Decision_Document_for_Big_Lake_(OT-04).pdf

DECISION DOCUMENT FOR

BIG LAKE (OT-04)

Dobbins Air Reserve Base, Georgia

Department of Defense . United States Air Foree

Installation Restoration Program Decision Document

Site owner:

94 AirUft Wing (94 A W)

1430 First Street Dobbins Air Reserve Base, Georgia 30069-5009

Restoration Project Manager:

94 Support Group/Environmental Quality Fllgbt (94 SPTG/CEV)

884 Industrial Drive Dobbins Air Reserve Base, Georgia 30069-4210 l1 MaylOOO

DECISION DECLARATION STATEMENT AND SUPPLEMENTAL INFORMATION

To FINAL DECISION DOCUMENT dated September 1997

--------BIG LAKE(OT.04)--------------

Dobbins flJr Reserve Base, Georgia --------------United States flJr Faroe

11 May2000

DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997 and SUPPLEMENTAL INFORMATION dated 11 May 2000 for Installation Restoration Program Site

BIG LAKE (OT .04)

Owner: Dobbins Air Reserve Base, Georgia United States Air Force

11 May 2000

The following information is supplemental to the Decision Document dated September 1997.

Please insert these pages in the front of the September 1997 Decision Document just prior to the Cover Page.

Executive Summary:

The following supplemental information is provided to further document actions taken in the approximate two and one-half years since the unsigned Draft Decision Document was released for comment. This Draft Decision Document, dated December 1996, was released for Public Comment in June-1997 and received by the State of Georgia Environmental Protection Division (EPD) on 6 June 1997. The Air Force did not receive any comments from either the State EPD or the Public. After the comment period terminated, the Air Force prepared the Decision Documents in final format in September 1997, correcting minor spelling and grammar errors noted during another internal review.

The final Decision Document remained unsigned at the request of the State's Hazardous Site Response Program Office and Headquarters Air Force Reserve Command while awaiting the State evaluation under the Hazardous Site Response Act for status on the Hazardous Site Inventory. In January 1998, the Georgia EPD notified the Air Fotce that a listed site was de-listed from the Hazardous Site Inventory and that releases at other sites did not exceed reportable quantities.

The finalized document does not change any of the facts and positions postulated in the original draft document that was made available for public and State review. This supplement restates the Declaration Statement· made in the original Decision Document. The Air Force, fulfilling its responsibility as lead agent in this process, signs this Decision Document into record in accordance with Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the National Contingency Plan (NCP).

DECISION DECLARATION STATEMENT AND SUPPLEMENTAL INFORMATION

·------BIG LAKE (OT-04}-------------

Dobblns Air Reserve Base, Georgia ---------------United States Air Force

11 May 2000

DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997 and SUPPLEMENTAL INFORMATION dated 1 May 2000 for Installation Restoration Program Site

BIG LAKE (OT -04)

Owner: Dobbins Air Reserve Base, Georgia United States Air Force

1 May2000

DECLARATION

This Decision Document has been prepared for Big Lake (OT -04), which is designated under the Installation Restoration Program (IRP) located at Dobbins Air Reserve Base (ARB), Georgia (Figure 1-1). This Decision Document has been prepared based on Category III decision criteria presented as guidance by United States Air Force (USAF) entitled NFRAP Guide, A Resource for Making, Documenting, and Evaluating No Further Response Action Planned Decisions (USAF, 1995). This Decision Document is organized into two parts. The first part presents the Declaration, and the second part presents the Decision Sununary.

STATEMENT OF BASIS AND PURPOSE

This Decision Document presents the selected action for the site, located at Dobbins ARB, Georgia. This decision is based on information obtained from the Remedial Investigation (RI) Report prepared by Parsons Engineering-Science (ES) (ES, 1995) and the Comprehensive Analytical Report (CAR) prepared by Montgomery Watson (Montgomery Watson, 1996). The primary information from these reports used in this Decision Document is the comparison of site concentrations in all environmental media with applicable or relevant and appropriate requirements (ARARs) or to be considered (TBC) criteria, and risk assessment of current or existing exposures to public health and the environment. The risk assessment also evaluated hypothetical future exposures and this evaluation is sununarized in Section 3.0. However, for the purposes of this Decision Document, only current or existing exposures were critically reviewed. This is consistent with Air Force guidance. (USAF, 1995)

The primary purpose of this Decision Document is to demonstrate that the response at the site is complete and therefore "no further response action is planned" (NFRAP). Section

2.2.9 of Air Force Instruction 32-7020 (USAF, 1994) states that NFRAP status has been achieved when any of the following conditions apply:

• Investigation finds no evidence of contamination, insignificant levels of contamination, or low levels of contamination that pose no significant current or existing threat to public health or the environment.

• The removal of contamination is complete.

I

I I I I I I

I I I I I I

I

DECISION DECLARATION STATEMENT AND SUPPLEMENTAL INFORMATION

To FINAL DECISION DOCUMENT dated September 1997

·--·--------- BIG LAKE (OT-04)-------------

Dobbins Air Reserve Base, Georgia U nlted States Air Force

11 May 2000

• The cleanup system is in place and operating effectively.

DESCRIPTION OF SELECTED REMEDY

Studies have demonstrated that contamination is limited in nature and does not pose a significant existing or current risk to human health or the environment. Dobbins ARB, therefore, has determined that the response at this site is complete and NFRAP status has been achieved. ·

DECLARATION STATEMENT

This Decision Document represents the selected action for this site developed in accordance with the IRP which uses as its basis the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended by Superfund Amendments and Reauthorization Act of 1986 (SARA), and the National Contingency Plan (NCP). I! also satisfies the requirements of the National Environmental Policy Act that applies to CERCLA response actions. It has been determined that the selected remedy of no further action is protective of human health and the environment, attains federal and state requirements that are applicable or relevant and appropriate, and is cost effective. The statutory preference for further treatment is not satisfied because contaminant levels at the site have been determined to present no significant threat to

•-~~·-•~·-mM foc~-:-~-t'te_.t-o_o ____ _

William P. Kane, Colonel, USAFR D;;&J · Commander, Dobbins Air Reserve Base

SUPPLEMENTAL INFORMATION AND DECISION DECLARATION STATEMENT

-------BIG LAKE (OT-04)------------

Dobblns Air Reserve Base, Georgia ----------------United States Air Force

11 May 2000

DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997 and SUPPLEMENTAL INFORMATION dated 1 May 2000 for Installation Restoration Program Site

Site Manager:

94SPTG/CEV

884 Industrial Drive

BIG LAKE (OT .04)

owner: Dobbins Air Reserve Base, Georgia

United States Air Force 1 May2000

Dobbins ARB, GA 30069-4210

(770) 919-4898 or (770) 919-3547

SUPPLEMENTAL INFORMATION TO FINAL DECISION DOCUMENT DATED

SEPTEMBER 1997:

The following supplemental information Is provided to further document actions taken In the approximate two and one-half years since the unsigned Draft Decision Document, dated December 1996, was prepared and forwarded to the State of Georgia Environmental Protection Division on 6 June 1997and released to the public for review and comments. Following an extended period where the Air Force awaited State and Public review and comments and having received none, the Air Force finalized the draft documents, correcting minor wording errors made in the original draft document, finalizing the Decision Documents in September 1997. Again, these documents remained unsigned at the request of the State's Hazardous Site Response Program Office and Headquarters Air Force Reserve Command while awaiting the State evaluation under the Hazardous Site Response Act for status on Hazardous Site Inventory.

These finalized document do not change any of the facts and positions postulated In the original draft document made available for public and State review. Lastly, this supplement restates the Declaration Statement made In the original Decision Document. The Air Force, In its position as lead-agent In this process, signs this Decision Document into record In accordance with Comprehensive Environmental Response, Compensation, and LlabUity Act (CERCLA) and the National Contingency Plan (NCP).

SECTION 1.2: SITE HISTORY AND ENFORCEMENT ACTIVITIES

Addition as a new bullet statement: Section 1.2, include as the 41 h bullet: The Georgia EPD notified the Base by letter dated 24 Jan 94 that a site at Dobbins ARB warranted listing the Base on the State's Hazardous Site Inventory.

Renumber bullet statements: Section 1.2: Renumber the original 4th bullet to become the 5th bullet: "Georgia DNR reviewed .... •

Addition as a new bullet statement: Section 1.2, Include as a 61 h bullet: The Air Force delivered the Draft Decision Document to the State of Georgia Environmental Protection Division on 6 June 1997. Review was officially requested by 30 days, but since the Decision Document was not signed and published at that time, Dobbins AFB remained open to accept any comments until today. To date, the Air Force has not received any written comments or recommendations from the State on this Decision Document.

Addition as a new bullet statement: Section 1.2,include as a 7th bullet: In September 1997, the Air Force Incorporated minor corrections as recommended through Internal Air Force sources

Page 1 of Supplemental Information

·-'--~-------BIG LAKE (OT-04)---------------

Dobbins Air Reserve Base, Georgia ----------------United States Air Force

11 May2000 into the dreft Decision Document and prepared a fine I Decision. Document deled September 1997. The Air Force hes mede no substantlel change to the dreft Decision Documents thet would alter the data collected by the Air Force or the decisions made for the sites. The Air Force delayed signing these documents while awaiting further action, determinations and recommendations by the Georgie Hazardous Waste Brench pertaining to the listing of the site on the State's Hazardous Site Inventory, and the State's review of eny end ail other documents previously submitted to the Stele.

Addition as a new bullet statement: Section 1.2, Include as a 8th bullet: The State of Georgia Hazardous Site Response Program Management Office within the State's Hazardous Waste Management Branch indicated on 23 July 1998 and 31 July 1998 that either sites FT-02, OT-04, DP-06, DP-06 (by reference), and OT-07 did not have reportable quantities or that the State had no reason to believe that a release exceeding the reportable quantity had occurred at these sites.

The State, in effect, de-listed the sites from the Hazardous Site Inventory, Addition as a new bullet statement: Section 1 .2, Include as an glh bullet: The Facilities Compliance Program Office of the Hazardous Waste Management Branch performed a RCRA Facility Assessment (RFA) at Dobbins ARB on Tuesday, 20 July 1999, To date, the Base has not received any written comments or direction from the Stele on the results of the RFA or the Intents of the State. In addition, the State Hazardous Waste Branch has not provided any review comments or suggestions on any of the subsequent Installation Restoration Program draft and final reports and plans forwarded by the Air Force after the Draft Rl report submitted In 1995.

SECTION 1.3: HIGHLIGHTS OF COMMUNITY PARTICIPATION

Clarification to second paragraph: Page 1-2, Para 1.3, Second paragraph, Third sentence:

The Air Force made Public Notification on 22nd, 24th, 25th, and 26th June 1997 via the local newspaper and letter mailed to the local community leaders, adjacent property owners, and parties that had previously expressed and interest in the environmental restoration program at Dobbins ARB. The Base sponsored Public Meeting was held at the Cobb County Central Llbrery on 26 June 1997, as scheduled, in conjunction with the Restoration Advisory Board's (RAB) Scoping Meeting. Public review and comment period was officially left open until 1 August 1997, but since the Decision Document was not signed and published at that time, Dobbins AFB has remained open to accept any comments 1 May 2000. The Air Force has received no comments.

During this second RAB Scoping meeting held on 26 June 1997, representatives from the Base outlined the overall Installation Restoration Program at Dobbins ARB, described the purpose and benefits of the establishment of a Restoration Advisory Board, announced the availability of the Draft Decision Documents for review, and _announced the comment period. The representatives from the Base outlined the pian to prepare the final Decision Documents, after the public had been afforded the opportunity to address concerns. Community members participating had the opportunity to ask questions; none of the attendees expressed either exception to the data provided or concern with the Air Force's stated position or future plans. In addition, the Base received no additional comments at that time or at any time since that date. As a result of the apparent limited interest from the public and regulatory agencies, the Base Commander detennined that community stakeholder interest was neither sufficient nor sustainable to fonn a RAB; however, attendees were placed on the mailing list for subsequent environmental restoration notifications and advertisements.

Addition as a third paragraph: The Air Force sponsored a third Restoration Advisory Board Scoplng Meeting to determine community and regulatory agency's Interests in the formation of a Restoration Advisory Board on 30 Sep 1999. Only one community member attended; no regulatory agencies attended. The Dobbins Remedial Program Manager outlined the overall environmental restoration program on-going at Dobbins Air Reserve Base. The community member attending this scoping meeting did not express concern with the Air Force's management of the program, or any past action to investigate the sites, nor future plans. Based

Page 2 of Supplemental Infonnation

SUPPLEMENTAL INFORMATION ANO DECISION DECLARATION STATEMENT

~-------------BIG LAKE(OT.Q4)--------------

Dobbins Air Reserve Base, Georgia ~-----------------United States Air Force

11 May 2000 on guidance provided by the Air Force, and the limited community stakeholder attendance at the seeping meeting, the Base Commander elected not to form a Restoration Advisory Board, opting instead to continue notifying local interested parties, elected officials, and State regulatory agencies of changes, phases, or discoveries.

APPENDIX B:. ADMINISTRATIVE RECORD INDEX

The following documentation and correspondence has been introduced Into the Administrative Record since the June 1997 submission of the draft Decision Document. Each line item is an addition to the line Items currently shown in the referenced draft Decision Document and should be included In the appropriate location as indicated by the Administrative Record File No (AR File No.) found in the first column.

Addition as a new Administrative Record database line Item updates:

AR TIUe Type Author Recipient Date Slte(s) Notes File N

A.20. Untwed correspondence - Corr ref Robert P. Jennifer 5Jun LF01, ltr of ltr of T ransmlttal of Draft Draft DO Doerschner, Kaduck, GA 97 FT02, TransmU of Dacislon Documents to Base Civil EPD FT03, Draft DOlo GAEPD Engineer, 94 OT04, Stale EPD

SPTGICE, DP06,

(USAF) OT07

A.2o. Untitied correspondence - Corrref WllllamF Jennifer 19 June LF01, Llr to Public

Letters announcing Dec Dec Doc Haber, Kaduck, GA 1997 FT02, Officials, Doc and RAB scoplng and RAB Colonel, EPD, el. al. FT03, Regulatory

Scoplng Commander OT04, agencies, DP05 and DP06, community OT07 Stakeholders

A.21. Untitled oorrespondence Corr ref Alexandra Y. Doerschner July 23, FT-02, HSRAde-reference "Listing on the HSRA Cleary, GA (USAF) 1998 OT.Q4, listing of Hazardous Site lnven!OIY" EPD DP-05, sites And de~lsting of DOB OT-07 sites

A.21. Untitiedcorrespondence Corr ref Jennifer R Ooerschner July 31, Ref HSRAde-reference "HSI 1 0178" HSI Kaduck, Haz (USAF) 1998 DP-06 listing of site (DP.OS) (HSRA) Waste Mnmgt (Implied

Branch, GA reference Is EPD to ail sj~s on

Dcbblns

A.22. Staff Summary Sheet- Corrfor 94SPTG/CEV 94 AW offices 8Juty AOC 1 lntemal Decision Document for AOCDD 1999 AOC2 Review&

0010 Areas of eoncem Coordination Sheet for AOC's DO

8.07.

Decision Document- Fire DO Jeffery W. General Public April ACJC..1 Final

Training PK Industrial Ippolito, 1998 Decision Wastewater Uno (AOC-1) Colonel, Document

Commander

B.o7. Decision Dccument - DO Jeffery W. General Public April AOC-2 Final lockheed POL and lppoillo, 1998 Decision Industrial Wastewater Colonel, Document Lines (AOC-2) Commander

C.o1. Community Relations PP-CRP Col William P Public Affairs, Nov LF01, Plan

Plan Kane, Environmental 1999 FT02, reviewed

Commander, Quality Flight FT03, semiannually DcbblnsARB OT04, ,ARIIRwlll

DP05, maintain DP06, latest edition.

OT07,

ST06

Page 3 of Supplemental Information

·------------BIG LAKE(OT-04}-------------

Dobbins Air Reserve Base, Georgia ----------------United States Air Force

11 May 2000

C.o2. Mise RAB Meeting PP- 94SPTG/CEV General Public 26 June LF01, RAB Scoplng

.0040 Documentation - 1997 RABMIS< 1997 FT02, Agenda and

FT03, Sign-In OT04, Sheets, DP05, DP06, OT07

C.o2.a Mise RAB MeeUng PP- 94 SPTG/CEV General Public Sop LF01, RABScoplng

.0050 Documentation- 1999 RAB Mls 1999 FT02, Sign-In

FT03, Shaets, OT04, agenda, and DP05, presentation

DP06,

OT07

C.o2. Untitied COITOSpondance- Carr ref William F Jennifer 21 Feb LF01, Ltr to Public

.0030 Letters announdng RAB RAB Haber, Kaduck, GA 1995 FT02, Ofllclals, scoplng Scoplng Colonel, EPD FT03, Regulatory

Commandar OT04, agencies, DP05 and DP06, community OT07 Stskeholders

C.o2.1 Untitied correspondance- Carr ref William F Jennifer 19 June LF01, Ltr to Public Letters announdng Dec RAB Haber, Kaduck, GA 1997 FT02, Olllclals, .0040 Doc and RAB scoplng Scoplng Colonel, EPD, et.al. FT03, Regulatory and Dec Commander OT04, agendas, Doc DP05 and

DP06, community OT07 Stakeholders

C.o2.t UntiUed Correspondence Carr ref Joyce H. Hal Huddlestun 26June LF01, LtrtoBase

- Letter Hal Huddlestun RAB Carter 1997 FT02, Restoration .0045 dated 26 June 1997 FT03, Project

OT04, Manager DP05 about DP06, Interest In

OT07, RAB

ST-08 .• membershlo

C.02.t UntiUed COITOSOQndence- carr ref Jeffrey W. Jennifer 24 LF01, Ltrto Public Letters announdng RAB RAB I Pool! to, Kaduck, GA Septem FT02, Olllclals, .0050 scoplng with mailing list Scoplng Colonel, EPD, et. al. ber FT03, Regulatory

Commander 1999 OT04, agendas, DP05 and DP06, community OT07, Stskeholders

ST-08

C.o2. Restoration Advisory PP- JelleryW HQAFRCICEV 8May LF01, Cmd(s

.0055 Board Status RAB Con Ippolito, 2000 FT02, Decision to

Chairperson. FT03, Not Form a Environmental OT04, RAB Protection DP05, Committee DP06, OT07, ST08

C.oa. Fact Sheet, RAB PP-Iact 94SPTG/CEV General Public ~95 LF01, Fact Sheets Sheets &94AW/PA FT02, 0010 FT03, OT04, DP05, DP06, OT07

C.oa. Fact Sheets, RAB, IRP, PP- Fac 94SPTG/CEV General Public 1999 LF01, IRP program

0030 Sites Sheets &94AW/PA FT02, and all sites FT03, Fact Sheets

OT04,

DP05,

DP06,

OT07,

ST08

Page 4 of Supplemental Information

FINAL

DECISION DOCUMENT FOR

BIG LAKE (OT-04)

ENVIRONMENTAL MONITORING PROGRAM

DOBBINS AIR RESERVE BASE, GEORGIA

Contract No. F09609-95-D-0001

Delivery Order No. 5008

Prepared for:

94SPTG!CEV

84 Industrial Drive

Dobbins Air Reserve Base, GA 30069-421 0

Prepared by:

Montgomery Watson 460 East Swedesford Road, Suite 3010

Wayne, Pem1sy1vania 19087

September 1997

TABLE OF CONTENTS

Section Page No.

DECLARATION

DECISION SUMMARY

1.1NTRODUCI10N .......... ; ......•............•.•..........••...................••.............. 1-1

1.1 SITE LOCATION AND DESCRIPTION .•....................•.•....•................ 1-1

1.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES ...................••........ 1-2

1.3 HIGHLIGHTS OFCOMMUNITYPARTICIPATION .............................. 1-3

1.4 SCOPE AND ROLE OF RESPONSE ACI10N ....••.••..•.....................•.... 1-3

2. SUMMARY OF SITE CHARACTERISTICS ......•...........................•......•..•... 2-1

2.1 GEOLOGIC SETI1NG, PHYSIOGRAPHY, AND CLIMATOLOGY .•.......... 2-1

2.2 SOIL •....•.........•..•.•........•.....................•.......•.•..•.........•..••......... 2-2

2.3 GROUNDWATER .......•.............•.............•...•...........••................... 2-2

2.3.1 Hydrogeologic Setting ............................................................ 2-2

2.3.2 Groundwater Contamination ....................................•.........•....•. 2-2

2.4 SURFACE WATER ...................................................................... 2-3

2.4.1 Surface Water Setting ............................................................. 2-3

2.4.2 Surface Water Contamination .................................................... 2-3

2.5 SEDIMENT ...........•.........•...••.•........•......•...•............•.................. 2-3

2.6 BIOTA ...•.•.....................................•.......•.........................•..•..... 2-4

2.7 RECEPTORS .............................................................................. 2-4

3. RISK ASSESSMENT ........................................................................... 3-1

3.1 HUMAN HEALTH RISK ASSESSMENT ............................................ 3-1

3.1.1 Current or Existing Exposures ................................................... 3-3

3.1.2 Hypothetical Future Exposures .................................................. 3-4

3.2 ECOLOGICAL RISK ASSESSMENT ........•........................•..•..••....••.. 3-4

3.2.1 Benthic Receptors ................................................................. 3-5

3.2.2 Surface Water Receptors .......................................................... 3-5

3.2.3 Consumers ......................................................................... 3-5

3.3 SUMMARY ................................................................................ 3-6

4. NFRAP DECISION SUMMARY .............................................................. 4-1

APPENDIX A REFERENCES

APPENDIX B ADMINISTRATIVE RECORD INDEX

September 1997 SHAR.ED:FB.D PROJECTS:AFRC·I26700S:08 Dobbins llMP:ReportS:DDs Flnai:Big Lake (Of-04) DD:'IntTcli.IBigl...ake.doc

LIST OF FIGURES

Figure No.

1-1 Location Map 1-2 Installation Location Map 1-3 SiteMap

2-1 Sample Location Map

UST OF TABLES

Table No.

2-1 Maximum Detected Concentrations for Constituents of Concern in Groundwater During the 1995 and 1996 Sampling Rounds

2-2 Maximum Detected Concentrations for Constituents of Concern in Surface Water During. the 1995 and 1996 Sampling Rounds

2-3 Maximum Detected Concentrations for Constituents of Concern in Sediment During the 1996 Sampling Round

2-4 Maximum Detected Concentrations for Constituents of Concern in Fish Tissue Samples During the 1996 Sampling Round

3-1 Exposure Pathway Scenarios ii September 1997 SHARI!D:FED PROIECI'S:AFRC-126'1'005!08 DrobbiltiiiMP:Reportt:DDI Flna.I:BIJ: Late (O'J'-04) DD:TeJttToatBIJl,ake.doc 9112197

AFCEE

AFFF

AFI

AFP

AFRC

AFSC

ARARs

ARB

CAR

CPR

COPC

COPEC

DNR

EMP

EPA

ER-L

ER-M

ERA

ES

ESE

F

FS

HHRA

HI

HQ

HSI

HSRA

IRP

MCL

MSL

NAS

NFRAP

NOAA

oc PAHs PCBs

POL

RI

svoc

TBC

IDS

TPH

TSS

USAF

USAFOEHL

USEPA

voc

September 1997

LIST OF ACRONYMS AND ABBREVIATIONS

Air Force Center for Environmental Excellence Aqueous Film-Forming Foam Air Force Instruction Air Force Plant Air Force Reserve Command Air Force Systems Command Applicable or Relevant and Appropriate Requirements Air Reserve Base Comprehensive Analytical Report Code of Federal Regulations Contaminants of Potential Concern Contaminant of Potential Ecological Concern Department of Natural Resources Environmental Monitoring Program Environmental Protection Agency Effects Range - Low Effects Range -Medium Ecological Risk Assessment Parsons Engineering-Science Environmental Science & Engineering Inc.

Fahrenheit Feasibility Study Human Health Risk Assessment Hazard Index Hazard Quotient Hazardous Site Inventory Hazardous-Site Response Act Installation Restoration Program Maximum Contaminant Level Mean Sea Level Naval Air Station No Further Response Action is Planned National Oceanic and Atmospheric Administration Organochlorine Polynuclear Aromatic Hydrocarbons Polychlorinated Biphenyls Petroleum, Oil, and Lubricant Remedial Investigation Semivolatile Organic Compound To Be Considered Total Dissolved Solids Total Petroleum Hydrocarbons Total Suspended Solids United States Air Force USAF Occupational and Environmental Health Laboratory United States Environmental Protection Agency Volatile Organic Compound iii SHARED:FED PR0JECTS:AfRC·I267005:08 Dobbins EMP:Rej)()ns:DDJ Flnlli:Bis Lake (0T·04) DD:Ttt~l:TelllBisl..ake.doc 9112191

DECLARATION

This Decision Document has been prepared for Big Lake (OT -04), a site designated under the Installation Restoration Program (IRP) located at Dobbins Air Reserve Base (ARB), Georgia (Figure 1-1 ). This Decision Document has been prepared based on Category III decision criteria issued as guidance in the NFRAP Guide, A Resource for Making, Documenting, and Evaluating No Further Response Action Planned Decisions (USAF, June 1995). This Decision Document is organized into two parts. The first part presents the Declaration, and the second part presents the Decision Summary.

STATEMENT OF BASIS AND PURPOSE

This Decision Document presents the selected action for the Big Lake (OT-04) site, located at Dobbins ARB, Georgia. This decision is based on information obtained from the Remedial Investigation (RI) Report prepared by Parsons Engineering-Science (ES) (ES, 1995) and the Comprehensive Analytical Report (CAR) prepared by Montgomery Watson (Montgomery Watson, 1996). The primary information from these reports used in this

·Decision Document are the comparison of site concentrations in ail environmental media with applicable or relevant and appropriate requirements (ARARs) or to be considered (TBC) criteria, and a risk assessment of current or existing exposures to public health and ·the environment. The risk assessment also evaluated hypothetical future exposures and this evaluation is summarized in Section 3.0. However, for the purposes of this Decision Document, only current or existing exposures were critically reviewed. This is consistent with USAF guidance. (USAF, 1995) A summary of the administrative record index of documents prepared for IRP sites at Dobbins ARB is presented in Appendix B.

The primary purpose of this Decision Document is to demonstrate that the response at the site is. complete and therefore "no further response action is planned" (NFRAP). Section

2.2.9 of Air Force Instruction 32-7020 (USAF, 1994) states that NFRAP status has been achieved when any of the following conditions apply:

• Investigation finds no evidence of contamination, insignificant levels of contamination, or low levels of contamination that pose no significant current or existing threat to public health or the environment.

• The removal of contamination is complete.

• The cleanup system is in place and operating effectively.

D-1 Seplember 1997 SHARED: FED PROJECl'S:AFRC·I16700.S:08 Dobbins EMP:ReJ)OI'IS:DDs Flnai:Bls Lake (Of -04) DD:T~t:Te~lBlJLake.doc

DESCRIPTION OF SELECTED REMEDY

Studies have demonstrated that contamination was detected at the site at levels that pose no significant risk to public health or the environment. Dobbins ARB, therefore, has determined that the response at this site is complete and NFRAP status has been achieved.

DECLARATION STATEMENT

This Decision Document represents the selected action for this site developed in accordance with the IRP which uses as its basis the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended by Superfund Amendments and Reauthorization Act of 1986 (SARA), and the National Contingency Plan (NCP). It also satisfies the requirements of the National Environmental Policy Act that applies to CERCLA response actions. It has been determined that the selected remedy of no further action is protective of human health and the environment, attains federal and state requirements that are applicable or relevant and appropriate, and is cost-effective.

The statutory preference for further treatment is not satisfied because contaminant levels at the site have been determined to present no significant threat to hnman health or the environment under current use scenarios for the site.

Colonel William F. Haber, USAFR

D-2 September 1997 SHARBD:fBD PROJECI'S:AFRC·Il67005:08 Dobb!M EMP:Repons:DO$ Final: Big We (ar -04) DD:Text:Tell181gl..akc.doc 91121')7

Date

DECISION SUMMARY

1. INTRODUCTION

This Decision Document has been prepared for Big Lake (OT-04), a site designated under the Installation Restoration Program (IRP) located at Dobbins Air Reserve Base (ARB), Georgia (Fignre I-I). This Decision Document has been prepared based on Category III decision criteria issued as guidance in the NFRAP Guide, A Resource for Making, Documenting, and Evaluating No Further Response Action Planned Decisions (USAF, June I995). The Decision Summary is divided into four sections: Section I presents the Introduction; Section 2 presents the Summary of Site Characteristics; Section 3 presents the Risk Assessment; and Section 4 presents the NFRAP decision summary.

This Decision Document was prepared as part of Delivery Order Number 5008 of Contract Number F09609-95-D-OOOI dated September 30, I995. The contract was issued by the Air Force Reserve Command (AFRC), Dobbins ARB Contracting, Dobbins ARB, Georgia.

1.1 SITE LOCATION AND DESCRIPTION

Big Lake (OT-04) is located at Dobbins ARB, in Cobb County, Georgia, next to the cities of Marietta and Smyrna (Fignre I-2). Dobbins ARB is located approximately 5 miles northwest of the city limits of Atlanta and consists of I ,964 acres of land under the command of AFRC. An adjoining 709 acres in two parcels located to the north of the site house Air Force Plant 6 (AFP 6), operated by Lockheed-Martin for Air Force Systems Command (AFSC). The Naval Air Station (NAS) Atlanta occupies a tract of land located adjacent to Dobbins ARB. (ES, I995)

As shown in Figure I-3, the site is located north of the Dobbins ARB runway. The site consists of a man made lake approximately 7 acres in size that was constructed in I907 as a backup water source for the city of Marietta. The lake is controlled by a rock and concrete dam at its southeastern end. The lake is approximately I5 feet in depth at its deepest location adjacent to the concrete dam. Surface water from the central part of Dobbins ARB flows into the lake. Three streams contribute to the inflow to Big Lake. An unnamed tributary of Rottenwood Creek drains a portion of AFP 6 and flows east past AVGAS Sludge Burial Sites A and B (other IRP sites) from the northwest before emptying into Big Lake. Two other tributaries flow south from AFP 6, Zone I before entering the lake. It is reported that a subsurface drain system intercepts a groundwater contaminant plume at.

AFP 6; this drain system discharges to a tributary flowing into Big Lake. The subsurface drain system is being investigated as an IRP site by Air System Center, Wright Patterson Air Force Base (AFB), Ohio. Outfall from the lake discharges into a tributary of Rottenwood Creek, a primary tributary of the Chattahoochee River. (Montgomery Watson, I996)

1-1 September 1997 SHARED:FED PROJECTS:AFRC-1267005:08 Dobbins EMP:Reports:DDs Finai:Bill Lako (01'.04) DD:Ttxt:TtlltBisl.ake.doe 9!12191

1.2 SITE HISTORY AND ENFORCEMENT ACTMTIES

The following is a summary of the site history and enforcement activities applicable to the site:

• In April 1982, an IRP Records Search was completed by CH2M Hill Inc. for Dobbins ARB. The purpose of the records search was to identitY the potential for environmental contamination from past waste management practices and to assess the probability for contaminant migration. Big Lake was identified to pose a potential contamination problem. Analysis of the near surface lake sediments indicated the sediments to be non-hazardous, however no information was available to characterize the deeper sediments, or to determine whether contaminants were leaching from the sediments into the groundwater. Findings from the records search for the site indicate that Big Lake received discharges of unknown types and quantities of wastes from AFP 6 during the 1950s and 1960s. (ES, 1995)

• Following the record reviews, the site was then evaluated to assess its potential for hazardous constituent contamination and migration. Big Lake was found to have a significant potential for contaminant migration, and was recommended for further study. (ES, 1995)

• The site was included in the IRP in 1982. Based on findings at another site, Dobbins ARB was placed on the Georgia Hazardous Site Inventory (HSI) in 1994 (the year the Georgia Hazardous Site Response Act (HSRA) was authorized and implemented). As a result, subsequent investigations and risk assessments were conducted by Environmental Science & Engineering (ESE) in 1988 and 1991, Parsons Engineering Science (ES) in 1992, and Montgomery Watson in 1995 to address concerns at the site.

• Georgia DNR reviewed a Draft Rl Report prepared by ES for the site in 1995. The comments were incorporated into the Final Rl Report byES.

• On June 5, 1997 the Draft Decision Document for this site was submitted to the Georgia Environmental Protection Division (GAEPD).

However, the document was not reviewed by GAEPD.

1-2 September 1997 SHAREO:FED PROJECTS:AFRC·I267005:08 Dobbins EMP:Repom:DDs Flnai:Bii Lake (OT -04) DD;Tc!IU:Tex.t9JgLake.doc

1.3 IDGIH.JGHTS OF COMMUNITY PARTICIPATION

An Administrative Record was established in 1988 for the IRP in accordance with CERCLA. A scoping meeting was held in March 1995 to determine the public interest in and availability for the formation of a Restoration Advisory Board (RAB). However, based on the results of that meeting, the RAB was not formed. The USEP A was actively involved in the review and development of actions and documents during the early stages of the IRP. In addition, GAEPD has reviewed the initial RI documentation, and this documentation is retained within the Georgia HSRA section.

A public announcement was placed in the Marietta Journal on June 22, 24, 25, and 26 for the consideration of the formation of a RAB and for the release of the Draft Decision Documents for public review and comment. The public announcement invited interested parties to a public meeting of the RABon June 26. However, due to a lack of interest the RAB Meeting was not held. The public announcement also provided for a review period from June 27 to August 1, 1997 for the Decision Documents. During the review period there was no record of comment on the decision documents by the public or the state.

1.4 SCOPE AND ROLE OF RESPONSE ACTION

The following is a chronology of the investigations conducted at the site, which included an IRP Phase II Stage 1 Confirmation/Quantification study, a Site Characterization Study, a Remedial Investigation (RI), and an Environmental Monitoring Program (EMP).

In August 1986, ESE completed an IRP Phase II Stage 1 Confirmation/Quantification study. The purpose of this study was to confirm or deny the presence and/or migration of contaminants at the site. The investigation at the site consisted of a bathymetric survey of Big Lake, the installation of two groundwater monitoring wells, and sampling and analysis of groundwater, surface water and sediments. During the investigation, partially buried drums were observed in the southern extension of the southwestern arm of Big Lake. The age, contents, exact number, and origin were unknown. In August 1986, ESE prepared a Phase II -- Confumation/Quantification Stage 1 Final Report and submitted the report to USAF Occupational and Environmental Health Laboratory (USAFOEHL) Technical Services Division. (ESE, 1986)

In October 1988, Hunter/ESE conducted a two-part Site Characterization Study in support of an Rl to confirm previous results, establish the lateral and vertical limits of contamination, and assess potential risks posed by past waste disposal at the site. Prior to.

this investigation, Big Lake was drained and Base Civil Engineering requested that the drnms reported to be present during the Phase II Confirmation/Quantification study be removed. No records exist confirming their removal; however, the drums were not visible during subsequent site visits. In April 1991, ESE prepared a Final Site Characterization

1-3 september 1997 SHARED:FED PROJECTS:AFRC·l267005:08 Dobbln5 EMP:Ilcpons:DO$ Plnal:BI& Lake (Of..Q4) DD:Tc.r.I:Tc.r.IBI,We.doc 9/11197 during subsequent site visits. In April 1991, ESE prepared a Final Site Characterization Summary for the above investigation and submitted the report to AFRC and Air Force Center for Environmental Excellence (AFCEE). The report was revised by AFRC and AFCEE in December 1991. (ESE, 1991)

In 1992, Parsons Engineering-Science (ES) conducted an Rl that included an investigation of Big Lake. The purpose of the Rl at Big Lake was to document the nature and extent of contamination at the site. Analytical data collected during the previous investigations were supplemented with additional data from the chemical analysis of surface water, sediment and groundwater samples. In 1995, a Remedial Investigation Report was prepared by ES that documented the results of the 1992 investigations and the risk assessment conducted at the site as part of the IRP. The Remedial Investigation Report recommended that a feasibility study (FS) be performed for the site. (ES, 1995)

In 1995 and 1996, Montgomery Watson conducted an Environmental Monitoring Program (EMP) at the site. The purpose of the EMP was to obtain more recent data for the site, compare this data to previous data, and conduct a revised quantitative human health risk assessment (HHRA) that incorporated the new 1995 and 1996 data into the existing data for the site. In addition, an ecological risk assessment (ERA) was conducted for the site. In November 1995 and March 1996, Montgomery Watson collected two rounds of groundwater .samples from the two existing monitoring wells and one additional monitoring well (D4-W46) installed by Montgomery Watson. Two rounds of surface water samples and one round of sediment samples were also collected during the EMP. The results of the EMP as well as historical data were summarized and presented in the Comprehensive Analytical Report (CAR) (Montgomery Watson, 1996).

1-4 September 1997 SHARJlO:FED PROJECTS:APRC·I26700S:08 Dobbins BMP:Reporu:DDs Flnai:Big Lake (0Nl4) DD:Text:TextBijl..ake.doc

2. SUMMARY OF SITE CHARACTERISTICS

This section presents a summary of site characteristics, geology, physiography, soils, groundwater, surface water, sediment, and biota. The receptors at the Big Lake (OT -04) site are also discussed in this section. The analytical data obtained at the site were compared to applicable, or relevant and appropriate requirements (ARARs) or to be considered (TBC) criteria. Georgia Hazardous Site Response Act (HSRA) Type 3 risk reduction levels for soil (Georgia HSRA 391-3-19 Appendix ill) were used for soil ARARs at the site. Georgia HSRA Type 3 Risk Reduction Levels were used for groundwater ARARs at the site. For most analytes, the Georgia Type 3 Risk Reduction Levels for groundwater are the same as the USEPA Maximum Contaminant Levels (MCLs) for public water supplies. USEPA Water Quality Criteria for Protection of Human Health and Freshwater Aquatic Life (USEPA, 1986) were used for surface water ARARs. Sediment results were compared to TBCs genemted by the National Oceanic and Atmospheric Administmtion (NOAA) (NOAA, 1990). Figure 2-1 shows sample locations at the site. A complete summary of ARARs for detected analytes at the site is presented in the CAR (Montgomery Watson, 1996).

2.1 GEOLOGIC SETTING, PHYSIOGRAPHY, AND CLIMATOLOGY

Big Lake (OT -04) is located in the Centml Uplands district of the Piedmont physiogmphic province. This district is chamcterized by a series oflow, linear ridges sepamted by broad, open valleys. Streams flowing through this area are genemlly transverse to the underlying geologic structure and occupy valleys ISO to 200 feet below the ridge crests. The site is underlain by the Powers Ferry Formation, which is part of the Sandy Springs Group. The Powers Ferry Formation consists of interbedded gneisses, schists, and amphibolites.

Depth to bedrock was encountered at the site between approximately 4 and 20 feet below ground surface (BGS). (ES, 1995)

The general area around the Dobbins ARB is situated on a gently rolling plateau that slopes gradually downward to the Southeast The plateau is dissected by several small. stream channels, including Rottenwood and Poorhouse Creeks. Elevations at the site range from approximately I ,020 feet above mean sea level (MSL) to the North and West of the Big Lake to approximately I ,000 feet above MSL below the dam in the southeastern comer of the site. The elevation of Big Lake is approximately I ,007 feet above MSL based on staff gauge measurements obtained in March 1996 (Montgomery Watson, 1996).

The climate at the site is characteristic of the northern tempemte zone, with four clearly separated seasons and a predominant weather movement from west to east. The average annual temperature at Dobbins ARB is 61 degrees Fahrenheit ("F), with an average daily maximum and minimum of 70 "F and 51 "F respectively. Dobbins ARB experiences an average of 58 days with freezing tempemtures each year. (ES, 1995)

2-1 S.ptember 1997 ~~~D:FED PROJECJ'S:AFRC.I26700.5:08 Dobbin• EMP:Repom:D~ FW.I:Bis lAke (<Yr -04} DD:T~xcTexiBiat.ake.doc

The average annual rainfall at Dobbins ARB is 52.6 inches. Precipitation is distributed fairly evenly throughout the year, although minor peaks in the rainfall curve are generally recorded in early spring and in mid-summer. An average of about 2 inches of snowfall is recorded each year between December and March. Lake evaporation is approximately 40 inches per year; evapotranspiration over land areas may be greater or less than this value, depending on vegetative cover type. (ES, 1995)

2.2 SOIL

Because Big Lake is an aqueous unit, no soil was evaluated during the RI and the EMP at the site.

2.3 GROUNDWATER

2.3.1 Hydrogeologic Setting

Groundwater and surface water at the site flows to the southeast. The horizontal hydraulic gradient is approximately 0.0007 as measured between03-W45 and D3-W32 in November 1995. Groundwater potentiometric surface measurements obtained during the most recent sampling rounds at the site are consistent with data reported previously, indicating that the direction of groundwater flow does not change seasonally. (Montgomery Watson, 1996)

Measurements obtained during the RI and EMP indicate that depth to groundwater ranges from approximately 7 feet below grade on the southern edge of Big Lake to 18 feet below grade at the northeastern edge of Big Lake. Groundwater flow in the area surrounding Big Lake is generally to the east-southeast. Groundwater elevation measurements indicate groundwater discharges to surface water in the northern section of Big Lake. The concrete dam located at the southern end of the lake causes an artificially high surface water level.

As a result, surface water recharges to groundwater on the southeastern side of the concrete dam. Hydrogeologic information obtained during the EMP indicates that a strong vertical flow gradient is not present between the shallow and deep flow zones at the site.

(Montgomery Watson, 1996)

2.3.2 Groundwater Contamination

A summary of historical groundwater analytical results obtained at the site is presented in the CAR. Table 2-1 summarizes the maximum concentrations for constituents of concern detected in groundwater samples collected during the two most recent sampling rounds (1995 and 1996) at the site. Volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) were not detected in the groundwater samples collected from the site during these sampling events. Although lead and thallium exceeded Type 3 Risk Reduction Levels of 75 J..tg/1 and 2 Jlgll, respectively, in 1989 and 1992, no metals exceeded the Type 3

2-2 September 1997 SHARED:FBD PROJECTS:AFRC·12610()j:()8 Dobbins EMP:Repons:DI>s Flnai:Big Lake (01'-04) DD:Te~tt:Te~ttBiglake.doc 9112191

Risk Reduction Levels during the most recent sampling round in 1996. All three groundwater samples collected at the site during the 1996 sampling round were found to contain the pesticide dieldrin at concentrations that exceeded the Type 3 Risk Reduction Level of0.002 !Jgll for the site.

2.4 SURFACEWATER

2.4.1 Surface Water Setting

Surfuce water at the Big Lake site is influenced by three streams that discharge into Big Lake north of the lake, the dam, and to a lesser degree the discharge of ground water.

Reportedly, a subsurface drain system intercepts a groundwater contaminant plume at AFP 6; this drain system discharges to a tributary flowing into Big Lake. The quality of the AFP 6 effluent has not been determined as part of this investigation since the subsurfuce drain system is being investigated as a separate IRP site by Air System Conunand, Wright Patterson AFB, Ohio. As indicated in Section 2.3.1, groundwater at the site discharges to surface water in the northern section of the Big Lake, and due to the influence of the dam, surface water discharges to groundwater in the southern section of Big Lake.

2.4.2 Surface Water Contamination

A sununary of historical surface water analytical results obtained at the site is presented in the CAR. Table 2-2 summarizes the maximum concentrations for constituents of concern detected in surface water samples collected during the two most recent sampling events (I 995 and 1996) at the site. The laboratory results indicate that several aromatic and halogenated VOCs were detected in the surfuce water samples collected during the 1989 sampling rounds. However, no VOCs were detected in the samples during the 1995 and 1996 surface water sampling rounds. SVOCs were not detected in any of the surface water samples collected at the site. The only pesticide detected at the site was dieldrin. Several total metals (including arsenic, chromium, lead, mercury and zinc) exceeded the USEP A Water Quality Criteria (as listed in Table 2-2) for human health, and freshwater aquatic life at the site. The highest concentrations of metals detected at the site were in a surfuce water sample collected upstream of Big Lake during the 1996 sampling round. This indicates that surfuce water at Big Lake may presently be affected by off-site sources located upstream of the site.

2.5 SEDIMENT

A summary of historical sediment analytical results obtained at the site is presented in the CAR. Table 2-3 summarizes the maximum concentrations for constituents of concern in sediment samples collected during the 1996 sampling round at the site. The results of the

2-3 September 1997 SHARED: FED PROJECTS:AFRC·I267005:08 Dobbins EMP:Repons:DDs Flnii:Bi& Lake (Of .()4) OD:Texi:TeKIBiauke.doc 9/12197 sampling show detected concentrations of several polynuclear aromatic hydrocarbons (P AHs ), pesticides and polychlorinated biphenyls (Pest/PCBs ), and metals that exceeded the NOAA Effects Range-Low (ER-L) or Effects Range- Medium (ER-M) screening levels (as listed in Table 2-3) in several of the samples collected from the site. As a result of the number of analytes that exceeded NOAA screening criteria, the potential human health risks and ecological impacts from analytes detected in sediment at Big Lake were quantified in a Human Health Risk Assessment (HHRA) and an Ecological Risk Assessment (ERA) for the site.

2.6 BIOTA

A summary of the biota analytical results obtained at the site is presented in the CAR.

Table 2-4 summarizes the maximum concentrations for constituents of concern detected in biota samples collected during the 1996 sampling round at the site. Fish tissue samples were collected from Big Lake in May 1996 and were analyzed for P AHs, pesticides, PCBs and metals. The results of the analyses indicated the presence of three inorganic (metal) analytes (mercury, selenium, and zinc). There were no PAHs detected in fish tissues samples. Several pesticides were detected in fish tissues including alpha- and gamma chlordane; 4,4"-DDE, 4,4'-DDD, and 4,4'-DDT; dieldrin; and heptachlor epoxide. No PCBs were detected in fish tissues. The potential human health risks and ecological impacts of all analytes detected in fish tissues are quantified in the HHRA and the ERA for the site, respectively.

2.7 RECEPTORS

In the risk assessment, two risk scenarios were evaluated for this site; current use and hypothetical future use. For the purposes of this decision document, only the current use exposure scenario is critically reviewed. Under the current land use scenario, the potential human receptors at the site are the base personnel and nearby residents who may or may not have access and exposure to present AFRC operations. No exposure to groundwater exists for human receptors under the current land use scenario. Dobbins ARB presently receives its water from Air Force Plant 6 (AFP 6), located adjacent to the installation, which in tum, receives its water from the Cobb-Marietta Water Authority. This water supply is derived from off-site surface water sources.