Decision_Document_for_Little_Lake_(OT-07).pdf

DECISION DOCUMENT FOR

LITTLE LAKE (OT -07)

Dobbins Air Reserve Base, Georgia

Department of Defense United States Air Force

Installation Restoration Program Decision Document

Site owner:

94 AirHft Wing (94 A W)

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

Restoration Project Manager:

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

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

11 May2000

DECISION DECLARATION STATEMENT AND SUPPLEMENTAL INFORMATION

To FINAL DECISION DOCUMENT dated Sep1ember 1997

-----------LITTIELAKE(OT-07}---------

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

11 May2000

DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997 and SUPPLEMENTAL INFORMATION dated 11 May 2000 for Installation Restoration Program Site LmLE LAKE (OT.Q7)

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

11 May2000

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 Force 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).

SUPPLEMENTAL INFORMATION AND DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997

-----------LITTLELAKE(OT.(l7}------------ Dobbins I>Jr Reserve Bass, Georgia --------------United States Air Force

11 May2000

DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997 and SUPPLEMENTAL INFORMATION dated 11 May 2000 for Installation Restoration Program Site LmLE LAKE (OT ..07) owner: Dobbins Air Reserve Base, Georgia United States Air Force

11 May2000

DECLARATION

This Decision Document has been prepared for Little Lake (OT ..07), 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 ill 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 Summary.

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 (BS) (BS, 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 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 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 statns 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.

Page Dl

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I I I I I I I

I I I I I I

I

SUPPLEMENTAL INFORMATION AND DECISION DECLARATION STATEMENT

To FINAL DECISION DOCUMENT dated September 1997

------------------------LITTIE~~T~~----------------------

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

11 May2000

• 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). 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 human health or the · ent under current use scenarios for the site.

William P. Kane, Colonel, USAFR Commander, Dobbins Air Reserve Base

To ANAL DECISION DOCUMENT dated September 1997

------------LITILELAKE(OT-017}------------

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

11 May2000

DECISION DECLARATION STATEMENT

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

Site Manager:

94SPTGICEV

884 Industrial Drive

LITTLE LAKE (OT -07)

Owner: Dobbins Air Reserve Base, Georgia

United states Air Force 11 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, datad December 1996, was prepared and forwarded to the Stete of Georgia Environmental Protection DMsion 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 end comments and having received none, the Air Force finalized the draft documents, correcting minor wording errors made in the original draft document, finalizing tha 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 tha Declaration Statement made in the original Decision Document. The Air Force, in its position es 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 Pian (NCP).

SECTION 1.2: SITE HISTORY AND ENFORCEMENT ACTIVITIES

Addition as a new bullet statement: Section 1.2, include as the 4th bullet The Georgia EPD notified the Base by letter dated 24 Jan 94 that a site at Dobbins ARB warranted listing the Sese on the State's Hazardous Site Inventory.

Renumber bullet statements: Section 1.2: Renumber the orlglnal4111 bullet to become the 5111 bullet: "Georgia DNR reviewed .... •

Addition as a new bullet statement: Section 1.2, include as a 6th bullet: The Air Force delivered the Draft Decision Document to the State of Georgia Environmental Protaction DMsion 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 hes 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

To FINAL DECISION DOCUMENT dated Seplember 1997

-------------------------LrrnE~(OT~~----------------------- Dobbins Air Reserve Base, Georgia --------------------------United Slates Air Force

11 May2000 Into the draft Decision Document end prepared a final Decision Document dated September 1997. The Air Force has mede no substantial change to the draft Decision Documents that would alter the date 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 Georgia Hazardous Waste Branch pertaining to the listing of the site on the State's Hazardous Site Inventory, and the State's review of any end all other documents previously submitted to the State.

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 Brench lndlcetad on 23 July 1998 end 31 July 1998 that either sites FT -02, OT -04, DP-06, DP-06 (by reference), end OT -07 did not have reportable quantities or that the State had no reason to bellave 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 Bese has not received any written comments or direction from the State on the results of the RFA or the Intents of the State. In addition, the State Hazardous Waste Branch hes not provided any review comments or suggestions on any of the subsequent Installation Restoration Program draft and final reporta and plans forwarded by the Air Force after the Draft Ri report submitted In 1995.

SECTION 1.3: HIGHLIGHTS OF COMMUNITY PARTICIPATION

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

The Air Force made Public Notlficetlon on 22nd, 24th, 25th, and 26th June 1997 via the local newspaper and letter mailed to the local community leaders, adjacent property owners, end parties that had previously expressed end Interest In the environmental restoration program at Dobbins ARB. The Bese sponsored Public Meeting wes held at the Cobb County Central Ubrsry on 26 June 1997, as scheduled, In conjunction with the Restoration Advisory Board's (RAB) Scoplng Meeting. Public review and comment period wes officially left open untll1 August 1997, but since the Decision Document wes not signed and published at that time, Dobbins AFB hes remained open to accept any comments until 1 May 2000. The Air Force has received no comments.

During this second RAB Scoplng meeting held on 26 June 1997, representatives from the Bese 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 plan to prepare the final Decision Documents, afier 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 determined that community stakeholder Interest was neither sufficient nor sustainable to form a RAB; however, attendees were placed on the mailing list for subsequent environmental restoration notlficetlons and advertisements.

Addition as a third paragraph: The Air Force sponsored a third Restoration Advisory Board Seeping 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 scoplng meeting did not express concern with the Air Force's

Page 2 of Supplemental Information

------------------------LrrnE~~~n----------------------- Dobbins Air Reserve Base, Georgia ------------------------------United Slales Air Force

11 Mey2000 management of the program, or any past action to investigate the sites, nor future plans. Based 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 bean 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:

C.01. Plan

Page 3 of Supplemental Information reviewed semiannually

• ARIIR will malnlaln latest edition.

SUPPLEMENTAL INFORMATION AND DECISION DECLARATION Sl"ATEMENT

-------------------------urn£~~~,n------------------------- Dobbins />Jr Reserve Base, Georgia

.0050

.0055 Board 51atus

Kaduck.GA EPD,elal.

Page 4 of Supplemental Information

United Slates />Jr Force

Officials, Regulatory agencies, and community 51akellolden!

To FINAL DECISION DOCUMENT daled September 1997

------------------------LrrnE~~T~n----------------------- Dobbins PJr Reserve Base, Georgia -----------------------------United States PJr Force

C.04. RAB Sooplng Meeting PP-

Announcements, Allanta PubDc Journal Constllutlon and Notice Marietta Dally Journal

C.04. RAB Sooplng Meeting PP- 0050 Announcerromts,AIIanta Public

Journal Constllutlon and Notice Marietta Dally Journal

Abbreviation reference:

AF- Air Force AFRC-Air Force Reserve Command AOC- Area of Concern Cmdr- Commander Corr - Correspondence DD or Dec Doc- Decision Document DP - Disposal Site e-mail- Electronic Messaging

11 May2000 94AWIPA Generl!l PubHc

94AWIPA General PubUc

EPD- Envlronmen.tal Protecllon DMslon FT- Are Training facility · GA-Georgla HSI - Hazardous Site Inventory HSRA .:. Hazardous Site Response Act IRP -lnstallallon Restoration Program LF - past Basa landfill OT- Lake sediment PP - Public Partlclpallon RAD - Restoration Advisory Board ST· Tank Assoclatad Release

22,24. LF01, RABIDD

25,and FT02, Newspaper

26 FT03, A!J

June OT04;

1997 DP05,

DP05,

OT07

5ep LF01, RABIDD 1999 FT02, Newspaper

FT03, A!J

OT04,

DP05,

DP06,

OT07

------------End of Supplemental Information----------

Page 5 of Supplemental Information

FINAL

DECISION DOCUMENT FOR

LITTLE LAKE (OT-07))

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 30069-4210

Prepared by:

Montgomery Watson 460 East Swedesford Road, Suite 30 I 0

Wayne, Pennsylvania 19087

September 1997

TABLE OF CONTENTS

Section Page No.

DECLARATION ............................................................................................................ D-1

DECISION SUMMARY

1. INTRODUCTION ................................................................................................ 1-1

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

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

1.3 HIGHLIGHTS OF COMMUNITY PARTICIPATION .......................... 1-2

1.4 SCOPE AND ROLE OF RESPONSE ACTION ....................................... 1-3

2. SUMMARY OF SITE CHARACTER1STICS ..................................................... 2-1

2.1 GEOLOGIC SETTING, PHYSIOGRAPHY, AND CLIMATOLOGY ... 2-1

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

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

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

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

2.4.2 Surface Water CoDtamination ........................................................ 2-2

2.5 SEDIMENT ................................................................................................ 2-2

2.6 BIOTA ........................................................................................................ 2-3

2.7 RECEPTORS .............................................................................................. 2-3

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 ..................................................................................... 3-6

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

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

APPENDIX A REFERENCES

APPENDIX B ADMINISTRATIVE RECORD INDEX

i September 1997 SHARED:FED PROJECTS:AFRC~1267005:08 Dobbins BMP:Rcpol13:DDs Final:Littlc Lake (0T..o7) DD:Tm:Te:n UuJe Lake DD2.doe

9/121972!33 PM

LIST OF FIGURES

Figure No.

1-1 Location Map 1-2 Installation Location Map 1-3 Site Map

2-1 Sample Location Map

LIST OF TABLES

Table No.

2-1 Maximum Detected Concentrations for Constituents of Concern in Surface Water During the 1995 and 1996 Sampling Romtds

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

2-3 Maximum Detected Concentrations for Constituents of Concern in Fish Tissue Analysis During the 1996 Sampling RoWld

3-1 Exposure Pathway Scenarios ii September 1997 SHARED-.PED PROJECTS:AFRC-126700S:08 Dobbins EMP:RcporiS:DDs Fiaal:Li1tle I..ake (M-07) DD:Ten:Tcn Uttle Lake DD2.doc

9/121971:~ PM

AFCEE

AFFF

AFI

AFP

AFRC

AFSC

ARARs

ARB

CAR

CFR

COPC

COPEC

DNR

EMP

EPA

ER-L

ER-M

ERA

ES

ESE

F

FS

llliRA

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 SHAREI>-.FED PROlECTS:AFRC·I261005:0S Dobbins EMP-.Repon:s:DDs Final;Unle Lake (OT-07) DD:TextTe:u Lhllc Lake DDl.dtlc

9112197 I~ PM

DECLARATION

This Decision Document has been prepared for Little Lake (OT -07), 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 ill decision criteria issued as guidance in the 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 Summary.

STATEMENT OF BASIS AND PURPOSE

This Decision Document presents the selected action for the Little Lake ( OT -07) site, located at Dobbins ARB, Georgia. This decision is based on information obtained from the Remedial Investigation (Rl) 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 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 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 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, 1995) states that NFRAP statns 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 September 1997 SltAR.ED-.FED PROJECTS:AFR.C-JU700!f:08 Dobbins EMP-.Reporls:DDs Final:Uttlc Lake (0T..(J7) DD:Toxt:Text UuU! Lakt: DD2.doc 9/12197 l:SS PM

DESCRIPTION OF SELECTED REMEDY

Studies have demonstrated that contamination was detected at Little Lake (OT -07) at levels that pose no significant risk to public health or the environment Therefore, Dobbins ARB has determined that the response at OT-07 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 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 human health or the environment under current use scenarios for the site.

Colonel William F. Haber, USAFR Date

DECISION SUMMARY

1 • INTRODUCTION

This Decision Document has been prepared for Little Lake (OT-07), 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 Ill decision criteria issued as guidance in the NFRAP Guide, A Resource for Making, Documenting, and Evaluating No Further Response Action Planned Decisions (USAF, 1995). This Decision Summary is divided into four sections: Section 1 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-0001 dated September 30, 1995. The contract was issued by the Air Force Reserve Command (AFRC), Dobbins ARB Contracting, Dobbins ARB, Georgia.

1.1 SITE LOCATION AND DESCRIPTION

The Little Lake site is located at Dobbins ARB, in Cobb County, Georgia, next to the cities of Marietta and Smyrna (Figure 1-2). Dobbins ARB is located approximately 5 miles northwest of the city limits of Atlanta and consists of 1,964 acres of land under the command of the 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 also occupies a tract of land located adjacent to Dobbins ARB. (ES, 1995)

The Little Lake site is a small man-made lake constructed with an earthen dike, located north of the intersection of Atlantic Avenue and Andrews Drive (Figure 1-3). The lake was reportedly constructed in approximately 1910. The lake is fed by intermittent discharge from springs on the slopes northwest of the lake. An unnamed creek, which drains a portion of AFP 6, flows around the southwest end of the lake; a narrow ridge separates this creek from the lake. A spill pipe through the earthen dike allows overflow from the lake to drain into this unnamed creek. A bathymetric map developed during a Phase 11 Stage I study conducted by Environmental Science & Engineering (ESE, 1986) showed that the northwest end of the lake is shallower that the southeast end. Findings from the records search for the site indicate that Little Lake was the site of a major fish kill in 1962, caused by the aerial application of pesticides. (ESE, 1986)

1-1

1.2 SITE HISTORY AND ENFORCEMENT ACTIVITIES

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

• CH2M Hill Inc. for Dobbins ARB. The purpose of the records search was to identify the potential for environmental contamination from past waste management practices and to assess the probability for contaminant migration.

The site was identified to pose a potential contamination problem. Findings from the records search for the site indicate that Little Lake was the site of a major fish kill in 1962, caused by the aerial application of pesticides. (ESE, 1986)

• Following the record reviews, ES evaluated the site to assess its potential for hazardous material contamination and migration. The Little 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 program in 1982, and was placed on the Georgia Hazardous Site Inventory (HSI) in 1994 (the year Georgia Hazardous Site Response Act (HSRA) was authorized and implemented). As a result, investigations and risk assessments were conducted by ESE in 1988 and 1991, byES in 1992, and by Montgomery Watson in 1995 to address the concerns at the site.

• In 1995, the Georgia Department of Natural Resources (DNR) reviewed the Draft RI Report prepared by ES for the site. ES incorporated the comments into the Final RI Report.

• 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.

1.3 IDGHLIGHTS 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, hased on the results of that meeting, the RAB was not formed. The USEPA was actively involved in the review and development of actions and documents during the early stages of the IRP. In addition, the GAEPD has reviewed the initial RI documentation, and this documentation is retained within the Georgia HSRA section.

1-2 September 1997 SHARED!FED PROJECTS:AFRC·I26'1<m:OS Dobbins EMP-.ltepons:DDI Fiua1:Uu1c Lake (OT·O"T> DD:Tat:Text Little Lake DD2..doc

9112197 1:55PM

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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 1RP Phase II Stage I Confirmation/Quantification Study, a Site Characterization Study, a RI, and an Environmental Monitoring Program {EMP).

In August 1986, ESE completed an IRP Phase ll 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 Little Lake consisted of a bathymetric survey of the lake, and sampling and analysis of surface water and sediment from the lake. In August 1986, ESE prepared a Phase ll - Confirmation/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 a RI to confirm previous results, establish the lateral and vertical limits of contamination, and assess potential risks posed by past waste disposal sites. Additional sampling and analysis of surface water and sediment was conducted during this phase. In April 1991, ESE prepared a Final Site Characterization Summary for the above investigation and submitted the report to AFRC and the Air Force Center for Environmental Excellence (AFCEE). The report was revised in accordance with AFRC and AFCEE comments in December 1991. (ESE, 1991)

In 1992, Parsons Engineering-Science (ES) conducted an RI that included Little Lake site.

The purpose of the RI 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 fish tissue samples. (ES, 1995)

In 1995, ES prepared a Remedial Investigation (Rl) Report that documented the results of.

the 1992 investigations and risk assessment conducted at the site as part of the IRP. The RI Report recommended that no further action be required for the site. (ES, 1995)

In 1995 and 1996, Montgomery Watson conducted an EMP at the site. The purpose of the EMP was to obtain more recent data for the site, compare this data to previous data, revise

1-3

~:f>PM PROJBC'f&AFRC·1267im:08 Dobbins EMP-.Rcports:I>Ds Finai:Uule Lako (OT-071 DD:Text:Tcxt LiuJc Lake DD2.doc the quantitative human health risk assessment (HHRA) to include 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. Sediment and surface water samples were collected from the site and analyzed. The results of the EMP as well as historical data were summarized and presented in the Comprehensive Analytical Report (CAR) (Montgomery Watson, 1996).

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2. SUMMARY OF SITE CHARACTERISTICS

This section presents a smnmary of site characteristics, including geology, climatology, physiography, soils, groundwater, surface water, sediment, and biota. The receptors at Little Lake are also discussed in this section. The analytical data obtained at the site were compared to applicable, or relevant and appropriate requirements (ARAR.s) or to be considered (TBC) criteria. USEP A Water Quality Criteria for Protection of Human Health and Freshwater Aquatic Life (USEPA, 1986) were used for surface water ARAR.s.

Sediment results were compared to TBCs generated by the National Oceanic and Atmospheric Administration (NOAA) (NOAA, 1990). Figure 2-1 shows sample locations at the site. A complete smnmary of ARARs for detected analytes at the site is presented in the CAR (Montgomery Watson, 1996).

2.1 GEOLOGIC SETTING, PHYSIOGRAPHY, AND CLIMATOLOGY

Little Lake is located in the Central Uplands district of the Piedmont physiographic province. This district is characterized by a series of low, linear ridges separated by broad, open valleys. Streams flowing through this area are generally transverse to the underlying geologic structure and occupy valleys 150 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 amplnbolites.

The general area of 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. Elevation at the site is approximately 980 feet above mean sea level (MSL).

The climate at the site is characteristic of the northern temperate 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 of70 °F and 51 °F respectively. Dobbins ARB experiences an average of 58 days with freezing temperatures each year. (ES, 1995)

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

Since Little Lake is an aqueous unit, no soils were present at the site. As a result, no soil at the site was evaluated.

2.3 GROUNDWATER

No groundwater contamination was identified during the RI or EMP investigations as having the potential to contain contaminants of potential concern (COPCs) at Little Lake.

As a result, groundwater at the site was not evaluated further.

2.4 SURFACE WATER

2.4.1 Surface Water Setting

Surface water at Little Lake is influenced by intermittent discharge from springs on the slopes northwest of the lake. An unnamed creek that drains a portion of AFP 6 flows around the southwest end of the lake, and receives overflow from the lake via a spill pipe.

2.4.2 Surface Water Contamination

A summary of historical surface water analytical results obtained at the site is presented in the CAR. Table 2-1 summarizes the maximum concentrations for constituents of concern detected in surface water samples collected during the two most recent sampling rounds (1995 and 1996) at the site. Surface water samples were collected in Little Lake, as well as upstream and downstream of the lake for chemical analysis.

Laboratory results indicate that one pesticide, dieldrin, was detected in surface water samples collected from the site in 1985 above the Federal Water Quality Criteria of 0.0019 J.Lgll. However, pesticides were not detected in subsequent sampling rounds conducted in 1990, 1995, and 1996. These sampling rounds also found no evidence of volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), or polychlorinated biphenyls (PCBs) at the site.

Lead was detected in six surface water samples collected in 1990 and 1996 at concentrations that exceed USEPA Water Quality Criteria of 0.43 J.Lgll. Total arsenic in one sample and dissolved arsenic in three samples collected during 1996 exceeded USEPA Water Quality Criteria for human health and USEPA freshwater criteria, 190 and 0.018f.l.g/l, respectively.

2. 5 SEDIMENT

A summary of historical sediment analytical results obtained at the site is presented in the CAR. Table 2-2 summarizes the maximum concentrations for constituents of concern

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The PAHs detected at concentrations exceeding ER-L screening levels dwing the 1990 sediment sampling event at the site included benzo(a)anthracene, chrysene, phenanthrene, and pyrene. However, none of the PAHs detected dwing the 1990 sampling round were detected during the 1996 sampling.

The results of the sediment sampling events indicated concentrations of pesticides and PCBs that exceeded the ER-L or ER-M criteria in several of the samples collected from the site dwing the 1990 sampling round. Aroclor 1254 was detected in two of the sediment samples collected at the site during the 1990 sampling event at concentrations that exceeded the ER-L criteria of22.7 Jlglkg for total PCBs. However, none of the pesticides and PCBs detected during the 1990 sediment sampling round were detected during the 1996 sampling round.

The results of the sediment sampling rounds indicated concentrations of several metals (including arsenic, cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc) that exceeded the NOAA ER-L or ER-M sediment screening levels listed in Table 2-2 at the site.

In general, detected concentrations of metals were lower dwing the 1996 sampling round relative to the 1990 sampling round.

2.6 BIOTA

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

Table 2-3 summarizes the maximmn concentrations for constituents of concern detected in biota samples collected dwing the 1996 sampling round at the site. Fish tissue samples were collected from Little Lake in May 1996 and were analyzed for PAHs, pesticides, PCBs and metals. The results of the analyses indicated the presence of two metals, mercury and zinc. Two organochlorine (OC) pesticides, 4,4-DDE and dieldrin, were detected in fish tissues. There were no PAHs detected in fish tissues. However, it should be noted that there were elevated detection limits for PAHs due to sample matrix interference. No PCBs were detected in fish tissues.

As a result of the constituents detected in fish tissues, the potential human health risks and ecological impacts of all constituents detected in fish tissues have been quantified in a 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 docmnent, only the current use

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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. Human receptors are not expected to be exposed to groundwater under current land use scenario. Dobbins ARB presently receives its water from Air Force Plant 6 (AFP 6), which in turn, receives its water from the Cobb-Marietta Water Authority. This water supply is derived from off site surface water sources. No public groundwater supply wells exist within 3 miles of Dobbins ARB. Sixteen inactive water supply wells were located on Dobbins ARB or Air Force Plant 6, however, the wells have been inactive since the early 1950s. Fifteen of these previous well locations were filled in and covered during the early 1980s and are no longer accessJ.ole. The closure status of the remaining active well location is not known. (ES, 1992)

Limited exposure to surface water, sediment, or consumption of fish exists for potential human receptors, since swimming, fishing, and other recreational uses of Little Lake are currently restricted. Signs restricting fishing and swimming are currently posted.

Both aquatic and terrestrial receptors are present at Dobbins ARB. Terrestrial receptors consist of various types of forest flora and fauna. In general, the aquatic habitat areas of Little Lake consist of the lake itse~ the springs on slopes northwest of the lalre, and an 1mnamed creek that flows around the southwest end of Little Lake. Little Lake is approximately 2.5 acres in size and is surrounded by woods. An assessment of the color and clarity of the lake water indicates the presence of algae and fine suspended silt.

Faunal receptors at Little Lake include nine species of birds. amphibians and reptiles (mcluding snakes, frogs, and turtles), fish (including largemouth bass, minnows), and mammals (evidence ofbeaver).

The future use scenarios assumed that Little Lake would be developed for recreational use.

Adult and child residents· are the potential human receptors that were assumed to be exposed to surface water, sediment, and consumption of recreationally caught fish under this scenario. ·

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3. 0 RISK ASSESSMENT

A baseline risk assessment was initially conducted to characterize the potential risks to human health (HHRA) posed by constituents detected at Little Lake. The results of this assessment are presented in the RI Report. {ES, 1995) A revised quantitative HHRA was conducted by Montgomery Watson in 1996 that incorporated data obtained during the 1995 and 1996 sampling rounds into the existing data assessed by ES. In addition, an ecological risk assessment (ERA) was conducted by Montgomery Watson to assess whether there are risks associated with potential exposures of ecological receptors to contaminants of potential ecological concern (COPECs) at the site. The HHRA and ERA presented in this section are based on the revised HHRA and ERA presented in the Comprehensive Analytical Report (CAR) prepared by Montgomery Watson in 1996 (Montgomery Watson, 1996). The results of the HHRA evaluation of current or existing exposures are used in conjunction with the results of the ERA to determine the need for remedial action at the sites, or to support a no action alternative for sites, as appropriate.

3.1 HUMAN HEALTH RISK ASSESSMENT

The HHRA conducted for this site integrates the results of the RI conducted by Parsons Engineering-Science (ES, 1995), and data collected in the EMP conducted by Montgomery Watson. (Montgomery Watson, 1996) This revised baseline HHRA evaluates the contaminants detected at this site, potential exposure pathways between compounds and human receptors and the potential human health risks posed by these exposures. The four basic steps in this assessment are as follows: (1) identification of contaminants of potential concern (COPC), (2) exposure assessment, (3) toxicity assessment, and (4) risk characterization.

All constituents detected in the various environmental media during multiple sampling investigations {ES, 1995; Montgomery Watson, 1996) were evaluated tO determine COPCs for analysis in the risk assessment. Traditional risk assessment criteria (EPA, 1989a) used in selection of COPCs included frequency of detection, comparison with laboratory and field blanks, and comparison with background concentrations. Comparison of concentrations detected at the site with applicable or relevant and appropriate requirements (ARARs) and to be considered (TBC) criteria is presented earlier in Section 2.0 of this document.

In the risk assessment for this site, conservative site-specific current and hypothetical future exposure scenarios were evaluated based on the general physical characteristics of the site and the characteristics of populations on or near Dobbins ARB. However, for the purposes of this decision document only the current or existing exposures are critically reviewed.

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The exposure assessment included the identification of (1) a source and mechanism of chemical release, (2) a retention or transport medium, (3) a potentially complete exposure pathway, and (4) the presence of on-site or off-site receptors. The risk assessment was conducted assuming exposures to current and future installation workers and nea.rby residents. The hypothetical future use scenario assumed that Little Lake would be developed for recreational uses.

The potential exposure pathways that were considered in the Little Lake HHRA were associated with lake sediments, surface water, and fish. The general exposure routes via these potential pathways included:

• ingestion of surface water/sediment;

• dermal contact with surface water/sediment; and

• ingestion of fish.

These pathways were evaluated for completeness under current and future potential use scenarios for the site. Table 3-1 presents the results of the exposure pathway evaluation for current and hypothetical future scenarios for the site.

The primary sources of toxicity values for this assessment were the Integrated Risk Information System (IRIS, 1996) compiled by USEPA and the Health Effects Assessment Summary Tables (HEAST; USEPA, 1994).

Risk characterization involves the integration of health effects information developed as part of the dose-response assessment with exposure estimates developed as part of the exposure assessment The result is a quantitative estimate of chronic non-carcinogenic risks based on the presumption that a threshold dose is required to elicit a response, as well as a quantitative estimate of carcinogenic risks presumed to exist regardless of the dose.