Final_Correction_Action_Plan_Part_A,_Site_ST08.pdf

CORRECTIVE ACTION PLAN PART A

ST -08, Fonner Railroad Tanker Facility Name: Car Fuel Transfer Lines

9-033018, Facility ID: Release #2 City: Dobbins ARB

Corner of Atlantic Avenue and Street Address: Hawrltton Drive

County: Cobb Zip Code: 30069

Latitude: 33°55'19" N Longitude: 84"31'50" W

Submitted by UST Owner/Operator: Prepared by Consultant/Contractor:

Name: United States Air Force Name: Joan G. Hutton Col. Jeffrey W. Ippolito, USAFR

Company: Commander. 94th Sgpoort Grogp Address: 1492 FtrSt Street

Company: Montlll>mer.y Watson Address: Perimeter 400 Center

1100 Johnson Ferrv Road NE. Suite 460 City: Dobbins ARB State: _,G..,A"---- City: Atlanta State: GA Zip Code: _,3,0069=-"'-5,01.,0 ___ _ Zip Code: _,3~0'i!!34u.2 ___ _

Telephone: 770-919=3547 Telephone: 404-236-7400

I. PLAN CERTIFICATION:

A. UST Owner/Operation Certification

I hereby certify that the information contained in this plan and in all the attachments is true, accurate, and the plan satisfied all criteria and requirements of rule 391-3-15-09 of the Georgia Rules for Underground Storage Tank Management

Name: JeffrevW. Imx>lito. ~nder

Signature: /ijM/;;;:;r: Date:/;k/-U £ d /

B. Registered Professional Engineer or Professional Geologist Certification

I hereby certify that I have directed and supervised the field work and preparation of this plan, in accordance with State Rules and Regulations. As a registered professional geologist and/or professional engineer, I certify that I am a qualified groundwater professional, as defined by the Georgia State Board of Professional Geologists. All of the information and laboratory data in this plan and in all of the attachments are true, accurate, complete, and in accordance with applicable State Rules and Regulations.

Signature: L!,l.£2t,S£-A...L;_~~~-H-~

Date: 'Z-6.<11

CAP-A.FRM 1 5/98

General: READ THE GUIDANCE DOCUMENT FOR CAP PART-A BEFORE COMPLETING TinS FORM. FAILURE TO READ THE GUIDANCE DOCUMENT

WILL MOST LIKELY RESULT IN PREPARATION OF AN UNACCEPTABLE

REPORT. All text, figures, and tables requested in their respective sections should be prepared strictly in accordance with the Georgia EPD CAP-A guidance document. Please fill out this form as provided. Do not change the size of the fields or alter the placement of each section on each page.

(Appendix 1: AU Report Figures) (Appendix 11: AU Report Tables)

II. INITIAL RESPONSE REPORT

A. Initial Abatement

Were initial abatement actions initiated? YES_No...x_ If Yes, please summarize. If No, please explain why not.

The initial discovery of the fuel transfer lines (fill pipes for UST Facility ID 9-033018) did not include the discovery of soil and groundwater contamination. Field indications pointed to the presence of regulated material only within the lines themselves. Contamination in the vicinity of the UST fill Jines was later identified in 1997 dming soil gas and groundwater collection using direct-push methods dming preliminary assessment and site inspection. The discovered lines were removed dming 1998 and 1999, along with the petroleum products contents within these lines, and approximately 30 tons of fuel-contaminated soil found beneath the fill points and sections of the lines. [Reference Text Section 2.1.]

B. Free Product Removal (Table 1: Summary of Free Product Removal- must include Free Product thickness in each weU in which it was detected and volume of product removed)

Free Product Detected?

If Yes, please summarize free product recovery efforts.

Free product was initially detected in August 1997 in the sampling conducted using the direct-push method at location GW A504 [Figure 2-B of Supporting Documentation]. Subsequent to removal of the abandoned lines, a monitoring well was installed as part of this RIIFS for ST -08. Free product was not discovered when the well was sampled for groundwater analysis in Jnly 2000. [Reference Section 2.2.1 of Supporting Documentation.]

Continuing free product recovery proposed If yes, please indicate the method and frequency of removal. YES_NO...x_

CAP-A.FRM 2 5/98

C. Tank History List cu"ent andfonner UST's operated at site based on owner/operator knowledge (consistent with EPA 7530-1 Form). Systems must be iUustrated on Figure 2 (Site Plan), as described In sectlnn D below.

CURRENT UST SYSTEMS (if avolicablel

TankJD Number Caoacitv <gaD Substance Stored Age (yrs) Meet 1998 Upgnule Standards <Yes/No)

N/A

FORMER UST SYSTEMS (if aPPlicable)

Tank ID Number Caoacitv (gal) Subsumce Stored Date Removed

9-033018, Release#2, USTs 19-24

150,000 JP-4 jet fuel 1991

[Reference Text Section 2.3.2 of Supporting Documentation.]

D. Initial Site Characterization (Figure 1: Vicinity/Location Map) (Figure 2: Site Plan)

1. Regulated Substance Released (gasoline, diesel, used oil, etc): JP-4 iet fuel Discuss how this detennination was made and circumstances of discovery.

F"mgerprint analysis of direct-push groundwater sample OW A504 in August 1997 identified hydrocarbons as JP-4 present at 95.6 percent by weight. No other types of liquid were identified in the sample. The location of the OW A504 sample is consistent with a release from the former fuel transfer lines. The laboratory data are presented in Table 1 and in Appendix V. The sample location is shown on Figure 2-B of the Supporting Documentation. [Reference Text Section 2.4.1 of Supporting Documentation.]

2. Source(s) of Contamination:

CAP-A.FRM

Discuss how this detennination was made.

In 1993 Installation personnel uncovered pipes that were believed to be the former fuel transfer lines while excavating to install two 25,000-gallon temporary, abovegromtd fuel bladder tanks.

The pipes were reported to be surromtded by what appeared to be petroleum-contaminated soil.

The presence of COntaminated soil was not confirmed at that time. This site was included in a comprehensive investigation of a number of questionable sites. The assessment and site inspection was executed in 1997 using soil gas sampling, soil grab samples, and groundwater grab samples using direct-push technology. !Reference Text Section 2.4.2 of Supporting Documentation.]

3 5/98

3. Local Water Resources [Reference Text Section 2.4.3 of Supporting Documentation.] (Figure 3: Quadrangle Map -Public and Private drinking water and surface water) (Appendix III: Water resources survey documentation, including, but 1WI limited to: USGS database search, interview forms, and documentation of field survey)

a. Site located in high/average __ OR low ..1L groundwater pollution susceptibility area?

b. Water Supplies witliin applicable Radii? YES __ NO_lL_ If yes, I. Nearest public water supply located within: _ feet

ii. Nearest down-gradient public water supply located within: _ feet

iii. Nearest non-public water supply located within: feet

iv. Nearest down-gradient non-public water supply located within: feet

c. Surface Water Bodies and sewers:

I. Nearest surface water located within: 850 feet

ii. Nearest down-gradient surface water located within: 2000 feet

iii. Nearest storm or sanitary sewer located within 100 feet

iv. Depth to bottom of sewer at a point nearest the plume: ...2._feet

4. Impacted Environmental Media

CAP-A.FRM

a. Soil Impacted [Reference Text Section 2.4.4.1 of Supporting Documentation.] (Table 2: Soil Analysis Results) (Figure 4: Soil Quality Map) (Appendix W: Soil Boring Logs) (Appendix V: Soil lAboratory Reports) (Appendix VI: ATL Calculations, if applicable)

Provide a brief discussion of soil sampling.

A total of21 subsurface soil gas samples and 17 subsurface soil samples were collected along the former fuel transfer lines in areas where soil gas sampling indicated the presence of VOCs or where information obtained indicated a release bad occurred. Soil sampling depths ranged from 0-2 to 25-27 ft. BTEX compounds were detected in 11 of the 17 soil samples at concentrations that do not exceed applicable threshold levels.

4 5/98

CAP-A.FRM

I. Soil contamination above applicable threshold levels?

YES_NO,-'x~

If yes, indicate highest concentrations in soil along with locations and depths detected.

ii. ATLs calculated? YES __ NO.~x,___ If yes, present ATLs.

iii. If ATL 's calculated, is soil contamination above ATL 's?

YES_ NO_ N/A~x.___

b. Groundwater Impacted [Reference Section 2.4.4.2 of Supporting Documentation.] (Table 3: Groundwater Analysis Results) (Figure 5: Groundwater Quality Map) (Appendix VII: Monitoring Well Details) (Appendix VIII: Groundwater Laboratory Results)

Provide a brief discussion of groundwater sampling.

In June 2000, groundwater was encountered in only three of 26 direct-push locations due to refusal on shallow rock. In July 2000, four monitoring wells were installed; however, six borings were advanced due to auger refusal in two of the borings. BTEX was reported above MDLs in one of the seven samples (MWOl). Benzo(a)pyrene was below MDLs in the seven samples. TCE, associated with a plume migrating from adjacent Air Force Plant No. 6 site, was detected in four samples at 2.7-7 .3!'g/L.

I. Groundwater contamination above MCLs? YES X NO __

ii. Groundwater contamination above In-Stream Water Quality

Standards?

YES __ NO X

If yes, indicated highest concentrations in groundwater along with the locations.

Benzene MWOl 5.7 j.lg/L MCL=5.0 j.lg/L

5 5/98

c. Surface Water Impacted? YES __ NO X

If Yes, indicate concentration( s) of surface water sample( s) taken from the surface water body/bodies impacted.

[Reference Text Section 2.4.4.3 of Supporting Documentation.]

d. PointofWithdrawallmpacted? YES __ NO __ N/A X

If Yes, indicate concentration( s) of water sample( s) taken from withdrawal point(s).

5. Other Geologic/Hydrogeologic Data [Reference Text Section 2.4.5 of Supporting Documentation.]

a. Depth to Groundwater: 34.18-35_.22 ft 18129/00) (Table 4: Groundwater Elevations)

b. Groundwater Flow Direction: ESE (Figure 6: Potentiometric Surface Map)

c. Hydraulic Gradient: 0.0048

d. Geophysical Province: pjedmnnt

e. Unique geologic/hydrogeological conditions: A discussion ofpossible bedrock control and the Air EDfce Plant No. ~roandwater recpverv effort is vresented hlhe accompanying text.

6. Corrective Action ComPleted or In-Progress (if applicable) [Reference Text Section 2.4.6 of Supporting Documentation.]

CAP-A.FRM

(Table 5: UST System Closure Sampling) (Figure 7: UST System Closure Sampling) (Appendix IX: Contaminated Soil Disposal Manifests)

a. Underground Storage Tank (UST) System Closure: NIA __ If applicable, summarize UST system closure activities conducted.

In September 1998 five fuel transfer lines on the western side of Taxiway M were removed. Portions of the lines that extended under the taxiway or the asphalt road on the western side of the site were left in place after being filled with non-shrinking grout and capped. A total of 310 gallons of residual liquid was removed from the lines using a vacuum truck. The former fuel lines and residual liquid were transported to appropriate recycling facilities for disposal.

6 5/98

7.

b. Excavation and Treatment/Disposal of Backfill Materials and Native Soils Check one: No UST removal performed __

Returned to UST excavation X Excavated soils treated or disposed off site _x_

If soils were excavated, summarize excavation and treatment/disposal activities:

Soil removed from the excavation was segregated into two stockpiles based on headspace field-screening data, as follows: (a) soil presumed clean (<100 ppm) and (h) soil presumed contaminated (>100 ppm) or visually observed as contaminated. Confirmation soil samples were collected from the stockpiles. Based on analytical data, stockpiled soil was returned to the excavation or transported to a recycling facility for disposal.

Additioual information is provided in Text Section 2.4.6.2 of the Supporting Documentation.

Site Rankin~ Environmental Site Sensitivity Score: _ __,8,..0 __ (Appendix X: Site Ranking Form)

[Reference Text Section 2.4.7 of Supporting Documentation.]

8. Conclusions and Recommendations

CAP-AFRM

Complete applicable section below, one section only a.

b.

c.

No Further Action Required (if applicable) (provide justification)

NIA_

The release from the former foe! transfer lines does not pose a significant threat to human health or the environment. Residual hydrocarbons present in the subsurface soil do not exceed STI.s. The benzene concentration (5.7 Jl.g/L) in one groundwater sample exceeded regulatory standards. We expect no adverse impact to surface or drinking waters due to the distances to surface water bodies, low benzene concentration, and absence of public/non-public water supplies/intakes. Therefore, a No Further Action determination is requested.

Monitoring Only (if applicable) (provide justification)

CAP-B (if applicable) (provide justification)

N/ A _,x,__

N/A _.l!x,__

III. MONITORING ONLY PLAN (if applicable)

A. Monitoring Points

B. PeriOd/Frequency of monitoring and reporting

C. Monitoring Parameters

D. Milestone Schedule

E. Scenarios for site closure or CAP-Part B

IV. SITE INVESTIGATION PLAN (if applicable):

(Figure 8: Proposed additional boring/monitoring well location)

N/A...Lx.__

N/A..x__

A. Proposed Investigation of Horizontal and Vertical Extent of Contamination In:

1. Soil N/A..x__

CAP-A.FRM 8 5198

2. Groundwater

a. Free Product N/A._X_

b. Dissolved Phase N/A._X_

3. Surface Water N/A._X_

B. Proposed Investigation of Vadose Zone and Aquifer Characteristics: N/A

CAP-A.FRM 9 5198

V. PUBLICNOTICE

(Figure 9: Tax Map) (Appendix XI: Copies of public notification letters and certified return receipts or newspaper notice if approved)

Required documentation is presented. in Appendix XI. Reference Text Section 2.4.9 of Supporting Documentation.

VI. CLAIM FOR REIMBURSEMENT (for GUST Trust Fund sites only): N/A ..lL_ (Appendix XII: GUST Trust Fund Reimbursement Application and Claim for Reimbursement)

CAP·A.FRM 10 5/98

FINAL

CAP PART A SUPPORTING DOCUMENTATION

SITE ST-08, FORMER RAILROAD TANKER CAR FUEL

TRANSFER LINES

DOBBINS AIR RESERVE BASE

GEORGIA

FACILITY ID 9-033018, RELEASE #2

Contract No. F0%09-95-D-0001 Task Order 5101

Prepared for:

94SPTG/CEV

84 Industrial Drive

Dobbins Air Reserve Base, Georgia 30069-4210

Prepared by:

Montgomery Watson Americas Perimeter 400 Center

1100 Johnson Ferry Road N.E., Suite 460 Atlanta, Georgia 30342

February 2001

• TABLE OF CONTENTS

Page No.

1.0 INTRODUCTION

2.0 INITIAL RESPONSE REPORT

2.1 INITIAL ABATEMENT

2.2 FREE PRODUCT REMOV AL

2.2.1 Free Product Detected

2.2.2 Continuing Free Product Recovery Proposed

2.3 TANK HISTORY

2.3.1 Current UST System

2.3.2 Former UST System

2.4 INITIAL SITE CHARACIERIZATION

2.4.1 Regulated Substance Released

2.4.2 Source ofContamination

2.4.3 Local Water Resources

2.4.3.1 Water Supplies Within Applicable Radii

2.4.3.2 Surface Water Bodies

2.4.4 Impacted Environmental Media

2.4.4.1 Soil lmpacted

• 2.4.4.1.1 Soil Gas Survey Methodology

2.4.4.1.2 Soil Gas Survey Results -July 1997

2.4.4.1.3 Soil Sample Methodology

2.4.4.1.4 Soil Sample Results- August 1997

2.4.4.1.5 Alternate Threshold Levels

2.4.4.2 Groundwater Impacted

2.4.4.2.1 Direct-Push Groundwater Sample Methodology

2.4.4.2.2 Direct-Push Groundwater Sample Results -

June 2000

2.4.4.2.3 Monitoring Well Groundwater Sample

Methodology

2.4.4.2.4 Monitoring Well Groundwater Sample Results-

July 2000

2.4.4.3 Surface Water Impacted

2.4.5 Other Geologic/Hydrogeologic Data

2.4.5.1 Site ST -08 ............................................. :

2.4.5.2 Air Force Plant No. 6

2.4.5.2.1 TCE Spill

2.4.5.2.2 JP-5 Jet Fuel Spill

2.4.5.2.3 B-10 Aeration Basin

2.4.6 Corrective Actions Completed

2.4.6.1 UST Syatem Closure

2.4.6.2 Excavation and Treatment/Disposal of Backfill

Materials and Native Soils ....................................................... 15 • i

2.4.7 Site Ranking

2.4.8 Conclusions and Recommendations

2.4.9 Public Notice

2.4.10 Claim forReimbursement

3.0 REFERENCES

LIST OF APPENDICES

Appendix No.

I FIGURES

1-A Location Map 1-B VicinityMap 2-A Site Plan (Aerial View) 2-B Site Plan 3 Quadrangle Map, Public and Private Drinking Water and Surface Water 4-A Soil Gas Sample Results 4-B Soil Quality Map 5 Groundwater Quality Map 6-A Potentiometric Surface Map, August 29, 2000 6-B Potentiometric Surface Map, October 6, 2000 6-C Top of Weathered Rock Elevations 7 UST System Closure Sampling

IT TABLES

1 LNAPL Results, August 1997 2-A Soil Gas Data Summary 2-B Soil Analysis Results 3-A Groundwater Analysis Results- Direct Push Samples 3-B Groundwater Analysis Results- Monitoring Well Samples 4 Groundwater Elevations 5 UST System Closure Sampling ill WATER RESOURCES SURVEY DOCUMENTATION

IV SOU.. BORING LOGS

V SOU.. GAS MOBll..E LABORATORY RESULTS I SOU.. LABORATORY

REPORTS

VI ALTERNATE THRESHOlD LEVEL CALCULATIONS (NOT APPLICABLE) Vll MONITORING WEll. DETAll..S (SEE APPENDIX IV) Vlli GROUNDWATERLABORATORYREPORTS

IX-1 CONTAMINATED SOU.. DISPOSAL MANIFESTS FOR PIPELINE CLOSURE

IX-2 CONTAMINATEDSOll..DISPOSALMANIFESTFORCAPPART AIDW

X SITE RANKING FORM

XI PUBUC NOTIFICATION DOCUMENTATION

Xll OTHER SUPPORTING DATA ii

ARB

AFP

AVGAS

ATL

ATV

bgs

BTEX

CAP

CGI

DRO

DOT

EPD

ft

GA

GADNR

GAEPD

GOCO

gpm

GRO

GUST

IWTF

LEL

MCL

MDL

mg/m3

MSA

PAH

PID

POL

ppm

RW

STL

svoc

TCE

TPH

USEPA

UST

voc

LIST OF ACRONYMS AND ABBREVIATIONS

Air Reserve Base Air Force Plant Aviation Gasoline Alternate Threshold Level All Terrain Vehicle below ground surface Benzene, Toluene, Ethylbenzene, Xylenes Corrective Action Plan Combustible Gas Indicator Diesel Range Organic Department of Transportation Environmental Protection Division feet Georgia Georgia Department of Natural Resources Georgia Environmental Protection Division Government-Owned Contractor-Operated gallons per minute Gasoline Range Organic Georgia Underground Storage Tank Industrial Waste Treatment Facility Lower Explosive Limit Maximum Contaminant Level Method Detection Limit milligram per cubic meter Mine Safety Appliances Company Polynuclear Aromatic Hydrocarbon Photoionization Detector Petroleum, Oil, and Lubricant parts per million Recovery Well Soil Threshold Level Semivolatile Organic Compound Trichloroethene Total Petroleum Hydrocarbon U.S. Environmental Protection Agency Underground Storage Tank Volatile Organic Compound iii

1.0 INTRODUCTION

This report provides supporting documentation to the Corrective Action Plan (CAP) Part A for Site ST-08, Former Railroad Tanker Car Fuel Transfer Lines, located at Dobbins Air Reserve Base (ARB), Georgia (GA; Figures 1-A, 1-B, 2-A, 2-B). This document has been prepared according to the Georgia Department of Natural Resources (GADNR), Environmental Protection Division (EPD) publication entitled Guidance Document, Underground Storage Tank Release: Corrective Action Plan Part A (Guidance Document), effective May 1998. This report is organized as follows:

• Section 1.0 provides an introduction to the document and its organization.

• Section 2.0 contains the Initial Response Report detailing the site history and initial site characterization summary.

• Section 3.0 lists reference citations.

Figures and tables have been included in Appendices I and II following the text.

2.0 INITIAL RESPONSE REPORT

2.1 INITIAL ABATEMENT

The ends of the fuel transfer lines were uncovered during work to install aboveground bladder tanks during the spring of 1993. Due to photoionization detector (PID) readings taken within the newly discovered pipes, the Air Force identified the site as an Area of Concern and initiated a project to perform further investigation of these lines as soon as money and time allowed. The decision to investigate was based on the field discovery of lines previously believed to have been removed and the discovery that the contents of these lines exhibited strong odors of fuel and high PID readings. The Base completed a tasking (Preliminary Assessment/Site Investigation at AOC-5) to explore the entire area for signs of contamination in December 1997 using a technique that would not spread soil or groundwater contamination if discovered. As a result of this assessment and inspection, an action was completed in July 1999 to remove as much of the lines as accessible along with contents and surrounding contaminated soil. This action was followed by the action currently ongoing in the CAP Part A process. Reference CAP Part A Form, paragraph II.A, Fignre 2-A for locations of former buried piping.

2.2 FREE PRODUCf REMOVAL

2.2.1 Free Product Detected

In August 1997, free product was found in one direct-push groundwater sample (GWAS-

04) collected during a Site Investigation (Montgomery Watson, 1997). The sample was collected at a depth of 29 feet below ground surface (bgs) and was located in the vicinity of the former fuel transfer lines. The fingerprint of the sample indicated that hydrocarbons identified as JP-4 jet fuel were detected at a concentration of 95.6 percent by weight in the sample. Due to the nature of the analytical test (Method 8015 Modified Purgeable), the remaining 4.4 percent of the sample composition could not be identified.

The location of GW AS-04 is shown on Fignre 2-B. The analytical data is presented in Table 1. Reference II.B. of the CAP Part A form.

In June and July 2000, three direct-push groundwater samples were collected and four monitoring wells were installed and sampled during an investigation designed to fully delineate both free-phase and dissolved-phase petroleum hydrocarbons. Free product was not found at any of these locations; therefore, no free product recovery efforts have been implemented.

2.2.2 Continuing Free Product Recovery Proposed

No free product recovery is proposed.

2.3 TANK HISTORY

2.3.1 Current UST System

This section is not applicable.

2.3.2 Former UST System

The former fuel transfer lines were in use from the early 1950s to the early 1980s and consisted of a system of multiple 4- and 6-inch diameter gravity-flow pipelines of unspecified material and depth. These lines constituted the rail off-loading headers and fuel tank fill lines for six former 25,000-gallon underground storage tanks (USTs) located at the petroleum, oil, and lubricant (POL) Tank Farm. The six USTs were removed in August 1991. The fuel transfer lines were approximately 1,000 feet in length and extended from the former fueling system railhead to the POL Tank Farm. The GAEPD Facility ID for the ST-08 site is FllL LINES FOR UST 9-033018. The release was reported as 9-033018, Release #2. The locations of the former fuel transfer lines and the former fueling system railhead are shown on Figure 2-A. Reference n.c of the CAP Part A form.

The fuel transfer lines were visually inspected in September 1998 upon removal. The three 4-inch fuel lines appeared to have several threaded joints and were most likely components of the former off-loading headers. The two 6-inch lines contained no threaded joints and had welded pipe joints. They were located parallel to each other and approximately 8- to 12-inches apart. The fuel transfer lines transported aviation gasoline (A VGAS) and JP-4 jet fuel. Facility personnel reported that portions of the fuel transfer lines may have been previously removed.

2.4 INITIAL SITE CHARACTERIZATION

2.4.1 Regulated Substance Released

Free product was observed in a direct-push groundwater sample (GW A5-04) collected in August 1997. The free product was collected and submitted for analytical testing by United States Environmental Protection Agency (USEPA) SW-846 Method 8015 Modified Purgeable analysis. The sample was identified as containing 95.6 percent JP-4 jet fuel based on comparison to known purgeable standards (i.e., JP-4, JP-5, JP-8, gasoline, diesel, kerosene, and mineral oil). Since the analytical method compared the sample against purgeable standards only, the identity of the remaining 4.4% of the sample was not determined. Reference IT.D.1 of the CAP Part A form.

2.4.2 Source of Contamination

The source of contamination was JP-4 jet fuel conveyed in the former fuel transfer lines that extended from the former fueling system railhead to the POL Tank Farm (Figure 2-

A). Additional discussion of the fuel transfer line removal in September 1998 is presented in Section 2.4.6. Reference II.D.2 of the CAP Part A form.

2.4.3 Local Water Resources

2.4.3.1 Water Supplies Within Applicable Radii

Dobbins ARB is located in a lower susceptibility area, as defined by the Ground-Water Pollution Susceptibility Map of Georgia (Trent, 1992). Environmental activities conducted in October 2000 at Dobbins ARB included a survey to identify public and non public water supplies within 1.0 mile and 0.25 mile, respectively, of the site. Information from the following sources/agencies has been reviewed:

• U.S. Geological Survey, Georgia District well search

• Cobb-Marietta Water Authority

• Cobb County Environmental Health Department

No public or non-public water supplies exist within 1.0 mile and 0.25 mile, respectively, of the site. A well search by the U.S. Geological Survey, Georgia District provided records of six wells located within 1.0 mile of the site. (No wells were identified within

0.25 mile of the site.) The locations of these wells are shown on Figure 3 and keyed to the search output provided in Appendix ill. Reference II.D.3a,b of the CAP Part A form.

Three of the wells were installed on Lockheed-Martin property in 1951 and vary in depth from 131 to 550 feet. The wells are not used for drinking water (personal communication, Sue Matzurs, Lockheed-Martin Aeronautical Company (Lockheed Martin), October 20, 2000). The three remaining wells are located on the Southern Polytechnic State University campus. Well scr 1 was installed to 605 feet in 1993 to irrigate; new athletic fields. After installation, however, trichloroethene (TCE) was analyzed in a groundwater sample and the well was taken out of service. scr 1 is currently used as an observation well to monitor the TCE plume. In 1996, two additional observation wells were installed to total depths of 55 and 604 feet (personal communication, Jim Brown, Southern Polytechnic State University, October 24, 2000).

The Cobb-Marietta Water Authority confirmed that the two surface water intakes in Cobb County are not located within 1.0 mile of the site (personal communication, John Lemica, Cobb-Marietta Water Authority, October 20, 2000). Four public wells installed to supplement water supply during peak or high-demand periods are located in Cobb County. Two of the four wells are not used (personal communication, Glynn Paige, Cobb-Marietta Water Authority, October 23, 2000). The four wells are not located within 1.0 mile of the site.

Montgomery Watson reviewed Cobb County Environmental Health Department files on October 19, 2000. No records of an "Intent to Drill a Well" or of a "Request for Sample

To Be Collected from Private Wells" were located for addresses within 1.0 mile of the site.

Sixteen water supply wells are located on the Dobbins ARB military reservation. The wells have been inactive since the 1950s. Fifteen of the wells were filled in and covered in the early 1980s and are no longer accessible. The remaining well referenced here has been converted to a groundwater monitoring only well and is in use by Air Force Plant 6 as part of their Installation Restoration Program investigation. The water resource survey documentation is provided in Appendix Ill.

2.4.3.2 Surface Water Bodies

The nearest surface water body is a tributary of Rottenwood Creek located approximately 850 feet northeast of the site (Figure 3 ). Other surface water bodies within 1.0 mile of the site include Big Lake (2000 feet east southeast) and Little Lake (4000 feet east).

These bodies discharge to srpall tributaries of Rottenwood Creek.

Figure 3 shows the locations of two ponds situated immediately north of the site and a pond associated with a trailer park (Hill Crest Plaza) located approximately 4000 feet west northwest of the site. A windshield survey conducted on October 18, 2000 by Keriema Newman of Montgomery Watson revealed that the pond at Hill Crest Plaza does not currently exist A spring formerly existed at the trailer park but is now completely covered and overgrown with kudzu (personal communication, Brenda McMahan, October 18, 2000). The pond immediately north of the ST-08 site was a former Lockheed Aeration Basin that was part of Lockheed's Industrial Waste Treatment Facility (IWTF; personal communications, Harold E. Huddleston; Dobbins ARB, March 27, 2000 and Sue Matzurs, Lockheed Martin, December 11, 2000). The aeration basin has been closed and the area is currently under remediation as part of Air Force Plant 6's Restoration Program. The pond located west of the former aeration basin, as shown on Figure 3, no longer exists; however, a small catch basin is located north of the former aeration basin. The catch basin is currently dry but is designed to collect rainfall and spills from its drainage area (personal communication, Sue Matzurs, Lockheed Martin, December 11, 2000).

No impact to surface water by a release from the former fuel transfer lines is expected due to the limited areal extent of the petroleum-impacted groundwater at ST -08 and the distance to surface water bodies. Reference II.D.3.c of the CAP Part A form.

2.4A Impacted Environmental Media

The purpose of this section is to document the magnitude of soil and groundwater contamination resulting from a release from the former fuel transfer lines at ST-08. The soil investigation was implemented in July and August 1997 and consisted of a soil gas survey and direct-push soil sampling program. The groundwater investigation was initiated in August 1997 with the collection of one free product sample. It was continued in June and July 2000 with a direct-push groundwater sampling program and monitoring well installation. Reference II.D.4 of the CAP Part A form.

2.4A.l SoD Impacted

2.4A.l.l SoD Gas Survey Methodology

A total of 22 soil gas samples were collected from the unsaturated zone in July 1997 and analyzed on-site with a mobile laboratory to screen for vapor-phase volatile organic compounds (VOCs). The objectives of the soil gas survey were to:

• Determine the presence or absence of VOCs in the unsaturated zone to assess whether spills or leaks may have occurred.

• Determine the extent of VOCs in the unsaturated zone to assist in the assessment of source area, separate-, or dissolved-phase plume migration.

• Determine spatial and species variations in VOCs within the potential source areas.

The soil gas data was used to assist in locating subsequent soil and groundwater sampling points within potentially contaminated areas.

Sixteen soil gas samples were initially collected at approximately 100-foot intervals along the fuel transfer lines to assess the areas for potential releases. An additional six samples were then collected and analyzed to further delineate the extent of potential releases along the fuel lines. The soil gas survey data are presented in Table 2-A, Figure 4-A, and in Appendix V.

An all terrain vehicle (ATV)-mounted direct-push unit was used to install the soil gas sampling points. Samples were collected from the unsaturated zone and analyzed on-site using a mobile laboratory to screen for vapor-phase volatile organic compounds (VOCs).

The soil gas samples were collected using the following procedure:

• A hollow steel sample rod equipped with an expendable tip and tip holder was driven to approximately 2 feet below the anticipated depth of the fuel transfer lines.

• The rod . was then retracted approximately 6 inches, releasing the expendable tip from the holder, and creating a void through which soil gas could be drawn. Moist clay was placed around the rods at ground surface to prevent the flow of surface air into the sampling point.

• A length of 3/8-inch diameter disposable polyethylene tubing fitted with a reverse-threaded adapter was inserted down the inside of the rods. The tubing was then threaded into the tip holder, preventing the flow of ambient air from within the rods into the sampling tube.

• The front end of a decontaminated glass sample bulb was then connected to the exposed end of the tubing; and the back end of the bulb was connected to a Mine Safety Appliances Company (MSA1'M) personal sample pump. Approximately six bulb volumes of soil gas were drawn through the sample bulb at a rate of 2 to 3 liters/minute tq purge the line.

• The bulb was then over-pressurized by using a disposable syringe to inject an additional 300 milliliters of soil gas into the bulb.

Soil gas samples were analyzed for aromatic and halogenated VOCs using a modified SW-846 Method 8260. Upon completion of the soil gas survey, each sample location was surveyed by a State of Georgia registered land surveyor.

2.4.4.1.2 SoU Gas Survey Results- July 1997

The results of the soil gas survey conducted in July 1997 indicated that several VOCs including benzene, toluene, ethylbenzene, and xylenes were detected in nine of the 22 soil gas samples. The VOCs were present in four general areas, including the area of potential release associated with the aboveground fuel bladders. The soil gas data also suggested that the VOCs detected beneath the former fuel transfer lines are somewhat localized.

The hitest total VOC concentrations detected were 138 milligrams per cuhic meter (mgfm ), 75 mgfm3

, and 20.9 mgfm3 in soil gas samples SGA5-12 at 8ft, SGA5-13 at 8 ft, and SGA5-14 at 8ft, respectively. VOCs along the remaining portions of the former fuel transfer piping were detected at concentrations ranging from 0.1 to 3.6 mgfm3

• Total VOCs were detected at 1.4 mgfm3 in sample SGA5-17 at 7 ft. This sample was collected in the southwestern portion of the site where potentially contaminated soil was observed adjacent to exposed underground piping during installatiOn of the temporary, aboveground fuel bladder tanks in 1993. These potential release areas were further investigated during the soil sampling effort discussed below.

The soil gas survey data are presented in Table 2-A and Appendix V. The sampling locations and VOC data are shown on Figure 4-A.

2.4.4.1.3 SoU Sample Methodology

Seventeen soil samples were collected at the site in July 1997 in areas where either soil gas sampling indicated the presence of VOCs, or previous information indicated that a release may have occurred. An ATV-mounted direct-push unit was used to collect the soil samples. The soil sampling locations are shown on Figure 4-B. The analytical data for soil samples are presented in Table 2-B and Appendix V. Reference II.D.4.a of the CAP Part A form.

Soil samples were collected continuously using a 4-foot-long, stainless-steel Macrocore™ sampler lined with a disposable acetate sleeve. The soil sampler was pushed from ground surface to 2 feet below the anticipated depth of the fuel lines, the groundwater table, or refusal, whichever was encountered first After retrieving the sampler from the borehole, soil samples were examined for indicators of potential contamination, such as soil discoloration and odor. The samples were field-screened with a PID for the presence of organic vapors. Soil lithology and other field data were recorded on boring logs which are provided in Appendix IV. ·

The soil sample from each borehole with the highest PID reading was transferred to laboratory-supplied glassware, packed in ice, and shipped to Savaonah Laboratories, Inc., in Tallahassee, Florida for analysis. When field screening did not indicate the presence of contamination, a soil sample was collected immediately below the estimated depth of the fuel transfer lines and was submitted for analysis.

Soil samples were analyzed for VOCs by SW-846 Method 8260, semi-volatile organic compoundS (SVOCs) by SW-846 Method 8270, and priority pollutant list metals by SW- 846 Methods 601on000. Upon completion of the soil sampling program, the soil boring locations were surveyed by a State of Georgia registered land surveyor.

2.4.4.1.4 Son Sample Results- August 1997

The analytical results for soil samples collected in August 1997 were compared to Soil Threshold Levels (STI.s), as defined in Georgia Underground Storage Tank (GUST) Rule 391-3-15.09(3), Table B.

VOCs were detected at low concentrations in 14 of the 17 samples collected. Low concentrations of SVOCs were detected in nine of the 17 samples and metals were detected at low concentrations in all of the samples. None of the sample concentrations, however, exceeded the current STI.s for benzene, toluene, ethylbenzene, or xylenes

(BTEX).

Soil analysis results are presented in Table 2-B and the analytical data reports are presented in Appendix V. The soil quality map is shown on Figure 4.

2.4.4.1.5 Alternate Threshold Levels

The application of Alternate Threshold Levels (ATI.s) is not warranted since the soil quality data for the site are below STI.s, as defined in GUST Rule 391-3-15.09(3), Table

B. Reference II.D.4.I of CAP Part A form.

2.4.4.2 Groundwater Impacted

2.4.4.2.1 Direct-Push Groundwater Sample Methodology

In June 2000, groundwater was encountered in three of 26 direct-push sampling locations across the site. Refusal of the direct-push sampler on weathered rock occurred at 23 of the locations at depths ranging from 4 to 36 feet bgs. The direct-push test data are summarized on Table XII-2 in Appendix XII and the sampling locations are shown on Figure 2-B. A map contouring the top of weathered rock is shown on Figure 6-C.

Reference ll.D.4.b of CAP Part A form.

Initially, 10 direct-push groundwater samples were to be collected at the site to begin delineating the potential groundwater plume associated with UST system closure sampling (Figure 7). The first three samples were located on the eastern portion of the site, at sample locations S8-8B04, S8-SB08, and S8-SB10 where elevated petroleum hydrocarbons as diesel range organics (DRO) were noted. However, because the depth to groundwater was deep and refusal on rock was encountered during drilling, no groundwater samples were collected at these locations. A total of 12 offsets were made around the three original locations, and refusal was encountered at all of the locations.

Because groundwater was reached on the western portion of the site in the 1997 investigation, additional attempts were made to collect groundwater samples near the location at which free product was previously found (GWAS-04). Three groundwater samples were collected in 11 attempts and no free product was encountered. Figure 2-B shows the locations of the direct-push borings.

The groundwater samples were collected with a bailer-style sampler that consisted of a stainless-steel body that acted as a sample chamber. Housed inside this body was a telescopic screen assembly which consisted of a conical point, a 1-foot wire wrap stainless-steel screen and a check valve assembly. Sampling was conducted by pushing the sampler to a predetermined sampling depth with the screen assembly in the closed and sealed position (retracted in the sample chamber). When the sampling depth was reached, the sample chamber and rod string were pulled back 1 foot The pressure in the sampler held the screen assembly at depth while the rods were retracted and the sample chamber was opened. Once the screen was exposed, hydrostatic pressure forced the groundwater through the screen, past the check valve and into the sample chamber.

Small-diameter tubing connected to a peristaltic pump was lowered down the drill rod to collect the groundwater sample from the sample chamber.

The direct-push groundwater samples were analyzed for VOCs and TCE, polynuclear aromatic hydrocarbons (PAHs), and total petroleum hydrocarbons (TPH)-DRO/gasoline range organics (GRO) by USEPA SW-846 Method 8260, Method 8270, and Method 8015, respectively. TCE was analyzed in the samples because of the proximity of the Air Force Plant No.6 TCE plume and the commingled nature of the plumes.

2.4.4.2.2 Direct· Push Groundwater Sample Results- June 2000

The groundwater results for direct-push samples were compared to the federal maximum contaminant levels (MCLs) for Safe Drinking Water. The groundwater analysis results are presented in Table 3-A and the laboratory data reports are included in Appendix VIII.

A grou~dwater quality map is presented on Figure 5.

TCE was the only VOC detected in one of the three direct-push groundwater samples, ST08-DP04C. TPH-DRO was detected at concentrations of 0.17 and 0.10 ug/1.. in the

ST08-DP04C and ST08-DP09 samples. There is currently no MCL established for TPH DRO. P AHs were not detected above MDLs in the samples .

2.4.4.2.3 Monitoring Well Groundwater Sample Methodology

Four two-inch diameter monitoring wells were installed at the site in July 2000. The rationale for well placement was developed based on the topography of the weathered rock and the occurrence of surficial groundwater. First, the top of the weathered rock was mapped using refusal depths from the 26 direct-push borings advanced in June 2000.

As shown on the resulting map (Figure 6-C), the rock dips steeply to the northeast and southwest from shallow rock located in the central site area. The only groundwater encountered during direct-push testing was found in three locations in the southwestern corner of the site. The monitoring well locations were selected based on the corollary that water flows downhill and that groundwater in the southwestern portion of the site will flow to the southwest following the dip of the rock.

Monitoring well ST08-MW01 was installed as the source well and was located coincident with GW A5-04, the direct-push location where free product was detected in 1997. Two additional wells designated ST08-MW02 and ST08-MW03 were installed west southwest and south southwest of the source area as downgradient monitoring wells. The fourth monitoring well, ST08-MW04, was installed upgradient and north northeast of the source area. Auger refusal was encountered in two additional borings designated 03-1 and 03-2 prior to encountering groundwater to the sou~ and southeast of the source area.

The locations of monitoring wells and borings advanced to auger refusal are shown on Figure 2-B. Monitoring well construction information is provided on the soil boring logs included in Appendix N. Reference II.D.4.b of CAP Part A form.

2.4.4.2.4 Monitoring Well Groundwater Sample Results- July 2000

The sample collected from ST08-MW01 had detected concentrations of benzene, ethylbenzene, TCE, and total xylenes. Benzene was reported in the ST08-MW01 sample at 5.7 !J.gil and slightly exceeded the MCL for benzene of 5.0 !J.gil. ST08-MW02 and ST08-MW04 had detected concentrations ofTCE at 7.3 and 2.7 !J.gil, respectively. None of the other detected concentrations exceeded the MCLs for these VOCs.

All of the groundwater samples had detected concentrations for TPH-DRO with ST08- MW01 having the highest concentration of 2.4 mgil. ST08-MW01 also had a detected concentration of 5.0 mgil forTPH-GRO.

Groundwater sample ST08-MW01 was the only groundwater sample with detected PAHs. F!ourene, phenanthrene, and 1-methylnaphthalene were reported in the sample at respective concentrations of 1.3, 3.0, and 7.9 !J.gil.

Groundwater analysis results are presented in Table 3-B and the analytical data reports are presented in Appendix VIII. The groundwater quality map is shown on Figure 5.

Reference II.D.4.b of the CAP Part A form .

2.4.4.3 Surface Water Impacted

The nearest surface water body is a tributary of Rottenwood Creek located approximately 850 feet northeast of the site. Other surface water bodies located witliin 1.0 mile of the site include Big Lake to the east southeast and Little Lake to the east. It is unlikely that surface water will be impacted by petroleum hydrocarbons migrating from the ST -08 site for the following reasons:

• Groundwater analysis results only slightly exceeded the applicable MCL for benzene in one sample.

• The occurrence of free product in one direct-push groundwater sample in 1997 was not duplicated in an adjacent monitoring well installed in 2000.

• Soil analysis results did not exceed applicable STI.s for regulated compounds.

• Three recovery wells operated by Lockheed-Martin to remediate the TCE plume at Air Force Plant No. 6 will potentially intercept and capture groundwater migrating from the ST -08 site. A discussion of the TCE plume is included in Section 2.4.5.

Reference II.D.4.c of the CAP Part A form.

2.4.5 Other Geologidllydrogeologic Data

2A.5.l Site ST..OS

The direction of groundwater flow was determined by surveying the relative elevations of each monitoring well casing and subtracting the measured depth to groundwater.

Groundwater elevation data is summarized in Table 4 and the interpreted groundwater potentiometric surface is shown on Figure 6-A for August 29, 2000 and on Figure 6-B for October 6, 2000. Based on water level elevations measured in the monitoring wells, groundwater flow across this area of the site is to the southeast. The horizontal hydraulic gradient was 0.0048 (August 29, 2000) and 0.0052 (October 6, 2000). An increase in water levels of approximately 1 foot was measured in the wells on October 6, 2000, as compared to the August 29, 2000 data. Reference II.D.5 of the CAP Part A form.

The site data suggest that groundwater movement in the southwestern portion of the site is influenced by two factors: the nature of the underlying rock and the operation of three recovery wells at adjacent Air Force Plant (AFP) No. 6. The shallow, weathered rock dips steeply to the southwest, as shown in Figure 6-C, and appears to be the primary structural control causing groundwater in that area to flow to the southwest along the rocky contour. The long-term pumping of the aquifer at AFP No. 6, however, has stressed the surficial aquifer creating cones of depression that anpear to have altered the naturally-occurring groundwater flow regime at ST -08. Based on limited gauging data, • this correlation appears to be supported by an observed increase in water levels in ST -08 monitoring wells during an interval in which one of the recovery wells (RW-102C) was out of service due to biological fouling or one or more of the recovery wells were offline for maintenance (personal co=unication, Steve Lanter Project Geologist, IT Corporation, December 13, 2000). ·

A discussion of AFP No. 6 is presented in Section 2.4.5.1. Monitoring wells associated with the Air Force Plant No. 6 plumes are shown on Figure 2-B.

2.4.5.2 Air Force Plant No. 6

AFP No.6 is located on approximately 720 acres in Cobb County, Georgia and is part of a 3,336-acre military complex that includes Dobbins ARB, Atlanta Naval Air Station, U.S. Army Reserve and Georgia Air National Guard units (Aeronautical Systems Center, undated). The location of AFP No. 6 is shown on Figure 1-B.

AFP No. 6 is a Government-Owned Contractor-Operated (GOCO) aircraft manufacturing facility managed by the U.S. Air Force Aeronautical Systems Center at Wright-Patterson Air Force Base, Dayton, Ohio. Lockheed Aeronautical Systems Corporation has operated the facility since 1951. Plant operations have included production and modification of the B-47, C-130, JetStar, C-141, C-5 military aircraft and C-130 and P-3 aircraft production, C-5 and C-141 aircraft repairs and F-22 fighter aircraft development.

AFP No.6 generates hazardous wastes from metal fabrication, metal finishing, chemical treating, and coating operations. The primary waste generating operations include:

• Vapor degreasers to remove preservative compounds, oil and forming compounds from aircraft parts. This process generates an oily/greasy sludge in spent TCE.

• Organic solvents used to clean excess paints from aircraft parts, residues from paint containers and paint equipment. These solvents are contaminated with a variety of resinous compounds based on the paints used, a broad variety of colorant pigments, and corrosion-inhibiting pigments, flattening agents, and fillers.

• 1,1,1-trichloroethane solvent used in cleaning of aircraft fuel tanks results in a solvent waste contaminated with a trace amount of organic residues (Lockheed-Georgia Company, 1984a).

2.4.5.2.1 TCE Spill. A TCE spill occurred on March 22, 1983 in the chemical storage yard on the east side of Building B-76. The incident occurred during the transfer of 10,000 gallons of TCE from a railroad tank car to the 14,100-gallon aboveground storage tank. The release was caused by the apparent failure of the end cap of a pipe junction which allowed the TCE to be pumped into the surrounding fill. The pipe failure was noticed when TCE came up through the asphalt pavement and ran downhill into a stonn drain inlet beneath the elevated TCE storage tank. The overland flow distance was a maximum of 50 feet. Inventory calculations indicated a loss of 1,066 gal.

Approximately half of the spill volume was estimated to have entered the storm drain system and was isolated in a stonnwater retention basin. The remainder seeped into the subsurface (Golder Associates, 1985; Lockheed-Georgia Company, 198Sa).

An additional minor spill of TCE occurred on February 24, 1984 at the TCE transfer station along the railroad track west of B-99. The spill volume, apparently, was only a few gallons but was sufficient to flow across the paved area, enter the storm drain system, and reach a stormwater retention basin (Lockheed-Georgia Company, 1985b).

IT Corporation is currently operating a pump and treat groundwater recovery and treatment system in the TCE spill area. The system includes three recovery wells designated RW-101, RW-102, and RW-103. Recovery well RW-101, located approximately 400 feet northeast of ST -08, is considered the primary well inducing groundwater movement in the site area RW-101 is screened at the overburden/rock interface from 40 to 80 feet and pumps continously at approximately 50 gallons per minute (gpm). Recovery well RW-102 is located approximately 550 feet north of ST-08 and is screened from 113 to 133 feet into bedrock. Recovery well RW-102 pumps at approximately 10 gpm. Recovery well RW-103 is located approximately 90 feet north of the former fuel transfer lines at ST-08 and has been in operation since June 1999. The well is screened from 30 to 70 feet and pumps intermittently at approximately 10 to 15 gpm.