

reduce TCE contamination to near MCL's within 5 to 10 years. SVE treatment for the TCE soil

contamination at the northwest corner of the Pride Hangar should be performed if adverse impacts on the

in-situ ground water remediation can be avoided. Evaluation of possible TCE vapor in the Pride Hangar

building should continue.

Operation of the South Docks pump and treat system should continue as well. The extraction wells at the

down-gradient end of the South Docks system, located near the base drainage, should continue to be

operated pending the further development of in-situ technologies for TCE remediation. These

technologies include the permeable reactive barrier and the "biowall" technology currently being pilot

tested at EAFB. Within 5 years, it is reasonable to expect that one or more of these technologies will

have matured to the point where they can be implemented near the base drainage to effect containment.

At that point, the ground water pump and treat systems could be shut down and the minor remaining

contamination could be addressed through natural attenuation and the action of the in-situ remediation

containment systems.

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The monitoring in the ST-23 area should be completed and evaluated to determine whether additional

remediation is warranted in this area. The monitoring in the area up-gradient from OU-12 should be

completed and evaluated to determine whether remedial action is required in that area.

Former Fire Protection Training Area: Ground water contamination in this area should be

addressed through continued operation of the ground water pump and treat system.

Operable Unit Four Area: Ground water contamination in this area should be addressed through a

continuation of the in-situ biodechlorination treatment options that are being pilot-tested at this time.

If, as expected, these measures are effective, they should be expanded into full-scale remediation

with appropriate revisions to the Record of Decision. After the source is removed or remediated, an

aggressive program of in-situ treatment can be expected to substantially eliminate the TCE

contamination within 5 years. This is expected to be more effective, and in the long run less costly,

than sole reliance on the ground water pump and treat system and is also expected to be less

expensive than permeable reactive barrier technology

Flightline Refueling Area: After Pumphouses 1, 2, and 3 (and their related UST's) are removed,

and if free-phase contamination is present as expected, ground water collection facilities should be

constructed in order to achieve removal of the free-phase product and ground water contamination.

When the free-phase product has been removed, this portion of OU-I 1 should be placed into No

Further Action (NFA) status with the South Dakota DENR. NFA requires that free product is

absent, contaminant concentration is stable or decreasing, and there is little current of future risk to

human health and the environment. With the site in NFA status, natural attenuation will reduce the

remaining concentrations of petroleum compounds in the ground water.

Area 2

Efforts should continue to locate and address the source of TCE contaminants in this area. If sources are

found, they can be addressed through in-situ means or, if in soil, by soil vapor extraction or soil removal

and disposal. It will be necessary to maintain containment measures at the base boundary for a period of

time after the sources are addressed because of the large volume of contaminated ground water in the

on-base portion of the BG-04 plume. Containment at the base boundary has been performed with ground

water pump and treat since 1997. Those measures should continue while in-situ treatment measures (such

as the permeable reactive barrier technology or the "biowall" technology currently being pilot-tested) are

evaluated. Within five years, it is reasonable to expect that one or more of these technologies will have

matured to the point where they can be implemented at the base boundary. This could achieve

containment, preventing the movement of contamination off-base, without the ongoing cost of O&M for

the ground water pump and treat system. With respect to the off base ground water plume, it is

recommended that the natural attenuation currently underway be allowed to continue. This is in

accordance with the ROD. Potential exposure has been eliminated by the installation of the water supply

system, which will need to be maintained until the TCE contamination has been reduced below MCL's by

natural attenuation. This is expected to require approximately 30 years.

Monitoring of the off-base plume should be reduced substantially, since there is ample monitoring data to

demonstrate that the off-base plume is stable in extent and is slowly decreasing in concentration.

Institutional controls identified in the ROD can be maintained under the Base Compliance Program.

Following site closure, ,Area 1 is considered buildable within the restrictions applied by the institutional

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controls; in this area, a variety of land uses would be possible since there are no issues of buried waste as

in the case of the landfill sites. The Area 2 sites also will be buildable. Off-Base properties have few

buildability restrictions related to the presence of the ground water plume, with the exception of the

prohibition on water wells construction. County zoning limitations would be more significant than

contamination-related constraints.

9.2.9 Flightline Refueling Area (SS-08, ST-10, ST-14)

Management and cleanup of contaminated ground water in the Flightline Refueling Area was shifted to

Operable Unit 11. This action consolidates LTM activities within OU-I 1.

The remaining pumphouses (Nos, l, 2, and 3) should be demolished when no longer needed and their

UST's removed. Contaminated soil should be removed to the extent practicable at the same time,

sufficient to remove contamination that could contaminate underlying ground water. At that point, these

sites can move into No Further Action status.

9.2.10 JP-4 Jet Fuel Release

This jet fuel release, located south of Operable Unit 2, has been cleaned up in accordance with State of

South Dakota Standards. The remediation system is shut down. The site will be sampled a final time

during the next five years to ensure that rebound has not occurred. Then the Air Force will initiate closure

procedures with the South Dakota DENR.

9.2.11 North Docks

Thee free product plume at 80 Row will continue to be monitored and product recovery efforts will

continue as long as product is present.

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10.0 PROTECTIVENESS STATEMENTS

INTRODUCTION

Based on the current review, the remedial actions at Ellsworth AFB are protective of human health and

the environment and are effective in removing immediate risk of exposure to contaminated media.

Institutional controls, including restricted access and fencing, prevent access to this area. A continuing

order from the installation commander prevents unauthorized actions at the sites (scc Appendix C). Some

of the remedial actions will require long-term operation of treatment systems. Compliance with cleanup

goals will be evaluated in future reviews. Effective 7 July, 2005, all ground water management was

moved to OU-11, but ground water issues are addressed as part of the specific OU descriptions below.

10.1 OU-I

The remedy at this site is considered to be protective of human health and the environment and immediate

threats have been addressed. The OU-1 remedy consists of SVE and ground water extraction components

which are designed to remediate hotspot contamination in the immediate vicinity of the old fire training

pit area and to contain the plume onsite. A fence has also been installed to restrict access to the operable

unit. A long-term ground water monitoring program is also in place at this operable unit.

Information gathered to date at this site indicates a significant amount of contaminant mass has been

removed and continues to be removed from the site and the ground water contaminant plume has been

contained.

10.2 OU-2

The remedy at this site is protective of human health and the environment. A landfill cap was installed at

this site preventing the infiltration of rainwater as well as direct contact with contaminated soils and a

drainage flume was also installed in this area to reroute drainage around the landfill. A fence has also

been installed to restrict access to the operable unit. Recently, additional soil cover material has been

placed to fill areas of settlement in the waste trenches. Ground water extraction wells have effectively

contained TCE contamination moving south from this landfill and have remediated the TCE ground water

contamination located to the south.

The landfill cap is inspected for integrity on a quarterly basis and a long-term ground water monitoring

program is also in place at this operable unit. Information gathered to date at this site indicates that the

landfill cap and drainage flume appears to be functioning as designed.

10.3 OU-3

The remedy at this site is protective of human health and the environment. A landfill cap was installed at

this site preventing the infiltration of rainwater as well as direct contact with contaminated soils. A fence

has also been installed to restrict access to the operable unit.

The landfill cap is inspected for integrity on a quarterly basis. A long-term ground water monitoring

program is also in place at this operable unit. Information gathered to date at this site indicates that the

landfill cap appears to be functioning as designed.

10.4 OU-4
Ellsworth Air Force Base

Final Five- Year Review

The remedy at this site is protective of human health and the environment. Immediate threats have been

addressed. A landfill cap was installed at this site preventing the infiltration of rainwater as well as direct

contact with contaminated soils. An off-base property that was impacted by the chlorinated hydrocarbon

plume originating under the landfill was acquired by the Air Force. Ground water extraction wells were

installed on and off base to address the offsite movement of the chlorinated hydrocarbon plume. These

extraction wells are reducing the concentration and extent of the off-base plume. A treatability study is

underway to assess the effectiveness of in-situ biodechlorination techniques, which would supplement the

pump and treat if they are effective. A fence has also been installed to restrict access to the operable unit.

Affected parties have been supplied with an alternate source of water via a water main system constructed

and operated by the Air Force.

The landfill cap is inspected for integrity on a quarterly basis. A long-term ground water monitoring

program is also in place at this operable unit. Information gathered to date at this site indicates that the

landfill cap appears to be functioning as designed.

10.5 OU-5

The remedy at this site is protective of human health and the environment. A landfill cap was installed at

this site, preventing the infiltration of rainwater as well as direct contact with contaminated soils. The

landfill cap in this area has experienced subsidence problems over time and has been repaired several

times. In 2001, a system of ground water underdrains was placed in this area to reduce ground water

levels and pore pressures near the Pierre Shale surface. The underdrains have been successful in lowering

the water table and eliminating the slide movement. A fence has also been installed to restrict access to

the operable unit.

The landfill cap is inspected for integrity on a quarterly basis. Minor grading and re-vegetation is

performed as necessary, typically every two or three years, to maintain the cover. A long-term ground

water monitoring program is also in place at this operable unit.

10.6 OU-6

The remedy at this site is protective of human health and the environment. A landfill cap was installed at

this site preventing the infiltration of rainwater as well as direct contact with contaminated soils. A fence

has also been installed to restrict access to the operable unit.

The landfill cap is inspected for integrity on a quarterly basis. A long-term ground water monitoring

program is also in place at this operable unit. Information gathered to date at this site indicates that the

landfill cap appears to be functioning as designed.

10.7 OU-7

The remedy at this site is protective of human health and the environment. The remedy for the OU-7 area

is institutional controls and monitored natural attenuation. Semi-annual monitoring is conducted at this

site to assess natural attenuation and plume movement. A fence restricts access to the site. Information

gathered to date at this site indicates that the plume is stable.

10.8 OU-8

L IWORKIERSI846IOIWPiEAFB5- }'EARREVIEW 2005 DOC ]08

3057 11{
Ellsworth Air l"orce Base

Final IQve-Year Review

The remedy at this site is protective of human health and the environment. A soil cover was installed at

this site preventing direct contact with dioxin-contaminated soils. A fence has also been installed to

restrict access to the operable unit.

The soil cover is inspected for integrity on a quarterly basis. A long-term ground water monitoring

program is also in place at this operable unit. US Air Force personnel disturbed the soil cover in the fall

of 1999 while disposing of some unexploded ordinance. The soil cover was repaired in the fall of 1999.

Recently, prairie dogs have moved toward the debris burial area and threaten to disturb the cover by

burrowing in the cover soils. The Air Force is monitoring this situation and is evaluating options that

could be implemented in case the cover is affected, lntbnnation gathered to date at this site indicates that

the soil cover appears to be functioning as designed.

10.9 OU-9

A no-action ROD was signed for this operable unit. Some of the ground water in this area is being treated

and remediated under the OU-I 1 base wide ground water ROD. This action is still protective.

10.10 OU-IO

A no-action ROD was signed for this operable unit. This action is still protective.

10.11 OU-I1

The remedy at this site is considered to be protective of human health and the environment and immediate

threats have been addressed. The remedy at OU-II consists of eight remedial systems. Five of the

remedial systems are connected to a common treatment plant located at FRA-Ptt 1. The remedial systems

are located in the South Docks Main area, 30 Row and 50 Row, the Building 102 area and the

Pride Hangar area. Ground water collection systems have been added at Pumphouses 4, 5, and 6. The

remaining three systems are located in the BG04 west, the BG04 base boundary and the BG05 base

boundary areas. A lift station is under construction to address contaminated ground water at the South

Flightline Drain. A potential vapor intrusion pathway is being evaluated in on-base buildings.

The remedial systems in the OU-I 1 area appear to be functioning as designed, containing the plumes and

reducing the mass within the plumes. Monitoring of specific areas continues to address areas where

complete containment needs to be confirmed. These include BG-05 and the South Docks Main areas.

Parties affected by ground water contamination have been supplied with an alternate source of water via a

water main system constructed and operated by the Air Force.

10.12 OU-12

The remedy at this site is protective of human health and the environment. A landfill cap was installed at

this site preventing the infiltration of rainwater as well as direct contact with contaminated soils. A fence

has also been installed to restrict access to the operable unit.

The landfill cap is inspected for integrity on a quarterly basis. A long-term ground water monitoring

program is also in place at this operable unit. Information gathered to date at this site indicates that the

landfill cap appears to be functioning as designed.

L I WORKIEflSi846IOiII'PE4 FB 5- }_AR REVIEII 2005 D()C 109 September 2005

3057 117
Ellsworth Air Force Base

Final Five-Year Review

11.0 NEXT REVIEW

The next five year review should be:

Initiated By: 1 April 2010.

Completed By: September 30, 2010.

L ,WORKIERS!846101WPiEAFB5-YEAR REVIEW 2005DOC ] 10 September 2005

3057 118
ElLs'worth ,4 ir Force Base

Fmat Five-Year Review

12.0 MISCELLANEOUS COMMENTS
FIGURES

" 3057 120
/

N I NORTH DAKOTA _o_--_

UONTANAi SOUTH DAKOTA

MINNESOTA

ELLSWORTH AFB /

• Pierre I

l NEBRASKA
/

I WEAPONS INSTALLATION BOUNDARY

F STORAGE

I

J -i)I OU-"7II ' -- _°_' ,-3 \

/

/

DEBRIS

_, _ _, BURIAL AREA

\ ST. b, \ z

N OU-lO

HOUSING"

AREA

\

DOOLITTLE DR. HOUSING I

AREA I

, I I SPAATZ

Q:

WASTEWATER

0 1200 2400

I I I PLANT

SCALE IN FEET

EASEMENT

LEGEND ou-1 u-611

I HOUSING I

OPERABLE UNITS OU-2 I GATE L ARE.A/

OU-1 FIRE PROTECTION TRAINING ....

AREA (FT-Ol) I

OU-2 LANDFILLS 1 & 6 (LF-O2)

OU-3 LANDFILL 2 (LF-03) INDUSTRIAL tr

OU-4 LANDFILL ,3 (LF-04) GATE

OU-,.5 LANDFILL 4 {LF-OS)

OU-6 LANDFILL 5 (LF-06)

OU-7 LOW LEVEL RADIATION WASTE BURIAL AREA (RW-07)

r-, OU-8 EXPLOSIVE ORDANCE DISPOSAL AREA & PRAMITOL SPILL (SS-11) l,

OU-9 OLD AUTO HOBBY SHOP AREA (OT-15) '

_, ou-,o .OR OU-ll BASEWTlDE GR HHANGA_COUP OUND WATERLE×(ST-_9)

_,_ OU-t2 HARDFILLNO. 1 OO

_'o E LLSWORTH ELLSWORTH AFB SITE LOCATION MAP

Qo

-_o AIR FORCE BASE RAPIDCITY, SOUTH DAKOTA

zo

• 13 PROJECT MGR DESIGNEDBY DRAWNBY CHECKED BY SCALE DATE

_ STAFF AS SHOWN OCT 94 60.378.86 3-2

3057 122

Ii II

\\, ,e,, / \\\ \

i I _ _ J'x ', _ _l ' \ _ _ ABOVE GROUND _ , "k

\ I _ W' I] "X / F STORAGE TANK /([,-_)

OL.N,-01 B(_)i_:hN.DA,RY=,__i \X':_..).? _,F,' ._

\ I ' \ _ \\ _ v/<--It-EXTENT OF _} '\I \ '_ \ _ \ _ "<,_"/ GRAVEL /I, )l - W ',,,l ...... i

__ \ ILA\ ',,t Lj,

_ \ -_ II ,I\. ]__MOST RECENT --

\ _i |r, _, ""----Y,. ) BURN PIT AREA _-_

] i 1"','_ I _" ( "' _ ,//-"EXTENT OF

-__ ] _"\ I \ { ""'. , ."IHISTORICA_,/_ __

" ( _ _ _ "X I / _ \ \,,, _/ BURN Ply"A____--'--__

: (_ I_URN, PIT _REA_-_ \ ,.---.-. 1 Y //,J/

\ BOUNDARY-- ""_ 2.,

• • • SUR

__ ,I)I)_)l) TOPOGRAPHIC ELEVATION ..... ,

ABOVE MSL .......-. t' -'' "_i

• !

SCALE SOURCE: EPA 1991, BURNPIT HISTORICALAREASFROMAERIALPHOTOGRAPHS1952-1992 ,

1993 RI DESIGNED BY DRAWN BY DATE PROJECT NO.

¢_SWO_H ELLSWORTHAIR FORCEBASE OU-1 (FPTA) MGL OCT94 60378.84 _t,,lllt I_"OIIICI i" BASIl" RAPID CITY, SOUTH DAKOTA SITEARF.A CHECKED BY PROJECT MGR. SCALE FIGURE

AS SHOWN 3-4

3057 124
i

106 /

"'% z_EL9128MW \

/"7_ I'TPWO11M / (..)ITPW011D |

_-J ITPW0t 1S _4[j_ I

%

N _ DP930110

I

@s.9_o1,,#x/ DP93013_/

I_MW930107 SB930116

DP930112

)106

_MWB9( )102 @ DP930103 SB930107 /_MW890103

@

O •

SBC" DP930105 SB930148 .... DPC.

A DP93014 _, i]2 ................. Xl _.- uwgso_o: ............

///

) SB93014_/'i: ..... DP9301 _'3/

3ol _3 ,"]'"

OU- I .,., /" SB930115

DP930111 ,/,

ALERT

i / APRON .......

SB930131

DP930129

SB930129

DP930127 SB930134 .... -'_-'-,--_.. DP930132

\ o_ss/

0131 k.,

-....

\ LEGEND: _ILMwgsolo8 ', SB930140 ' _, "_

C) IRP PIEZOMETER \, "'""" CLUSTER/NEST , '"'" B930124 , \

_ 1993 RI MONITORING WELL \ ,930122 '" "- .....

SOIL BORING LOCATION _It

1993 RI FIELD SCREENING/ . / SOIL BORING LOCATION ..

\

/_ IRP, PHASE II, STAGE 1 &:

2 MONITORING LOCATION

..... SURFACE DRAINAGE

I " I BASE BOUNDARY FENCE \.

_11--- TOPOGRAPHIC ELEVATION -.

ABOVE MSL """--

%-.

200' 0 200'

SCALE

_'mFmmmmm_mm_'___ _ 1_==__=_m_ OESIGNEDBY DRAWN BY DATE PROJECTNO. EXTENTOF"

REPORTEDCOCIN SOIL- MGL JUNE 95 60378.84

o.,c,,o ,ow,

3057 125
6925 o

EllM _

311D "_

ts I

\l

/

@s_, OPg3013et / o,,#/ _- _To\\ f 44.00

\ \

f

/(_ SB930148

DP930142

I

OU-1

ALERT

APRON

SB930131

DPg3012g

S_30134 DP930132

\

LEGEND: "" MW930108

SB930140

@ IRP PIEZOMETER CLUSTER/NEST

1993 RI MONITORING WELL/ _22

SOIL BORING LOCATION POND001

(_) 199,3 RI FIELD SCREENING/ SOIL BORING LOCATION \

A IRP, PHASE II, STAGE 1 &: 2 MONITORING LOCATION o,so

..... SURFACE DRAINAGE

BASE BOUNDARY FENCE

--3oo-- TOPOGRAPHIC ELEVATION ""L..,_I

n 20I

0'

SCALE

0

I ' [ 20 o,1

L 1993 RI DESIGNED BY DRAWN BY I DATE PROJECT NO, ELLSWORTH ELLSWORTHAIR FORCE BASE REPORTEDEX OFcoc L_ TENT MGL ]____JUNE__95 60378.84

AIR FORCE BASE RAPID CITY, SOUTH DAKOTA IN GROUND WATER KED BY PROJECT MGR. ISCALE FIGURE

OU-1 j AS SHOWN 3-6

3057 126
f

/

m _ m m m m _

J u_3

BURIAL I

%

_, / z I

,_

N _,_. J

HOUSING

I AREA

, LEVY _

B£RG, DOOUTTLEDR. HOUSING I

sTROI AREA i , -_

' "it" ""

o ,_o 2,00 _ I ,'L_--3JW_AST_ATER

I I I _ _ ,,TREATMENT

SC/¢IEIN IqEET ._ " PLANT

LEGEND oO _.

OU-1 FIRE PROTECTIONTRAINING MAIN TM HOUSING%

AREA(FT-01) GATE ARD_ _ OU-2 LANDFILLS1 & 6 (LF-02) C

OU-3 LANDFILL2 (LF-03) ...... __J OU-4 LANDnLL3 (LF-04) OU-2

OU-5 LANDFILL4 (LF-05) INDUSTRIAL

OU-6 tANOFILL 5 (LF-O6) GATE

OU-7 LOW LEVEL RADL_11ONWASTEBURIALAREA (RW-O7) OU-8 EXPLOSIVEORDANCEDISPOSALAREA & PRAMITOLSPILL (SS-11)

OU-9 OLD AUTO HOBBY SHOP AREA (0T-15)

OU-10 NORTH HANGARCOMPLEX (ST-19)

OU-t 1 BASEWIDEGROUNDWATER _. OU-12 HAROFILLNO. 1

O PRIVATEDRINKINGWATER

OR LIVESTOCKWELLS v _

A PRIVATEDRINKINGWATER

SUPPLY FROM SW04

......... 1993L94 LOCATION

ELLSWORTH ELLSW0RTHAFB OF PRIVATE AIR FORCE BASE RAPID CITY,SOUTH DAKOTA ANDDOMESTICWELLS

3057 129
3057 130
1,2-DICHLOROETHENE, TOTAL - 110[ UG/L

VINYL CHLORIDE - 28.0 UG/L BENZENE - 1.OJ UG/L

1:2 _ , UG/L HEXAMETHYL-CYCLOTRISILOXANE - 5.0TI UC/L ETHYLBENZENE - 5.0 UG/L

J N-NITROSO01-n-PROPYL/_41NE - 2.0J UG/L VINYL CHLORIDE - 2.0 U_/L

NAPHTHALENE - 1,OJ UG/L I_,4-TRICHLOROBCNZENE - ) UG/L

UG/L b|m(2-ETHYLHEXYL) PHTHALATE - 2.0J UG/L I_-DICHLOROBENZEEIEO; 8J _.L

p,p'-ODE - O.028PJ UG/L 1,4-DICHLOROB[NZENE - 11 .... 2,4-DICHLOROPHENOL- 1.G

1,4-DICHL(_qtOBENZ[NE - 23.0 IIG_/L 2-MET_LBENZENESULFONAMIDE - 14,0T1 UG/L

2-ETHYLHEXYL DII_ENYL ES1 !HOSPHORIC _ - 13.OTI UG/L

2-METHYLBENZENESULFOI_MI _ 12.OTI UG/j _/_|

4-CHLC_;K)-3-METHYLPHENOt -- 2.0J UO/L _ /. /J DIETHYL PHTI-IALAT[ - 1.0J t G/L _ / _,.._ / |

DIETHYL PHTHAU_TE -- 5,OJ UG/libel- 21.0TI UG/L N,N-DIETHYL-3-METHYL-B-EN. rJLMI)£ - 24,0T_ /L .:_J] I

bls(2-CHLOROETNYL)N'N-DIETHYL-(: - '-MET_I_HLYL-B _I_}ETHYL ETHE _NZA_ETHER R) - 12.0 UG/L 1,1-DICHLOROETHAN[ - 0.5OJ UG/L NAPHTHALENEPHTHALAZINONE-__OT,_,_, / -J fl I 1,2-DICHLOROCTHENE, TOTAL - 5.D UO/L b; 2-CHLOROET ) ETH 2- ETHER -/_UG/L

,C_ON- 1_E_,L o _ _c_AL'_.E__ - O_S _/L II I TR_HLOROETHYLENE (TCE) - 16.0 UG/L [NDRIN KETCqN[ - _ZIP; tJQ/_ .--" ]1 |

DIBENZOFURAN - 2.OJ UG/L ,,,

NAPHTHALENE - _.OJ UG/L / li'_-_ /",, I / 1,_-D_CHLOROETPi_t,0,NE- : C/E']

1 I 4 / 1 1-DICHLOROETHENE - q.6

I / I_-DICHLOI_ETHEN_ TOJAIf 57.0 UG/L \, "

1.2-DICHLO_ _ ¢ BENZENE - 0.8OJ UG/L _t

TRK_HLOROE_TY_LENE _TCE) - 6.O t)G/L \ / DICHLOI_DD_FLUOROMETHANEl - 2,0TI UG/L

VINYl. CHt.OR_II[ - 1.'2/L / _ / DICHLOROFLUOROMETHANE_1_"44.0TI UG/L r DIETHYL ETHER (ETHYL ETHER) - 6.OTI _/L \

IIJ VINYl. CHLORIDE - 5.1/L i I_ .,_-_x .""J"-I _/ MW930401 TRICHLORO 1,4-D_CHLOROB ETHYLEN ENZENE E _ l (TCE_ Il.OJ UG - 10.0 UG /L /L "_ _'_\ /_'_T" I

DtETHYL PHTHN.ATE - 4.D,_ UG/L /}" _'_ _ "1

_ErONE - §.0 Ua/IL N.N-DIETHYL-3-METHYL-B_NZAMID[ - 30.OTI UG/U_/' _// l' I

OCTAMETHYCYCLO'I_R/_ILOXANE - 12.0TI UG/L bis(2-CHLOROETHYL) ETHER (2-CHLOROErHYL E'll_ER) - 1WO_UG/L/ I

TRICHLOROETHYLEN[ ,CrCE) - 5.0J UG/L _MW870401 I ALDRtN - O.018PJ UG/L_ i[ // ! I

tr.,TE-,.o -O.O2', +:HE_T_OI_- "O.053UG/_ • _,,', / I I

/ = ...... I1 2-DICHLOROErHENE. '_0_'_- 7,.0 UG/L ",. ",_.'11

, 1 2-DICHLOROP E , 2.OJ UG L ".'\ '_

1, I-OK_HLOROETP_E - ,U, / R (2-CHLOROETHYL ETHER)- 3._J IJ_

_ET 1,2-O_:ONHLO'-

ROE1_T9oHEN_E,/L T¢AL - 14.O UG/L /

- 1"'_1_",_, / :_"

:CHLOROFORM - O,80BJ _11 _ _ _ "_

TRICHLOROETHYLENE (TCE _ 15.0 _/L t APPROXIMATE _..e<. VINYL CHLORIDE - 11.0T JU_/L .,

2-M1.4-OICHL ETHYLB_NEZEN NZENESULFONAMI [- ',_tDOMUG/L / t IRP LANDFILL 3 "_' IE - 5.0TI UG/L ",.

N.N-DI[THYL-3-METHYL-.BENZAMI_ - 22.0TI UG/L BOUNDARY • 2-ETHYLHEXYL) PHT ' iT[ - 1.0J UG/L

ALPI-_-CHLORDa_NE - 9400_IPJ' UG/L

BETA BHC (BETA HEXJ_CHLORI_CYCLOHEXANE)- 0.083P _/L \

BETA [NDOSULFAN - O.O0_PU UG/L

HEPTACHLOR - {),0.,_ UG_I_. PHTHALATE - 1,0J UG/L

HEPTACHLOR [POXIC_ -_ 9.P_SP U_/L UG/L

_LOR -- 0.1l_J_._O/L _ Mw93 #ws9c_ p,p'-DOE - O.0¢_PJ tlK]/_ _

PRAMITAL - O.9_G/L I t _,

MW870409 1,1-DICHLORO_THANE - O._I(_J_/L I / 1

1.Z-O,CHLOROCr TOTAL HE:- \_NE0 U . _/ I / VOC.SVOCof PE . S'r¢,DE/RE_ PC,OmEOJ DETHYL ETHER _ETHYL ETHER) -\_,0TI U /L

O.70J UG/L TRICHLOROETHYLENE (TCE) - 0.30_ UG/L

- 1.0B,J UG/L VINYL CHLORIDE - 3,0TI UG/L '\_

1,4-DICHLOROBENZENE - fl.0J UG/_I_ ]

2-METHYLB[NZENESULFONAMID[ - 7,1)TI _ 3/L 1. _IG_L/L

P_A_Z,NONE- 1o.oT,UC/L \_\ 1.

Mwg_o.l_

[

PHTHALAT[ - 1.0J UG/L I

i

_I

(2-CHLORO

OEUCETHYL ET/L HER) - 1,0J UG/L I

UG/L J

/_ _7o_o_ ] _wg_._ .0 _/L - O.007J UG/L

PESTIClDE/PCB REPORTED _ _ .....

NO VOC, SVOC. _'MW930421 1,1-DK4OROt-_E - O.BO UG/L I _._ I 1_27DK HLOROETHENLTOTAL - g,O UG/L I t ......

J TR1CHL(_ETHYLENE ('rCE) - 1.0 UG/L I I..... - B.o uWL L._ LW93040d _2 I t,I,I-TRICHLORO_THANC - 0.20 UG/L I _4'_I I -DICHLOROETHENE TOTAL- Ig.O UOIL 1,1,1-TRICHLOROETHANE - O.2OJ U_/L I

1,1-DICHLOROETHAN[ - 0.40J UG/L I / I _MW930413

I_-DICHLOROETHENE, TOTAL - 5,O UG/L

4_ TRICHLOROETHYLENE (TCE) - 7.0 UG/L rI_2-DICHLOROETHENE, TOTAL - 0.50J UG/L

D DW93041 (_ DW930402 _o.o bhI(2-ETHYLHEXYL) PHTHAL_TE - 2.0J /L --_ _ _w_o,_

CHLOROMETHANE - 0.60,/ UG/L TRICHLOROETHYLENE (TCE) - 4.0 UG/L

------ -- ..... ---_"_ _ NO VOC. SVOC, or PESTIC,DE/PCB_ ......

O DW93040_ 1CH"2-f HLO LO I_OETHANE " l"OJ UG/L I _ _--

1.1 - DICHLOROETHANE

i_ MW930417 I 1,I-DICHLOROETH&_IE -- 3.0 U_/L

1, DIE.: THYI. ETHER uG/UG/LL 1,1,1- 1.1-DfCHLORO TRICHLOROETHETENHANE - 5 E - 0,90J UG .0 UG//

LL

-METH _/L MW930426 \ I 1,1,1-TR1CHLOROETH_I( - O.8OJ UG/L I_-DtCHLOROETHENE, TOTAL - 5300 UG/L

l CHLOROFORM - 52.0_0 UG_L

P[NTACHLOROPHENOL - ETHER)- 21_/LUG/L \1 1,I-D_CHLOROETHANE - 5.0 UG/L METHYLENE CHLORIDE - _O.OBD UG/L \] 1,2-DICHLOROETHENE, TOTAL - 14.0 UO/L TETRACHLOROETHY_rNE(PCE) - 0.5OJ UC/L

BHC - 0.027J _ 1 2-DICNLOROPROPANE - 5.0 UG/L TRICHLOROETHYLENE (TCE) - 86OD UG/L C_LO_ - O.4O_ P-/L

I TETRACHLOROETHYLENE(_ , - 0.50J UG/L

! I_ J TRfCHLOROETHYLENE (T(_ - t_O UG/L

I b|I(2-ETHYLHEXYL) PHTk kTE - 1.0J UG/L

# ACETONE- _.O t_/L J_ i.....1 _ DW930407 [ b_2-ETHYLHEXYL)PHTHAI_TE- 2.0J _/L ]

/ __ I._,, _.o_/, I I"_'°_."=. " 'E"_:,DE/'_BRE"O'_EDI _ _0,:_ "-% j

L_L... I.:--JL_

IL___[3. CHLOROMDETI'M,

.N

L

E - O.60J UG

,,OoE- .= I /L .,. E '1 • " ............... " .......

l r_. ,) I I I,I-DK:HLO_O_THENE - 0._ O0/L l | 1,2-DICHLOROETHAN - 1,oaEUO/L I 1993/94 RI MONITORING

I I 1,2-DICHLOROETHEN 1,2-DICHLOROPROPAN[ - 2 OT:0 UG AL-E.T 3/

20L EUG/

/L I WELL/SOIL BORING LOCATION I CHLOROME'THN_E - 2,0 UG/L /

| TOLUENE - 0.20J UG/L /

J_ TmCHLOROETEHYrcEL[)- NEr_OEu_/cj A IRP, PHASE II, STAGE1 &:: " 2 MONITORING LOCATION

c_ 0---_ I [ NOvoc.svoc.o_,STODE,_.et_EO _-,_ MW930,2, 0 DOMESTICAND LIVESTOCK

300' 0 300' _ _w9_0_22 NS NOT SAMPLED WELLS

I ' I I I I INo"_ "=, _ _oDE/_BRE,,O_oI ..... SURFACE DRAINAGE t

SCALE ------BASE BOUNDARYFENCE

VOC, SVOC AND

¢_SWOmTH ELLSWORTHAIR FORCE BASE PESTICIDES/PCB IN

AI_ _OIIRC r _11_!_ RAPID cn"r, SOUTH DAKOTA MONITORINGWELLS0U-04 c_cKc° _ IPROJEC_T.,R. sc_¢ [SHEET NO,

AS SHOWN

3057 131

/

"_'STAL.LAI'_ OOUNDARY

WEAPONS

r STORAGE - - ----.-- .

m

, OU-8

I

,,_ J-7""/" . . ' OU-3 k :

BURIAL I

ST. _ AREA I

• z I

I

N ou-,o I] J

HOUSING

,

BERG _ml"_ DR. HOUSING m

! Z i

0 1200 2400 9 _._A_/TREATMENT w_TEw,,,TE_

I I i _" PLANT

EASEMENT .

ou-_ HOUSING.

GATE AR_

OU-1 FIRE PROTECTIONTRAINING

(FT-O1) --._ ..... OU-2 LANDFILLS1 & 6 (LF-02) OU-2 ,,

_I 3 LANDFILL2 (LF--03) INDUSTRIAL

OU-4 LANDFILL3 (LF-04) GATE

,i OU-6 LANDFILL5 - OU-5 LANDFILL4 !_.-(_ /

OU-7 LOW LEVELRADIATIONWASTEBURIALAREA (RW-07)

OU-8 EXPLOSIVEORDNANCEDISPOSALAREA,it, PRAMITOLSPILL (SS-t 1)

OU-9 OLD AUTO HOBBY SHOP AREA (OT-t5)

OU-10 NORTH HANGARCOMPLEX (ST-19)

OU-I 1 BASEWIDEGROUNDWATER

OU- 12 HARDFmLLNO. I % _'_ ELI_SWORTI-I ELLSWORTHAFB SITELOCATIONMAP AIR F'ORCE BASE RAPID C113',SOUTH DAKOTA

STAFF SHOWN T 94 60,378.86 - 1,3

3057 133

/
"-",\ "\ A=_,,_-R_"N" : _ Io_,_o_o_,'+ bt's_")l \ .,;" '\ r I--.--STORMDRJtlN

ii >_.\'\-' _\ "X\//.K" ."\"<_T,_';.... + J i 111" /I _,"X / _J-'C"\\ \", TREATME WASTE WATER NT PLANT "'/ " ", .... /" " \ k \ _,' II..... --w SURFACEDRAINAGE WATER LINE \ = \ _ "- , \ / '....¢. \ +, .# ! / .<...- ; ---- ,, , +'++\ I R,,.,O,+,TOR,NGWE,,' \x_\ \,\ x -- _ :: / I /='_-.."-. I " ; / \\ "\ I _[_ SOL BORING LOCATON

K\ \ -_ _'_._ " --AP-'r qr--'_w_.___ j/ "., \ // ...',O/_ I _ MONITORING WELL SOIL

\\ v---- ,70_ __/ H+,: / I t ./ _\ ......;o_--F- _ \ _ / ,,, ./_o_\\ I _ BORING IRP, PHASE II STAGE

I \X%\ </ t+¢rl'i,l_ ii+,lr_rpr__!_ P _7, II1 f*llllqr_ I X _,I. ,,._-il/l__........ b-" v_9_3P..16_)_. I d,' / ,' ; /1 ',]fI1TWITllll =.,.,,, 0 !| l !| | !l !|!+i ! + • " _J .,- \ _ \ /'_'_, '... I / I /^\ I,._+, ................. RPPHASEI1

\_ S 0 bE N b / I _. '" BEC[_eER1_7 I I / .. _-_ I_ I { \/ _ MAIN GATE _" "X\ ", /. I '_\ . ,_ ,m .' I I_ U_'__._C.LOR_ l,o/+it • i _U lllllllllllll , I V "\ "_" /I II_ SOL BORING

_C\ _ /_-, ._ f !;' _ o.o_,l;,#_.,_, _r _ '----_ _, \.. ( I _ IRPPHASEIISTAGE2

k\ _ _/_ _ :, ! ° .%_-_-m_ sl Fi.-po)i_JLjI_] -T---_---"" " - j' , \_\ - - "\'-. \ I NS - NOT SAMPLED

\>+.__ / I/TO? | r, I ' \ / l !il _/ ; : \ \ _ "" t % _ _1 liO VOC REPORTED I "+-. I

\ ,,'i_ \ • . v I i "./ _, " • .1_i_,=_i' .-A Ai I r , } ,_-"-- _ ---. ' "-I NOTE. ALL CONCENTRATIONS IN ug/k m'_ _ _ 'r • } " _ +JO I I _ _gllg .- -. •

,,\. ",X / (_;-_4) I,i If -,,. L_tJj_ l,,_<N<_,<.,o,<,{+.,-,).. /Jq 17 _ I (DEPTH) IN FEET

\\\ "XxX A-^ v. _R ^, N_/ i t - m'X tit _ ": "3 [[ _=o _ _/_ : / _-_o_ _, _.s-eX_ LL_ U ir_ ' I _ DATA QUALIFIERS

_\ x_\ .;> _- T_I_t_ r- _ UU I_ /_ =' ". II L.:_-+ I t ] .iooi_,r--_ i _., ] / / _ _'-_------_// /_ _- I DEFINED IN TABLE 2-13

\',. v,, <o \ t _/_+ '....... "+ I _ ' , +., _ j/ , //,-...__/ \ /? L_ k ",.. \k "-',_ __i / I l! k "> _ _t_et:_,_+ - "---J-/" /'_ /" / -"' + ¢ _ <'t _

\ \ , ,,_ ,_ 'k t t}11. _.] Bg,_!,, ! . ,,w++o+o7 _ "_ _ / _ -- ; . J I

'\ '\ #"I+_++1_1 '+'";'_"_q'X _ ] "I_ Jl_--[__ 3. ..... i ........ (_i / EAF-SBI2_" // i'_ -- _/--S>> z r-_ I,_- t ' _ *k, _ = f4K..I_IIP.-IPITL_Tt..,LUtP.../ILU_/I.IN_ J'_t.U lUO--I UI \ ^ NS " ! - " _ _ , ! L _ , _ ', +_ t I_.rw_ILIHYLL*T_,LUILII_A_LU*_P4_I:..)UIJJ I,U,:_--I,IJIJ . 1 ' I -- /J l ,

" "' '_ ............. -- _, _ _ I i /

", " '\ "(',4, _ f_ i "'.. "_-._ " " biUP_M UKAIP4 F_AF-SBI3". t/ _1._._.=.=._

" ', ' ", X t_ _ ] i ._ 2BW_O_ +.._,.._ . NS ,. ' ". d .... !.,....."_:m r_ f /'_' BLUE WING k,OBILE .......

,, :_.

'_ _ I

_ / / + _ ...... ........_ "- EAF-SBI 0 _o_ b_Jubu{} " _ v _+. .u d t_, i -- ' ' ', ,o_EP.RK ,, ', ' ',_'\ I _ i -- r-, . ' _"- _ _-sm+L]'./ I .-';.",.... if;/ ' ', ', X +- ; / MAY 1993 ". " N$ " ': -/ / "" f .... liT ' ' ' '<_; < " " _.8 -- I _-. .'.,_ NO YOC fEl:_ EO

'_ ',, , ',, ,, '..&+, / / j I ._ ,4,, Mw93060_. i . ..".

i

. \ (rJe-sao_)_I'- -_--+. ." " .'

.+,__./"-_ -. /:%._

/ \ "7 '+a' t l '.;_ fl_SB9306g_6 X\ t MW930611 _ _J I__ /_". ":_ t?

• \ r', S<_/ f " _E 7 UE#_-S_\ I x . $B930611 "-. _'_" // Z'-- "_*. //

./ k i " ] '_[ 1" ..... I_ "-. I NOV0CREPORTEDI "+" i//"" "" "- i I /+7' .... \ _ *_ , " -. _ +", z/ // "--_ "-+t/ / /

."+-" ," .....- ;" / / ;\ i ._r_rNrC_LOe2,_4(_-2,.+). + + o_.rm "" .."t>".... ---'-L 4;' . -".."-', I . ""_L- i i ', ,,,,c_l:,_ _l ¢zo-_,,.s\ "-.. ) o_co_l_. ,_? _ ..... '' .It /'/' 4"- ....- /I /'/'-' ./ / ' i _ _ m.lq_<ll_" k I k _" -- -- X - MEIH_JEI_ CHLO_ DIE 6 (0-2) . i , -+' // _ _--- , /

: -" i , '\_ - .', _ \ . ._._u:_c_.oRo_ _ Os-2o)\ _-. __ . "v .. -- ---_'-.' />

./ ./ _+, _, _ + \ , _ / X " • _ . .. _ 'I]MW930610 _ _ ".'_ "':I ," d`r

/'/ _', \+ , \ _+.' / \ -'--: i+ \ +m,-.+.'o+,o "_ ,,, _-.."-_4/

./ ,, fl _+,_o+o_\ [ _............. , +,,__[]o+ G-%_o+>\ ++ '_-_' - - O ,,,".',+""---_ "-. /7 X////7 N

_,. f/ I kT _ ...... \1 ,+..,.,,8, I _ ,_,o,-, ,........ <.7 /7_ _ L//t '. +I _t 1 _'_0N__'(_-_,-_)1 i+ u // /']'_ -""...V,_L

t" ! I / I Ir_F-SBO6 . " . , _.j/ / /

,\\ . I t _ . -,. .t,,.._ I!It ':' I _ _, , _ / _ GOLFCOURSE '_u

DS

<' I i -- ' "" '+ D( ],'q If . +t \

I I I

_I_ F:\HORIZONS\NEW\OUO\2OOARRAYDWG ~ B_

1993 RI _S_C,NEO BY OR,_WNBY I_TE PROarCT NO. riLE

ELLSWORTH ELLSWORTAFH B REPORTEDVOC-IRPAND MGL FEB94 60378.81

AIR FORCE BASE RAPIDCI]Y,SOUTHDAKOTA S01LBORINGS(VALUEW/DEPTH) O_CKrOBY PROaE:uCC__. SOUJE _ NO. :SHEENOT . - OU- 6 AS SHOWN 3-16

3057 136
N ",'\ .d-" _ i ",',, . \c,, I /_ LEGENO

• ' \" \ _<--_ _ i, SURFACE DRAINAGE

,X

__ ," I_ \ /,% / \ , _ WAII'R LNI" V', . _ f/-- \ ') '-,'.2 \ / \ _-" "4 1993 RI MONITORING WELL/ _ _'k_ .:_ \, ABOVE GROUND -" 'k X " \ " @ SOlE BORING LOCATION

-'_ <<,,\ \ \, v TANKS t _ \ " , ',

.i _" \ _':_X"\ _j-K,.. , I f-"X \\. WASTE WATER__ \ I \ _. A. IRP, PHASE I', STAGE I

k_ '\.'f_\._ \ "X _ | ,, \,.+ x \ TREATMENT PLANT / . / \ ./ ". _ MON TOR NG LOCAT ON

I % ',.'_,,,"_.'_.\ \ '-+ t i I ..=_i ,_ _. / .. . ...,v .... t'r'ELD SCREEN RESULTS '_

I % \,._;_ikX'\'\ "-, ." ; I _ i _L_'-. / \ : ,-', "_ _.... J \\_,\'<_r,j_\,\... _-__j,...j_,____. ,_,I -, ,. / /"_._-. // \ i / "\ 'L'..."\ _.-,o, /\ IRP, PHASE If, STAGE 2

_';'_X',,\v-'--R';_ "_ _'7 I-I--- --v--t.--__J/..;L_.. _.i_,,_'-_.... _ . _ ./ \\X)_ /X MONITORING LOCATION .

, -,,.,\ _ ,,,u_ _._,t, uJN ; L=__// rj., _____j-'_ -. - /" ..._X. (FIELD SCREEN RESULTS) _, <_' " "'/'C ' ' _ ==_ . / " _'" "\

'X_, :,_, UNDERGROUND ,i] _l_s_"_r_ _,,+c_'_9_t/ i l_r_ 1,,.,.,,,_ J " _r _ ,,_'q_'\ '\ , m 1993 R, DIRECT PUSH

j\'\ 'X'\ STOP_GE TAr+KS -7 _ _'_I r" Ill l_f'l _r-_ _-_1._ I; _u_ +g_3 ." I /+" \\ .......... _., ...... "\ "... ,/ LI_ MONITORING LOCATION

I "\\ _% _ ,_. ,. / / _/ / // +" Y_b|lllil]_l_ ', __ _] : / V _ ....Bf _*-c "\ ......_// (FIELD SCREEN RESULTS)

I \ % ".',_ / _ . "+_:, J =IIl I ,_'_ _ '.-Z__ _ i "_+'.._'_c,..omm ,_m '_'I ""-,.. ( _¢ m_T ¢^.D,_n

i +\' xX.. ,,'_ ",i' "\ , "_ ,i._,o` ;__"_ _ ". ''-i ,ll" \ I (_ - "_---_--" , "_', -:,, /

i_" ._ " " I \_ "-" ............. "*'. NOTE" ALL CONCENTRATONS N ug/ i \, , -. "_k x. \ • ' ' II \, ... . .. _ I __ " . m"_%_11 _ / I w_---- ....... . "- "

\'\ .\. ,'_, , {J A_, I ,. ' ,. --.> t_J/4,,_l. ./ I ." " n n _ NOTE- DATA QUALFERS DEFNED IN

\-\ ".. 'X\ i il _ \ |! ,----_ . '- '/ \ _::i"",';) J,/ _V_.BE. ,m,+.+i'/. ._. [Jl !I ,_ " _ " TABLE 2-13 I

_',,\ XX _ ABOVEGROUN0_ I[ _ \, ,-k[ I_'I. . _ I "° I _---_-_." A l_.n_ .o._I\_"-_ ]J LJ // "_ I

....\ _'_ IX T TANK " t_ \.. _'_ tl_', t,--_" " :. _ , _ L.f _ .. // I _ / L \" ..._-----_.'_/ ,.-> ". -- _ r

,.,,. ',.,X,__ , ,_.: _+._+-, ..I .+_o,_-+o.,.- , _. F-_ ++ )r_) L) ","\ A: %,X X F+/:_II,_ ;_ ; ,+o_o,/ , _ ,/\ _i,_ !-o "--'--_--+ /_-_ _, ",\, ? 'x:','xk i_ i /"U L_ _ - ,,._," I NOVOCR_m_01/ -/ '" _'-_ i F:-/ ., ,+ _ _ _ 1 " ' \ _ --_ _ # _ '*k _ • Lf j " +" i '

' ' • _ .... .+ ._--,,+=--l_+*.,nl.._'_,+_ln_n :. • o f i

",.\, \, ',?','__ _--:_.._ _-+_k l ^ --... ,', I / ,,ET'PPtLB[NZEI_, d_" ! [ "_= m [ _- BLUEWINGMOBILE '+-- L..... ', ',, .... "("I ._;_,',q_ ""..... _<.---+ IX'`........ I uW,30608 / O-)_tLENE\ ....::::_,'..+-LItl +C__, NOMEPARK .... ' _- ..... : /

" ", " ' ?'_ ; ; ,/ ' I .. ""- _ _, o_=,oeo_ _ • . ,'. ' . .. ,'_ 'S++_ ' +.

', , , ,% i ] : _ "-.T'_. , _ _ _r.._v.,r.._ ,-'F,I_'BT"O00_ "--/I Tl_il_ I_._DICHI.I_I_P.rrHrN ¢ "_. f/

.. _..- -. \ _ _ _ [_og_c_0a I "- I '_ t , "+-. "--- / / ,.. .- .- / .....-, . ! , _ I I NO_OC_m:_m_:--oL ------_ t::UD,+_ _ . l . I ..+ ,->"-. "-.-_ .,7

•/ /" , k [ / '_ [ ,"_,,____ " ! | " I_ w -- DP9_06+7/ . _t /"I"-. --_ _ %

• / _ t t _ ,. -" JUNE 993 _ -- ,,

/'// _,', \j ' " l l . '_'_L_ ...... SB_'_ ° "_-. _DISUI.FIDE O4J ,,'0_ "-_ "-. /./

/. '_ F_ 'MW930602 _ I I =_ _ . ..1.. ,_l_l,t_ll/o_o_ • TOLUENE 0.44 /, // .,'_; -.+ -. _i ¢/

..'/ ',, /'_ ;+_++ ',,_ \ _ _,_,"+°"' \. . .- ""-"' " "" 6' .z//?'+---_/jl//7 ;7,.-, ..._.-. '+x ' l ++ "xi _ X _ ". "t NO_ m_:_,o I / ,+m"E,,,m.,,m', " I! ,';_. _ i111/I/7 . ;

+_, i / _--,_-,_,'_"c:, \. -,, .t ..>_Go+couRs_ #/7 _ ,_i

'_'\ , , ; -- ", ', ." / PONDS // /1 ,

'1 t [ I '-, _ _ -.

"; -" ; ) f ", ""_ "'_

200" 0 2OO

I I 1 NOra

F:\HORIZONS\NEW\OU6\20OARRAY.DWG ~ 132

1993 RI _S¢,N_0BY 0_WNmr 0_TE PRO_EC_NO. r_ N_

ELLSWOR-rH ELLSWORIHAFB REPORTEDVOC-FIELDSCREENING MGL FEB94 60378.81

AIR FORCE BASE RAPIDCITY,SOUTH DAKOTA AND MONffORINGWELLS OU-6 CH_CKEO BY PROJIE:CMGR. _ T FIIGUR,IE I'40. SHEET NO.

AS SHOWN 3-17

3057 137
/

i_r _ ml m _ n m m l_

-- ,Ns_-_,o_;;_;_AR_!--)" WEAPONS

•, SJ _ ISTORAGE " ".""'I __OU__3_" "I OU-__3

N <,.

' LEMAY BLVD. ! -- "

BER1 DOOLITrLEDR. t" HOUSING I

STR(: ARNOI ._1 AREA I ' -

LAK

_ _ __ E SPAAT; DR, _ ! ' I

'

1 _TEWA_.WAST

_AKEi /TREATMENT wI 0 1200 2400

SCALE IN FEET J ""

\ _'_"

LEGEND OU- 1 _ 1-61 J

MAIN I HOUSING I

OU-I FIRE PROTECTION TRAINING

_ (n-ol) /,_ OU-2 LANDFILLS I & 6 (LF-02) OU-2 / I - -

j OU-3 LANDFILL 2 (LF-03) INDUSTRIAL

II I OU-4 LANDFILL 3 (LF-04) GATE • I ou-5 LANDFILL 4 (LF-05)

III I ou-6 LANDFILLs (u:'-o6) • I OU-7 LOW LEVEL RADIATION WASTE BURIAL AREA (RW-07)

II I ou-8 EXPLOSIVE ORDANCE DISPOSAL AREA & PRAMITOL SPILL (SS-I 1)

• I ou-9 OL0 AUTO HOBBY SHOP AREA (OT-15)

• I OU-10 NORTH HANGAR COMPLEX (ST-19) __

• I OU-11 BASEWIDE GROUND WATER

ill_°-'-__°_'_ '_ __ _____--_-_ !

II/ I I STAFF I ASSHOWNI OCT94 I 60,378.86 -18

ao57 lsg
IF_R_

J 3-19

3057 139
_ CLI.SWOI_TH ELLSWORTHAFB REPO1993 RTEDVO /94 RI C _S¢,NrO eY OR_WN_eY _ _m:_¢CrNO"'_. , SVOC, I _ 1 MGL _ 60,378.86

_'0 CITY,SOUTHDAKOTA PESTIODES/PCB- c._c,_o . _a_c, .,. l_c_u_ ,._ MONITORINGWELLS, OU-8 SHOWN 3-20

3057 140
REPORTE

DVOC, ¢_I.SWOR_M SVOC,TPH-

.___Y95

AI R_AS E _

t_ ,,,, FORCE CAPILLA

RY FRINGEITM IFIGURE OU-.i_i ,LAS SHOWN i 3-21

3057 141
25,o 240.0 ;0

"II1,,_ 1go vv

' - 90Jl 90__ "'-_

x , ,., x \ ',, £3

,_ <2 .....,

--''. -t / , .0 301_12 LAKE

'\\',"_\ 2_ '\ _ I 34 .(

_ ,. ',eO.. 1 "_' '_C"A_EL "\X _ _ .3405

'\\ .....,_ = =:_, DR_ZE

'\\ ({ ../:

/,

909

<2,0 '\ \'\.X\,,X"

• / ..'" \ --.\, \ '% _

!.._. _0'2{" &uw89,

", "X /X_ <2,0 1.0

-lJ

......",,Xx\ 6081 _ 14_3 i_ WP930904

<20 S_6 [

"\\''x l

'\\ <2,0 ',, _ '__ _ '", 0 \,-. ',, ',_ _"_ "\ ,.1,6119 z ,"

\/x ! I '%.>::' _ _9,o

TAXIWAY C \\ 59 |/ \._ i _____\_ \ _ I _ ', .:: _8o

' ....". " \ _" ":,"<'/_'. t l <2.0 _ ,,.. ,

"\\, "\ \ _ ,, _i(/ ...... ),, _t "_-

/

.\,, L /',.

",,\, 'x" x\\

LEGEND: " '" "

'\" \" I 709

• TOTALTCE CONCENTRATION ,' ."_'

1790 ,,.'_..,.- _702 ,\

WELL POINT ]_ \

LOCATION 1' "i... _.

MONITORING WELL/

SOIL BORING LOCATION ""

/_ IRP, PHASE II, STAGE 1 &

2 MONITORING LOCATION x,,,i),,,' EXTENT OF REPORTABLE COMPOUNDS " \,

AT NOTED CONCENTRATION __

.... SURFACE DRAINAGE

---eeee---- TOPOGRAPHIC ELEVATION

ABOVE MSL

MW9309 - 1993 OU-9 SAMPLE LOCATION 400' o 4.00'

MW93CP - 1993 FLIGHTLINE CORRECTIVE ACTION I I I

PLAN INVESTIGATION SAMPLE LOCATION SCALE

MW9321 - 199.3 SITE ST-21 SAMPLE LOCATION

NOTE:

MW941 1 - 1994 0U-11 SAMPLE LOCATION THE SUBSURFACE AREAS SHOWN REPRESENT OUR EVALUATION OF

THE MOST PROBABLE CONDITIONS BASED UPON INTERPETATION OF PRESENTLY

AVAILABLE DATA, SOME VARIATIONS FROM THESE MUST BE EXPECTED,

__1_993 RI _ DESIGNED BY DRAWN BY DATE PROJECT NO_

R ISOPLETHMAP

T_] Aim O_ m_ I_$e:: I RAPID CITY, SOUTHDAKOTA I MONITORINGWELL SAMPLES

'%_.Y I I FALL 1993 CHECKED BY IPROJECT MGR. I SCALE FIGURE

OU-9 _ J, AS SHOWN 3-22

3057 142


/

- - "" fNStALLAT_N BOUNDARY

WEAPONS

STORAGE

" AREA .....

, OU-8

I

,,J .....-...:. mS \ Bjla_

s

_, ST.

N _-ao

i AREA

i MW93BG05

LEMAYBl._

POND I DOOL_ DR. L_ HOUSING I

#003 I _...,_,,I [_ AREA' AREA

, __ I ! _'-,z f _.3_'---"

OPERABLE UNITS OU- 11 " ""

OU-1 RRE PROTECTION TRAINING

ARk (FT-01) GATE AREA _ OU-2 LANDFILLS 1 & 6 (LF-02) ....

OU-3 LANDRLL 2 (LF-03) !

OU-4 LANDFILL 3 (LF-04) ...... -.,.-.a

OU-5 LANDFILL 4 (LF-05) _-2

OU-6 LANDFILL 5 (LF-06) INDUSTRIAL

OU-7 LOW LEVEL RADIATION WASTE BURIAL AREA (RW-07) GATE

i OU-8 EXPLOSIVE ORDNANCE DISPOSAL AREA & PRAMITOL SPILL (SS-11)

OU-9 OLD AUTO HOBBY SHOP AREA (0T-15)

OU-10 NORTH HANGAR COMPLEX (ST-19)

0U-I 1 BASEWIDE GROUND WATER STUDY

0U- _ 12 HARD OPERABLE UN FILL NO. , ITS

OU! 1 ADDITIONAL STUDY AREAS

_t,c'_J_,_ _

*_,*,_ ¢t.I..SWOmTM ELLSWORTHAFB 0U-11 RI

,8_11_ W'_OI_I_ _ll_lC RAPID CITY, SOUTH DAKOTA SITE LOCATIONMAP

iil- ___ " I-'" I-S"

TAFF -'" I= ' AS SHOWN 95 I 60378 -" .90

305? 145

.. , 4--

- .. . /MW96BG0405 y_1

- "" / IMW96BG0408

" " / /MW96BG0425. I

,E ._ / /TCE 17 ug/, I

'rR "' / ; /. /MW96BG0422 I ° : :'" : '" - "_ / ; / /!1,1-DCA O. 46 ug/II

:Z :'') ";: ' -" ,,.._.¥ _ / .:_ / ICIS:'I,,'2-DCE 0.19 tug/ll . ....... _ __ ',,("b£\ . i / _/ IPCE,, . O.95 _ug/II

'_:"ff!;.:_.,:--:.- -:"?+-:.... ':""_"_ '°"; _.X_,.,_ <..-_,:1_. /_ II,1,1-TCA 3.6 ug/I / /MW972408 t ._ --;::- _ ....._"_........?- _ _ __I .... /- ' ITCE ..... 11- ugt |- ./11-, 1-DCA. 0.- 13 ug/II

:--:*_- ;. : ",o\ _-_ _--- . ' / ICiS-1,2-DCE- 0:'15 ug/! I -.......... :-.- "X _(../ . _ . / IPCE I"'.7ugll I. :- ........ " ,:'" -..... , \ _'A _ / 11,1, I-TCA O;52-Ug/11 "

% I. I ugll

• [MW96BG0419' i,-I,I-TCA 0.33 ugll

tCIS'1 2"DCE 0.2t uglL " -_ I • IPCE. O. 4T _ug/L 7240

1l ,;4--,,.1-TCA 4.2. ug/L "* .66 ug/I

[TCE_ - 8.9 u(

,L " .#_"

" L-_C.:

-. . MWIIBG0427 .._ _ -'_

'' I , 1-DCA O. 38 ugl I f \ ,, "_ '_Lo-.-_ -- . " " :': .... "- CI S-1,2"DCE 0. 14 ug/1 / \ -" ",

- -• '_ PCE 1,1 1-TCA 2 4 ug 0.83 ugll tl / _\ _'_\ • ,

TCE 8.6 ug/I / \ N(

g [MW982421 V / \\

.K IALLCOMPOUNDSN:-D ' k, : ". ,:

>- LEGEND I I Lr)

oO_ @ 1_?4+_N_RO_T,_T_R _ / " __ o_ V' /._ "" I o DRO DIESEL RANGE ORGANICS .--- \ _," ,..-

_/ DCA DICHLOROETHANE - j_ ,

P"°4 DCE DICHLOROETHENE

_ GRO GASOLINE RANGE ORGANICS

o IALL COMPOUNDSND _ PCE TETACHLOROETHENE MW982420

___ TCA TRICHLOROETHANE I ALL COMPOUNDS ND

,1)',<"

u_ TCE TRICHLOROETHENE O' 1000 2000'

/_.. ND NOT DETECTED _ FIGURE 3-27

L_ " _ TCE CONCENTRATION ISOPLETH(BASEDON SCALE CONCENTRATIONS LTO OFFSITE SAMPLE LOCATIONS /LTM OU-11, AREA 2 /ORGANIC

_-z 1998 AOC-24 PA/SIREPORT) APRIL 2000 EVENT

ELLSWORTH AFB, SOUTH DAKOTA

PREPARED FOR U.S, ARMY CORPS OF ENGINEER_

3057 147
TCE PLUME BASEDON FIGURE3-4 FROM

THE ADDENDUMTO BG04 PRE-DESIGN SITE

INVESTIGATIONREPORTDATEDDECEMBER1996.

TO THI' REPORTFOR OFF-SITE

)NTINUATIOI

APPROXIMATE GROUND-WATER

_' FLOW DIRECTION N

1994 RI MONITORING WELL/

SOIL BORING LOCATION (OU11)

1994 RI SOIL BORING LOCATION

• PRIVATE WELL

_ TCE PLUME

AREA OF A'n'AINMENT

A _ 4ool Ol _, SCALE 400'1

IFIGURE

[ 3-28

3057 148
/

\ LEGEND:

"__ _ 1994 RI MONITORING

WELL/SOIL BORING LOCATION/

FIELD SCREEN SAMPLE (OU-11)

_ 199,3 RI WELL LOCATION

._ _',-//x _ _ ..... SURFACE DRAINAGE BASE BOUNDARY FENCE

. -- _ AREA OF AFIAINMENT

kk ,_

\

OF • N

39 74;'

,,_ PZ941114 700" 0 700"

-- '_ SCALE

ELLSWORTH ELLSWORTHAFB 6._,£._8_.90

AIR FORCE BASE SOUDATKOH TA 0N-BASE AREA OF ATI'AINMENT Cm:CK_[OSC__ S -- IO_W"_NO. Ir_ "_ 0U-11 ROD HOWN j 3-29

3057 149 '
! w

i

• z>:_,_:.

" ' '. • _ 2,.,_ . !_ .t;,

J

IRP PIEZOMETER -_ ] \ __I

CLUSTER/NEST i#L... / _ l_I_

19EZL3//SgO4'R/oMO N_OLR/NGAT'ON " "_ --_--_!_

e 1993/94 RI FIELD SCREEN/ "._'_1'___ so,LBo_,NGLOO,T,O, "__-,.-- .-. ..Z.- =_,-_

TCE CONCENTRATION I

l[ ..,._,.._..!

..... SURFACE DRAINAGE ._ _o_._A_Y_.c_ "'..

-_':_.. ;_f

I

"! _OlOO _ _o

,,

SCALE

_ O_S_.,N_O_' Omm BY o_r _0_ NO.

0U-11 ROD JUNE95 60378.90 ELLSWORTH ELLSWORTHAFB DISTRIBUTIONOD TCE

AIR FORCE BASE RAPID CITY', SOUTH DAKOTA ON-BASE CHECKED BY I:q_OJIECl' MGR. S_.,3M.[ FIGUR1E

GROUNDWATER AS SHOWN 3-30

3057 150

'/"
I LEGEND: I

"., ", . _ 1993 RI MONITORING WELL/

.,_ ,, ..,, " SOIL BORING LOCATION

J-----,-J"'ki ?'/ "'\ "\""_-_-_ "" xT t_t 1993 RI FIELD SCREEN/

/f /_:!/'/," \, -"x X -[_ SOIL BORING LOCATION

: ,,?? \ "-..."., L

/// /I/

<?d _ ,,_ ,u_,,_,-,),,o uo/,o(,,-,,)l '',,_,.:, " :'"'.. 'I _._ STOPO URFA

GCRAP E DHRICAINELAGEVAE TION ABOVE

/ //t _/ .," ) "_'_'x _i!_ MSL-CONTOUR INTERVAL = 10' / t t ...._',, ..'" /I \ ' _SB931202"k "_./," .... _ EXPOSED HARDFILL AREA

/ i} i '\',., ...."\. _ HISTORICAL HARDFILL AREAS

/ % HI "_ ' ") _ LOCATION OF SOIL PILE I I_AIEIHYIZYELOTFIR/L_II.DiL_Nt. - 1I.OTI UG/KG _21.2_t-Z2.5) I _ " '

:NE- _.oJ_IKO(_ _ , ........ ,

' " - -- SURFACE"DRAINAGE "",, '",,

1 _ (EPHEMERALX',STREAM ) "\, ",, ',,

1 :_::..i.:._ ....."'" PRIMARY""",,

_""'_ J t_ I_ $B931203 " ""-

,,.. .cLm___%... _,,/.\< s ,, , --"x - -... "-. o \_ "] _) ) I NOO_,,_,CS _I_'T_:_, I t J

"": -_--"-. ""-. (::",.';,_t t ' _ ' ( q

",,,. ".. f_.._ _._iu_f_ 0 -_ii)

fq-ll _ /v,Z__t/#.:.:.:.:.):.:'..*i.:.::Kx_,\_.. ...",;'...'::.:,\ r

21

, " 7 .".7 ''" ". " ".L" • .!.d S;

_-=---=/ _ ""/_""""":""' "":C.,:'..":..":"""" li_} _ ......::::::::::::::::::::::::::::::: l)L_<...,........, :,..., ._, /(, , ,o_,,,,_,._,<--,o-__ ;LA:..'... .,.._:.,....../ /

> I

'""'_> \" "" J _b908 P ".......... '_'= "

(:_L-_UU /....... X "_'_:.J, I I¢' _-_,_u_,_.)p_,_ - _ ooi_o(,-,)

//" I-- f '_;'--- J TOLUENE- _ UG/KGI_-_1 I ws._s_2_o

t'" ,"/ / ' ___- ,-i _se9s_20_A_s_z_°o° _-'-"--"-"

/ // // , '/ SB93120BB _ "_ / P "

,/ ,/ / / 1 LI-11) ,

..,/ ,..././ <,,-,,> 1

i 1,, i _f _. i _,, .//< r ii I

200' 0 200'

I I I

SCALE

OU-12 0_S¢,NEDS_ DR_ BY _ir mOnitOrNO.

CULSWOm'rM ELLSWORTH AFB REPORTED VOC, SVOC, STAFF MAY 95 60378.85 PESTICIDE/PCB,.TPH,

Aim I_OmCIE BA_ II" RAPIDCITY,SOUTH DAKOTA SOIL SAMPLES .(VALUE CHIrCKED BY PR_:)JECTMGR. SCAI.Ir IrlCAJRE

W/DEPTH) AS SHOWN 3-31

3057 151


I /

"4 74 _ LEGEND:

I_ 1993 RI WELL POINT

qq)'_ N LOCATION

g_ 7, li_ 199,.3 RI MONITORING WELL/

SOIL BORING LOCATION

\ 75; _-

_,_-_'g _ _) 1993 RI FIELD SCREEN/

\ UL_ SOIL BORING LOCATION J

_X_ " 4 A IRP, PHASE I1, STAGE 1 &: o. _, _ ,,,_ 2_o.,tOR,.OLOC_T,O.

( >_ _ _ ..... SURFACE DRAINAGE

_' _ BASE BOUNDARY FENCE

/ _ TOPOGRAPHIC ELEVATION

_SBg; 17 ABOVE MSL

_ssg_" i_sa9 --loo--TPH AS JP4 (PURGEABLE) IN \ 18 GROUND-WATER CONTOURS

CONTOUR INTERVAL = 10'

! _. ,,_.,.2.,, 1-' r'''F H,,-,

)/_ ' "

• _ dc_

\ REFUELING _ /_ "x,

_sd_,cPo/3 33 I

7327

I_ SB93CP55

, t7

X -

TAXIWACY

" 1Im

9 ' [ i

@g24_ N23

206 207 208 209 210 21 _"

ALERT APRON _ /

600' 0 600'

I I I

SCALE

@ DESIGNED BY [DRAWN BY _E PROJECT NO.

TPH AS JP-4 C 94 60,.378.88

ELLSWORTH ELLSWORTHAFB (purgeeble) AIR FO RC E BASE RAPID CITY, SOUTH DAKOTA iPROJECMGT R. I SCALE -- -- FIGURE IN GROUND-WATER(ug/L) CHECKEDBY 1 J AS SHOWN 3-34

3057 154
_UMP HOUSE 7 s ...... ".... '_"_'_ "'_ " "\" " " _ ' "/-- " ..... "_ ..... " ' ' '-- -_ "_ ..... " ""-

- +. - i _ +_ " -, ._ ,. \ " _'. "_. ............. -...... _, , -, : . - ( " ". _. . ..' _ +-_ >7 ' = ,= b-5 - " ] y

.PUMI HOUSE ...... " ......... + . .°-. +,_-= , < ..... _ ...................... ..... _ -":<. ...... ."..... .-.-<. -

_ ....... -_,"._ <-. _.'j_':,...4=-. . _ . _ _-_ ......... _:_,c_., ,,-/ _, " -..... -. . ;, k: -:, ., ! : ' - _ _ i] ":-_'._C: "_ - _;1"

PUMP HOUSE "_.... _ "" " " ":....... ; .... '_ ....

"_° - '-, <i /7!1

',.; i - :£

PUMP HOUSE 4 , ........... - -- w

i I MW930902

I0RO ND

- ___J GRO "' 54 ug/L

1 BENZENE ND

.... / TOLUENE ND

................. IETNYLBENZENE ND 0' 150' 300' 6OO"

I XYLENES ND SCALE

#

LEGEND I - .,-

"' i/ - I_ MONITORINGLTO GROUINLTDLocATIoNWA M TER

PUMP HOUSE 3 --J

-_.-,. _ MONITORING WELL/SOIL BORING LOCATION

i EXTRACTION WELL LOCATION /

/ COLLECT ION TRENCH h_) = [ -- .

,-.o - J -z- - FREE

-_ L_ -.-:.- PUMP HOUSE 2 _ ---,_-- r"l DELINEATED CONTAMINANT PLUME

/ (BASED ON 1994 CORRECTIVE ACTION PLAN)

...._ NOTES: L_

>-LC DRO=DIESEL RANGE ORGANICS

/GRO=GASOLINE RANGE ORGANICS

o_ND=NOT DETECTED O

- o _ , PUMP HOUSE 1 C_ / .-_.

.. ('-,

_ MW930903

4_ / OR0 ND

GR0 ND

_--_ ,_" _" -- BENZENE NO

TOLUENE NO

_ . ETHYLBENZENE ND

OC \--d M_I95FRA0101/DUPL ] GATE XYLENES NO

z"" ORGRO O Y920 U ,Oo_O/L ,'L ,,,*_Z,O_ IOR /GRIIIC O> ,_O/, " NO/NO BO FIGURE 3-35

" T -"-: BENZENE ND DRO 3Z ug/L IBENZENE NO/NO TPHIBTEX CONCENTRATIONS LO TOLUENE 9.2 ug/k GRt_ . ND _ /TOLUENE. ND/ND

I--Z ETHYLBENZENE ND BENZINE _ IETHYLBENZENE NO/NO LTOILTM JANUARY 2000 EVENT-FLIGHTLINE <_ C XYLENES NO TOLUENE NO /XYLENES NO/NO

_C - ETHYLBENZENE NO ; ELLSWORTH AFB, SOUTH DAKOTA

XYLENES, NO PREPARED FOR U.S. ARMY CORPS OF ENGINEERS

3057 155
N"

.::,], O. 98 ........ :.......... - " '_MWo_3O_T....

_,,. ._- | LANDFILL NO, 1 -'--':--_= - -"_'° :: _..- _.__ : . , - -. LEGEND

IIATE _ MONITORING LOCATION

• -.... ALL COMPOUNDSNO- _-- -.............. _ MONITORING WELL/SOIL BORING LOCATION -DC 3.5/3,6 _: IRANS-t ,,,2-ICE o

EXTRACTION WELL LOCATION T

_ - L"'_ LIMITS OF COVER MATERIAL MW8 ............

_ " -'-:: - -i-. -- ........ " .......... o._ .........; ":-'_._:" _ DELINEATED CONTA RESULTS OBTAINED THROUGH JAN MINANT PLUME BASED ON UARY 2000.

122_O N-......... --Jr- ........... -[- + : ,,,,-._!:I_:G_:::-,. ,ws,_oz0_

PLUME .... .... DCA D I CHLOROETHANE

_::-_"_'_;_::-: __ IIlL_.2-DCEI_940O.5210u2o/L I DCE OI CHLOROETHENE

I''.930z°2 I H roof OR_ _ MEK 2-BUTANONE IFREE PRODUCT MEASUREMENTI 0203 _TRAN5-1.2-DCE i50"32 uou_/L/L TCE TRICHLOROETHENE I(NONE OBSERVED)- I _I'CE .5 ugZL ND NOT DETECTED

-"' DRO DIESEL RANGE ORGANICS

GRO GASOLINE RANGE ORGANICS

::: _ DCP D ICHLOROPROPANE

121 ,-500 N -Jl- -I- -I- _--

L_ DWJPO8

, DWJPO_+ .__)WdP04

C

- MW930215 [ , WJP10

o 4 121,.,-1_0_ N ITO].UENE 0#8_ ullL| + _DRO 1 'L + +

c_ c: _; :.;,_ _..! MW930217

_ .... _ik_Q: "'" -. RO 70 /L

_ "............... o ", . o o_ " o- o o

_._ oo _ .-. o

o- ,°

u_ oo _

o I FIGURE 3-36

"_ ..... ,_"_ i,- oRGANIC CONCENTRATIONS

120,-500 N -,. -._ I LTO/LTM JANUARY 2000 EVENT OU-2

I

<_ • " "- "- "- I ELLSWORTH AFB, SOUTH DAKOTA

IPREPARED FOR U.S. ARMY CORPS OF ENGINEERS

3057 156
/

i AREAoATTAN

,,"r_s_3o_3o

s.

....... z:_

o

//

5 L

/( J_-EXTENT OF HISTORICAL

' _)s89_o,44 l_s_,_ t_-_ BURN PIT AREAS

\ \\ _s_o_29 / , - _ 199.3 RI SOIL

I \\ \_,,._.,, L::t:........ _\2o_ ) Bse93°'_ - BORING LOCATIOIS oo,

i '_ TITLE: FIGURE: DWN BY: APP'D:

} A'RELLSWORTH FORCE SAS¢ SOURCE-AR AREA OF ATTAINEA MENT SOILS 4- FOR 1 STA DATE: PJ FF TTRNO:

MAR 96 60378.84

3057 157
#

o!!!i _"_--..__._._J_ _ ,,

- I _,,,,j

' so_,°ol',_ _ DP9SO,2_ _ ARE/l, OF ATTAINMENT

t P_ ___s°_'I°" _ 199,3 RI SOIL

i i

_\ ,._ _ _2, _ _11_]Oo,],_/ MONITORING/SOIL

_ so,,X (_B_°_2°' -1% _' I BORING LOC/_TION

i_ I _i_II_ i_ SB9 TITL@ S E: B9300117_lX _2_0' FIGURE: DWN BY: A SCALE PP,D:21_0'

11 : i,__ AEi_ili-_FwOOi=Bi%¥ASE'i AREA2RFouANTTDAIT FOR 4- NwMAfNR 2 :/_ITF_5 6_).,iT:;78,4

3057 158

• OU--5 " "" NCH I " I

" ' , - AREA 3 I ,

" -- ......,, ' AREATRENCH---'2 ......._I"CHLOR_ENZENE-_ 0.21.ug/L

I

<- , TRENCH _ .....

- , AREA.I_/ e 2_._ _.

sc_E

.':- -....... LEGEND

L_

---...... ....... w_ WATER/GAS/ELECTRIC/SEWER LINE

"x TRENCH _. "-. AREA .... " _- _ MONITORING WELL/SOIL BORING LOCATION

- / ..... L_J DELINEATED LANDFILL/TRENCH AREA BOUNDARY

I @ LTOILTM GROUND WATER

13e.Ix)ON MONITORING LOCATION

" IBENZENE ; I CARBON DISULFIDE' 0.81/0.86 ug/Ll

j..,,"'ICHLOROBENZENE 0.2lIND uo/L I

I CHLOROMETHANE 0.39/0.34 ug/L I

/.___/ I BENZENE 0.7910.77 uglL I

Z

£>

Eb

6

c_

©

0

/

kJ

if-)

7

o _ MW970302 "- _'r-- POSSIBLE BURN

o_o " ".......... LO P l T AR _ NO ALL, COMPOUNDS

137,500 N

3057 160

-__ ,., " FIGURE 4-4

•-, $ 8 SAMPLING LOCATIONS/ORGANIC " "' " CONCENTRATIONS LTO/LTM MANUAL

,-z_<l:O _," _ -=. JULY 1999 EVENT- OU-3

o a - . - ELLSWORTH AFB, SOUTH DAKOTA

PREPARED FOR U,S. ARMY CORPS OF ENGINEERS
+ -I- _ + IM*m30416/0ue,l rC,TE . , . + : :: + _ + + + _. I

11,1 -OCA • 0.tT/O";'t-t:C_/L_ ,. _.::

ITCE s.o/4.9, L_/L : o_ ARY OF /BENZENE O. 90 ug/L

....... SOUTHWEST PLUME AC=S-I,Z-DCE17ug/L t

/IPCE 0.25 ug/LI

.........................., ..... __ , _:::" .... . / [TCE 1.9 uO/L I

TRAN5-1 •2-DCE : :...... _'_'"" r. _-. _ "" " - :.... / PCE J J

....................... I 1 / ....

I1,1-DCA 2.6 I J

Ic 18-1 • 2-OCE |

IPCE O. 45,

|I,I,I-TCA 0.51

ITCE 3.3 !

l w960405/0UPL]CATE I- BOUNDARY OF t_

J= ;_ Icls-I,2, P.

-

_

OCE 2.6 0.7912.6/0.7u

6

g/

u_L, r,l

! _ _ S " O_-

lIT-";: .... lq PLUME _ LANDF '_ ...... tLE3-

.9304. ! ..o,o,

1,1-DCA 0.18 ug/L _ : CHLOR I ,Z-DCAOETHANE 0.65 ug 96 g/L_'"

clS-1o2-DCE 0.48 ug/L I L _ 1,1-OCA 0.24 ug/L _ol-DCA 4.7 UG/I - _:_?

TCE 0.50 u_l/L I _ _ CIS-1,2-DCE 6.5 ug/L 22 ug/L PCE O.32 ug/L TRANS-1,2-DCE 0.25 ug/LL

TCE 1.0 ug/L 1,2-0CP 1.7 ug/L :

IMW930418 ETHYLBENZENE 0.87 ug/L _ TOLUENE 0.14 ug/L..

11• 1-DCA 1.2 ug/L TCE 1.8 ug/L •

I • 153,0_00 E IcIs-I,Z-LOCE 160 ug/L YL __HLORIDE 9.1 ug/L

_ ITCE [ 310 6.0 /5.2 ug/I '_*_JIIlI_Z

• 3-0CB 74/60 ug/L

,4-DCB- 5,6/NO ug/L

,Z,4-TCB 1301110 ug/L O" _00' 200" 400"

SC_.E

I'_93°42z LEGEND

ITCE O. 39 ug/L EJl04_1_

1,153,5R_) E _- ;. _- -I- ! Jr- (_ MONITORING WELL/SOIL BORING LOCATION

II EXTRACTION WELL LOCATION

I_ I

: ,iJ LIMITS OF COVER MATERIAL

" . ._. - M,8704o4 I DELINEATED CONTAMINANT PLUME

"_ -_: 1.1-0CA 1.5 _/LJ I---I BASED ON RI, PRE-DESIGN

/ CI5-1,2-DCE 33 ug/L "

1.1DCA 0.18ug/L 1,2-DCP 1.0u_/L" AND LTM DATA 1.154,_ E -_- -l- -}- CiS-I,2-DCl -}- -_ 1,1,1_A 2.3 ug/[

1.1.1TCA TCE -- 68 u_/r.. BCE BIS(2-CHLOROETHYL )ETMES _7 .........

-_ DCA D ICHLOROETHANE

I

Mw970401 DCB OICHLOROBENZENE

DCE D ICHLORETHENE J ; - 1.1-0CA , 0.53 ug/L

CIS-1,2-0CE 5.3 u_'l,' ..... DCP D ICHLOROPROPANE o TCE 7.2 uo/L / PCE TETRACHLOROETHENE

>-L_ E 1,154,-500 _ _:" _ _

. ,oc, r" c..,i=..--'o,o L,Z-OC.,l 1.: , _ ugh.I TCA TR ICHLOROETHANE ...... Tc_,-" 4.1 ugh._ -_ TCB TR ICHLOROBENZENE

/ I" TCE TR [CHLOROETHENE (D _ _'_

o _ _ ........ !::!_,.:: ND NOT DETECTED

C_ d _ __

-': - ._ - _5

_ E _._ss.,ooo + +,. _ " --- .:::.-_-.:.:':+r_- + + +

.(_-__ (_ IND ALL COIdPOUNOS Z L / _ _" Z Z': Z Z Z Z/ I" FIGURE 4 -5

_-.- o o o o. o. o o I SAMPLINLOCA G TIONS/ ' _ ;.. o ._ 8 I ORGANICCONCENTRATIONS , O O 0 _ " 0:-" 0 0 LU 0 _- u_ _ u"r, ---- O,_"

-".... ,, ,, ; -; I LTOILTMAPRIL2000EVENOU- T 4

°_ _

T '-" "- _,- "............ _" _" " '_ I ELLSWORTH AFB, SOUTH DAKOTA . IPREPARED FOR U.S. ARMY CORPS OF ENGINEERS
J

/

\ t" . _ \ ,7 f I , _ , \ i

i_..\.._ ) / _ _- \\ ( ( y -.._._u,,,_,_,_4\ j 'X I .,--_. "-'-..t9 ".._ -------'O'OORAPH,C'-LEVAAT,ON B V_ _ -,_-'_"-., t ./_ ....._., _ 0 / / .._-/_'_. _! x ",--/ I I x/x /' "_ , _ MSL - CONTOUR INTERVAL= 10

_.4.,,. -,. ,, <_._ \ L,_ j .s/- _- '_ '_-=-_%.-"-5_...... _-"--,. .... -..-...... , , ..."_X_U / I /" ..,\ .._._,.__ .,,_,,.o@_ .. .. i -,-,..,... ,/I--".'_ I( /f-----.. _. _z-.i-/-_ -_I .... -.. ,oo. o ,oo. •.....--....._.....,,._..--..._-/-----.._.. ,.s.,,x t # t / ".... ',!_ w ¢"J_.,Y"V'Ii,.-->_.. i % " ""-"'L'- " " " .. _ ._ -_ "'." ='-" ix. I . ",

"'-_.Q__',, _. \ _///)i'J)// /_ "_"'--___///_/.J_/J_{_AP'I:>ROXIMATE FENOE'_OOATION SCALE _-"._-_ t\ <'_' __<'_s_s,--------- '-.. ,.r', 'rllllZ...ZllA '. '.. ", .-.. "-........_._ .,.Q',. .., .t l / ,,- f { / f GATE_. \,, (///_..,(.ZJi ", ",. '\

\.-. --.:> -._------.z_----/ ) -.z_! ._.. 9o_oi )q / ' e"_df..ZJ-'_" i J ", \,

i '-_".<-',>_/'_-_.. ) _ _ ,I ...... -i /" _m ff ./ ', \

" "<"-_="- "_! "" '.......... " -X-- / -__ : : _............ , I / I --1,..... ,, ..............

. " If \ I ! I / I \ ""

/ _- 9o_ II. S ,'_'-] i / t ",.

- i,#._'_._- .,..,.o,,,,. C-" [I ! " .... "-'<........ " ', " _ "_

"\t '_-.. ;" '> ",.,, C"-/ ,'i ; _ \. \ \ L .... ", ) li _ _ _

\x "'L_. _ \ I" "<_7_ i+'/_/ {{ //II ;! _EXTENT Ol_OU-8 DEBRIS L bltU U I_l;J-k / i '\- )<":<_ _ / _ / ! _ BURIA" ''q' '-'Y A....

",._ _i <.._.__" 9o,, L-_.{o // t' (AREk 2) ...---/ 1 Y< ->-.- " >--.-_ _ Ht .,:/ _ t ?',--.. /

........_ I ,h , / \ 9032 " _ \ I I t _ // }

, --_ _ .J/ i _ -------_-.__.-" ,,

i _ DEBRISBURIALAREA O_Sm.,NrO m" OR_ mr _'E PROE,CT NO. _ ill[

_ ELLSWORTH ELLSWORTHAFB ALTERNATIVENO. 3 JSS FEB96 __) A,. F'ORC_-BAS_- S0u0,._0,_ S01LREMOVALVE(;rTATIVOVEC ER/ :.,c.E)_, P_tc_ll_t. _ .,_ .o. t'_l_ '

I _ INSTITUTIONALCONTROLS AS SHOWN 4 8 i

3057 164
'\,

p/I li__ \ ) i i +' --_ '._1 _ ",l _ \ .!1 IJ't.\ I .\ "

1"1./1"1 "!7 i ',, % \ s I _i,l'+.'i I ---. I:,"1 ti_ Ik: _, I il_d ...... / ..I;7_r..,L II%.i ,. ( r: 1 Ili ,.J_s I_D84+!- J \ \ I ;,_1/I,TJ"I.X +'- \ \,

,: I All _ _1 ".1 t I ,_ I f AI A\ _, I"_ I _ \ '\_

::.,l'lll I\1 II i it t /I l_/A/A._l.l,l..l%i. \< t i

i I l'/,_ J #.'lJ ). \ \/ /.,f. JA_lll/% \ \ ") -_ Vl##." ' I I/ IG /,'.if, X A kiLl I" \ )f" --'-I'1I I I I I t \ _ 7A'../XJf'P"l|_ , ' If

! I I I'LX.'XtlIIXlt}'\ \\ \\F

::!_1"3 \1 -,k.JoJ,II III P.;II { \ \_ '

:_fl IN I _-I" "i'l" i h'_, I.JJl I_1 I:11 \ ltl I\ I _l_,_,-J../ s'l I IItl IIII I t ]

"X_ _il I \. I . I i'13 _: I I I I I_lllli / /

\ I\I'I".+I i J"-'<i-l- ; ' ( / J'l t i I L(Vit_ t " /" ....

t k k% i. I I-J:I.IJIFPNI i li +o'o+il I I I I I.+17 I / \ /"--" .ll_d,il l-" I'il.tlMl_lf'l 7q • /I I J-J Ii11+/++ I ' \

)11 I _t I LI l--"::'.:-_f .... _,z,:: IJ"J I I jl I'

I J ,,!i I .,, ]i I "1 r- 0 I.IU NIIIIILIN',Uk I -i' "

x(I l:_',l"ild#l - / ] g rl _ (I I I L<'_II/l ) "\ I Xtl el".'O,'.,I l:Rs+x+_, / ,,i I I I;li Ill i { /J ,, r---+....... - . ........

1.1 II 12 ] ,I- + P% #' '+1I I IEI":II I", 1(/" " "' ' /X ]1 1@ \ _ t c ;_ ...... +l I I;l!T'll I t //i ./ .

t.\ll lXl_l't ' l _+,;o_' /I I 1+11Ilk i / 11 "+- .... '". %'_\1 I 'l.I It t., _7_] ! I I 111 I1 i,,..I _] "" ....

k\]l.,4 ,1 l\ -.V .'l I lii Ill i _ , _i\li, _ (. I IA,I III i t"_ /

_ i_]_ t ,," ,, _ I t_::a:V{ i t t"_ s I'_ _ \/' i\ ( i i!l_q'/\ I I \\

_1 l,k _ c i ,.t I It Itl/ \ i _ ') } -" , t 1" />_'i it.. t-', _'J I it.till / ; I it ,,

\ t Xi t",'.. ,..... i i_o,_q,o i l/,'V i i J /f'=

_, #' _- ' I+l#P/ I , ".._" /I

e,_ I " .+.__:.. i --A\g

I=. .......

) /- "" LEGEND: _ "_,

1993/94 RI SEDIMENT _ %'-_ [] SAMPLE LOCATION

199,:3/94 RI MONITORING /. .... u, "f--'_"\N. ''_J f

WELL/SOIL BORING LOCATION .l I/f-'''\, ,----_-, I ,,_ \ (

1993194 rl FIELD SCREEN/ // , [ ""J '/" '\,\'L., . t

///

SOIL BORING LOCATION ( <_ /,-- .... \ \-.,

L_ " k.,.

• 1993/94 RI SURFACE SOIL " %") l '_ I -.

GRAB SAMPLE ..... , \ I ,.s ..'_"xJ_ _ ' __ _ .....

_APPROxlMATE LOCATION OF t .... .... "

"\"\" i'I I --" ,...... _-L/-/-/-_PROMETON (PRAMITOL. 25E) SPILL .._i /'" ,.''/--'J_ f-",,k\

_PRIMARY AREA OF NEW COVER ", I -_

 oo- ¢o , =aeu o oo Nrcnv...w , <"-",(

I I ' I

SCALE

__ O_AWNeY oat( _o_rc'r NO.

EOD AREA O{S_,N(OBY JSS JAN 96 ce._.swo_'rM ELLSWORTHAFB ALTERNATIVENO. 3

AIII_ rOIl_Cl_ BASI_ RaPiDCITY,SOUTHDAKOTA VEGETATIVECOVER/ CH¢C*(OBY _O_¢Ct _r. scar 'r_JR¢

INSTITUTIONALCONTROLS AS SHOWN 4-9

3057 165
PUMP HOUSE' 7 . /.- IORI_:k)6' RO: 8_i_ _% -<' " +......... _ -................. I

• t IBENZENE 50 _ I- . 1- . - - ':.:. " -- _ " -

-.,I(:* I ETHYLBENZENE NO - I-: ,'_ " _ ...... /" I TOLUENE N_ " |_ - -

I, H -. ...... . XYLENES NO: """ }._.1-" " -- - -.

M_5FRA0401 I ,, _ " - -:-. - -

I I:

• . ":+"-. . I " I DRO 180 u_t'L _.. " :.. -- ':._ ...... ...

.' " /. lGRO 240 uQ/I_- - . PUMP HOUSE 6 - --- 1. I BENZENE 0.5@ ug/L -- " " " - " _ " "

........... : IEIHYLBENZENE

.... " TOEUENE NO" . ,;: -- _ ""'- _>

MWIgCP11 -

lo=o• 700_i_ I ! .... --_ ..... - " --"....." "- -"........." _: '][1:1- " "-:-•--" : -::............ :-::-".............

IGRO BENZENE 440 ug 3200 u/LglL } / // " _"" " " " ...... :- "'_" "" "-_ : : "'"-'k'-_ - -- f

IETHYLBENZENE 59 ugPl. | _xe!:_':,,_'_ /

I TOLUENE NO |. /_"_.LL_,_ l : - "_: " - _'_ ......

IXYLENE$ 330 uglL I:\_/ _@:" "-., ;71 .... . _ =, .-_z_,? " " :i-_-.{=..7:'.-:::],-i,:.._. : . .._. , ..,- ,::o :,_,

PUMP HOUS " _., ,. - - "

,_$B_41162 : - - _

PU/vP HOUSE 4 /.._ N

/ IDRO : i: " NO

.IGRO 130 ug/L I BENZENE O. 098

/ / ETNYLBENZENE NO

MW95FRA0402 / / /TOLUENE 1.3 ug/L o" tso' 300' 600" /XYLENES

DRO 110 /// / NO SCALE

GFE} 170 ug/L F /

BENZENE 26 ug/L LEGEND - ETHYLBENZENE 4.4 ug/L / "_

t,

TOLUENE NO ug/L _ LTO/LTM GROUNDWATER XYLENES ND ug/L / _ MON I TOR ] NG LOCAT ] ON

PUMP HOUSE 3----/ --

z _" _ MONITORING WELL/SOIL BORING LOCATION ,?-

A

,,_ / '::.... "-" _ ABANDONEDWELL I

/ MW93CP14: • EXTRACTION WELL LOCATION (EWFRA0101)

_ IMw89cP12/OUPL'cA'E HOUr. : /0o94FEElOFFREEPRODUCT -

_- IGRoIDRO 3700/3_00_600 gUO/1/L400u PUblP COLLECTION TRENCH ( SUF'RA0101) / IBENZENE 41/2.2 , g 'L

IETHYLBENZENE 2101180 u IlL

bJ ITOLUENE ND/ND L_ / !--'! DEL]NEATED CONTAMINANT PLUME

>- IXYLENES 4001350 ug/L (BASED ON 1994 CORRECTIVE ACTION PLAN)

_. ;i NOTES:

o _ _'__- ::' DRO=D]ESEL RANGE ORGANICS

o© _ :7- IMw93cPo4 I_ PUMP HOUSE I- GRO=GASOLINE RANGE ORGANICS

c-J_ . IIALL COMPOUNDS ND l--i _ ND=NOT DETECTED " DRO ND

L_ L_ _ GRO 320 ug/L

_r,_ _ '_ / BETHYLB ENZENEENZENE NOO. 58 ug/L / MW930903 I

_@__ XYLENEsTOLUENE _2"1 ug/L "-_ ALL COkg°OUNOS NO I :30_? :1_ (; i_

I..,.,OlOZ "

L,__

-../ IGRO 120U IORO NO _'/L IMWS3Z_OS _L CO_POUNOSNO FIGURE 4-I0

L_" -3"I, IBIETHYL ENZENBEENZENE NNOD ,i,_ COMPOUNDS NO TPHIBTEX CONCENTRATIONS I.-Z ITC]I.UENE NO LTOILTM APRIL 2000 EVENT-FLIGHTLINE _ IXYLENE5 NO

ELLSWORTH AFB, SOUTH DAKOTA

PREPARED FOR U.S. ARMY CORPS OF ENGINEER',


APPENDIX A

_ PUBLIC NOTICE OF FIVE-YEAR REVIEW

- 3057 169
Ellsworth Air Force Base

Environmental Restoration Program

Five Year Review

The EIIsworth Air Force Base environmental team announces the completion of its Five Year Review

for the year 2005.

EIIsworth Air Force Base is a Federal "Superfund" site under the Federal Comprehensive Environmental

Restoration, Compensation, and Liability Act ("CERCLA", also known as the "Superfund" Law). Under this law,

the Air Force is required to prepare a "Five Year Review" of the status of the environmental cleanup program.

The Five Year Review was first prepared in 2000. It has been updated in 2005 and is available for public review at

the locations listed below.

Rapid City Public Library Holbrook Library

610 Quincy St. 2650 Doolittle Dr.

Rapid City, SD 57701 EIIsworth AFB, SD 57706

394-4171 385-1686

Investigation reports of the various EIIsworth cleanup sites are available for review at these

locations, or by appointment at the base environmental office, (605) 385-2680.

For more information or to be added to our mailing fist,

contact the 2_ h Bomb Wing Public Affairs office,

at (605) 385-5056 or e-mail 28bw.pa2@ellsworth.af.mil.

3057 170
-- APPENDIX B

COPY OF BASE CONTINUING ORDER

" 3057 171
, ...... " ........_'- DEPARTMENT OF THE AIR FORCE

Q HEADQUARTERS 28TH BOMB WING (ACC)

ELLSWORTH AIR FORCE BASE, SOUTH DAKOTA

'I 8 SEP 2005

MEMORANDUM FOR DISTRIBUTION F & T

FROM: 28 BW/CC

SUBJECT: Land Use Restrictions at Environmental Restoration Sites

1. In 1990, Ellsworth AFB was placed on the Environmental Protection Agency's (EPA)

National Priority List because of soil and ground water contamination caused by past work

practices. In 1992, a Federal Facilities Agreement was signed with the EPA and State

Department of Environmental and Natural Resources that divided the base into 12 operable units.

2. The attachments summarize the existing restrictions and hazards on each of the 12 operable

units on base. A copy of the original Continuing Order with a map indicating the location of

each operable unit on base is at attachment 1. Attachment 2 summarizes the specific restrictions

of each operable unit. Attachment 3 delineates the requirement for construction waivers at all

restoration program sites. Any violation of these restrictions subjects the base to fines and

stipulated penalties.

3. Please be advised that the attached order continues to be in effect and must be strictly adhered

to by all Ellsworth AFB personnel and contractors.

4. If there are any questions, please contact Mr. Dell Petersen at extension 5-2675.

JE_M_I_olonel Commander , USAF

Attachments:

1. 28 BW/CV Memo, 27 Aug 97

2. Operating Unit Restrictions

3. Construction Waiver Memo, 6 Dec 96

4. OU8 Action Plan
'" "! DEPARTMENT OF' THE AIR FORCE

_ _ _F._---_C_JARTeRJI* 21114 gOMIII %':1.'_C IA¢;CI

FROM" 2g BW/CV

SUBJECT ContinuingOrder,Lend Use Restrictioatn.* Environmen:zlP.estomdonSites

h On 24 Jm-mzry1992,theUnitedS_atesAizForcethe , Star,e ofSouthDakota.endthe

EnvLron-rn-entzlProtectiogenA ncy(EPA)enteredintoa FederalFacilffieAgsreemen;.govendng

activities zssociated ",_-iLhthe env_om'nent_l restoration of Ei|sworth Air Force Base. As a part of

that agreement, 12 geo_raphic areas of environmental con_.miaafion, "kno_ as Operab|e Units,

were" idemif, ed for remedla_on. C]e_nup and installation of _'ound water trez,.mem systemsfor

those sites _/II be complete this construction season. Because correcth_.g the enviromnemal

impacts of the past _ill take many ),ears, the inte_uity of these Operable Units must be protected.

2. The z_ached figure indicates are_ where cle_.'mp _ctivi.:ies have taken or are taldng place.

SFecific detailed inTormation concerning the sites is ava.;l,.ble from the Ellswo_,h Installation

Res,'oradon Pro_arn (/R.P) office. Cleanup acdvh'es and furore ]and-u_e practices v.itb.in the

Operable Units are stated in enforceable Records of Decisions _sldch IL"aitand, in some cases,

forbid consu'ucdon activity.. The IR2 o_.]ce must be consu!.ed prior to construction x_iduin an.

Ope:zble Unit. The IRP office _ill review any proposed consu-ucfion _cti_,i_"and the Record of

Deo:sion to determine if h_-pact to c!-._nup activities or to exist,.'ng comz_,ni6_tcd media _:ill

occur. The EPA, the staze, and Ak Combat Command may be consulted to help dete,-ur_ne the

feaslbilky" of projects. Proposed cons;ruction ac;ivities _ill be accepted, accepted _i_h

mod.;ficatio_, or denied.

_. Fdlure to comply _ith the above r-.stdctions could pl,,ce the Air Force at risk for additional

cleanup work _.nd enforcemem actio_ by the StRte of South Dakota and the Environmental

Protec6on Agency. Modifications to this continuing order can only be made with concurrence

from the regulatory, agenc{es. Codification hutoan Air Force Instruction is pending. Add_ional

information is Rvail_ble from .MrDill Peterseu az 5-2675.

Attachment:

Site Location Map

• 3057 173
3057 174
Ellsworth Operable Units

OU-1

The selected alternative, source area soil and ground-water _eaunent, includes the following major

componenL_:

Continued operation o/the interim remedial action (IRA) which consisted o/contaminated

ground-water removal, soll vapor extraction (SVE), and treatment

Installation of addi6onal SVE wells within the historical bum-pit area to be added to the existing

IRA SV'E system;

Removal of contaminated ground water using additional ground-water wells and collection

u_nches to be added to the IRA ground-water recovery system

Trea_nent of ground water at the existing IRA treatment plant

Institutional controh for the area

Long-term monitoring

Long-termoperationandmaintenanceofequipment

OU-2

For Landfill No. I, the selected alternative, an earth cover and institutional controls, includes the

followingmajorcomponents:

Constructing an earth cover, capable of sus_g perennial vegetation, over those areas of the

landfill that are not adequately covered. Filling in low areas and grading the entire landfill

area to provide for positive drainage off the site

Instinmonal controls for the landfill area

Long-term ground-water monitoring

Long-termmaintenanceofsoilcover

Realignment and lining of the storm-wa_er channel

For Land/illNo. 6,theselectedalternativenstit ,i utiononalc trols,includesthefollowingmajo/"

con'lpon_nts:

Ins_tutional controls-for-the landfill area

Loag-term ground-water monitoring

Long-term maintenance of existing cover

3057 175
The selected alternative, capping, includes _e follo_dng major components:

Placing a soil cover capable of sustaining perennial vegezafion, over the landfill area

A pre-design study to examine the need for lsndRU gas'control measures

/nstimtinnal conUrols for the landfill area

Long-term ground-water monitoring, and long-term ma_tenance of soft cover

OU-4

The selected alternative for the landfall, soil cover, includes the following major components:

Institutional controls for the landt-tllarea

Placing a soil cover capable ofsustatuing perennial vegetation over the landfi]I area

LandfillgasmonRoringandpassivecollection systema,snecessary

Long-termmonitoringandmaintenance

The selected ahcrnanve for the ground water, pun_ and treat, includes the following major components

Continuedopera,on oftheintm'iml_medi_action(IRA)whichconsistofremov s aland

uceamacntof contaminated ground water

InstaJladon of recovery trenches and/or additional extraction wells to be added to the existing

IRA gzound-warcrrecoverysystem

T_atment of removed ground wat_ at the treatment plant built for the IRA

Discharge of treated ground water to a surface water drainage, to the Ba_e wastewatcr treatment

plant, or by tmderg_ound injection

OU-5

The selected alternative, Covering. includes the following major components:

•Placingtsoilcovercapableofsusuiningperenniavel getationoverthelandfillm-ca

institutionalcontrolsforthelandfill area

'Long-termground-watermonitoring;and,long-termma/ntcnanccofsoftcover

OU-6

The selected ahernadve, capping, includes the following major COmpOnEnts:

Placinga soilcovercapableofsustaining perenn_lvegetationoverthelandfillarea

Modification of storm-water dis=lurxe point and drainage

3057 176
hxstiru_ionalcontrols for the landfilJ area

Long-term ground-water, surface-water, and sediment monhoz-ing

Long-term maintenance of soil cover

OU-7

The selected alternative for soils, tnctimr3onal controls, includes the following major coraponeats:

Institutional controls for future land use

.AJaextensive records search will be performed that may provide additional information relating

to the boria] uenches. A removal action might be used to address waste within the trenches if

the weight of evidence from this record search combined with previous infonmtion ident_es

and warrants _ type of remedial activi_,.

The selected _ten-_tive for 8-m_mdwater, institutional controls with addieona] munitoring, includes the

following major componen_:-

Imtimtional cunt:rolsfor ground water use

Imp[ememing a long-term ground-water mordtor/ng and maintenance prog_m

OU-8

OU-8 is divided into two distinc_ areas of investigation. Area I andArea 2. Area I is the areasurrounding

the actual ]EODArea ksetf. Area 2 consis_ of the Debris Burial Area where waste from d_eEOD Area was

buried. Altermtives for remedial action were evaluated separately for each exeL

The selected alt_nztive for Area 1 _OD Area), vegetative u3_ cover and inst/mdonal ccmtmh,incl_]es the

following major components:

Co_ucung an _ cover over aportionoft_u: EOD Area

Institutional contro_ for the EOD Area

Long-termsediment sampling

Long-term maintenance of e_,h cover

The selected alternative for Area 2 (Debris Burial Area), vegetativesoft covetand iz_fitutionalcontrols,

includes the fol/owiag major corczponeazts:

Consu_tcting an earth cover over the Debris Burial Area

Iv_titulional contzols for the Debt-_ Burial Area and long-term maintenance of earth cover

OU-9

Based on the findings of the risk assessrnent, unacceptable risk to human health and the environment does

not exist and remediation is not warranted for OU-9. Presently, a corrective action plan (under.t_e State

petroleumreleaseprogram)isunderwaytoaddressfuelcomponentsinthegroundwaterinthesouthern

3 _tC_ _

3057 177
portion ofOU-9. Remed_tion of other areaswhere soil Jmd/orground water is contzmLnated by pelroleum

willbeperformedincompliancweithStatoefSouthDakotaregulations.

OU-IO

Basedou thefinding5ofnounacceptablerisktohumanhealtahndtheenvironmentrem, ediatioisnnot

warrrantedforOU-10. Remediafionofsoilsand/orgroundwatezcontaminatedby petroleumwillbe

performedundertheStateofSouthDakotaregulations.

OUOU-I l hasbeendividedintotwoa_e_,Area istheSouthDocksStudyArea,andArea2 istheBG04

and BG05 Study Areas.

The selected akernativc for Area I, Ground-Water Ex_c6on and Trot with Containment, includes

thefollowingmajorcomponent:

Ground-water removal and _eauncnt in the 5outh Docks Study Area

On-b_e cont_nmcnt of ground w_r cont_R_ contaminants at concentrations above Federal

Maximum ContaminanLtevels (MCLs) md State of South Dakota Ground-Water Quality

Standards

Imtimtionaclontrolsandlong-termmonitoring

The selec_.ed alternative for Area 2. Ground-Water Con_n and Treatment., includes the

followingmajorc,ompoaents:

Ground-wzzer removalandu_ur.cut along the northea__b_e boundaryand atare_ of .high

contaminantconcemr4fionson-base

Naturalauenuationoflow co_t concentration areasp,rimarily off-base

Alternatiwveatersupplytoresidenatffsc_ed bycontaminaticoonming fromthebase

Additionzl investigation to determine the eastern extenzof off-base ground-water

contamination

h_fimtionaclontrolsandlong.mrmmonkoring

OU-12

The selected _temative, capping, includes the following major components:

Placinga soilcovercapableofsu_alningperenniavlesetatiover on thehardfillarea

Pre-design study lo identify the source of rnethane and examine the need for hard.fillgas control

mea.su_csndev ,a aluatetheneedforerosiocon ntrolmeasuresalongthestreamadjacentto the

i_rdfill e_a_

Institutional controls for the hardfill areas

Long-term monitoring

3057 178
Implementationoftheremediesw/llreducethe fum_vrisktohumanheakhtnd the environmentto zcceptablelevels.

CHECKLIST

Access Excavation Contsndnation Remarks

Allowed Allowed

OU-I No No

No No Groundw._er/So_]

No Groundwater/Soil

---..-- _ •No _c_.__5-2680_=_f==

Soil

C_undwaterPSo/i C,_l5-26_fo_cc_s

Yes GroundwaterlSoil

Yes

OU-12 No $oi.ll __Call.__65_.-2.80for access

3057 179
•_.,._7:_'_._ DEPARTMENT OF THE AIR FORCE

AIR COMBAT COMMAND CIVIL ENGINEER SQUADRON

'_. _ _ 'S.=_/_ LANGLEY A'R FORCE BAS_. VIRGINIA

o6 DEC '_

HEMORANDUH FOR DISTRIBUTION

FROM: HQ ACC/CEV

129 Andrews Street S_e 102

Langley AFB VA 23665

SUBJECT: Construction Waiver Requests for Znstallation Restoration

Program (IRP) sites

i. Reference: Air Force Instruction (AFI] 32-1021, 12 Hay 94,

Planning and Proqramming of Facility Construction Projects.

2. This letter is to provide clarification of the ACC policy

regarding construction on IRP'sites. Even though AFI 32-1021

prir_arily addresses HILCON projects, the waiver described below

should be used for any type of construction activity on or near

sites. The waiver process is designed to ensure risks to human

health and the environment are considered before the start of

construction projects.

3. A problem developed recently when a request for waiver was

approved for an FY96 HILCON project based on the assumption the site

should'be remediated before the actual start of construction. This

conditional approval gave the construction agency the go-ahead to

continue design and contracting actions. Unfortunately, the M!LCON

project was moved forward to FY95, while the IRP project slipped a

year. The result was the HILCON was ready to go out on the street

for bids and the IRP cleanup was not under contract (in fact, the

Remedial Investigation/Feasibility Study [RI/FS) had not started).

4. In _nother recent instance, a chain link fence was constructed

across" an IRP site. The fence must now be removed to accomplish an

IRP remedial action. The project was not coordinated through the

environmental flight.

5. Written waiver for construction requests on an IRP site should be

sent from the _ase Civil Engineer to HQ ACC/CEV, copy ACC CE5/ES.

Waiver requests should be submitted for closed IRP sites as well as

active sites. The waiver request should include £he following .

information:

a. A description of the proposed construction

b The IRP site number

c The exoected impact of the proposed construction on the

site

d. Information regarding whether or not regulatory agencies have

been contacted regarding the proposed construction.

3057
e. A description of the plan to dispose of soil or groundwater

which'is to be removed from the site during construction.

f. A d_scription of potential conflicts between the project and

ongoing or planned IRP projects at the site. The request should

explain what will be done if unexpected contamination is found.

6. Once the request for waiver is reviewed_by HQ ACC/CEV, it will be

either approved, disapproved or returned for additional information.

The HQ ACC/CEV response will include an explanation of the action

taken. If additional information is required, a request will be

issued from ACC CES/ESV. Most waiver, requests are approved and

should be submitted early enough in the programming process to avoid

delays in construction activities. Coordination with the Restoration

Element at the installation should help avoid this type of siting

issue.

7. Installations should use discretion in their application for

waivers by keeping i_ _ind that the goal of the waiver process is to

"control reasonabl[foreseeable impacts to'human health or the environment. Cons_:ruction activities on an _RP site which implement

the site remediatlon as part of the IR_ do not require a waiver (e.g.

installation of wells, piping, pump-houses, etc.) In addition, mino_

activities on IRP sites which can be _emonstrated _o have negligible

risk and will not otherwise interfere with ZRp activities at the site

may not need a.waiver. Sound _echnical judgment should he exercised

by the installation in identifying such cases.

8. Please direct questions to ygur ACC iKP Prosram Manager or

Mr Normin Guenther, ACC CES/ESVE at DSN 574-3680.

Attachment:

Distribution list

cc:

HQ ACC/CKPD/CEPH/CEPR

ACC CES/ESPE/ESPW '

3057 181
OU-8 ACTION PLAN

1. Strategy: To restore the Op=able Unit (OU) g site quickly to its original configuration

undertheapproval of South Dakota Dcp_lmcnt of Environment and Natural Resources and the

Environmental Protection Agency (EPA). ensuring safety to the site and personnel. To

implementaprogramthatwillensureallRestorationsiteson basecomplywiththeRecordof

Decision(ROD) assignedby theWing Commander.

2. Status:On 26 August99,l 6 piecesofdyrutmRethawtexc exudingmtrogl_e_-in were

destroyedon theoldExplosivesOrdnanceDisposapOD) l Range,creatin2gpitsapproximately

8 feetindiametera,nd 3 feetdeep.Latertw, o more emergencydetonationoccs urredon,

25Aug 99 todestroaydditionalleakingdynamitea,ndon28 Sop99,a groundburstprojectile

simulatorandan M-I8 smoke grenadethatdudfiredurina tr g ainingexerciseT.he detonations

damaged thelandfill capthatispartofOUS. Lateon 5 Oct99,C_V identifiedthecratersand

/mmediazelybegannotificationsup thechainofcommmd. ACC, EPA andstateofficialswere

notifiedon 6 Oct99.

3 ActionItems:

Revair Site

3.1 Obtain funding and contract to restore site

3.2 Develop sampling plan and repair plan

3.3 Collect samples of site and restore to original design condition

Ir_provemcnt Process

3.4 Construct fence around OU-g boundary, limiting all future access

3.4.1 Survey fence location

3.4.2 Obtain diggdng permit

3.4.3 Submit work request

3.4.4 Install fence

3.5 /nstall signs on OU8 fence similar to those on other OU's that state,

"Closed, No Access, Contact 385-2680"

3.6 Preidcntify a location on base for emergency disposal of ordnance

3.7 Update EOD Team Chief Checklist to include notification requirements and a map

of approved disposal area

3.g Update CEV Spill Bil_der to include checklist that identifies notification mquirernents

and a map of approved disposal area

3.9 Redistribute copy of standing order

3.9.1 Redistribute original copy of standing order with cover letter by Col P.

3.9.2 Redistribute standing order with updated policy letters with every new WG/CC

3.10Provide lraining to all 28 CES Flight Chiefs, 28 CES/CEO Superintendents, and 28 CES

heavy equipment operators

3.11 Provide awareness training to all "On-Scene Commanders"

3057 182