STINFO - apps.dtic.mil · (RBSL) calculated for the current commercial use scenario was approximately 9000 mg/kg for the direct soil to skin contact ... APPENDIX A ANALYTICAL DATA

AFRL-HE-WP-TR-2000-0049

UNITED STATES AIR FORCERESEARCH LABORATORY

TPH CRITERIA WORKING GROUPDEMONSTRATION FIELD SAMPLINGREPORT: ROBINS AIR FORCE BASE,

WARNER-ROBINS, GA

Teresa R. SternerElaine A. Merrill

Erik K. VermulenOPERATIONAL TECHNOLOGIES CORP.1370 NORTH FAIRFIELD ROAD, SUITE A

DAYTON, OH 45432

January 2000Interim Report - January 1999 - January 2000

Air Force Research LaboratoryHuman Effectiveness Directorate20060705023 Deployment and Sustainment DivisionOperational Toxicology Branch2856 G StreetWright-Patterson AFB OH 45433-7400

Approved for public release; distribution is unlimited. I

STINFO COPY

NOTICES

When US Government drawings, specifications or other data are used for any purpose other thana definitely related Government procurement operation, the Government thereby incurs noresponsibility nor any obligation whatsoever, and the fact that the Government may haveformulated, furnished, or in any way supplied the said drawings, specifications, or other data isnot to be regarded by implication or otherwise, as in any manner licensing the holder or any otherperson or corporation, or conveying any rights or permission to manufacture, use, or sell anypatented invention that may in any way be related thereto.

Please do not request copies of this report from the Air Force Research Laboratory. Additionalcopies may be purchased from:

National Technical Information Service5285 Port Royal RoadSpringfield, Virginia 22161

Federal Government agencies and their contractors registered with the Defense TechnicalInformation Center should direct requests for copies of this report to:

Defense Technical Information Service8725 John J. Kingman Rd., Ste 0944Ft. Belvoir, Virginia 22060-6218

DISCLAIMER

This Technical Report is published as received and has notbeen edited by the Technical Editing Staff of the Air Force Research Laboratory.

TECHNICAL REVIEW AND APPROVAL

AFRL-HE-WP-TR-2000-0049

This report has been reviewed by the Office of Public Affairs (PA) and is releasable to theNational Technical Information Service (NTIS). At NTIS, it will be available to the generalpublic, including foreign nations.

This technical report has been reviewed and is approved for publication.

FOR THE DIRECTOR

DAVID R. MATTIE, PH.DActing Branch Chief, Operational Toxicology BranchAir Force Research Laboratory

REPORT DOCUMENTATION PAGE Form ApprovedR DOMB No. 0704-0188

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources,gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of thiscollection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 JeffersonDavis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503.

1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED

I January 2000 Interim Report -- January 1999-January 20004. TITLE AND SUBTITLE 5. FUNDING NUMBERS

TPH Criteria Working Group Demonstration Field Sampling Report: Robins Air Contract: DAHA 90-06-D-0014Force Base, Warner-Robins, GA PE 62202F

PR 77576. AUTHOR(S) TA 7757A2

Teresa R. Sterner, Elaine A. Merrill, Erik K. Vermulen WU 7757A214

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

Operational Technologies Corporation REPORT NUMBER

1370 North Fairfield Road, Suite ADayton OH 45432

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORINGIMONITORING

Human Effectiveness Directorate AGENCY REPORT NUMBER

Air Force Research Laboratory AFRL-HE-WP-TR-2000-0049Air Force Materiel CommandWright-Patterson AFB, OH 45433-7400

11. SUPPLEMENTARY NOTES

12a. DISTRIBUTION AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE

Approved for public release; distribution is unlimited.

13. ABSTRACT (Maximum 200 words)

Underground storage tank Site 70, Robins Air Force Base, Georgia, is part of a large aircraft refueling/defueling hydrantsystem. Site 70 was impacted by JP-4 and JP-8 jet fuels through spill, overflows and leaks dating back many years. Thistotal pertoleum hydrocarbon (TPH) contamination has been identified and interim corrective action applied to remove freeproduct from above the shallow groundwater table. Using limited site data and the Total Petroleum Hydrocarbon CriteriaWorking Group (TPHCWG or Working Group) approach for evaluation of weathered fuel spills, a Tier 1 Risk-BasedCorrective Action (RBCA) analysis demonstration was performed. Soils from the site were analyzed using the DirectMethod recommended by the Working Group to characterize the fuel residuals present in terms of 13 total petroleumhydrocarbon (TPH) fractions. The TPH contamination present was composed predominantly of aliphatic equivalent carbon(EC) fractions > EC8 to EC16 with some > EC10 to EC16 aromatics. The lowest average risk-based screening level(RBSL) calculated for the current commercial use scenario was approximately 9000 mg/kg for the direct soil to skin contactpathway. For a futuristic residential scenario, the lowest average RBSL was about 3000 mg/kg for the contaminant leachingto groundwater pathway. This demonstration, however, does not represent a complete site assessment as only soilcontamination pathways were evaluated.

14. SUBJECT TERMS 15. NUMBER OF PAGES

TPHCWG Weathered Fuels Field Demonstration 68Hydrocarbon Fractions Jet Fuel Direct Method 16. PRICE CODE

Risk Based Screening Levels JP-4 Analytical Methods17. SECURITY CLASSIFICATION 18. SECURITY CLASSIFICATION 19. SECURITY CLASSIFICATION 20. LIMITATION OF ABSTRACI

OF REPORT OF THIS PAGE OF ABSTRACT

UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED ULStandard Form 298 (Rev. 2-89) (EG)Prescribed by ANSI Std. 239.18Designed using Perform Pro, WHS/DIOR, Oct 94

THIS PAGE INTENTIONALLY LEFT BLANK.

TABLE OF CONTENTS

1.0 INTRODUCTION ................................................................................................................. 11.1 Objectives ............................................................................................................................ 11.2 W orking Group Approach .................................................................................................... 11.3 Demonstration Site Description ....................................................................................... 2

1.3.1 Soils ...................................................................................................................... 31.3.2 Hydrology ....................................................................................................... 31.3.3 Previous Investigations ..................................................................................... 3

2.0 SAM PLING AND ANALYSIS ........................................................................................... 62.1 Soil Sam ple Collection .................................................................................................... 6

2.1.1 Hollow Core Auger Sam ples ............................................................................ 62.1.2 Hand Auger Sam ples ...................................................................................... 6

2.2 Analytical Approach .................................................................................................... 72.2.1 Direct Method .................................................................................................... 82.2.2 Q uality Control Analysis .................................................................................... 9

3.0 WORKING GROUP APPROACH FOR TIER 1 ASSESSMENTS .................................... 93.1 TPH Fractions Physical Properties ................................................................................. 113.2 Fate and Transport Fractions Toxicity Criteria .............................................................. 124.0 ANALYTICAL RESULTS ................................................................................................ 134.1 Direct Method Results .................................................................................................... 134.2 BTEX Results .................................................................................................................... 164.3 Quality Control Results ................................................................................................. 174.4 Analytical Sum mary ........................................................................................................... 175.0 RISK-BASED SCREENING LEVELS ............................................................................ 185.1 Com m ercial Scenario RBSLs ......................................................................................... 195.2 Residential Scenario RBSLs ......................................................................................... 205.3 Risk Discussion ................................................................................................................. 215.4 Com parison with Georgia Guidance .............................................................................. 226.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................ 227.0 REFERENCES .................................................................................................................. 23

APPENDIX A ANALYTICAL DATA .................................................................................. A-1APPENDIX B RBSL CALCULATIO NS .............................................................................. B-1APPENDIX C RBCA MODEL RUNS ................................................................................ C-1

iii

LIST OF FIGURES

Figure 1-1 Site 70, Robins AFB, Georgia ................................................................................... 5

Figure 2-1 W orking Group Demonstration Sam pling Locations, Site 70 .................................... 7

Figure 4-1 Fraction Profiles ........................................................................................................... 16

Figure 5-1 Exposure Pathway Analysis ......................................................................................... 18

iv

LIST OF TABLES

TABLE 1-1 WORKING GROUP AROMATIC AND ALIPHATIC FRACTIONS ........................... 2

TABLE 3-1 FATE AND TRANSPORT PROPERTIES OF TPH FRACTIONS ....................... 12

TABLE 3-2 WORKING GROUP FRACTION-SPECIFIC RfDs ............................................. 13

TABLE 4-1 DIRECT METHOD RESULTS - HOLLOW CORE AUGER SAMPLES .............. 14

TABLE 4-2 DIRECT METHOD RESULTS - HAND AUGER SAMPLES ................................ 15

TABLE 4-3 BTEX RESULTS AND COMPARISON WITH GDNR CLEANUP STANDARDS .... 17

TABLE 5-1 TIER 1 COMMERCIAL SOIL RBSLs AND HIs ................................................. 20

TABLE 5-2 TIER 1 RESIDENTIAL SOIL RBSLs AND His .................................................. 21

v

PREFACE

This effort was performed by Operational Technologies Corporation (OpTech) under ContractNumber DAHA 90-06-D-0014, Delivery Order TGO1. OpTech activities were conducted underthe Project Management of Dr. Peter Lurker, 1370 North Fairfield Road, Suite A, Beavercreek,Ohio 45432. Lt Col Steve Channel of the Air Force Research Laboratory, Human EffectivenessDirectorate, Operational Toxicology Branch (AFRL/HEST) at Wright-Patterson Air Force Base(AFB), Ohio, served as contract monitor.

The authors acknowledge Mr. Paul Barker and Mr. Kevin Long of Warner-Robins Air LogisticsCenter, Environmental Management Division, Warner-Robins, Georgia, for their assistance inpreliminary site demonstration efforts. The authors extend their greatest appreciation toDouglas Peters (Geophex Corporation, Warner-Robins, Georgia) for coordination of samplinglocations and sharing of hollow bore auger samples, and to Lt Marcia Kankelfritz (7 8th

Aerospace Medicine Squadron, Bioenvironmental Engineering Flight (78 AMDS/SGPB) atRobins AFB, Georgia) for collection and packaging of these samples. The authors would like toexpress special acknowledgements to Maj Wade Weisman of AFRL/HEST for collection ofhand auger samples and provision of contacts. The authors would also like to acknowledge DelShumacher and Dick Entz of Lancaster Laboratories, Lancaster, Pennsylvania, for analyticalresults.

vi

LIST OF ABBREVIATIONS AND ACRONYMS

78 AMDS/SGPB 78th Aerospace Medicine Squadron, Bioenvironmental Engineering FlightAFB Air Force BaseAFRL/HEST Air Force Research Laboratory, Operational Toxicology BranchASTM American Society for Testing and Materialsatm atmospherebgs below ground surfaceBTEX benzene, toluene, ethylbenzene and xylenecm3 cubic centimeterCsat saturation concentration (mg/kg)DRO diesel range organicsEC effective carbon number of chemical moleculeEPA U.S. Environmental Protection AgencyFID flame ionization detectorft feetg gramGDNR Georgia Department of Natural ResourcesGC gas chromatographGRO gasoline range organicsHAZWRAP Hazardous Waste Remedial Actions ProgramH,: Henry's Law Constant (cm 3/cm 3)HI hazard indexHQ hazard quotientkg kilogramKoc organic carbon sorption coefficient (cm3/cm3)k, soil-water sorption coefficient (cm3/g)L literLOQ limit of quantitationm3 cubic metermg milligrammm millimeterMS mass spectrometryNAPL non-aqueous phase liquidND nondetectOpTech Operational Technologies Corporation.PAH polycyclic aromatic hydrocarbonPF partition factors for soil to water and soil to vapor concentrations at equilibriumRBCA Risk Based Corrective ActionRBSL risk based screening level (mg/kg)RES residual saturation (mg/kg)RfD reference dose (mg/kg/day)SCAPS Site Characterization and Analysis Penetrometer SystemTPH total petroleum hydrocarbonsTPHCWG Total Petroleum Hydrocarbon Criteria Working GroupUST underground storage tank

vii

THIS PAGE INTENTIONALLY LEFT BLANK.

viii

TPH CRITERIA WORKING GROUPDEMONSTRATION FIELD SAMPLING REPORT:

ROBINS AIR FORCE BASE, WARNER-ROBINS, GA

1.0 INTRODUCTION

Site 70, a large aircraft refueling/defueling hydrant system, at Robins Air Force Base nearWarner-Robins, Georgia, was impacted by JP-4 and JP-8 jet fuels through fuel transfer spillsand underground leaks. A Tier 1 Risk-Based Corrective Action (RBCA) analysis wasconducted, using limited site data and the Total Petroleum Hydrocarbon Criteria Working Group(TPHCWG or Working Group) approach for evaluation of weathered fuel spills. Soils from thesite were analyzed using the Direct Method recommended by the Working Group tocharacterize the fuel residuals present in terms of 13 total petroleum hydrocarbon (TPH)fractions. The analysis results were then used in the simple fate and transport modelsrecommended by the RBCA guidance document (ASTM, 1995) for soil exposure pathways.

1.1 Objectives

This analysis is part of a series of field demonstrations of the effectiveness of the WorkingGroup approach. The goals of this demonstration are to:

"* Calculate human health protective risk-based screening levels (RBSLs) using the DirectMethod fractionation analysis results and a Tier 1 RBCA approach

"* Evaluate human health risk at Site 70 using the RBSLs"* Determine the variability in the RBSLs"* Compare RBSLs with State of Georgia cleanup criteria

1.2 Working Group Approach

The Working Group approach is incorporated into the American Society for Testing andMaterials (ASTM) RBCA framework. The RBCA framework integrates site assessmenttechniques with risk assessment practices recommended by the U.S. Environmental ProtectionAgency (EPA) (ASTM, 1995). Risk assessment elements, including source contaminantcharacterization, exposure pathway identification, existing and potential receptor identificationand exposure calculation, are incorporated into a tiered approach using increasingly site-specific parameters and data analysis. In Tier 1, conservative default assumptions and simplemodels are used. In later tiers (i.e., Tiers 2 and 3), site specific parameters and selectedmodels replace conservative assumptions and models. This increased specificity in later tiers ismore costly but the more site-specific RBSLs generated from higher tiers may result in lowercosts for cleanup without compromising human health. The RBCA user must decide if the costof the higher tier analysis is warranted by the potential reduction in cleanup costs. A tieredapproach is generally considered more cost-effective than traditional approaches, which requireuniform standards and analysis procedures.

1

The Working Group approach assesses human health non-cancer risks from petroleumhydrocarbons. Since TPH is composed of multiple types of hydrocarbons, the Working Groupapproach relies on the analytical separation of petroleum into 13 fractions (see Table 1-1). Thefractions are based on their aliphatic or aromatic nature and their equivalent carbon (EC)number, a function of boiling point. Fractions are analyzed by retention time on a gaschromatograph (GC) relative to n-alkanes with specified carbon numbers. The fractions havebeen assigned toxicological and transport parameters which resulted from extensive reviews ofdata from individual compounds in the fraction or from petroleum mixtures represented withinthe fraction. Volumes 3 and 4 of the Working Group publications explain this rationale fortransport and toxicity, respectively (TPHCWG, 1998a and 1998b).

TABLE 1-1 WORKING GROUP AROMATIC AND ALIPHATIC FRACTIONS

Aromatic Fraction Aliphatic Fraction

EC5-EC7 (Benzene)* EC5-EC6

>EC7-EC8 (Toluene) >EC6-EC8

>EC8-EC10 >EC8-EC10

>EC10-EC12 >EC1O-EC12

>EC12-EC16 >EC12-EC16

>EC16-EC21 >EC16-EC21

>EC21-EC35

Notes: * Evaluated only as a carcinogen.EC - equivalent carbon fractions are determined by the retention time on aGC column, relative to alkane compounds of known carbon number(TPHCWG, 1998a)

The Working Group fractionation data results, fraction toxicity information and transportparameters can be used to perform a risk-based analysis for each fraction present at the sitebeing evaluated. The hypothetical risk and the resulting soil screening level (i.e., the RBSL) forthe "whole TPH" mixture are calculated by combining the non-cancer risks from individualfractions weighted by their percent composition within the TPH mixture.

1.3 Demonstration Site Description

Robins Air Force Base (AFB) lies in central Georgia south of Macon and immediately east ofthe city of Warner-Robins. The base is home to the Warner-Robins Air Logistics Center, AirForce Material Command and several tenant air groups (HAZWRAP, 1996).

Underground storage tank (UST) Site 70 is located in the northeastern portion of Robins AFB.It serves as a large aircraft refueling/defueling hydrant system providing ground support to the19th Air Refueling Group and the 93rd Air Control Wing. The aircraft refueling/defuelinghydrant system at Site 70 consists of a small storage building. (Building 28) and apumphouse/control room (Building 2070). Six 50,000 gallon steel USTs contain jet fuel, a 2,000

2

gallon steel UST contains waste fuel and a 400 gallon UST contains water. Approximately5200 feet of 4- to 6-inch diameter steel lines supply six hydrants located on the adjacentparking apron (HAZWRAP, 1996).

Site 70 was contaminated from a combination of various JP-4 and JP-8 spills, overfills andleaks that date back many years. The USTs and associated lines were originally installed in1958. The tanks were used for storage of JP-4 jet fuel until June 1994 and JP-8 since. A leakwas documented in 1995 at lateral control pit #3. Soil contamination and free product werefound relatively near this lateral control pit, suggesting that it may represent a significant sourceof contamination. Free product has also been found up to 150 feet away from the tankfield,including several areas near the valve junction boxes just off the east end of the concretetarmac. These junction boxes may also have been significant sources over time.Environmental staff report that various fuel spills and overfills have occurred on the tarmac.These spills were washed over the edge of the concrete tarmac and may have contributedsignificantly to the contamination (HAZWRAP, 1996).

1.3.1 Soils

Much of Robins AFB lies within the Ocmulgee River Valley, characterized by gently slopingterraces and swampy floodplains. The floodplain and terrace system extends one to threemiles in width. Total relief within one mile of Site 70 is less than 20 ft. UST Site 70 is situatedon fill material and alluvial sediments which are recent floodplain deposits of the OcmulgeeRiver and include sand, clay and peat rure 1) (HAZWRAP, 1996).

1.3.2 Hydrology

Site 70 overlies the Cretaceous-age upper Providence sediment layer. The groundwater tableat Site 70 ranges from 6 to 9 feet deep and discharges to the floodplain east of the site. Thefloodplain that lies about 800 feet to the east is a critical wetland environment (hardwoodswampland) which may be impacted by contaminated discharge. The Ocmulgee River isapproximately 1300 feet downgradient (i.e., southeast). Site 70 lies within one of Georgia'smost significant groundwater recharge zones (HAZWRAP, 1996).

Under the sediment layer lies the Cusetta clay aquitard. The Blufftown Aquifer below is used asa regional drinking water source. Base well WS-8, the closest supply well, lies about 1600 feetnorthwest (i.e., up-gradient) from Site 70. There are no other public or private wells within threemiles down-gradient (HAZWRAP, 1996).

1.3.3 Previous Investigations

Vapor monitoring wells were installed in the tankfield of UST Site 70 during a base-wide USTenvironmental upgrade program in 1992 and 1993. The wells are approximately 12 feet deepand extend into the shallow groundwater at the site. Free product was detected in most of thevapor monitoring wells in September 1993. Initial remedial actions at the vapor monitoring wellsincluded manual bailing of free product and cleanup with petroleum-adsorbent pads, removingapproximately 16 gallons of free product. In October 1993, electrical contractors encounteredfree product on groundwater while excavating a pit for new underground lines. The excavation

3

was approximately 35 to 40 feet south-southwest of the tankfield at UST Site 70. Remedialactions included removal of approximately 20 gallons of liquid hydrocarbons using a vacuumwaste pumping truck (HAZWRAP, 1996).

In response to the detection of free product, an Initial Site Characterization in the area of Site70 was undertaken in late 1993. Following completion of the initial site characterization, the AirForce conducted a UST contamination assessment. Monitoring wells were installed near USTSite 70 during January 1994. Free product was removed from the monitoring wells usingmanual and skimmer techniques. In March 1994, a DPI Petro-belt hydrocarbon-only beltskimmer was.installed on monitoring well EA-2 to recover free product. Nearly 2,000 gallons ofliquid hydrocarbons were collected through July 1995 (HAZWRAP, 1996).

Assessment activities were continued with additional monitoring wells installed in August 1994.Analytical results indicated a large residual petroleum hydrocarbon pool surrounding thetankfield at Site 70 and a large dissolved phase petroleum hydrocarbon plume extendingdowngradient east and southeast of the site (HAZWRAP, 1996).

These findings were supported in February 1995 with the demonstration of the SiteCharacterization and Analysis Penetrometer System (SCAPS) at Site 70 by the U.S. ArmyCorps of Engineers. The SCAPS system uses a laser induced fluorescence tool to indicatefree product and/or residual contamination thickness and depth. The demonstration was limitedto an area around the EA-2 monitoring well. The results showed a 2.5 ft interval from 6 to 8.5 ftbelow ground surface (bgs) of elevated hydrocarbon fluorescence, which correlated well withthe maximum free product thickness measured in the nearby monitoring well (HAZWRAP,1996).

In July 1995, Batelle performed a short-term field pilot test of the Bioslurper system at Site 70.In 1996, the Batelle Bioslurper began running full time at monitoring well EA-2. Approximately3,400 gallons of free product were recovered. The Bioslurper was removed in October 1997when the free product layer had been removed in the vicinity of monitoring well EA-2(HAZWRAP, 1997).

In October 1996, the Department of Energy's Hazardous Waste Remedial Action Program(HAZWRAP) investigated soils and groundwater upgradient and to the east of the knownsource using the Geoprobe direct push system or hand augers. The investigation includedcontaminant transport in groundwater and natural attenuation modeling for the site (HAZWRAP,1997).

4

%VV~LI)

.... .....-

Figure 1 -1 Site 70, Robins AFB, Georgia**Adapted from HAZWRAP, 1996

5

2.0 SAMPLING AND ANALYSIS

2.1 Soil Sample Collection

Samples collected for moisture content, fractionation and BTEX (benzene, toluene,ethylbenzene and xylene) analyses were packed into glass jars with minimal head space.Samples were stored on ice and shipped the same day to Lancaster Laboratory, Lancaster,Pennsylvania, via an overnight express service.

2.1.1 Hollow Core Auger Samples

Hollow core auger soil samples were taken on two occasions, 19 January and 4 February 1999.These samples were collected by Geophex Corporation and split with OpTech for the purposeof this demonstration. The soil was packaged and shipped to the laboratory by Lt MarciaKankelfritz of the 7 8th Aerospace Medicine Squadron, Bioenvironmental Engineering Flight (78AMDS/SGPB) located at Robins AFB.

Samples were taken from two separate borings at depths ranging from 2 to 13 feet bgs. Soilfrom each sampling interval was composited; a sample taken from the composite wassubmitted to the laboratory for moisture content and fractionation analyses only. BTEXanalyses were not run.

Soil sampling locations were chosen based on the Geophex sampling plan. The main intentgoverning sampling location was to determine and characterize the extent of contamination andthe edge of the plume (Peters, 1998, personal communication). The sampling performed on 4February was located immediately adjacent to monitoring well EA-2. Sample GX-4 is locatedover 100 feet west of EA-2. Sampling locations are presented in Figure 2-1.

2.1.2 Hand Auger Samples

Hand auger samples were taken on 12 February 1999. Samples were taken from two separateborings at depths ranging from three to six feet bgs. Sampling sites were chosen tocharacterize soil contamination 8 feet east and 12 feet southeast (down-gradient) from a knownhot spot, monitoring well EA-2. Soil from each foot-long sampling interval was composited in anew plastic bag. A photo-ionization detector, appearance (i.e., staining) and smell were used tohelp determine the presence of petroleum in the composited sample. Only positive sampleswere submitted for analysis. Three samples were submitted per positive composite; moisturecontent, fractionation and BTEX analyses were all performed.

6

UXWJ(NA TAX"I4y

EA2 01 "M I ,,,

I ' !~

GX-4 • u I .

NORTH RKN

(concrete)

Figure 2-1 Working Group Demonstration Sampling Locations, Site 70**Adapted from HAZWRAP, 1996

2.2 Analytical Approach

TPH in environmental matrices may be measured by several analytical techniques. TPHanalytical methods currently in use for quantification of hydrocarbons in soils and water arediscussed in Volume 1 of the Working Group's publications (TPHCWG, 1 998c). Methodsidentified by product type, like diesel range organics (DRO) and gasoline-range organics (GRO)analyses, indicate the approximate carbon range for the method. For example, GRO uses agasoline standard and quantifies over an effective hydrocarbon range of EC6 through EC10 or12. However, presence of GRO hydrocarbons in a sample does not indicate that gasoline isactually present. The GRO method can be used to quantify the lighter hydrocarbons present inenvironmental samples contaminated with other products such as mixed napthas, Stoddardsolvent or light mineral spirits. JP-4 and JP-8 fuels are comprised of hydrocarbons both in theGRO and DRO effective carbon ranges (EC6 to EC12 and EC12 to EC24, respectively). UsingGRO and DRO to characterize a jet fuel spill may result in overestimation of hydrocarbonconcentrations.

7

Analytical techniques vary in how much TPH is measured. Methods using more rigorousextraction techniques and more efficient solvents will remove more TPH from soils. Infraredtechniques (e.g., EPA Method 418.1) can measure naturally occurring organics in topsoil orother carbon-rich soils (TPHCWG, 1998a). Such interference can result in TPH concentrationshigher than what is attributable to the petroleum contamination.

Conventional TPH analyses do not correlate well with site human health risk. Two sites with thesame TPH value may have completely different risks. At one site, the TPH may be composedalmost entirely of carcinogens while the other site may have very low concentrations ofcarcinogens. Cleanup criteria based on TPH values, therefore, do not relate directly to healthrisk. Many conventional TPH-method based criteria were set based on aesthetics, analyticaldetection or reporting limits, or other non-risk-based values. Frequently these criteria arecoupled with analyses of carcinogenic indicator compounds (e.g., benzene). The use of non-risk-based criteria can result in higher cleanup costs without human health benefit. At somesites, however, human health risk is not the driving factor. Ecological risk, aesthetics or otherfactors may drive the cleanup values at these sites.

Quantification of TPH in soils from Site 70 was performed using both a conventional TPHmethod and the Direct Method for comparison. The Direct Method was developed by theWorking Group for use within a risk-based framework for determining cleanup levels. Itquantifies TPH in terms of the 13 aliphatic and aromatic fractions, as seen in Table 1-1.

2.2.1 Direct Method

The Direct Method first employs a single analysis for the entire EC6 to EC28 range. n-Pentaneis used to extract the sample. It is then analyzed with a GC/FID (flame ionization detector) todirectly obtain the "whole" TPH measurement. This preliminary analysis can be used to"fingerprint" the contaminant (s) (i.e., determine the nature of the hydrocarbons present).

Aliphatics and aromatics must be separated prior to the fractionation analysis of the n-pentaneextract. Either alumina (modified EPA Method 3611 B) or silica gel (modified EPA Method3630B or C) may be used for the separation into saturates, polars and aromatics. Althoughsimilar to these EPA Methods, the Direct Method uses a smaller column to minimize dilution; n-pentane is used not only for extraction but also for elution of the aliphatics. Use of n-pentaneinstead of n-hexane allows the detection of TPH starting at EC6 and includes quantification ofn-hexane. Aromatics are eluted from silica gel by methylene chloride and from alumina bymethylene chloride with acetone. Total aromatics and aliphatics can then be reportedseparately.

Aliphatic and aromatic extracts may be fractionated by GC/FID. If light-end constituents smallerthan EC9 are measured in the direct sample, GC/MS (mass spectrometry) is also used. TheDirect Method is a tiered analytical approach in that the entire process does not have to befollowed and that useful analytical data result from each step in the process.

Direct Method analysis is not necessary for all soil samples collected at a site. The DirectMethod should be used to characterize the contamination present. If the "fingerprint" isconsistent across the site, less expensive conventional analytical methods may be used duringadditional sampling to determine the extent of contamination. Depending on state specific

8

requirements, additional EPA analytical methods may be necessary to characterize indicatorcompounds (e.g., polycyclic aromatic hydrocarbons) or carcinogenic risk.

2.2.2 Quality Control Analysis

Trip blanks, method blanks, lab controls and matrix spikes were analyzed for each round(occasion) of sampling. All samples were analyzed at Lancaster Laboratories located inLancaster, Pennsylvania.

3.0 WORKING GROUP APPROACH FOR TIER 1 ASSESSMENTS

The Working Group approach RBSLs protect for human health non-cancer risks. Ifcarcinogens are detected, carcinogenic risk must be evaluated separately, using EPA riskvalues and methodology (TPHCWG, 1998a). At Site 70, BTEX analyses were run only on thehand auger samples. Benzene concentrations were found at one of the two hand augerborings. Specific tests for carcinogenic polycyclic aromatic hydrocarbons (PAHs, e.g.,benzo(a)pyrene) were not performed at this time and were not reported in previousinvestigations (i.e., HAZWRAP, 1996 and 1997). Since benzene was detected, carcinogenicassessment should be evaluated. The present project is being conducted as a demonstrationof the Working Group approach to non-carcinogenic risks from TPH contaminated soils. Itshould be noted, however, that the remedial actions at Site 70 would likely be driven by thestate of Georgia's benzene cleanup level of 0.008 mg/kg (GDNR, 1996).

RBSLs are calculated for each exposure pathway using the TPH fractionation results and theWorking Group approach. Beyond the scope of the RBCA guidance (ASTM, 1995), theWorking Group approach incorporates the chemical saturation concentration (Csat), the residualsaturation (RES) and the additivity of risks across the fractions. Treating TPH as an additivemixture instead of a single compound allows toxicological and fate and transport interactionsbetween the fractions to be considered.

Noncarcinogenic risk for each fraction is the hazard quotient (HQ). The HQ is the ratio of theestimated daily intake of a contaminant in a given medium (e.g., soil) to the reference dose(RfD) (see Equation 1). All equations in Section 3.0 were adapted from Volume 5 of theWorking Group's publications (TPHCWG, 1999).

HQ = IntakeRate( lkg-day) (Equation 1)RfD(m-gl -dy)mkg

The intake rate depends upon the frequency and duration of exposure, the sourceconcentration and the transport rates between the source and the receptor for cross-mediapathways. Additivity is incorporated into the calculation of "whole TPH" hazard index (HI) andRBSL. Total risk is apportioned over the different fractions present. Rather than each fractionassuming risk equal to a HI, each fraction is allotted a portion of the risk, with the sum of theHQs from each fraction equal to the HI for the mixture as depicted in Equation 2. If the HI isless than or equal to 1, then the "whole TPH" does not represent an excess health hazard.

9

HI=n HQ iCTPH (Equation 2)

i=1 RBSLi

where:HI = Hazard Index [unitless]n = Number of fractions (1 3 total)HQj = Hazard Quotient for ith specific fraction [unitless]fi = Percent Weight of ith TPH fraction in "whole TPH" mixture [unitless]CTPH = TPH concentration in soil [mg/kg]RBSLi = Tier 1 risk-based screening level for a TPH fraction [mg/kg]

The assumption of additivity for calculating a "whole TPH" RBSL is conservative. Thetoxicological information for the fractions indicates that these fractions impact different organs(TPHCWG, 1998b). Typically, additivity of individual HQs is only applied to constituents orconstituent classes that impact the same organ.

Transport and exposure for cross-media pathways are maximized at the saturationconcentration. For cross media pathways where specific fractions are at saturationconcentration, the following equations are solved:

i~~n(ficT C.1-HI= .'IMin ,i < 1 given, (Equation 3)

'~RBSL~ 'RBSLL

i=13

Ci (Equation 4)i=1 CTPH

where:CTPH = TPH Concentration [mg/kg]Csat.i = Saturation concentration for ith TPH fraction [mg/kg]C, = Concentration of the ith TPH fraction (mg/kg)

Csat is the upper exposure limit for cross media pathways. It represents the chemicalconcentration in soil at which the sorption limit of the soil particles, the solubility limit of the soilpore water and the saturation limit of the soil pore air have been reached. A concentrationabove the Csat does not automatically indicate the presence of mobile, free-phase chemicals.Actual mobility of a non-aqueous phase liquid (NAPL) depends on the contaminant and soilproperties, including various capillary, gravitational, hydrodynamic and surface tension forces.However, at soil concentrations greater than Csat, the likelihood of free phase NAPL should beconsidered. Once free product transfers, the assumptions of the Working Group approach areno longer valid and multi-phase transport should be considered. Csat is defined by Equation 5.

10

Cst, [mg /kg] = SI [_jO , + 0,, + k,,,p,] (Equation 5)PS

where:Si = Water Solubility for ith TPH fraction [mg/L]

Ps = Soil Bulk Density [g/cm3 ]H0. = Henry's Law Constant for ith TPH fraction [cm 3/cm 3]0 as = Volumetric air content of the soil [cm3/cm3 ]w = Volumetric water content of the soil [cm 3/cm 3]

ks = Soil-water sorption coefficient for ith TPH fraction (k. = c* f) [cm 3/g]

The Csat limit does not apply to direct exposure pathways, such as the surface soil contactpathway. The direct exposure is to the original impacted media (e.g., contaminated soil) ratherthan to the cross media, to which the contamination has been transferred.

Residual saturation should not be confused with C,,t. A value of RES may be reached whencalculating a "whole TPH" RBSL. RES means that the selected risk level (e.g., HI = 1) couldnot be reached or exceeded for the pathway and scenario given the constituents present,regardless of the contaminant concentration. RES can only be obtained at the TPHconcentration where the Csat of the TPH mixture is reached (i.e., each fraction has reachedCsat). This means that even if the concentration of each fraction is set equal to Csat for thatpathway, the combined risk of each fraction still does not equal a HI of "1".

3.1 TPH Fractions Physical Properties

The 13 Working Group fractions were selected based on order of magnitude differences inpartitioning properties (TPHCWG, 1998a). These properties are used in the simple fate andtransport models for RBCA analysis (ASTM, 1995). These models evaluate the partitioning andmigration of the TPH fractions for the different applicable pathways. Using fraction propertiesallows a more accurate estimation of exposure to the complex mixture than can be modeledfrom single TPH measurements.

Chemical properties govern how a chemical interacts with its environment. These propertiesinclude solubility, vapor pressure, sorption coefficient and Henry's Law Constant. In general,for chemicals of the same equivalent carbon number, the solubility of aromatic hydrocarbons isgreater than that of aliphatic hydrocarbons. This is especially noticeable at high EC values.The variability in solubility at any given EC is about an order of magnitude. Aromatichydrocarbons are more likely to be present as dissolved constituents in groundwater than arethe corresponding aliphatic hydrocarbons. There is very little difference in vapor pressurebetween aliphatic and aromatic constituents of an equivalent EC. In effect, the EC and vaporpressure are closely related (TPHCWG, 1998a).

The soil-water sorption coefficient (k,) represents the tendency of a chemical to be adsorbedonto a soil particle. Aliphatic fractions are more likely to remain bound to a soil particle than thearomatic fractions of an equivalent EC. As stated above, aliphatics exhibit lower solubility(TPHCWG, 1998a).

11

Henry's Law Constant (He) is the ratio of a compound's concentration in air to its concentrationin water, when at equilibrium (TPHCWG, 1998a). Although aliphatic hydrocarbons tend to beless soluble and more volatile than aromatic hydrocarbons, benzene is a very volatile aromaticand is more toxic than the corresponding aliphatic fraction. Therefore, when present, benzeneis likely to drive risk calculations for pathways involving volatilization from soil or groundwater.

The physical properties used to determine partitioning factors for the 13 TPH fractions are listedin Table 3-1. The equations used to develop these fate and transport properties are found inVolume 3 of the Working Group Publications (TPHCWG, 1998a).

TABLE 3-1 FATE AND TRANSPORT PROPERTIES OF TPH FRACTIONS 1

Solubility Henry's Molecular Vapor log Koc2 PF3 PF 3

(mg/L) Constant Weight Pressure (cm 3/cm 3) (soil/ (soil/(g/mole) (atm) water) vapor)

AliphaticsEC5-EC6 3.6E+01 3.4E+01 8.1E+02 3.5E-01 2.9E+00 IE+01 3E-01

>EC6-EC8 5.4E+00 5.1E+01 1.0+02 6.3E-02 3.6E+00 4E+01 9E-01>EC8-EC10 4.3E-01 8.2E+01 1.3E+02 6.3E-03 4.5E+00 3E+02 6E+00>EC10-EC12 3.4E-02 1.3E+02 1.6E+02 6.3E-04 5.4E+00 3E+03 5E+01>EC12-EC16 7.6E-04 5.4E+02 2.OE+02 4.8E-05 6.7+EQO 7E+04 1E+03>EC16-EC35 1.3E-06 6.4E+03 2.7E+02 7.6E-06 9.OE+00 1E+07 1E+05

AromaticsEC6-EC6 1.8E+03 2.3E-01 7.8E+01 1.3E-01 1.9E+00 9E-01 4E+00

>EC6-EC8 5.2E+02 2.7E-01 9.2E+01 3.8E-02 2.4E+00 2E+00 9E+00>EC8-EC10 6.5E+01 4.9E-01 1.2E+02 6.3E-03 3.2E+00 2E+01 5E+01

>EC10-EC12 2.5E+01 1.4E-01 1.3E+02 6.3E-04 3.4E+00 2E+01 2E+02>EC12-EC16 5.8E+00 5.4E-02 1.5E+02 4.8E-05 3.7E+00 5E+01 2E+03>EC16-EC21 5.1E-01 1.3E-02 1.9E+02 7.6E-06 4.2E+00 1E+02 4E+04>EC21-EC35 6.6E-03 6.8E-04 2.4E+02 4.4E-09 5.1E+00 1E+03 3E+07

Notes: Table extracted in part from Volume 3 of Working Group Publications (TPHCWG, 1998a).SProperties based on an equivalent carbon number. Values are for pure compounds. Behaviormay differ in complex mixtures.2 Kc - organic carbon sorption coefficient3 PF - partition factors for soil to water and soil to vapor concentrations at equilibrium

3.2 Fate and Transport Fractions Toxicity Criteria

The Working Group approach focuses mainly on non-carcinogenic impacts to human health.Carcinogenic impacts are evaluated separately if carcinogenic indicators are found duringsampling. Some of the indicator compounds used to assess carcinogenic risk include benzeneand the carcinogenic PAHs such as benzo(a)pyrene. Carcinogenic risks often drive cleanupeven in relatively low concentrations. The majority of constituents in TPH are noncarcinogenic(TPHCWG, 1998b).

12

Reference doses are developed for non-carcinogenic compounds. RfDs are estimates of dailyexposure to the human population, including sensitive subgroups, which are likely to be withoutappreciable risk of deleterious effects during a lifetime. In the Working Group approach, thesame toxicity criterion is assigned to more than one fate and transport fraction due to thesimilarity of toxicity findings across these fractions or limitations in the available toxicity data(see Table 3-2). Fractions are still assessed separately, allowing the exposure potential ofeach fraction to be estimated appropriately.

TABLE 3-2 WORKING GROUP FRACTION-SPECIFIC RfDs

Effective Carbon Aromatic RfD Critical Effect Aliphatic RfD Critical EffectRange (mg/kg/day) (mg/kg/day)

Aromatic 0.20 - Oral Hepatotoxicity, 5.0 - Oral Neurotoxicity>EC6-EC8 0.10 - Inhalation Nephrotoxicity 5.0 - InhalationAliphaticEC5-EC6

>EC6-EC8

>EC8-EC10 0.04 - Oral Decreased body 0.1 - Oral Hepatic and>ECIO-EC12 0.05- Inhalation weight 0.3 - Inhalation hematological>EC12-EC16 changes

>EC16-EC21 0.03 - Oral Decreased body 2.00 - Oral Hepatic granuloma>EC21-EC35 weight (foreign body reaction)

Adapted from TPHCWG, 1998b.

Aromatic fractions generally have lower RfDs than aliphatic fractions and are approximately anorder of magnitude more toxic than the corresponding aliphatic fraction. RfDs are based onchronic effects, including hepatotoxicity (liver toxicity), nephrotoxicity (kidney toxicity) anddecreased body weight.

The Working Group approach is most appropriate for use at sites where carcinogenic indicatorcompounds are not present or are present below regulatory action levels. Information on thedevelopment of TPH fraction RfDs is provided in Volume 4 of the Working Group Publications(TPHCWG, 1998b).

4.0 ANALYTICAL RESULTS

4.1 Direct Method Results

The aliphatic and aromatic fraction distributions from UST Site 70 soils are displayed in Tables4-1 and 4-2. Total TPH concentrations ranged from nondetect (ND) to 16300 mg/kg. Of theten samples analyzed, only five (EA-2-4, EA-2-7, E-8-4, SE-12-5 and SE-1 2-6) resulted indetectable hydrocarbon levels across the fractions. Two additional samples, GX-4-13 and E-8-

13

3, showed hits in one or two fractions; these hits are not indicative of a fuel fingerprint and mayrepresent organic carbon content.

TABLE 4-1 DIRECT METHOD RESULTS - HOLLOW CORE AUGER SAMPLES1

LOCATION GX-4 GX-4 GX-4 EA-2 EA-2 EA-2DEPTH (ft) 3 7.5 13 2 4 7Laboratory ID: 3074868 3074869 3074870 3086915 3086916 3086917AliphaticsEC5-EC6 <0.252 <0.24 <0.23 <0.24 <45 433.2>EC6-EC8 <0.25 <0.24 <0.23 <0.24 160 825.8>EC8-EC10 <10 <10 <9 <9 1078.4 4269.3>EC10-EC12 <10 <10 <9 <9 1495.8 4236.7>EC12-EC16 <25 <24 <23 <24 1128 2883>EC16-EC21 <25 <24 <23 <24 27 <452>EC21-EC35 <64 <60 1423 <59 <57 <1130AromaticsEC5-EC6 (benzene only) <0.006 <0.006 <0.006 <0.006 <1.1 11.4>EC6-EC8 (toluene only) <0.006 <0.006 <0.006 <0.006 2.0 <5.6>EC8-EC10 <10 <10 <9 <9 137.2 455.5>EC1O-EC12 <10 <10 <9 <9 352.5 992.9>EC12-EC16 <25 <24 <23 <24 340 864>EC16-EC21 <25 <24 <23 <24 <23 24>EC21-EC35 <64 <60 165 <59 <57 <56Total Aliphatics 4 <127 <120 154 <118 3915 12781Total Aromatics <127 <120 173 <118 846 2350Total "TPH" ND ND 327 ND 4761 15131Notes: 1 Units: mg/kg dry weight

2 < -Value is less than limit of quantitation (LOQ) value presented.3 Bolded values indicate detected quantities.4 Totals do not reflect the arithmetic sum of the detected fraction values because NDs are notnecessarily zeros and contribute to the total area under the chromatogram curve.

14

TABLE 4-2 DIRECT METHOD RESULTS - HAND AUGER SAMPLES1

LOCATION E-8 E-8 SE-12 SE-12DEPTH (ft) 3 4 5 6Laboratory ID: 3092072 3092069 3092070 3092071AliphaticsEC5-EC6 <0.242 <0.24 <45 84>EC6-EC8 0.603 52 127 313>EC8-EC10 <10 146.7 1697 3870>EC10-EC12 <10 245.2 1923 4501>EC12-EC16 <24 194 1260 3290>EC16-EC21 <24 <24 <227 <449>EC21-EC35 <60 <59 <568 <1124AromaticsEC5-EC6 (benzene only) <0.006 <0.6 1.92 2.54>EC6-EC8 (toluene only) <0.006 <0.6 1.71 1.55>EC8-EC10 <10 16.2 127.9 773>EC10-EC12 <10 61.9 293.7 1657>EC12-EC16 <24 73 287 1586>EC16-EC21 <24 <24 <23 <225>EC21-EC35 <60 <59 <57 <562Total Aliphatics 4 <120 660 5110 12207Total Aromatics <120 161 726 4093Total "TPH" ND 821 5836 16300

Notes: 1 Units: mg/kg dry weight2 < - Value is less than LOQ value presented.3 Bolded values indicate detected quantities.4 Totals do not reflect the arithmetic sum of the detected fraction values because NDs are notnecessarily zeros and contribute to the total area under the chromatogram curve.

The Direct Method quantitation limits are variable variable for the samples in thisdemonstration. Reporting limits tend to be lower for this method if most of the petroleumhydrocarbons represented in a given fraction are from fewer GC peaks (i.e. fewer constituents)(Tuomi et aL, 1999). This method is still under development and refinements of limits ofquantitation (LOQs) are expected.

The fraction profiles of samples resulting in detectable hydrocarbon levels across the fractionsare depicted in Figure 4-1. The similarity of the profiles between samples indicates that thesame fuel exists across the sampled portion of this site and that the same types and extent ofweathering of the fuel has occurred. The TPH present is comprised mostly of >EC8 to EC1 6aliphatics and >EC10 to EC16 aromatics. More specifically, >EC8 to EC10 aliphatichydrocarbons make up 19 to 30% of all hydrocarbons, the >EC10 to EC12 aliphatic rangemakes up 28 to 34% and the >EC12 to EC16 aliphatic range contributes 19 to 25%. Aromaticscontribute smaller overall percentages; the >EC10 to EC12 and the >EC12 to EC16 aromaticranges make up only 5 to 10% each. The highest aliphatic percentage (34% >EC10 to EC12)and subsequently lowest aromatic percentages (about 5% each >EC10 to EC12 and >EC12 toEC1 6). were found in the SE-12, 5 ft bgs sample; this pattern, although similar to the othersamples, may be more typical of a fresher jet fuel profile.

15

35

30

0 EA-2, 4ftM EA-2, 7 ft

"0 15" EOE-8,4 ft

M SE-12, 5ftS10-"O• SE-12, 6ft

0~M LU U

A - N co E N U LUA w. 0 w -A L ,, W < "-.-- C '

A A A (D Co W .J 'Fraction Profiles W , A W UW WALU Lu

A

Figure 4-1 Fraction Profiles

4.2 BTEX Results

Results of the BTEX analysis performed on the hand auger samples are found in Table 4-3.These results are compared with Georgia Cleanup Standards for Hydrocarbon ContaminatedSoil. Site 70 lies within an area defined by the Georgia Department of Natural Resources(GDNR) as a "zone of higher contamination susceptibility" and also within "one of Georgia'smost significant groundwater recharge zones" (HAZWRAP, 1996). The standards reportedbelow pertain to an area within 2.0 or 0.5 miles of public or non-public water supplies,respectively, with no water supply withdrawal point located within 500 ft of the contaminated site(GDNR, 1996). At Site 70, the closest well is 1600 ft upgradient, the Ocmulgee River is 1300 ftdowngradient and the Ocmulgee floodplain/recharge zone is 800 ft downgradient (HAZWRAP,1996).

16

TABLE 4-3 BTEX RESULTS AND COMPARISON WITH GDNR CLEANUP STANDARDS 1

Location, Depth2 Laboratory ID Benzene Toluene Ethylbenzene Total XylenesE-8, 3 ft 3092072 <0.006' <0.006 0.042 <0.24E-8, 4 ft 3092069 <0.59 <0.59 3.7 39

SE-12, 5 ft 3092070 1.8 1.6 7.7 110SE-12, 6 ft 3092071 2.5 1.5 15 <170

GDNR CleanupStandards 4 0.008 6.0 10 700

Note: ' Units = mg/kg dry weight (EPA Method SW-846 8021A)2 BTEX results not available for hollow core auger samples; Direct Method was performed onthese samples alone.3 < - Value is less than LOQ value presented.4 GDNR Cleanup Standards for Hydrocarbon Contaminated Soil

Benzene and toluene were detected in both samples from the location SE-12; benzene levelsexceeded GDNR cleanup standards. Xylenes were found in the 4 ft sample from E-8 and the 5ft sample from SE-12; none of these values exceeded GDNR standards. Ethylbenzene wasdetected in all four soil samples; only the 6 ft sample from SE-12 exceeded ethylbenzenecleanup values. The reported LOQ value for benzene in the E-8, 4 ft sample exceeded GDNRcleanup standards. Lancaster Laboratories frequently documented interference from thesample matrix, resulting in an increased LOQ, and poor surrogate recovery due to dilutionnecessary to perform analyses.

4.3 Quality Control Results

Trip blanks, method blanks, lab controls and matrix spikes were analyzed for each round ofsampling. Values were not outside of quality control limits. Matrix spike analysis results areprovided in Appendix A.

4.4 Analytical Summary

Total TPH contamination, as measured by the Direct Method, increased with depth at eachsampling location. The highest concentrations were found directly downgradient (SE-12) of theformer hotspot, monitoring well EA-2. Additionally, samples at SE-12 exhibited marginallyhigher percentages of aliphatics, a profile likely more similar to fresh jet fuels. The lowestconcentrations were from sampling point GX-4, which was located over 100 feet west (across-and upgradient) from EA-2. The lack of hydrocarbons in the shallow samples indicates thatcontamination at these points was from the free product plume that had been distributed on topof the groundwater. During periods of increased rainfall, the hydrocarbons would have beenforced up into the shallower soil by higher groundwater tables. Subsequently, somehydrocarbons would have remained in the soil well above the water table after the groundwaterhad receded to normal levels.

17

5.0 RISK-BASED SCREENING LEVELS

The RBCA analysis using the Working Group approach was based on a site conceptual modelof soil contamination with hydrocarbons leaching from the soil to the groundwater and withcontaminants volatilizing to indoor and outdoor air. Exposure pathways evaluated include directsoil contact, contaminants leaching from the soil to the groundwater and ingestion of thegroundwater, volatilization of contaminants from subsurface soils to outdoor air andvolatilization of contaminants from subsurface soils to indoor air (see Figure 5-1).

PRIMARY SECONDARY TRANSPORT EXPOSURE POTENTIAL* SOURCES SOURCES MECHANISMS PATHWAY RECEPTORS

Affected Soil . .... Exposed Reptors" Product Surface Soils Dermal Contact/ On- 0 Residential

Storage (_3 ft depth)0 Wind In etion 5ite: N Non-Resid.• Erosion And

" Pipin" Atmospheric Off- U ResidentialDistribution Dispersion Site: 0 Non-Resid.

"* Operations UVolatilizationO Affected L and Exposed Persons

Q Waste Subsurface Atmospheric a Air On- N ResidentialManagement Soils Dispersion Inhalation of Site: N Non-Resid.

Unit (> 3 ft depth) Vapor or Dusta Volatilization Off- OResidential

o3 Other: and Enclosed- Site: 0 Non-Resid0 i••la . Sbace

Groundwater Accumulation

Plume] Groundwater UsersN Leachinz O On- E Residential

and Potable Site: * Non-Resid.Groundwater Wtr(•

Off- CaResidentialSite: 0 Non-Resid.

Liaui Plum • Fee-LiauidMiration Surface Water Users

On- 0 Residential

130Affected 0 Surface Water Site: 0 Non-Resid.Surface Soils, U Starmwater Recreational

Sediments. or Surface Water Use / Sensitive Off- C] ResidentialSurface Water Transport Habitat Site: 03 Non-Resid.

Figure 5-1 Exposure Pathway Analysis

Currently Site 70 has a commercial-type land use, being located adjacent to the runway andcontaining the refueling/defueling hydrant system. Direct soil contact is likely at the site whenworkers maintain the hydrant system. Leaching to groundwater is a common concern at TPHsites. At Site 70, the closest well is 1600 feet upgradient; however, Site 70 lies within 800 feetof a significant groundwater recharge zone, the Ocmulgee River floodplain. Furthermore,groundwater levels at the site are very shallow (HAZWRAP, 1996). Volatilization to outdoor airis a concern for workers during normal activities at Site 70 as well as during maintenance of thehydrant system. Volatilization to indoor is a very minor pathway at Site 70. The only buildingson the site are a small storage building and the pump house (HAZWRAP, 1996). Neither is afull-time place of work; however, because workers must occupy those buildings for some timeperiod, contaminant volatilization to indoor air has been included.

18

Site 70 will likely remain in commercial land use as long as Robins AFB operates the runway.Future land use, should the base not remain operational, does not preclude an industrial orresidential scenario. Therefore, residential RBSLs for each exposure pathway have beenincluded.

The Tier 1 RBCA assessment results are presented in the following sections as a pathway-specific RBSL and HI for each soil sample evaluated. The RBSLs represent soil concentrationsthat do not result in unacceptable risk. The hazard index is a comparison of the TPHconcentration and the RBSL (see Equation 6).

Hazard Index (HI) = TPH concentration (mg / kg) (Equation 6)

RBSLpathway (mg / kg)

RBSLs were calculated using zero for nondetects. Weathered TPH, in general, and jet fuels,even when fresh, contain very low concentrations of the light end and the heavy end aromatics.The lack of light end aromatics is reflected in the low BTEX results shown in Table 4-2, eventhough free product was present at the site fairly recently. Use of one-half the nondetect level,a typical risk assessment assumption, for fractions which are not present at a site causes thenondetect fractions to drive risk (Merrill, 1998), thereby defeating the benefits of speciationusing the Direct Method and the Working Group approach. This highlights the need forobtaining the lowest detection level feasible for samples that will be used to calculate risk.

Appendix B contains a detailed discussion of RBSL development. Appendix C provides theRBCA model runs complete with risk results.

5.1 Commercial Scenario RBSLs

Current use commercial scenario Tier 1 RBSLs are presented in Table 5-1. RBSLs for thedirect soil to skin contact pathway averaged approximately 9000 mg/kg and the HI for thepathway was just under 1.0. The average RBSL for the contaminant leaching to groundwaterpathway was a little higher, approximately 10,000 mg/kg, and the average HI was just over 1.0.The RBSLs for the volatilization to outdoor air pathway reflect the low risk of that exposureroute; the average RBSL exceeded purity (i.e., more than 1 kg weathered product/1 kg soil) andthe average HI for the pathway was only 0.01. Since the leaching to groundwater pathwayexceeded a HI of 1.0 and the direct contact pathway was very near 1.0, further samplingcombined with a Tier 2 analysis is recommended. The average HI exceeded 1.0 by only a verynarrow margin for the leaching pathway; the His ranged from 0.06 to 2.7. Typically, theshallower samples had lower His which offset the higher His of deeper samples. The sametrend is displayed in the His for the direct contact pathway. Because the contaminationrepresenting the highest risk is deep (i.e., about six to seven feet bgs), direct contact with thesoil is likely only in cases of hydrant system maintenance involving considerable excavation.Leaching to the groundwater is already occurring due to the shallow water table at the site;remediation of the soil would not address the water contamination (i.e., the media of greatestconcern). Therefore further delineation of the contamination and a Tier 2 assessment of thesoil risk would be appropriate.

19

TABLE 5-1 TIER I COMMERCIAL SOIL RBSLs AND His

Total TPH Direct Contact Leaching to Volatilization to Volatilization toGroundwater Outdoor Air Indoor Air'

Location, (mg/kg) RBSL HI RBSL HI RBSL HI RBSL HIDepth (mg/kg) (mg/kg) (mg/kg) (mg/kg)

"EA-2, 4 ft 4761 9199 0.52 9981 0.48 2617725" 0.00 254 18.75EA-2, 7 ft 15131 9786 1.55 9208 1.64 498007 0.03 208 72.64E-8, 4 ft 821 9207 0.09 14397 0.06 80321 0.01 293 2.80

SE-12, 5 ft 5836 9733 0.60 12355 0.47 10505722 0.01 215 27.19SE-12,6 ft 16300 8291 1.97 6094 2.67 18863252 0.01 238 68.55Average 8570 9243 0.94 10407 1.06 1226590W 0.01 241 37.99Note: ' This pathway included for demonstration purposes only.

2 Exceeds purity (_ 100% TPH)

The volatilization to indoor air pathway was included in the commercial scenario because of thepump house and the storage building located on Site 70. This pathway is useful fordemonstration purposes only. The calculated RBSLs and HIs for this pathway areunrealistically conservative. The RBCA indoor air model makes several conservativeassumptions: the concentration of the contaminant is constant and does not attenuate overtime, the partitioning between vapor, dissolved and sorbed phases of the contaminant is linearand in equilibrium, and the diffusion through the vadose zone and the foundation (with 1.0%foundation cracks) is steady state. Most conservatively, the model assumes that theconcentration of the contaminant is constant with respect to distance, thereby not allowing forany degradation, sorption or other attenuation to occur between the contaminated zone and thefoundation. Because of these overly conservative assumptions, model developers and the EPAitself recognize that this model does not provide worthwhile output (Tuomi et aL, 1999). Thispathway could be re-examined in a Tier 2 assessment, using validated models and moreappropriate occupancy times (i.e., part-time work schedules instead of 40 hours/week for 50weeks/year) for these two buildings.

5.2 Residential Scenario RBSLs

Tier 1 RBSLs for the futuristic residential scenario pathways are provided in Table 5-2. The soilto skin direct contact pathway is considered incomplete, as residents do not typically come intocontact with soil at depths greater than three feet bgs. Construction activities at a residentialsite fall under the commercial scenario. Therefore, RBSLs and HIs for this pathway areprovided merely as points of interest, but have no bearing on decision making in this scenario.

20

TABLE 5-2 TIER 1 RESIDENTIAL SOIL RBSLs AND His

Total TPH Direct Contact' Leaching to Volatilization to Volatilization toGroundwater Outdoor Air Indoor Air 2

Location, (mg/kg) RBSL HI RBSL HI RBSL HI RBSL HIDepth (mg/kg) (mg/kg) (mg/kg) (mg/kg)

EA-2, 4 ft 4761 6227 0.76 2798 1.70 1234858" 0.00 97 49.06EA-2, 7 ft 15131 6624 2.28 2976 5.08 156080 0.10 80 188.10E-8, 4 ft 821 6233 0.13 2799 0.29 51248 0.02 110 7.46

SE-12, 5 ft 5836 6587 0.89 3857 1.51 495588 0.01 83 70.66SE-12, 6 ft 16300 5615 2.90 1921 8.48 591515 0.03 91 178.28Average 8570 6257 1.39 2870 3.42 505858 0.03 92 98.71Note: 1 This pathway is incomplete.

2 This pathway included for demonstration purposes only.3 Exceeds purity (> 100% TPH)

The average RBSL for the contaminant leaching to groundwater pathway was approximately2900 mg/kg. The accompanying HI was calculated at 3.4. Again, the RBSLs and His for thevolatilization to outdoor air pathway reflect low risk. The average RBSL of 500,000 mg/kg isequivalent to 50% contaminant and 50% soil. The HI of 0.03 is marginally higher than thesame pathway in the commercial scenario. Since the HI for the leaching pathway exceeds 1.0by a factor of 3, soil remediation or addition sampling for a Tier 2 assessment would again beindicated. As with the commercial scenario, the leaching pathway His are lower in shallowersamples and higher in deeper samples; they ranged from 0.29 to 8.48. As stated in Section5.1, due to shallow water tables, contamination of the media of greatest concern, thegroundwater, has already occurred. Further delineation of the soil contamination followed by aTier 2 assessment is again the most appropriate option. Separate evaluation of thegroundwater is indicated.

The volatilization to indoor air pathway was included because future residential use of Site 70has not been excluded. As stated in Section 5.1, this pathway is for demonstration purposesonly due to overly conservative assumptions in this RBCA model. Evaluation in a Tier 2assessment using validated models would be appropriate in the event that residential use of thesite is foreseeable.

5.3 Risk Discussion

Five of the ten soil samples evaluated using the Direct Method had detectable levels of TPHuseful for RBSL development. The RBSLs for the leaching pathway were lowest for both thecommercial and future residential scenarios; the average RBSLs were 10,000 and 2900 mg/kg,respectively. The commercial RBSL was exceeded by two deep samples, EA-2 at 7 feet andSE-12 at 6 feet, causing the average HI to be greater than 1.0 even though the average TPHcontamination across the site was less than the RBSL. The future use residential RBSL wasexceeded by all but one shallow sample. Further sampling and a Tier 2 assessment for soilcontamination risk is recommended under both scenarios.

The Working Group's approach was developed solely to provide risk-based soil cleanup criteria.Therefore only soil pathways were evaluated in this demonstration. Risk from impactedgroundwater was not assessed.

21

5.4 Comparison with Georgia Guidance

The State of Georgia expressed interest in this demonstration project as they are currentlyworking to address TPH contaminated sites that do not contain chemicals of concern(Heathman and Lurker, 1998). Georgia's current regulations focus on BTEX and PAHs. TheState currently has no rules regulating TPH itself at contaminated sites (Muhanna, 1999,personal communication). The Working Group approach advocates sampling for carcinogeniccompounds prior to evaluating non-carcinogenic risk from TPH (TPHCWG, 1998b). In this way,the Working Group approach correlates well with current Georgia regulations. Additionally, theWorking Group approach offers to the State a method for dealing with TPH sites containingnoncarcinogenic components without carcinogenic chemicals of concern.

Four of the ten Site 70 soil samples were tested for BTEX. At two sampling locations, theBTEX levels exceeded Georgia's cleanup standards. The confirmed presence of benzene, aknown human carcinogen, indicates the need for further action. PAHs were not assessed inthis demonstration; this additional sampling is necessary prior to use of the RBSLs generated inthis Tier 1 assessment.

6.0 CONCLUSIONS AND RECOMMENDATIONS

The TPH Criteria Working Group approach was demonstrated at Site 70, Robins AFB, Georgia.Five of ten soil samples resulted in detectable levels of TPH as measured by the Direct Method.Total TPH concentrations were highest approximately 12 feet downgradient of the former hotspot, monitoring well EA-2 (i.e., sampling location SE-12). Total TPH levels increased withdepth at the sampling locations. The TPH fractions present were similar between samples andconsisted primarily of >EC8 to EC16 aliphatics, along with >EC10 to EC16 aromatics. Tier 1RBSLs and His were calculated using these Direct Method fractionated concentrations andASTM RBCA models. In the current commercial scenario, average His were greater than 1.0for the leaching to groundwater pathway only; the direct soil to skin contact pathway was verynear, but did not exceed, 1.0. The Tier 1 RBSL was calculated at 10,000 mg/kg based on theleaching pathway. In the futuristic residential scenario, the average HI was 3.4 for the leachingto groundwater pathway, resulting in a RBSL of 2900 mg/kg. Further sampling to characterizethe extent of contamination and a Tier 2 evaluation are recommended. Additionalcharacterization was ongoing by Robins AFB at the time of this demonstration.

During the course of future contamination characterization and Tier 2 evaluation, soil samplesshould be divided and analyzed not only by the Direct Method but also by conventional analyses(i.e., GRO and DRO). The total TPH values from both types of analyses should be correlatedagainst each other. If they correlate well, the cheaper conventional analyses should be used todelineate contamination. Using the correlation coefficient, the TPHCWG approach can be usedto determine RBSLs based on a larger number of samples at a lower analytical cost. TheDirect Method, however, should be further refined to obtain consistently low quantitation limits.The LOQs reported for several samples in this demonstration were high and exhibitedconsiderable variability.

Only soil risk and the risk of contamination from the soil transferring into other media areaddressed by the Working Group approach. At Site 70, the groundwater is not only already

22

impacted but the groundwater is currently acting as the source for TPH contamination, insteadof the TPH residing predominantly in the soil. This is evident from the site history (i.e., the poolof free product on top of the shallow groundwater table that was removed from well EA-2). Thepattern of TPH concentration in the soil (i.e., concentrations increase with depth bgs, thehighest being just above the water table, downgradient from EA-2) is indicative of smearing thatoccurs with the temporal rise and fall of groundwater levels. Further assessment of soilcontamination is recommended after the groundwater contamination is resolved.

The Working Group approach effectively provided noncarcinogenic risk-based cleanup criteriafor TPH impacted soil at Site 70. Carcinogenic risk must still be addressed. BTEX wasanalyzed in four of the ten soil samples. Benzene, a known human carcinogen, was found tobe present. Analyses for carcinogenic PAHs were not conducted. Both the Working Groupapproach and the Georgia Department of Natural Resources require the assessment ofcarcinogens present at the TPH site. The Working Group approach for noncarcinogenic risk isbest utilized at a site without these carcinogenic contaminants of concern. As stated above, theshallow groundwater appears to be acting as the source for the soil TPH contamination. Afterthe groundwater contamination is resolved, the soil benzene levels may drop below the GDNRcleanup criteria (i.e., 0.008 mg/kg for this type of site) and the Working Group approach fornoncarcinogenic risk may be more applicable to Site 70 soils at that time.

7.0 REFERENCES

GDNR. 6/25/1996. Rules of Georgia Department of Natural Resources EnvironmentalProtection Division. Chapter 391-3-15: Underground Storage Tank Management. 30 pages.

HAZWRAP. November 1996. Draft Corrective Action Plan - Part A for Underground StorageTank Sites 70 and 72 at Robins AFB. Hazardous Waste Remedial Actions Program,Department of Energy, Oak Ridge, TN.

HAZWRAP. February 1997. Draft Corrective Action Plan - Part B for Underground StorageTank Sites 70 and 72 at Robins AFB. Hazardous Waste Remedial Actions Program,Department of Energy, Oak Ridge, TN.

Heathman, TW. and Lurker, PA. 1998. TPH Criteria Working Group field demonstration sitereport:: Robins Air Force Base, Warner-Robins, GA. Air Force Research Laboratory,Operational Toxicology Branch, Wright-Patterson AFB, OH. AFRL-HE-WP-TR-1 999-0001.

Merrill, E. 1998. TPH Criteria Working Group field demonstration: Scott AFB, Belleville, IL. AirForce Research Laboratory, Operational Toxicology Branch, Wright-Patterson AFB, OH. AFRL-HE-WP-TR-1 999-0025.

Muhanna, Shaheer. 7 July 1999. Personal communication regarding current Georgia TPHregulations. Office of Underground Storage Tanks, Department of Natural Resources, GA.

Peters, Doug. 22 Dec 1998. Personal communication regarding Geophex sampling plan.Geophex Corporation, Warner Robins, GA.

23

TPHCWG. 1998a. A Risk-based Approach for the Management of Total PetroleumHydrocarbons in Soil, Volume 3. Selection of TPH Fractions Based on Fate and TransportConsiderations.

TPHCWG. 1998b. A Risk-based Approach for the Management of Total PetroleumHydrocarbons in Soil, Volume 4: Development of Fraction Specific Reference Doses (RfDs) andReference Concentrations (RfCs) for Total Petroleum Hydrocarbons (TPH).

TPHCWG. 1998c. A Risk-based Approach for the Management of Total PetroleumHydrocarbons in Soil, Volume 1: Petroleum Hydrocarbon Analysis of Soil and Water in theEnvironment.

TPHCWG. 1999. A Risk-based Approach for the Management of Total Petroleum Hydrocarbonsin Soil, Volume 5. Human Health Risk-based Evaluation of Petroleum Release Sites:Implementing the Working Group Approach.

Tuomi E, Stroo H, Weisman W. Field Demonstration Report - Defense Fuel Support Point,Mukilteo, Washington. Air Force Research Laboratory, Operational Toxicology Branch. AFRL-HE-WP-TR-1999-0030.

24

APPENDIX A ANALYTICAL DATA

A-1

25

E Ei

C)LC) <ZZZZZ <~ZZZ~

C6 = -8 ,

E co U

-2 c .1- .2 E2-

(D <E :2 ~ E2 0 2

E <

0 OONNL 0 z 9 - N( N

0 N>C lC C DC OL

-~C i

0.E ECC.,CD

0 D0 0 0 0 O a 0D O O0~ 0Ezzzzz 0 0zzzzzzzzz 41EoZZZZZZZZZ E0) 0 0 D

<0 c) 0

3 LOL00 0- N04 0 (D LO' ~ 00 o

0 - -i -

00

*

= E~0 > 0 E a E

0 .0 L ( zo zzZzzzzz CM z

( ~EL In E111

<n m - -Q - c

0. -0

c0 0

C, 0 C C o 0 <, <aO O40 z~< 0 Q 0 z~ Nz zz a, aO

=0 CV C:. <0

C a0n 0Z

cU Lxo 04oa) cm m-

cc < < .- a a-- - -<-- - -0 0 0 r

co o 4ooo) co -. r- E :ý a)co ~ I a, IL aOa

-j X E> 0

to~ 0 2-Cl

A-2 0 n Ncu C11 1 aE m CU 26

I E_ 2 2

.9 q .2

M UJ <)

*0 a) to 0 0 000M

Z t ~ -2- ca

0) 0)

0 00 2 0C 0. 0)0-Tc)coC

0.O 0) fl0 0000C c0

q Nco N -oqq-

(. 0 a 0 cc> Cu~. -- - - - - - 0- )

E0 C~.

1..N

Cu

.2 0.2

o~~~~~ 00 0.) Z Z Z Z ,c, o. 0)ZZ Z 0 00

2--c2. Do 2 r-n-D o

Z 4--2

2CO .50 >1 Q0 a)<c ~ -~c < ~ E

a. NZ 0 Z 'CD'tJ 't 0 0.0 0C14 N _ociN c

.00(I) C.)c m

M -3 -2

mU =W)= C -@ C 0)CuClI--c 0)0) 0 0 00 0 0 0) CD

= cE m=CE

<~ 0 00S-2 -2 E

0 x0~ 0cm~0 cm~0 Co. CN C CD.J 0 0

0) cm- < < ~ < XE>>

0~ i= cA

0 0 0 0zzzz a~ _ zzzz

CD 'o tý:0)co CL co -"T = v a:-c

X CL 0 27

< EEo 2I2

0 )

04

- cam m WE E

CO CO

a)~ 0 0000004Lt-'0l co 66S C

2 0

c N3 L n Dc*o -=I. 00C00 0)4 ' )CR00N NL

E 0 c

<0 0

C: 00 o co0OOI0 o z ' 0 _ZZ Z Df-*

2-2 20

0 a) 00

E "E

0 a -0.' C) C) C,0 C i CiC)r

00ocoC ý ou o

OCl C1 U) N co0. CD. CD w Z _

>, 0

U)0 > ~< ~ o~ 2~<Q Q ~

m~ *m.~ 0 00c~~. 0 MME-ec 0 m0 *-

0 0 01 mt

0 U-)0 COO~ O o. 0 0 C - ~ O

.0

0 <000 )C)00cCD z A ~jN L 0 0 1 L

2~~ ~~ >O OOL5 2 O O Q00 -o

U)U

_________ 0E w wm (D cm (

U < <A<4280 nz z zr: c

0) 0

E -C cmo (n EOZZZZ en E~~ZZZZ

m 0 01 0

2J 0

0U' LO~C CO Co-

0o00 0 cOO 0 0 o0 0 00 00 c 00 0 O0 00 4C4L

E- -

on 0

0 0 i

0.0 zzzzzzzzz0)zzz z z z a

-0 'a

Z:O( 2 mC 05*0 cu

L-(~ 0 00 o0) o .00 co , 0 C N N

CQ 00 C1 N o 4

Io :p 4) 0 co0 .0

0 .0 Z f

LCO 0 C 1- Or-(0 00zzzz wf 0.ZZZ mzzzzzzzzzQ 00

E~

- -CO X 0 A -

00 0. _ cn Cb C 0

oO Co Co Cc0 < 0 Z

0 )' L0) Z 0 =OE.E

0. z z 6 NU

IL -1.-; L:

00, <0 cc:0,o ,

a cu coC0 150

m ) 0) - C.)CD 0) a)1cm W

r-~~ - c c

0o LC<)L< << < - c /

on toU C~l w0 C' 0)0

U 0

wLo LO 00 Cu VO ý VC

M C -J l .. 0 a) cC0 co >AOCO cm LO 0 .h DNC L

A A A CV 111 o- 00 0 1 1 C )C

1 co ggo -5

E> >0. qAA A

A CCu)LA A A AA A A

A-5

29

o) 2K?

6 <Z0 0

E I.2 Cl Cf N I0 t. N t O O0 0 IT0o )0 l c02 o oC C Z~ m o0c 0c t c I .

-N cu -T Z LOr

Z -o

o 0ý E O o o o~

00 0 C )CL 0 5 -e Y)r-'

0 N0c ) 4N L

C

0 E. E

c 0 a V- r- c.. o a

0 0

'a co 7

* .0 0 -

0.0. CU

0 00 0 0) 0)

co - -=Co

tm Nr C ) COO

0~~~~~~li Ixt 0UII - c - -00 _L a CIN z N - ZM Z -

=~ E z C fm in.- 0 "r 2 -0

o~~~~t 0 r-o ~ c '

co 0 A2

00

CL

0) 0 a)0ýa

-l < < n L <<C r

c 0 coC~4 Cl coC

o0 0 . ,C' C coLO w. N -------------------z 0

LC)inLo - 0 LO~C "o -Mo 0 co

o NCc LOC)L o~2~ 0 N 0 coJC0LO

MoC .0 V Eor '0 CU 5oL )L

co 0.O m- -a)co,

A A AA -60AAA6

30

E E

o Lo 0

o <e

E cvz 0Ouz0 cn z o ~ ~ o

0 (D-cc to- -o C--(C 0, 0 OC -v -m 0nC) c O Nc 'o I- *clr- N r- m z lO L

E <~ E

2 2

0 _o c 04 04L l

EE

000 0 mc

't - 0 l- Qo m cm Ec W ) LOC E o zLO) N (D a E

a <

a -. 0

U) - 2 D

0) 0

Im ~ ~~ ~~ C)C C0 D0C C D0L

N. C-4 t ItC O0 - It

Cv c 1- 0- >

2 .~ 0

Cgo

EE -- a- 20 00 0- 0. 0oo- ~ =

CM Cu co -- - - - - - - - -

C6 Lo mE 0N t 0.0)co C; C) CO o)~ LO o O

=f Z-c j 0 0't L m c 0 m co z z N C*00 re CLC 00 0 C O 40 ,Cl)~ -- CO 14, O

u)_ E _l _l CO) 0 ' l

'P <<oa~g a - -D

.0A

20 X.U, LZ5 ;- -Z

mu -e N CNOO cc. m-

o3 < C)C>C ) )C C < < V') Lo O < E 0ECD 0 - N LOC Z Z v C4 L

m cu~I 0 0c

0 0 0

S L C) 0 0 C\! CO -)

0) o 0 )L to ~0 (D

L En~ 0 o 0 w w Cý 0

0 0 Cu I0 0CL .0 CV Ioo

A0 0 2~ 2 CD

I-h- >e C) W a m-e -1 - - - 04 CO(

Co CD

CD C, 11 L0

v v v v v vAu-7mo cl 00 0 . .31

< ElE

0) c r-.

C.)N

E + +

n . . I,- -r - f - 0

• . ,.. . " "E0 w o a ,0 m u z " t o t o

oo cc z ,- co (l I,'I-6 Lo .. O Q z .. N" z zl -I,--I

E E•

2 2'L0 5

0 CILOLOa

M 0 o -. , N O 0 0 N N M0 .0

D "' 0, I I i i i

_- 0 z . -. cn z lal-I l .

o 00.2~~~* n- LO1,r-N M(

o t.., ," • • o < E

-- ) 0 C,

'-~~~c N (D z z• "m " < z z W!o•z= =1,• 2 m- t I a -2 0O

.0. . _ . . . . ,a )-N 0 0 0 a 0-co.

00

(.* IJ. II IIII III

U) E ) ) U

0 0L

Cc -lz M - , v v v v

0 0 0r D o c

00

<I - N-

, o

.- 0,Z Z O O 1v Zv 0/vl l,_

" , - - - •l | ," I -"a) -,- -'l)l ' - -

•.z " 0 A A •

00 X0 LU0

0 4

-A-80-- -- - - -< -Z5

IL ~2 2

00 w ~m (Do o~~ CE:N~ a,)a

QE r-N~ 2i 0 N CD.

0.- AAA z 0.0 z~ Az 0 z0. E. CO

T(-0 CL-- - - - en-- - - w

A-Cc8ca: cm32

< ~ E WE

Cc mt NCO 0~ Z oZ+ ZZ( I O

.00 ZC 0 CD - C) 0 0aDN

0~U --

0 0

E E

Oe 0 0 0 No~ cc M U- -- c)t

0 0 2

0) 0) N)04 LO .N C t

a, - cc

~o. 0)CD

0 m

EO0CO LO N CO Lo* E 0 )1 1 O 0 0 c04 0

0 0) 00a

E ..- -5 -2(UO >5 LM >

om ao CoD C)C0t-- c 4

C) 00)C)L O oL

oi ItN .c 0 O0 maE4N t 0 .

CL - 1. 1 04 C0*L ',ý

(U~~-c 2)rc , 0 C

2 2= CD-mo It << 0 o o g wacf- 3 u00 )0w

0Z 'ItCO z zLo I tZ 0) CcME4ZZ0 DLE~ = E

0 00 0. o L

L) - W ko -1 N111(U 0 0- (A CO 0 1

Uý 0 C) <<0CO0 o < 0)=oo 00z c0- z - 0)zN L~ co- E E

V~~ N oU.), 5 Na

<, < e'i C

00

m (D CM- -- -co-----------

S of 0 0l oL

22 C4 2 2 0_

co 2 2 2a

m co O .0) m m '

m 11 1 11 v v mCU V V V C;) 0m0 (U - v = V V Ov v~I COC (

.C . .0 o L m0 o c

C)I C,> A R-(U C4A A D>a,0

CL 0-

A-933

2- 2IZ< Z- <o0) cII< < <Z<O<

+) z - 0z+ zzrE '' c

0

0 0000 o m o D C

u r- ý t- 00

.2 cc-

o 0) to COU)

Ml. w)' w 000 ' C4L-j N N LID c

EC

x 0 .) 0~~U~

N-oc f - 0CO ItL M N t - f

MC CO c: -T mLDL n C o0

0) 0

L- C) -3 00 O0 0 DC4 " o ;ý -

0.0

U) m cu cc~- (

0z 0 > 0 = c' -cca

qr~~~~ ~ ~ ~ w co r- Oc, 0 0 cC OCCU-----------e CO

0 a ) Nc o n~ co Clo U)0mCOC4JC0 m 04 0 0.) to mC.I) 0

to. < 0L D . -Xw A

<)0 0 0 << E)c: m * '< coEcc 3

U)

- C C*

<) Cl) < < < 'C))

o -I -' - - - - -- T. .E2 f V)L Q C/D~.0C) -CL~O 0m co)~ ~ . CW) ~ C N Vo = 4I

U) -

(Ut- mL)~C

0. C) )

___u__ u_____N___ D

cu CC)EDE c

c-1L) c uE ) Q Q -)34 z

I 2C) 0)

~ +~ +E co 0) I

m. m (n:~Z Z ZZ Z E- .r. Z 0 ZZECD 0 0.

0 0 2

x <~ E0

LO LO co to-

0 CDC CD~0 CDCD "CD 0 0 co 0 C) 0 D 0 C T -- )u, ,

0 0) 0l ' ) DCi .~ q Nu

CD

0)V >.0

=L C 0 a0 c 0 a

m E 0zzzzzzzzz E0 z zz z zz zz z E0L <- 0- < uc

CD mC C.) -0 0 00

m 0 0 2 M

00

0.

tm 0 )0 I 0 C I )C 0

.2- -1 -0 -= r_.C

)Zý c" EuOC

0 I =-z 6 zzzzzzz O ~zO~DOzDDQcou-g E .2-ZZZEZZ 0 0

*0 ZZ -

CO XAA

<~C. <_ C_ Co Co 0< < 0 o T T C < m E Co Coc Z Zzr

.0

CD W

3o Cul Cu 114zz C DI. I- .- 0) Z Z Z Z - C

00C 2 2-~

oo CLO CD C

Oc LOL 0 0o - aLU C Cue C)m e

oo - ------- D-- -O ----------- o C.0

2 co a 0 0 0 C)0 DMC

Ua)fl -~ 04 11 10I04C11 11 1111 C1,..0~ V V V V vC v vIC

T- C u 1 N .00 Cu4 A3 I A CD D

A0C' C0

C) 0 OC\JCA 0 ) _)

02 00-

A-1il35

Lancaster LaboratoriesA division of Thermo Analytical Inc.

LLI Saample No. SW 3092069 FCollected: 2/12/99 at 11:50 by EM Account No: 09729 P.O. 8309-223-TH08/S002

Operational Technologies Corp. Rel.Submitted: 2/16/99 Reported: 5/ 5/99 4100 N.W. Loop 410, Suite 230Discard: 5/27/99 ISan Antonio TX 78229-4253

E-8-4 Composite Soil Sample

TPHCWG Demo. - Robins AFB - GAE-8-4 SDG#: OPT07-01

AS RECEIVED DRY WEIGHTCAT LIMIT OF LIMIT OFNO. ANALYSIS NAME RESULTS QUANTITATION UNITS RESULTS QUANTITATION

BTEX (Total Xylenes)

8183 Benzene < 500. 500. ug/kg < 590. 590.8184 Toluene < 500. 500. ug/kg < 590. 590.8185 Ethylbenzene 3,100. 500. ug/kg 3,700. 590.8186 Total Xylenes 33.000. 1,500. ug/kg 39,000, 1,800.

Poor surrogate recoveries were observed for this sample due to the dilutionneeded to perform the analysis.

Due to interferences from the sample matrix, the limits of quantitation forthe above determinations were increased.

Sl. Lancaster LaboratoriesA division of Thermo Analytical Inc.

LLI Sample No. SW 3092070 "Collected: 2/12/99 at 12:20 by EM Account No: 09729 P.O. 8309-223-TH08/S002

Operational Technologies Corp. Rel.Submitted: 2/16/99 Reported: 5/ 5/99 4100 N.W. Loop 410, Suite 230Discard: 5/27/99 San Antonio TX 78229-4253

SE-12-5 Composite Soil Sample

TPHCWG Demo. - Robins AFS - GASE125 SDG#~: OPT07-02 AS RECEIVED DRY WEIGHT

CAT LIMIT OF LIMIT OFNO. ANALYSIS NAME RESULTS QUANTITATION UNITS RESULTS QUANTITATION

BTEX (Total Xylenes)

8183 Benzene 1.600. 1,000. ug/kg 1,800. 1.100.8184 Toluene 1,400. 1,000. ug/kg 1,600. 1,100.8185 Ethylbenzene 6,800. 1,000. ug/kg 7,700. 1.100.8186 Total Xylenes 94,000. 3,000. ug/kg 110,000. 3,400.

Poor surrogate recoveries were observed for this sample due to the dilutionneeded to perform the analysis.

A-12

36

Lancaster LaboratoriesA division of Thermo Analytical Inc.

LLI Sample No. SW 3092071Collected: 2/12/99 at 12:40 by EM Account No: 09729 P.O. 8309-223-TH08/S002

Operational Technologies Corp. Rel.Submitted: 2/16/99 Reported: 5/ 5/99 4100 N.W. Loop 410, Suite 230Discard: 5/27/99 San Antonio TX 78229-4253

SE-12-6 Composite Soil Sample

TPHCWG Demo. Robins AFB - GASE126 SDG#: OPT07-03

AS RECEIVED DRY WEIGHTCAT LIMIT OF LIMIT OFNO. ANALYSIS NAWE RESULTS QUANTITATION UNITS RESULTS QUANTITATION

BTEX (Total Xylenes)

8183 Benzene 2,200. 1.000. ug/kg 2.500. 1,100.8184 Toluene 1,400. 1,000. ug/kg 1,500. 1,100.8185 Ethylbenzene 13,000. 1,000. uglkg 15,000. 1,100.8186 Total Xylenes < 150,000. 150.000. ug/kg < 170,000. 170.000.

Due to interferences from the sample matrix, the limit of quantitation forthe xylenes determination was increased.

Poor surrogate recoveries were observed for this sample due to the dilutionneeded to perform the analysis.

* Lancaster LaboratoriesA division of Thermo Analytical Inc.

LLI Sample No. SW 3092072Collected: 2/12/99 at 11:40 by EM Account No: 09729 P.O. 8309-223-TH08/S002

Operational Technologies Corp. Rel.Submitted: 2/16/99 Reported: 5/ 5/99 4100 N.W. Loop 410, Suite 230Discard: 5/27/99 San Antonio TX 78229-4253

E-8-3 Composite Soil Sample

TPHCWG Demo. - Robins AFB - GAE-8-3 SDG#: OPT07.04

AS RECEIVED DRY WEIGHTCAT LIMIT OF LIMIT OFNO. ANALYSIS NAME RESULTS QUANTITATION UNITS RESULTS QUANTITATION

BTEX (Total Xylenes)

8183 Benzene < 5.0 5.0 ug/kg < 6.0 6.08184 Toluene N.D. 5.0 ug/kg N.D. 6.08185 Ethylbenzene 35. 5.0 ug/kg 42. 6.08186 Total Xylenes < 200. 200. ug/kg < 240. 240.

Due to interferences from the sample matrix, the limit of quantitation forthe xylenes determination was increased.

A-13

37

APPENDIX B RBSL CALCULATIONS

B-I38

The procedure for calculating a TPH RBSL for cross-media pathways based upon summing therisk from each fraction is complex. Please note that the following procedure is only appropriatefor calculation of RBSLs for cross-media pathways since it sets as an upper limit for the RBSLthe degree of saturation, which does not limit exposure for direct routes such as soil ingestion,dermal exposure, and inhalation of particulates. An additional procedure used to calculateexposure for direct pathways is also provided. These procedures are based on Volume 2 of the

Cross-media Pathways

Partitioning qualities govern how a chemical interacts with its environment. Specific physicalproperties responsible include solubility, vapor pressure, sorption coefficient and Henry's LawConstant. A brief discussion of the role these parameters play in basic partitioning in theenvironment is provided in the following paragraphs. The fraction-specific values for each ofthe described fate and transport parameters is provided in Table 3-1. The equations used todevelop these fate and transport properties are available in the TPH Criteria Working Group"Volume Ill. Selection of Representative TPH Fractions Based on Fate and TransportConsiderations" (1998).

The solubility of aromatic hydrocarbons, for any EC number, is generally greater than that ofaliphatic hydrocarbons, especially at high EC values. The variability in solubility around anygiven EC value is about an order of magnitude. The higher solubility of the aromatics meansthat aromatic hydrocarbons are more likely to be present as dissolved constituents ingroundwater than are the corresponding aliphatic hydrocarbons.

The soil-water sorption coefficient (ks) expresses the tendency of a chemical to be adsorbedonto a soil particle. The magnitude of the sorption coefficient for most soil/water systems is afunction of the hydrophobicity of the chemical (as indicated by its solubility) and the organiccarbon content of the soil. For non-ionic, hydrophobic chemicals such as petroleumhydrocarbons, the primary property controlling sorption is the organic carbon content (f0,) of thesoil.

In general, aliphatic fractions are more likely to remain bound to a soil particle than the aromaticfraction of an equivalent EC. This tendency was previously indicated by the low solubilityobserved for aliphatic fractions. The majority of log koc (carbon-water sorption coefficient)values presented in Table 3-1 were derived from the octanol-water partitioning coefficient.

There is very little difference in vapor pressure between aliphatic and aromatic constituents ofan equivalent EC. In effect, the EC and vapor pressure are closely related. This relationship isexpected because both EC and vapor pressure are largely functions of a compound's boilingpoint.

The Henry's law constant (Hc) is definable as an air-water partitioning coefficient and may bemeasured as the ratio of a compound's concentration in air to its concentration in water atequilibrium. Aliphatics and aromatics behave differently based on Henry's law constant. Foraromatic fractions, the Henry's law constant decreases with increasing EC; for aliphaticfractions, the Henry's law constant is virtually unaffected by EC. In general, aliphatichydrocarbons are less soluble and more volatile than aromatic hydrocarbons. It is important tonote, however, that benzene, an aromatic compound, is very volatile and more toxic than the

B-239

corresponding aliphatic fractions. Therefore, when present, benzene is likely to drive riskcalculations for pathways involving volatilization from soil or groundwater.

The parameters described above are combined into simple fate and transport models toevaluate the partitioning and migration of chemicals for the different applicable pathways. Forleaching and volatilization pathways where transport and therefore exposure are maximized atthe saturation concentration for specific fractions, the following equations are solved. Thesethree equations were adapted from Volume 5 of the Working Group's publications (TPHCWG,1999).

i~n(f CT CsaHI 7.HQi= .Min < 1 given, (Equation B-i)

,RBSLL 'RBSLi)

i=13 C

i= P (Equation B-2)

where:HI = Hazard Index (typically _< 1) [unitless]n = number of fractions (13 total) [unitless]HQ = Hazard Quotient for 1th TPH fraction [unitless]f = Percent Weight of ith TPH fraction in total TPH mixture [unitless]CTPH - Concentration of TPH mixtureCsat = Saturation concentration for ith TPH fraction (mg/kg)RBSL, = Tier 1 risk-based screening level for ith TPH fraction (mg/kg)

The saturation concentration is defined by Equation B-3:

Catj [mg / kg] = Si [Hc,,iO,,, + O0, + k,,jp, ] (Equation B-3)PS

where:S = Fraction effective solubility [mg/LIPs = Soil Bulk Density [g/cm3]Hc = Henry's Constant for ith TPH fraction [atm-m 3/mol]

s = Volumetric air content of the soil [cm 3/cm 3]OWS = Volumetric water content of the soil [cm 3/cm 3]ki = Soil sorption coefficient for ith TPH fraction (koc*foc) [cm 3/g]

Note: The effective solubility of a hydrocarbon fraction is equal to the fraction's solubility limit multiplied bythe mole fraction of the hydrocarbon fraction in the mixture (i.e., TPH).

The value obtained for Csat will vary considerably if the effective Csat of each fraction present inthe sample is considered through the use of Raoult's law. Equations B-1 through B-3 areiteratively solved for each TPH fraction, which is the additive mixture RBSL for the soil sample.

B-340

Residual saturation is the point at which any increase in chemical concentration will not changethe risk, up until the point at which free product migration becomes an issue. For purposes ofcomparing RBSLs obtained using different analytical fractionation methods, such as theMADEP TPH Method, Raoult's law was not used to calculate the RBSLs presented in thefollowing sections.

Soil Leaching to Groundwater Pathway

Leaching of contaminants from impacted soil into groundwater through infiltrating water is oneexposure pathway evaluated in the RBCA analysis. Soil RBSLs are calculated to be protectiveof groundwater quality. This involves: 1) calculating a groundwater RBSL (RBSLgw) todetermine an acceptable water concentration, 2) calculating a leachate concentration protectiveof groundwater (based on the groundwater RBSL), and 3) calculating a soil concentration whichwould result in this leachate concentration. Equation B-4 (adapted from ASTM, 1995)calculates the ingestion RBSLgw for each TPH fraction. The RBSLgw is based on a targethazard quotient of 1.0. Exposure parameters are provided in Table B-I. RfDs for the fractionsare listed in Table 3-2.

S,[ ,g ]=THQx RJ D o,,X BW x AT,, x 365 dayRBSL (Equation B-4)

W' tL-waterJ IRwater x EF x ED

where:THQ = Target hazard quotient [unitless] = 1RfDo,i = Oral chronic reference dose for ith TPH fraction [mg/kg-day]BW = Body weight [kg]ATn = Averaging time for noncarcinogens [yrs]IRwater = Daily ingestion rate [L/day]EF = Exposure frequency [days/yr]ED = Exposure Duration [yrs]

B-441

TABLE B-1 TIER I DEFAULT EXPOSURE FACTORS

Name Parameter Units Residential CommercialScenario [Scenario

Averaging Time: carcinogens AT, y 70 70Averaging Time: non-carcinogens AT, y 30 25Body Weight BW kg 70 70Exposure Duration ED y 30 25Exposure Frequency EF days/y 350 250Ingestion rate: soil IRso1 mg/day 100 50Inhalation Rate: air-indoor IRair-in 20 20Inhalation Rate: air-outdoor Rairut "m/day 20 20Ingestion rate: water IRwater /day 2 1Soil Adherence Factor M mg/cm_ 0.5 0.5Dermal Absorption Factor RAFd, c.s. c.s.Oral Absorption Factor RAFo _ - 1 1Skin surface area SA cmZ/day 3160 3160Target Hazard Quotient for THQ - 1 1Individual Constituents.Target Excess Ind. Lifetime Cancer TR i E-06 1 E-06RiskNote: c.s. = chemical specific

The analytical model used to estimate soil leaching to groundwater determines the partitioningof a constituent into water, vapor and sorbed phases based on the physical and chemicalproperties of the constituent. In this model, infiltrating water migrates through contaminatedsoils in the vadose zone. At this point, some of the contaminant partitions from the soil or vaportransfer into the water phase. This leachate is then assumed to migrate completely andinstantaneously into groundwater. Some dilution of the leachate is included using anattenuation factor based on infiltration rate, groundwater velocity, source width and height of themixing zone in the water column. Equation B-5 describes this attenuation factor (AF).

AF= 1[ IW I (Equation B-5)

where:Ugw = Groundwater velocity [ft/day]5g = Height of groundwater mixing zone [ft]I = Precipitation infiltration rate [ft/day]W = Width of the source area parallel to the mixing zone [ftl

Partitioning into the three phases, soil, water and air, is governed by the partitioning factor. AsHenry's law constant is applicable only to dilute solutions, the use of this model is notappropriate when free phase liquid is present. The partitioning factor (PF) for each TPHfraction is shown in Equation B-6.

B-5

42

PFi = 1 0. + k,,=p, + H,,8,, (Equation B-6)PS

where,w = Soil volumetric water content [cm 3/cmI]

ki = Soil sorption coefficient (ko,*foc) for ith TPH fraction [cm 3/g]Ps = Soil density [g/cm 3]Hc = Henry's Constant for ith TPH fraction [atm-m 3/mol]eas = Soil volumetric air content [cm 3/cm3]

The inverse of the product of PF multiplied by AF, which accounts for dilution of leached waterinto underlying groundwater, is termed the soil to water leaching factor (LF5w). The ultra-conservative leaching model assumes that no attenuation of leachate occurs from the vadoseto the saturated zone. In fact, biological degradation of the constituent or repartitioning ontosoil or into the vapor phase are all likely to occur as the leachate migrates to groundwater.Other assumptions of the model include: 1) a constant chemical concentration in thesubsurface soils, 2) linear equilibrium partitioning within the soil matrix between sorbed,dissolved and vapor phases, 3) steady-state leaching from the vadose zone to groundwater,and 4) steady state, well-mixed dispersion of the leachate within the groundwater mixing zone.Therefore the LFsw, which governs the movement of contaminants from soil to infiltrating water,incorporates both the PF and the AF, in Equation B-7:

[+, +ki+Hci,41 + 9 (Equation B-7)

where:LFw. = leaching factor for ith TPH fraction [mg/L-H 20 / mg/kg-soil]

Parameters for cross-media pathways are provided in Table B-2. Equations B-5 through B-8were adapted from ASTM's risk-based corrective action (RBCA) standard guide (1995). Oncethe LF has been established, fraction-specific soil RBSLs may be calculated as follows:

1PBSLW, i[-9--RBSL,, Lg ]L aL"iTr (Equation B-8)•g-soi! F w

B-643

TABLE B-2 PARAMETERS FOR CROSS-MEDIA RBSL CALCULATIONS

Description Parameter Units Tier 1Default Values

Ambient air mixing zone height 8air cm 200Areal fraction of cracks in foundations/walls M ncm/ 0.01Averaging time for vapor flux s 7.88E+8Carbon-water sorption coefficient koc cm/g c.s..Depth to groundwater (hcap+hv) LGw cm 300Depth to subsurface soil sources Ls cm 61Diffusion coefficient in air Dair cm"/s c.s.Diffusion coefficient in water Dwa' c/sý c.s.Enclosed space air exchange rate ER 1I/s 0.00023Enclosed space foundation or wall thickness L=ck cm 15Enclosed space volume/infiltration area ratio LB cm 300.Fraction organic carbon in soil foc gig 0.01Groundwater Darcy velocity pqw cm/yr 2500Groundwater mixing zone thickness _ _ cm 200Henry's Law Constant H (cm_/cm_ ) c.s.Infiltration rate of water through soil I cm/yr 30Lower depth of surficial soil zone d cm 100Particulate emission rate PE g/cm?-s 2.2E-10Particulate Emission Rate VFP (mg/mi)/ 6.90E-14

(mg/kg)Pure component solubility in water S mc/L c.s.Soil bulk density p g/cm, 1.7Soil-water sorption coefficient ks Foc*kocThickness of capillary fringe hc 0 cm 5Thickness of vadose zone h, cm 295Total soil porosity eT cm /cm• 0.38Volatilization Factor VFj (maim c.s. & m.s.

(mg/m3)Volumetic air content in vadose zone soils Oar cmM/cm' 0.03Volumetric air content in capillary fringe soils Oacap 0.038Volumetric air content in foundation cracks eacrack cm /cm' 0.26Volumetric water content vadose zone soils e0 cm'/cm' 0.12Volumetric water content: capillary fringe ewcap cmO/cmT 0.342Volumetric water content: foundation cracks ewmck cm7/cmi 0.12Width of source area parallel to flow direction W cm 1500Notes: c.s. = chemical specific

m.s. = media specific

B-744

Volatilization to Indoor Air Pathway

The mathematical model used to estimate volatilization from soil to indoor air is based upon thepartitioning of a constituent into water, vapor and sorbed phases as determined by the physicalproperties of the chemical. The model accounts for the contaminant partitioning into soil poregas and migrating through the vadose zone to the base of a building foundation. From therethe gas diffuses through cracks in the foundation and into the building air space, whereexposure through inhalation may occur.

The first step in calculating a soil RBSL for the indoor air pathway requires the calculation of anair concentration or RBSL, which is protective of indoor air quality (based on a target HQ of1.0). Indoor air RBSLs are calculated for each TPH fraction and then a whole TPH RBSL iscalculated based on the percent composition of each fraction. Equation B-9 is used to calculatethe air RBSLs for TPH fractions. Parameter values are presented in Table B-2.

THQx RfDi,ix BW x AT, x 365 dayy x 1 0 3/mg

RBSLair i[ P9 yrmB mS3 rair] IRairxEFxED

(Equation B-9)

where:THQ = Target hazard quotient [unitless] = 1iRfDjj = Inhalation chronic reference dose for ith TPH fraction [mg/kg-day]BW = Body weight [kg]ATn = Averaging time for noncarcinogens [yrs]IRair = Daily inhalation rate [m3/day]EF = Exposure frequency [days/yr]ED = Exposure Duration [years]

The second step in calculating a soil concentration (RBSLso01 ) which will result in an acceptableindoor air concentration (RBSLair) is to model the transport of contaminants from the vadose soilto indoor air. This model is extremely conservative, assuming: 1) a constant chemicalconcentration in subsurface soils; 2) linear equilibrium partitioning in the soil between sorbed,dissolved and vapor phases; and 3) steady-state vapor- and liquid-phase diffusion through thevadose zone and foundation cracks. In addition, the model assumes that vapors migratecompletely and instantaneously into the building, i.e., no attentuation occurs. It does notaccount for any biodegradation and soil sorption which could occur as the vapor migratesthrough the vadose zone.

Dilution of vapor is expected to occur between the source and the building. Therefore thefollowing diffusion coefficient in soil (Deffs) for each TPH fraction is used (see Equation B-10).

B-845

DseI =Dii _a_ + D _x (Equation B-10)I vr0 Hý,i 02

where:Dair = Diffusion coefficient in air for ith TPH fraction [cm 2/sec]Oas = Soil volumetric air content [cm3-air/cm3-soil]OT = Total soil porosity [cm3/cmr3]Dwati = Diffusion coefficient in water for ith TPH fraction [cm2/sec]H = Henry's constant for ith TPH fraction [cm 3-air/cmV-soil]

ws = Soil volumetric water content [cm3-water/cm 3-soil]

The diffusion of the pore gas through cracks in the foundation is governed by Equation B-1 1.Equations B-9 through B-11 were adapted from ASTM RBCA (1995).

Deff/m o2 i H",1 0 (Equation B-11)

where:D air = Diffusion coefficient in air for ith TPH fraction [cm 2/sec]eacrack = Volumetric air content in foundation [cm 3-air/cm3]O = Total soil porosity [cm 3/cm 3]Dwat = Diffusion coefficient in water for ith TPH fraction [cm 2/sec]Hj = Henry's constant for ith TPH fraction [cm 3-air/cm -soil]ewcrack " Volumetric water content in foundation [cm 3-water/cm3]

Chemical Partitioning

Equation B-1 2 accounts for the movement of chemicals from the soil into the vapor phase ofthe soil pore space. This is defined as the partitioning factor (soil/vapor phase) and is fractionspecific.

PF, - H,; = (Equation B-12)O.s +ks,,ip, + Hc, i a

where:PFS-v, = SoilNapor phase partitioning factor for ith TPH fraction [unitless]H = Henry's Constant for ith TPH fraction [cm3-water/cm3-air]Ps = Soil bulk density [g/cm 3]OW = Soil volumetric water content [cm 3/cm]k = Soil sorption coefficient (koc*foc) for ith TPH fraction [cm 3/g]eas = Soil volumetric air content [cm 3/cm 3]

B-946

The diffusion coefficients and partitioning factor are combined to yield a subsurface soil toenclosed space volatilization factor (VFsesp) for each TPH fraction. VFsesp takes into accountpartitioning, diffusion in the vadose zone, effective diffusion into an enclosed space and addsterms for accumulation of vapors in the enclosed space (see Equation B-13).

Deff/L,(PF~-,) S s " 3

VFMesp, i -F ERxLB xi0 m CM 3 _kj (Equation B-13)D /L -- D , + L L _

1+ +" + ,ERxLB (Dff Qi/L

where:PFsv= Soil/Vapor phase partitioning factor for ith TPH fraction [unitless]eft t

D e s Effective diffusion coefficient in soil for ith TPH fraction [cm 2/s]Ls = Depth to subsurface soil sources [cmrER = Enclosed-space air exchange rate [s"]LB = Enclosed-space volume/infiltration area ratio [cm]Deffcrack,i- Effective diffusion coefficient through foundation cracks for t TPH

fraction [cm 2/s]Lcrack = Enclosed-space foundation or wall thickness [cm]T1 = Areal fraction of cracks in foundation/walls [cm 2/cm 2]

Values in these calculations are provided in Table B-2. The term VFsesp, when combined withthe allowable concentration of contaminant in the air space (RBSLair), determines the maximumallowable concentration in the subsurface soil source area for each TPH fraction. The RBSL forthe volatilization to indoor air pathway (RBSLvi,) is shown in Equation B-14. Equations B-12through B-14 were adapted from ASTM RBCA (1995).

RBSL5 vin, i mg = B La, i["mg-ir (Equation B-14)L kg - soil= VFMsop, i

Volatilization to Outdoor Air Pathway

The volatilization to outdoor air model is similar to the indoor air model. It assumescontaminants partition into soil pore gas that migrates through the vadose zone to the surfaceand mixes with the ambient air. Dispersion into ambient air is modeled using a "box model",which is typically valid for source widths of less than 100 feet parallel to wind direction. Steady-state well-mixed atmospheric dispersion of the vapors within the breathing zone is assumed.Other assumptions listed for the indoor air model include linear equilibrium partitioning, steady-state vapor diffusion through the vadose zone and no attenuation of the chemical as it migratesthrough the vadose zone.

The calculation of a soil RBSL protective of outdoor air quality is similar to that used for theindoor air pathway. A volatilization factor for ambient air (VFsamb) is derived for each fraction,using the same effective diffusion coefficient in vadose soils and partitioning factor. Equations

B-1 0

47

B-1 5 and B-1 6 were adapted from ASTM RBCA (1995). Default values are provided in TableB-2.

"b -,F,, xlO3 cm 3 -kg] (Equation B-15)

3,eff

where:PF5 .v,v - SoilNapor phase partitioning factor for ith TPH fraction [unitless]Uai = Wind speed above ground surface in ambient mixing zone [cm/s]5air - Ambient air mixing zone height [cm]L = Depth to subsurface soil sources [cm]Deftf

_

s.i Effective diffusion coefficient in soil for ith TPH fraction [cm 2/s]W = Width of source area parallel to wind direction [cm]

VFsamb is then combined with the allowable concentration of contaminant in the air space(RBSLair) to determine the maximum allowable concentration of contaminant in the subsurfacesoil for each fraction. This concentration, RBSLsvout, is defined by Equation B-16.

,B SL~i. i gair, IB ,= R LMa,,i (Equation B-16)VFsab,

Direct Contact Pathway

For direct exposure routes to soil such as ingestion, dermal absorption and inhalation ofparticulates, exposure is not limited by Csat. The assumption is made that intake will continue toincrease linearly with soil loading beyond Csat. For the direct contact pathways, the EquationsB-17 and B-18 are solved (adapted from TPHCWG, 1999 and ASTM, 1995, respectively).

i=n i elnHI = HQi =Z" < 1 (Equation B-17)

= RBSLI

B-1148

RBSLs, i 16THQxBWxATx365day

EFxEDx 06 x (IRsii x RAFi x SA x M xRAFd, i) 1 x (VF3,, + VFpj)1RfUDo,i RJDf, j

(Equation B-18)

where:THQ = Target hazard quotient for constituent [unitless]BW = Body weight [kg]ATn = Averaging time for noncarcinogens [years]EF = Exposure frequency (days/year]ED = Exposure duration [years]IRsol = Soil ingestion rate [mg/day]RAF,, = Relative oral absorption factor for ith TPH fraction [unitless]SA = Skin surface area [cm 2/day]M = Soil to skin adherence factor [mg/cm2 ]RAFdj = Relative dermal absorption factor for i TPH fraction [unitless]RfDoj = Oral chronic reference dose for ith TPH fraction [mg/kg-day]IRair = Inhalation rate [m3/day]VFssj, = Surficial soils to ambient air partition factor (vapor) for ith TPH fraction

[unitless]VFP = Surficial soils to ambient air partition factor (particulates) for ith TPH

fraction [unitless]RfDj = Inhalation chronic reference dose for ith TPH fraction [mg/kg-day]

Similar to the HI calculation, the RBSL equation is solved iteratively to find CTPH such that HI isunder the constraint of a target hazard index of 1.0. Default exposure parameters are providedin Table B-I. The fraction specific RfDs are provided in Table 3-2.

REFERENCES

ASTM. 1995. Standard Guide for Risk-based Corrective Action Applied at Petroleum ReleaseSites. American Society for Testing and Materials, West Conshohocken, PA. E-1 739-95.

TPHCWG. 1999. A Risk-based Approach for the Management of Total Petroleum Hydrocarbonsin Soil, Volume 5. Human Health Risk-based Evaluation of Petroleum Release Sites:Implementing the Working Group Approach.

B-12

49

APPENDIX C RBCA MODEL RUNS

C-1

50

00 00 N -, 04LOCO - CD JLOcq )UC ~ E aoz Zo 0 ( N~ ' 6 -i.:6C 6Cý66wcýo

cn~ )( 00 00 00 00 00000000000000 -c,

S ..... + + +

> 1, o (M 04 LO LO 0)~ > Eo

LUN~' LO N -e N n m CD) m0 C) m ') 0 0 .t m~ ---t-c 0 .a0D000~ 0 0 00 C,~ 00 0 0 000000 -0 0

. ..... . .+ *+C00) L iw UL WwL JJ W W W W U I~ *L) C)d L iU LL6ILJ

wE . o F-t-N ~ m I -C )c 1O - )co o O t -0' O CD00 u 0oo)

N)C:.NDONOOO 00 00 00 000 N r NC>C)0 0 0

*E~

U,~~C Cl .C. .

~E E~E ~~~E E-r E E E E -

A E a2 cL

-. 0~(0.~.c~ C) C) I?~ e C)( C)C? C6~ v ,--. I?. 00CA A co Lo LO A A 00000 000 00

LO * L * mCl)m mm *) o 00C CD t - - C))0 0)( 0CI CD N 0d NtC t- C) t 0(0C,0 0 ~ C, 0C) oC).No0a CD o CD , 0-aC

L) + + b L U bL LýW+ + uC4OWWWW WWLU WWWWw ujWM WWMWWWtC) WWWW C

H : u>cl Ert- N NC)Lýt r_ >6 EON ý O O 1

0 D- D0 )C -LdoNCD(0 CD C)C o - 0C)o oC )C) S0

C) (DE Cc a) M CD co N C C) (D0; Ie OO r- C ( 0t N 0 co EoL& o D( L_ N E )~ N - N- Lo Net 4F 4 mmL C) C) NO 00 O ')u) 0) N t -- N4 '0) CD- E5c

N O C N C)N U') - N c N -M co 4 0 0 N.t No m N 000000coo000,0000 0 C0)0 00000000000

cO ý2( Nc R R - o I* -. cot D - N 't- E

N CO ~ OU ( C14' MN (((.(~ NIe I N- DC )maaCC) 0~- C) o os , C)t C)C)O O)NC )C C) C

r.E( (0 ~ - V, O0 NN(0 M DCCEo r- rD Lo6 m)c)c )oc C lN N O *cC

co) AAAAAAA0 . S

cQ 1 0 L)0 = = = = = - 0-2 n0 0 .- = m M m M m M M.- = m -c51c

W oo mmtm 0

0toLri~

.- -It MmULU

C2 Cj -N N ,4 Cjm mU-)-t D m0

N N, N m 000 C.D CDU) 0acu 0 00000000000C a0 00 00 0009 9999000D-c ............. C) + + Lb S di +

z 00 Co o g ELU02 ) C,4 No N ) C-e CDCq 0o m ~ 0 mS oS -n ýt-0 0OO000 00 000.o 00 CDC-eMMý eý 0 C 0

0,- . 0 . C . . . .. . L C )0 C) 9 90 C)

~~~~~~o I ( , Z o60 -jL Uu iwu iww LL ýd ic

cmaw , O 00f00r. 000M0L0Z 0 m M 0. D0 COj - r. w NU 00

0 C)

_N _l 04MC40)-C4ý 1 ~ ~ 1 r

._ . o Mo CCD ~ 9 C C) C- -

E 0~ m 0 I co-, . - N r- N) Na

0 ~ 0 0 0 0 0 0 0 0 .~ 0 0 0 0 0 0 0 0 0 C) 0

- -- Cco cu..N 6

E -& 2~N~ 2 E z E E CU<0-2 2= ý;E 2 0 -a0

00N0OC)4 C) (D (D to 0< <

0 O6 (D (6 L6A 0 0 0 0 0 0 00 0 0 00 0 0 0 0 0 0 0 0 00C

-A -A NA A AWAWA A A

0 00 ,- N ~ 0)0000aC 01 ~ - N- 6 C. D

. . ..0000000000000 . 0 0000000000000 a +C~~~~~~~o~i w iUww iww i U u di US Li Lb LLUS LL LW+ CU) m N N m-cr C) C)00C)M M 'I~t Cl - 0 0 toC>CD U 'ul Cý Uý Cý C> ~~~o CD o 00CIJ L o l U 0

N 1 . . . .~C~cC C C C . . . . . .. . . + +

E a.C 0ý .- o CU!UCDCa.C .CE C 20O .C vC N L N0 Nm -It

C D 0 N N c ., .C)< 0 0 )C)C m )C) -+ CDCD oo C Cd)9/ 9~A 9 9AA 0 5 A

+ .. .. .. .. +diLbLbLýd0-3 (ZOOC)W WWW WWW WWWww. MNW Www520

a 0 0 )0 00CD000)D0000D 000000000 00 0 S (.~- . h a + +,,,b,++ C +

o3 M2c to~ 0 tMIrn 30Nl - M- t- 0 cr 0D0 ntC OC Itc

0D

0o

0oot

0O

0 T0 .=D ooo0-T0E0o000

~ -9 2' m~ LO N- 6 Ný LO Cý -: ,Z -: 6 4 q- 0 0z z 6 L00 0 0 0 0 0 0 0 0 'C6 0 0

00 0 00 00

-g y - -1.

ýý .y -o - - -n r-- -0I ýC ý . . C D0

M0 r- 0 00- t- -M C0 M M . Oc l - 0 M t-C )C ,* -q r-O q q U

C~~~x~~C 00 0 0 0 0 0 m ooo ooCD~

CD2 C)~ -~ C C> C' 0 0 C CDN' -- 6o6 . ~ ~ ~ u N .O N~~~ 0 ,99999c>0C0CU)O w- 0 0 0 0 0 0 0 0 0 0 0 0 = Ew w w o o o o o od o O ý0

M M-, O -~ CI +) + + "a m a E + LO +t +l 0+ 04 CD I, +0- Wti co iD ,W W WU o o U1-C)(D C

r-~~ (Du) N.d mc a C) 0 ( LO, CD( 0U) 0

W, C,-6 Z EL'Z 5 1 61

( C ) - 0 -N -0 ) (D CDLO CD C~)N N, CD 00000 U(0 ~ ~ - o C DONco6Ce -

. L6 (6 7 C? C?)( C.,?C -- 777 ýLO t U')Lo c r- cb a 0 C-4(0 C C/

A A 'ACCA A~

2 2 E 2

CON m- 11O NI W~r M c, NMC * c tIt=Emý lLO IJLn 4 -0 f- I- 0 v: U

V-- qqq-tc : qU

C6 -:m .r: jr. N r. Ci ýLO t N CO - ---4I2 mN m mm 1- e o -CDM 0-53

0000000000000 -,OI I +4-4 4 4 4 4 4- -4 Lý d*,,i + L 4-,,,I,,,L + .i- 000WJW W WW W U Lr- V 0 NW t 0.JOt- WWUJ C)Ca~~~ ~ ~ o- 0 -) - 00-C'J -, qr0M )Ir 'e L O c.04. . .. q q1* 0 'ITCl C . V)E0G

S~~ CD O o O C)C' 0 N 0 0o CD C) 0Nom 5C

_j + ChL ýT 9999 'f+

zW w ~ w ~ ~- vic5t 6 0LiC C ~ l 6LO ~ j N -O~ o o o o M

2~~~ ~ ~ ~ U)o)octco~. 000 Lo eqq NL om DmtMNVC Mt ;C )

M_ 0a0 00 D0-0 c) N0 o 0 0 c., 000 C

C

9 0 0 )

en 0)0) Co o 0 0 ~C) CDr-~~~ w o N 4 -1 CD Ia CO N C tco o 0Cl c () I 0 ~obo 0 ON CD M - C: -D 0 .

c6~ ~~ A c6 NC') Nr-06 ýo ý

0 ) O 0 0 0 0 0 0 0 0 0 l~ ~ * i) C) ~ ( 0 )+a M + M + 4-4 +Z +Z +M-+ + . o 0 0 0 0E) LJU WJJ W W j W E. = E E EE ~~ E a.2 20.ýN 2 2

oo C? C? - N\C' -7)ýto 0 N 999?(0 CD0)0

S 00000000000000 = 000 0 0 000 -DoooC )oC

0) '- ) 0 I 0- ;; 00 ý- C') 0) in M CNMO . ý,-

qU E N 0C i) *14:6~ 0ý l V )ULU -I) T

-. ~~ m~o - - J~ N N- J m' 0 O CI 0w0) 000 000000C>0 0 00 oC C(U-~~I +44444444444w w4- w 14 14 + 0

9 9 9 +0 0 0DLN o.-t. l oCOL-. M - ciLo0 " 1CUCMUUC U

_) 0 C

-j ~ ~~~~ ~ ~ ~ ~ Ný ECOi) ~lL 4C C )c)1E U) 0 0 CD CD .0 C= ,. C> " A K-'N CO- MN)m0 0 CC/) A A A A A A A ACA

. . .. . . . .. 9 9 0 0 00-5(w w w w w U w w w w + ý h ý LL+54

2) LO -; - --- -p n p mC D - N - - - - 0 CM0000000000000 000000000 o000

00 000000000000000O0000000000000 co0Eo z * i 4Cý 6vi0 C

<0 0)* LJwwUwwwwwwwwLI wwoww"."."wwww 0-> CN 0)LCD -o MD0~ N 0)O 0 000 -)~ODC 0 000

w o0 Z N r--i ' -Cir.: o C 066 ~C6 r-vi 66

m -2C)J CD C'J D C ') C O' o0 0 -CC 0 0 CD 0 CD 000 0 0 C Dr

0 16 Q L6_) aww w w w w ww WuWWJWWUJWWW Clau

0 ,L Er ON ) 0 )N M0 MM )CD- Il O 0 1-Cl)L OD -C 000 0 CCN 0 0 M -04 N V*T00 IR0 C'4 ') r.. CD 0 - 600 C) - C

NC')Ný C ')CSJr- C-3 ,-: N -N 0 4 ~0 C6 6 vi N6 0 0 0 0 e

N) 000000000000N -CD- C C C40 0 0Q0000 00 a

CD CD CD 0C D C') -0'0 ) CD CDo aC>D 0 CN0) o - NO)C)600.D-C

C) .99 M .- tZ - m 00) C ) .C

(6N CN Mt- N N D D- jAAAAAAE

Lt)~D ~C')C')C') CJ)C C'0 ' 0 c . '. -. , 000000000000 n 00 00 0 00 0

m~~~~~~ ~ ~ ~ + + om UcII m~ E - E - E - E + m 1+ + Cc EE+

EONO -C 2 2--2 ')2

Z 0 C6 ~ 0ý 00 (6 c) C?)' (? ? CD 000 0C)A~ OA 00AL ) bA-

O 1-TCDC .-.-MMM-MCDMLOr-- oomo 0 )

-N66 ---- coo

11I .+.++.++.++.++.+++ C) ++ Lh+ ''''US ''L L ..

M 0 C0 (D 0C. 0)C')CF) CC)N N- 004D 0 Ca C)~ ClM E r 0 M. 0- M 0)M' M- - n 0))C '4ý -e 'Iot (CO)r0)00 -EoEl' o0x CNJ N.-m - w F- Lo m--ý 00q -6 q i~ > q~~ 66 q Clq) t

0 _ l N C') NCl)NM Cl'C) -N N.r- ( -1 0 C) N 0

-N - N'j ,4-t N 0000D

NDM -D O O0)C0) )N 0) 0 F M c 'r ') M LO to _7

> M: ).N M to 0 o _ _ )C

0) Cý M __ M 0aCN , ') NCD M- 0)0M O0-Ce )0 )CD

I- w - 0*)

2: 0) N DON- NCD4 CO - o CD r. 1- C N NCD C3- 10)

2) AA AA A N6 -:m , l 4Cý66C DMNt-T N00C

c0-w5

000000' 000000M-,tcoV 0M 00C M0 o 0 00 00

0iI w IwwI IwI wbww WWWLUW J

N N - N .- N '- M co LU "to

I 0w w w w w w WW W W ww .0;-WM

uJ

0 ~ ~ ~ ~ ~ ~ ww w w ~ w w w w w w d +weL ýdiL i +LM F-0~ 0~ 00 N ) N N o mwm0aM0r-Cl oL I -C

0 Cl ) C m - C-4 4 F o a aI- f 00 0 C NL 0 - 0

la D 0 00c)a00C a aa 00 a000000 0. . . .. . . . . . . . . 0

c w w ~ N ~ C w w iE Lý L LU iU ý

.2

E E EE E~E E E2 -- I2

r-r r. A -(bC rC -- C' -ý N

AA AA AAA A A A A A A Aw

.~~ .+ ...... + + ++MLo N Lo N N~ r- 1, U' - t-t-rc )0

'a0000000000000o :-_ 0000000000000c L)0 b + .+++.... r , + C)+

Z > C)W CW)WWWW M- W J WLIJ W WW L 0* M r- -, -

0ýCi41:C l 06~' 6 LO6 a tN M 1-6 66 cLo NC- ý o-0 00 -

1,- -ac~ww wwUJ uWWOWUIW UJ WLJULJ cW

R ~ ~ ~ o . -l RRc

Wý 06' ýT:N 4 ~ 60 ~) a-:0MNr t N0C

0) 0000000000000 ~ c 000 a 00 a0 5000a0 00a 0

VMWWWUWWWWUJLJWWW C.) ww wWW WW wwwwjrl-0 - -0 00 c ' 0 O OC L O DLo aao0O

L)E ( )0 taWC)C 0 ~C~) 0) COL )CqNC C N R q . . . .COi f l

co Cc =- = M

E E E == E E EE0.9 o _2 2 _ -z

=2- c 2 2--9 -2-2 -L- 2

Ao A A A A Ao A C/

C-756

a M~ 0000000000000o Oooooooooo0 0 00C l

0 2 -~~ LO M~ U-j M~ '0 Cýr t M -cr 0 0 ~j - 0. ,d. r. 0 c 0 0 0 OC\

LU

M 000 l c0 ,0 Do0000 0 >o0000C,0 C) lt)

Z +6 + + +ý +ý +6 +: CD +o a + +o )0 0 0wwwwwjwuuu

2 g N N g N0 m w 0 p 0000C Ca- 0000000 I.00 000C aCL

f. L r r.. 0? M to C - i- M~ M -C e )rC ' r r- r0 C) C~) 0)C,AN A) A 0' -N -I -'t0 oe r t C'J

cm ),0 00C D0000 0000 o 00000000000o0C,0 0

W M' C-0\-,- C0C' M~ ~ C r-.a 0- N' MC r. WT 00C a0

U 0)' 000 00 00 00 00 0000000000.2h ~ S .2+= 4+ . -ým0O ~ m m -Z6 Mm MW m M

LU - E m E -- 2C -2 -~CO t) E.N2 .'- .OO 2 2o2

r.- co 0N0( )0

0

0 0 1- o 0) C 'JCo ~ CftU21 o 0 *- CD CN4C CO co COLo (_~ A' O C'J - N" A- A NNCC~ N" 0

_ C) C~)C 0 a CDJ CD~ CD 0 C) ) C 0 ~ 0 0. a 0j\, C ., 0 C)000C)P

CO N.O6,0 C) wwwwww0- M -lC PO.- O (0 W' 0 000 L

LO"J C- r- COC L.0)N O ON ' 0 0 M 0 000 (

000 c 0 0 00C)C )c a' CDOCOU)a-aOC) 00 -aCOL:,-L

w . .. T . T . . . . . . 0 '5 + C2 + ýý bL 6L bL b...-ýCODO WW W W W W W ,,,,,,,,,,,,,,,w ,w 0 -

> M 0CD toM 0 0 N M -0-8 M-M- U)ML ncý 0LU E -u) o-e( c Nc v o ) -- ) c ý 0 ,:"t 57>

CD w w wWjw w w jww w w w- Wu uLWWLwwjjw

to --r00CU) m D000 00 D0 0 00000 C0 C)c0 > 0 900 C00>0~> wwwwwwwUwwwww w WWWWWWWWL.I;J6w-

o-C O 0 0 0 0 ~ 0 0000000000 00C)0 C) E o:>c)

-- jL ~ eN Omc l l 't oCCD O.-oCl) m E; e to C, CD C

0 0 0 04C 5O04c 04 O 00-00 0~0 C)o o D 0 o ) C)0 0 ) L

0 = .o20Z +0 ~ ~~ ~ ~ r- coF-L ,F I Ot )0 )1 C:). Sl *.) 0) - -) LO L 't r 0404 C)C0 NC)0 m- q04 I O C COr-o - Tr, 0 6 -JI0CDE

C.0) +l o+++ 9 0 0w w w w w wUw ww w w w udi WUJWWWWU U uWWwLu w L in

E C.2

0 0 0 0 0 0 0 0 0 0 0 00. C.0m -m m + + + + = +- +- + + + +u m4 + +t m m7ý.C =ELL-EE mm E

0 40 4CO0COO1.c)CO, 0

U)'AA AA A7-CO-CA w C~~.0C.SN'

Co 0. -tmC)c

oLOmm0 T-0

CDO4 O 4C 0 0 , C) o 0ý CD 04D -04:0 , C) C 0 S C+ . . . . . . . .+ + + + + 0 r00 0 0 00 0L~ i UJW U.) ww jww ~ W W l ~ uu w w w v LM "IM ItM - O OD 0) L C 0C0 t0) r.- CO(.0 0cto 0 00 C)cC)t

0 0 )

MO CO 0 ,'3 0 l )aC )L) u) E 't m m m O OI-m _ -O CD '7 'I )r-( O ýc

cn o E 2 ~ ; -S - 0 oa oc~c~oo 00 :i-_ CD o C) C) 0 9 9 0C ) C S rig 1 .. .. . . . .. +Uý ý AAAAAAA d U- 0 LU i w w L ui w w w w LU Lr u w U '

Z ) Z L 1 m N o m -q NC) a l)0 C U 0 14,N coa0-9 Cuj a C - vt CD - N W - 0 :) (D ce I -5 8t

- 2Lo ýt 0 -, q *M-tML OL t00) oa000000000000 0000000000000 S

. . . . .. . . . .

Cl)..~ cm 0C M 0 M - I M -I -It M ' 0) N N- I'0 Ci)..... C-

Cd, 00 000000c000 000000 000 :- Da a D0 0 00C ac C)N

LULUWWWWW W W W W W

> M CO - 0 M r- C-.'r - .- 1-. 0 N0 CCC 0CR q O7 U ý0COCO)o

LU

Smocao0o00000000 f= 00000000D00000C S '0=bwwwwU wwww www~U W-UWWUWWJWLWWWW =eo

M r-N) 0 N ~ CO O Q 0 N O 0 LoCC) -'):t C) 00 (0

C)O

0. M aam N w 0 OýCý C CR r*-' 1-NOD OCO OC

0 M 00 0 0 0 0 0 M N0M0NE00000000 00ýC lC D C) a CD a 0 C) m 0N CO 0 0CD 0 a a a aO 00

. .. .. . .. . .0 . . .. . di O O. 0Nw COCOCw )N.COCO -- 0)4 wtN N O)600

E .r-ow0 a conw_ 0 _I 0M00co00aCCO Ne CO6OO0.,GC )Nc4) ý-ý c6 6 vi N c6 CO Ni C= 6 . . .

C O' N C UON (n0N(0 0MCO~~A~~CO

0N~~2N A 8

0000000000000 C Co E -000 0E00 00

< < CO) ON a 0)4 U')C LO 000Cl o C? CC) N? C C N 0) 0 N C C Co N C-4 N O CO 0 0 LO) -oM

N NO gb rC. CON L COco 6 6 6coc

0 00aa a 0 0 ~C> 0 CD D LC) 0 C:CCCa 0 a a>

z a~0WWWW w w w w WWWiWWWWL ww- WWWUWUWJWLIU

LU 0)0 at

CM N M M CO M ~ C M -t -t 0 C') r - - -N NC -) O CO N ,CO000C

z N M -M Cd 0' M' 0 M ( 'e M ) LO-O to N= C-N C)Cdoo

N N NOC 6C 6C <- 6 :vi646 lNC)CO 4 LOCC~-

_ NC C N CU ) N CW NO OO , ý-'- -. - C') N '

N ;: ) ý:M M NCD NCO qt a ,l -e- OV - 0 e C C 00 n :uj M 0 CO- -qN 0 CO- 0CONQP: U .ý 00N" q C.O : --Eý 06AA -C4 ý -4- '-'- 06C Cc oM0 ) - t N666

COA AA A AA A AwC aa,

S) ý C C a 0a 0C)a aa ) 00)C-la aC>C a ) ). . .. . . . . . .59

C)C~OOO0 00 000000oooo o0o 0000 _

-; m - 0W o0 0 * ' eCo

to ýt 0Ne j ~ ~ o C) C

C;, w w w w w w .. .iLI~W .. Q.. .. ..

wS0 0 0 D0 0 0 a00 0 00 ' 0 0 0 0 0 00 C:

0 l.wwwuwwwwwwwwww~ WWWWLIIWWWWWWW =,6w"m

0 ý 0 r.-r.-N mm mw mr..M ''r M r~- 0 0 m ýr -- 0 0 C O 2 L 0C

0) CLw- 'tr - NN ~0

0)wwwwwwwwwwwww 0WWWWWWW0 M r.- 0- 113' 0 N 0 M N M 000 M t 000 0 u

S2

E E = E EE E_E o 2- .2-o .- o E r- E'r-E 2 2 -F

2D 'c 2 c -- <<<

CCW W WU W W W C? r7.WU U U~ w~ 0?- -- ýC6~ Cc2 CD CO r.- 6 6 64 Cý ccf 0 ' ~C 0

LO- O u l)c C)c m0 ~ D mo Lo mEoLOLOL N-ý -00C

M It 0000V00 00000 00O- 0000 000 000 0 0 r-' -*C ,C

0. N ND C 0 6 N ' N-NNmC

.- a w w ww w w w WW UU.JLW W WW w

Z >) w

< ) 0000000000000 e- C0) 00aC)000000 )0000 0> S

ZrmwwwwwUwwwwLIJUJ EUWWWWWWWUJWWWWW0 ~ ~ ~ ~ ~ ~ 0 0 UN L . OC o, O-tC - t ý O1 . ,NC DC =w E cn 0- D-ItC 'rNmC -oc.t~oo 'Vr. 0t r- -r I CDf--~ C) ( 0000 2C 0

N~~~~~ Cl 00C VC N -N -ýCD 0 coo 0 00 CDCCC 0 l -'Nto-NC40C C) r-

.U.O .E E. . 00 .... 0.2o) .C) o 000 o 0 CD ) C C)ND M~ & < <~ LO 'I_ ' DC : )

0 OC '0 M~ COI )M- mc I2 m ( Vý 004 CO C q0CU AA AA A mA A C6C -' D - - ý4 - l i

E-la602