U S EPA P t l H d b VU.S. EPA Petroleum Hydrocarbon …iavi.rti.org/attachments/WorkshopsAndConferences/02_Hers_Truesdale...Methane ggg generated from gasoline containing ethanol

U S EPA P t l H d b VU.S. EPA Petroleum Hydrocarbon Vapor Intrusion (PHC-VI) Database – A

C h i A l i f A tiComprehensive Analysis of Aromatic and Aliphatic Hydrocarbon Data

Ian Hers, Golder AssociatesR b t T d l RTI I t ti lRobert Truesdale, RTI International

22nd Annual International Conference onSoil, Water, Energy, and Air

San Diego, March 19-22, 2012

PRESENTATION OUTLINE

Acknowledgment: Great work by Robin Davis (in part the source of this database) and complementary efforts by Matt Lahvis and Jackie Wright (& input by many others)

Motivation and project objectivesD t b t t d t t

Lahvis and Jackie Wright (& input by many others)

Database structure and contentScreening indicators for dissolved versus LNAPL source sitessource sitesDatabase analysis methodsDatabase analysis results and recommended exclusion distancesInclusionary criteria

March 27, 2012

2

MOTIVATION AND OBJECTIVES

AF ? Approaches for assessment of PHC-VI that do not account for aerobic biodegradation are overly conservative Through (i) empirical data analysis and (ii) modeling studies develop better(ii) modeling studies develop better understanding of conditions for vapor attenuation and conversely potential f l t PVI thfor complete PVI pathwayDevelop better screening approaches based on exclusion distances

GOLDER ASSOCIATES

based on exclusion distances (together with inclusionary criteria)Focus Subtitle I UST sites

MOTIVATION AND OBJECTIVES

Approaches for assessment of PHC-VI that do not account for aerobic biodegradation are overly conservative Through (i) empirical data analysis and (ii) modeling studies develop better(ii) modeling studies develop better understanding of conditions for vapor attenuation and conversely potential f l t PVI thfor complete PVI pathwayDevelop better screening approaches based on exclusion distancesBio zone

GOLDER ASSOCIATES

based on exclusion distances (together with inclusionary criteria)Focus Subtitle I UST sites

CONCEPTUAL SITE MODEL

Aerobic biodegradation of petroleum hydrocarbon vapors is

a) LNAPL SOURCE

UNSATURATED ZONE sharp reaction front

O2

VOChigh mass

fluxpetroleum hydrocarbon vapors is robust and relatively rapid process

CAPILLARY ZONE

SATURATED ZONE

VOCsflux

constituent distributions

Key is sufficient oxygen supply relative to oxygen demand , which is a function of PHC flux

b) DISSOLVED-PHASE SOURCE

Owhich is a function of PHC fluxSignificant difference in source vapor concentrations and flux for CAPILLARY ZONE

UNSATURATED ZONE

limited mass flux sharp

reaction f t

O2

VOCs

dissolved vs. LNAPL sourcesSATURATED ZONE

front

constituent distributions

Lahvis et al. (2012)

March 27, 2012

5

( )

CONCEPTUAL SITE MODEL

Conceptual site factors that could result in increased potential for PHC-VI:potential for PHC VI:

Shallow LNAPL, large releasesPreferential pathways – direct connectionsLarge buildings and capping effect – modeling studies suggest only potentially significant at LNAPL sites, will also depend on O transport through concrete whichalso depend on O2 transport through concrete, which can be significantMethane generated from gasoline containing ethanol –g g gpotential significance not well understand, research in progress to address this

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6

INCLUSIONARY CASE STUDIES

Sites with likely or confirmed complete PHC-VI pathway and oxygen < 1 % in subslab vapor

Site DistanceLNAPL-Building

Building Size

Source TPHVapor Conc.

(mg/L)

Faciilty Comment

C (L t 1 5 ft 2 300 ft2 100 R fi Sh llCasper (Luo et al., 2007)

1-5 ft 2,300 ft2 ~ 100 Refinery Shallow source

Chatterton (Hers t l 2000)

5 ft 610 ft2 ~ 40 Petro-h i l

Only when ΔP10 Pet al., 2000) chemical ~ 10 Pa

Perth (Patterson & Davis, 2009)

10 ft 2,700 ft2 ~ 20 Refinery 30 ft. buildingapron 3 sides

Unknown (Luo et al., 2010)

25-30 ft 2,100 ft2 ~ 60-160 Refinery Capping effect from geology

All large volume releases

March 27, 2012

71 mg/L = 106 μg/m3

g

DATABASE PROCESS & SITES

Robin’s database starting point (great body of work!)ACCESS and EXCEL databases created, with references

Minnesota 22Utah 15

Added data for new sites (primarily Maine) and for existing sites (new fields)Checked data, screened

Maine 12 California 7Ohio 4N J 3

Checked data, screened data based on quality indicators, added filters – process to ensure MN

CA New Jersey 3Maryland 1South Carolina 1US unknown 1

process to ensure completeness and “data of known quality” Most gasoline sites (data UTME

CA

Canada 3Most gasoline sites (data obtained 1995-2011)38 sites with buildings

UTME

70 Sites

March 27, 2012

8

DATABASE FIELDS

Background data: Site location, generic soil description, contamination type, etc.Facility type: UST, terminal, refinery, petrochemical.Site conditions: Soil type, porosity, moisture, surface cover at soil gas probe (ground pavement building)cover at soil gas probe (ground, pavement, building), depth to water table, depth to contamination, etc.Soil gas probe data: Depth, construction, & lateral distances: well, UST facility infrastructure, building.Analytical data: Date, analytical method, QC data, soil chemistry groundwater chemistry soil vapor chemistrychemistry, groundwater chemistry, soil vapor chemistry.Building data: Building use (e.g., residential, commercial, institutional), foundation type, building size, etc.

March 27, 2012

9

) y g

DATA SCREENED OUT BASED ON QC INDICATORS

Analytical data obtained by unacceptable methods [Acceptable PHC methods: EPA Method TO-15, EPA Method TO-3, Modified EPA 8260/8015 and Massachusetts Air Phase Hydrocarbons (APH), Acceptable fixed gas methods: ASTM D1946 and EPAAcceptable fixed gas methods: ASTM D1946 and EPA Method 3C]Soil gas data from fractured rock systemsBenzene concentrations in groundwater below detection levelLateral spacing between groundwater monitoring well andLateral spacing between groundwater monitoring well and soil gas probe (for paired data) > ~ 30 ft (information not available for all data).

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10

NUMBER SOIL VAPOR ANALYTES

Benzene 879Toluene 362BCH4

879

362594

357Ethylbenzene 362Xylenes 377Naphthalene 266224 Trimethylpentane 43

B

T

CO2

362

36237787

645224‐Trimethylpentane 43Hexane 147Heptane 143MTBE 121

EO2

3772364314714312187

772 1,3‐Butadiene 87TPH 772MADEP TPH FractionsOxygen 645

XNTPH

Oxygen 645Carbon Dioxide 594

823 paired benzene groundwater-soil vapor records

March 27, 2012

11

p g p

DATA ANALYSIS OVERVIEW

Soil gas proximate to LNAPLor dissolved source?

Database contains data from following facilities:

1 Exploratory Data Analysis

g1. UST2. Refinery3 Terminal1. Exploratory Data Analysis 3. Terminal4. Petro-chemical

A l i d t d f2. Vertical Distance Method Analysis conducted for:1. Dissolved (all facilities

but mostly UST)

3. Clean Soil Thickness (Davis) Method

y )2. LNAPL (UST only)3. LNAPL (all facilities)

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12

LNAPL PHC INDICATORSType Indicator Measures & Screening Values

Adopted for this study Direct LNAPL presence [controlling

indicator ~ 80% of time]LNAPL in wells, sheens in soil, shake and dye test resultsindicator ~ 80% of time] shake and dye test results

Indirect Concentrations approaching (>0.2) effective solubilities or “Csat” concentration [controlling indicator ~ 15% of

Groundwater - benzene > 5 mg/L - TPH > 30 mg/L (gasoline) Soil[controlling indicator 15% of

time] Soil - benzene > 10 mg/kg - TPH > 250 mg/kg (gasoline)

Indirect Proximity to source area likely to be impacted with LNAPL

Soil gas probes < 20 ft UST infrastructureto be impacted with LNAPL

[controlling indicator ~ 5% time] infrastructure

Other potential indicators Indirect Fluorescence response in

LNAPLUV, LIF, or UVIF fluorescence

LNAPL rangeIndirect Organic vapor analyzer (e.g.,

photoionization detector) >500 ppmV

Indirect Petroleum hydrocarbon vapor, PHC vapor & CO2 concentrations

March 27, 2012

13O2 and CO2 profiles that show no decrease

Indirect Elevated aliphatic soil gas concentrations

Hexane > 100,000 ug/m3 (Lahvis et al, 2012)

DEPTH TO TOP OF CONTAMINATION

NAPLSoil gas probes

Top of LNAPL smear/soil contamination zone estimated from logs, PID results, historical maximum water table height

DISSOLVEDWater table measured approximately same time as soil gas

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14

VERTICAL DISTANCE METHOD

Compare soil vapor concentrations to risk-based vapor concentrations for varying source-building distancesFor benzene, estimate probabilities for vertical source-separation distances bins: ≥ 0, ≥ 2,.., ≥ N, for dissolved & LNAPL sources:LNAPL sources:

P [Cv <=Cthreshold /z > d; NAPL or dissolved]

P = N [C < C ] / N [TOTAL]P = N [CV < CTHRESHOLD] / N [TOTAL]

Non-detects addressed through ½ DL replacement method and Kaplan-Meier methodand Kaplan Meier methodProbability > 95% less than threshold suggested as a basis for exclusion distance

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15

CLEAN SOIL THICKNESS (DAVIS) METHOD

Vertical thickness of clean soil required for benzene vapors to attenuate below 100 ug/m3vapors to attenuate below 100 ug/mMethod 1

Distance from top of contamination to first soil gas probe where benzene vapor < 100 ug/m3

Method 2 InterpolationDi t f t f t i ti t i t l t dDistance from top of contamination to interpolated distance between probes with benzene vapor > 100 and < 100 ug/m3

Both methods subject to maximum vertical probe spacing (10 ft) constraint to ensure adequate resolution

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16

RISK SOIL VAPOR CONCENTRATIONS

General approach for estimating risk-based vapor concentration (Cthreshold)

Cthreshold = Cair/AF

Where Cair = risk-based air concentration (from EPA IRIS database for lifetime exposure and no amortization)AF = 0 01 (based on modeling studies & EPA (2012)AF = 0.01 (based on modeling studies & EPA (2012) database for subslab AF where 50th and 95th percentiles of the subslab attenuation factor = 0.0025 and 0.02)For benzene, thresholds (50 and 100 ug/m3) adjusted based on practical considerations [within 10-5 and 10-6 cancer risk level ]

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17

cancer risk level ]

GROUNDWATER FOR DISSOLVED AND LNAPL SOURCES

100000/L)

Benzene Groundwater Concentrations

NAPL (all) N=198

1000

10000

Conc. (ug

/

Dissolved N = 98

100

1000

ound

water

10

Benzen

e Gro

10% 20% 40% 60% 80% 100%

B

Cumulative Frequency

March 27, 2012

18

q y

GROUNDWATER vs. DEEP VAPOR

Benzene ‐ GW vs SV ‐ Dissolved (N=45)

DISSOLVED LNAPL (all)Benzene ‐ GW vs SV ‐ NAPL (all) (N=127)

1.E+05

1.E+06

1.E+07

m3)

( )

1.E+05

1.E+06

1.E+07

/m3)

Benzene GW vs SV NAPL (all) (N 127)

Henry's Law prediction, CVH

Henry’s Law prediction

1.E+02

1.E+03

1.E+04

or C

onc. (ug

/

CvH/ 10

1.E+02

1.E+03

1.E+04

or Conc. (ug/prediction

1.E‐01

1.E+00

1.E+01

Soil Vapo

1 E 01

1.E+00

1.E+01

Soil Vapo

1 m

g/L

1.E 011 10 100 1000 10000 100000

Groundwater Conc. (ug/L)

1.E‐011 100 10000

Groundwater Conc. (ug/L)

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19

VERTICAL DISTANCE METHOD - DISSOLVED

33 sites233 data points

1.E+04

1.E+05

1.E+06

/m3)

Benzene vs. Distance ‐ Dissolved

> DL

< DL

949698

100

Threh

old

Benzene Conditional Probability ‐Dissolved

1.E+01

1.E+02

1.E+03

Vapo

r Con

c. (ug

100 ug/m3

50 ug/m38688909294

ty Vapor Con

c. <

Probability < 100 (1/2DL)Probability < 50 (1/2DL)

1.E‐01

1.E+00

‐10 0 10 20 30 40

Benzen

e

Distance soil vapor probe & contamination (ft.)

808284

0 1 2 3 4 5

Prob

aili


y ( / )Probability < 100 (KM)Probability < 50 (KM)

20

25

(%)

Oxygen vs. Distance ‐ Dissolved

1.E+04

1.E+05

1.E+06

. (ug

/m3)

Xylenes vs. Distance ‐ Dissolved

> DL< DLRBCv

5

10

15

Oxygen Co

nc. (

1.E+01

1.E+02

1.E+03

enes Vapor Con

c.

March 27, 2012

200

5

‐10 0 10 20 30 40Distance soil vapor probe & contamination (ft.)

1.E‐01

1.E+00

‐10 0 10 20 30 40

Xyle

Distance soil vapor probe and contamination (ft.)

VERTICAL DISTANCE METHOD - DISSOLVED

1.E+04

1.E+05

c. (u

g/m3)

C9‐12 Aliphatic vs. Distance ‐ Dissolved

> DL

RBCv

1.E+05

1.E+06

1.E+07

(ug/m3)

C5‐C8 Aliphatic vs. Distance ‐ Dissolved

> DL

< DL

RBC

1 E 01

1.E+02

1.E+03

phatic Vapor Con

c > DL

< DL

1.E+02

1.E+03

1.E+04

hatic Vapo

r Co

nc. RBCv

1.E+00

1.E+01

‐10 10 30 50

C9‐12 Alip


1.E+00

1.E+01

‐10 10 30 50C5‐C8 Aliph


1.E+04

1.E+05

c. (ug

/m3)

C9‐C10 Aromatic vs. Distance ‐ Dissolved

> DL

< DL 1.E+04

1.E+05

. (ug

/m3)

Hexane vs. Distance ‐ Dissolved

> DL

< DL

RBCv

RBCv

1 E+01

1.E+02

1.E+03

phatic Vapor Con

c

1 E+01

1.E+02

1.E+03

ane Vapor Con

c

March 27, 2012

211.E+00

1.E+01

‐10 10 30 50C9‐C10

Alip


1.E+00

1.E+01

‐10 0 10 20 30

Hexa


VERTICAL DISTANCE METHOD – NAPL (UST sites)


1.E+05

1.E+06

1.E+07

(ug/m3)

Benzene vs. Distance ‐NAPL (UST only)

> DL

< DL

80

100

120

Threshold

Benzene Conditional Probability ‐NAPL (UST only)

1.E+01

1.E+02

1.E+03

1.E+04

ene Vapo

r Con

c.

40

60

80

y Vapo

r Con

c. < T


100 ug/m3

50 ug/m3

1.E‐01

1.E+00

‐10 10 30 50

Ben

ze


0

20

0 5 10 15 20 25 30 35

Prob

aility


y ( )Probability < 100 (KM)Probability < 50 (KM)

20

25

30

)

Oxygen vs. Distance ‐ NAPL (UST only)

1.E+05

1.E+06

1.E+07

(ug/m3)

Xylenes vs. Distance ‐ NAPL (UST only)

> DL

< DL

RBC

10

15

20

Oxygen Co

nc. (%)

1.E+01

1.E+02

1.E+03

1.E+04

nes Vapor Con

c. RBCv

March 27, 2012

22

0

5

‐10 10 30 50

O


1.E‐01

1.E+00

. 0

‐10 10 30 50

Xylen


VERTICAL DISTANCE METHOD – NAPL (UST sites)

1.E+05

1.E+06

1.E+07

or Con

c.

C9‐12 Aliphatic vs. Distance ‐ NAPL (UST only)

> DL

< DL

RBC1.E+06

1.E+07

1.E+08

or Con

c.

C5‐C8 Aliphatic vs. Distance ‐NAPL (UST only)

> DL

< DL

1.E+02

1.E+03

1.E+04

12 Alip

hatic Vap

(ug/m3)

RBCv

1.E+02

1.E+03

1.E+04

1.E+05

8 Alip

hatic Vapo

(ug/m3) RBCv

1.E+00

1.E+01

‐10 10 30 50

C9‐1


1.E+00

1.E+01

‐10 10 30 50

C5‐C8


1 E+04

1.E+05

1.E+06

por C

onc.

C9‐C10 Aromatic vs. Distance ‐ NAPL (UST only)

> DL

< DL1.E+05

1.E+06

1.E+07

(ug/m3)

Hexane vs. Distance ‐ NAPL (UST only)

RBCv

RBCv

1.E+02

1.E+03

1.E+04

10 Alip

hatic Vap

(ug/m3)

1.E+01

1.E+02

1.E+03

1.E+04

ane Vapor Con

c.

> DL

< DL

RBCv

March 27, 2012

23

1.E+00

1.E+01

‐10 10 30 50

C9‐C1


1.E‐01

1.E+00

‐10 0 10 20 30

Hexa


VERTICAL DISTANCE METHOD – NAPL (all sites)


1 E 05

1.E+06

1.E+07

1.E+08

g/m3)

Benzene vs. Distance ‐NAPL (all)

> DL

< DL

90

100

Threshold

Benzene Conditional Probability ‐NAPL (all)

1 E+01

1.E+02

1.E+03

1.E+04

1.E+05

Vapor Con

c. (ug

60

70

80

y Vapo

r Con

c. < T


1.E‐01

1.E+00

1.E+01

‐10 10 30 50

Ben

zene


40

50

0 10 20 30 40

Prob

abilit


Probability 50 (1/2DL)Probability < 100 (KM)Probability < 50 (KM)

20

25

30

)

Oxygen vs. Distance ‐ NAPL (all)

1.E+05

1.E+06

1.E+07

g/m3)

Xylenes vs. Distance ‐ NAPL (all)

> DL

< DL

RBC

10

15

20

Oxygen Co

nc. (%)

1.E+01

1.E+02

1.E+03

1.E+04

s Vapo

r Con

c. (ug RBCv

March 27, 2012

24

0

5

‐10 10 30 50

O


1.E‐01

1.E+00

‐10 10 30 50

Xylene

s


VERTICAL DISTANCE METHOD – NAPL (all sites) – EFFECT SURFACE COVER

100

d

Benzene Probability Different Surface Cover ‐ NAPL (all)

25Oxygen for Different Surface Cover ‐ NAPL (all)

80

90

nc.< Th

reshold

15

20

tration (%

)

60

70

ility vap

or C

on

Probability < 100 ug/m3 ‐ Building Scenario

10

gen Concent

40

50

0 10 20 30 40

Probab

i y g g

Probability < 100 ug/m3 ‐Ground Cover Scenario

Probability < 100 ug/m3 ‐ Pavement Scenario0

5

‐10 0 10 20 30 40 50Oxyg

O2‐ BuildingO2‐GroundO2‐ Pavement

Distance soil vapor probe and contamination (ft) Distance soil vapor probe and contamination (ft)

March 27, 2012

25

VERTICAL DISTANCE METHOD - SUMMARY

Dissolved Source

LNAPL Source-UST sites

LNAPL-All sites

Oxygen Most O2 conc. > 4% and no

O2 < 1% to 6 ft separation

O2 < 1% to 11 ft separation> 4%, and no

O2 < 1% separation separation

Benzene (100 ug/m3

PKM > 97% for Ds = 0 ft

PKM ~ 100% for Ds = 15 ft

PKM > 90% @ 15 ft and ~ 95% @ 30 ft

threshold) Benzene (50 ug/m3 threshold)

PKM > 94% to 95%, for Ds = 0 ft to 5 ft

PKM ~ 100% for Ds = 15 ft

PKM > > 90% @ 15 ft and ~ 95% @ 30 ftthreshold) ft to 5 ft 30 ft

Xylenes Ds <= 3 ft Ds <= 11 ft Ds = 12 ft Hexane Ds = 0 ft Ds <= 4 ft N/A C5-8 Ali Ds <= 3 ft Ds <= 3 ft N/AC5-8 Ali Ds <= 3 ft Ds <= 3 ft N/AC9-12 Ali Ds = 0 ft Ds < = 2 ft N/A C9-10 Aro Ds = 0 ft Ds <= 2 ft N/A Ds = separation distanceDs = Separation distance where concentration less than threshold

March 27, 2012

26

pDs = Separation distance where concentration less than threshold

CLEAN SOIL METHOD - DISSOLVED

30p of

Thickness Clean Soil (Davis Method) ‐ Dissolved

Thickness Clean Soil Attenuate Benzene< Threshold ‐Method 1

20

25

l (from

top

n) (ft)

Benzene < Threshold ‐Method 1Thickness Clean Soil Attenuate Benzene < Threshold ‐Method 2Thickness Soil Where Benzene Not Attenuated < Threshold

10

15

Clean Soi

amination

5

10

ckne

ss of

cont

01 10 100 1000 10000 100000

Thi

Benzene Groundwater Conc. (ug/L)

March 27, 2012

27

CLEAN SOIL METHOD – LNAPL (UST)

30p of

Thickness Clean Soil (Davis ) ‐ NAPL (UST only)Thickness Clean Soil Attenuate Benzene < Threshold ‐Method 1hi k l il

20

25

l (from

top

n (ft)

Thickness Clean Soil Attenuate Benzene < Threshold ‐Method 2Thickness Soil Where Benzene Not Attenuated < Threshold

10

15

Clean Soi

taminatio

5

10

ickness of

cont

01 10 100 1000 10000 100000

Thi


March 27, 2012

28

CLEAN SOIL METHOD – LNAPL (All)

30op

of

Thickness Clean Soil (Davis Method) ‐NAPL (all)Thickness Clean Soil Attenuate Benzene < Threshold ‐ Method 1

20

25

il (from to

on (ft)

Thickness Clean Soil Attenuate Benzene < Threshold ‐ Method 2Thickness Soil Where Benzene Not Attenuated < Threshold

10

15

f Clean

Soi

taminatio Not Attenuated < Threshold

5

10

ickness of

cont

01 10 100 1000 10000 100000

Th


March 27, 2012

29

CLEAN SOIL METHOD – SUMMARY

95th Percentile Clean Soil

ThicknessSource

Scenario and Facility Type

Number Sites

Number Data Points

Method 1 Method 2

y ypDissolved 47 170 10.0 5.4

LNAPL (UST only)

53 172 13.9 13.5 only)

LNAPL (all facility)

60 216 20.0 16.2

Note: The above statistics include site data where no benzene groundwater concentration was available

March 27, 2012

30

CONCLUSIONS

Natural attenuation of PHC vapors provides opportunity for better screening approachesg ppKey factor is whether LNAPL or dissolved sourceStatistical analysis of empirical data supports vertical exclusion distance approach of 5 ft for dissolved, 15 ft for LNAPL UST sites, and 30 ft for LNAPL all sitesAnalysis of aromatic and aliphatic data shows thatAnalysis of aromatic and aliphatic data shows that benzene is the risk driver

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31

CONCLUSIONS (cont.)

Exclusion distance framework requires supporting protocol for identifying LNAPL sites – given weak correlation y g gbetween dissolved and soil vapor concentrations, suggest groundwater benzene concentrations should not be primary line of evidenceprimary line of evidenceSurface cover type appears to have an effect on benzene vapor attenuation and oxygen concentrations, when data for all facility types includedInclusionary factors include large buildings/capping effect, gasoline containing likely higher quantities ethanol (subjectgasoline containing likely higher quantities ethanol (subject to further research), preferential pathways, possibly high organic content (peat) soils

March 27, 2012

32

2,2,4-Trimethylpentane – NAPL (all)

1 E+07

1.E+08/m

3)224 Trimethylpentane vs. Distance ‐NAPL (all)

> DL

1.E+05

1.E+06

1.E+07

or Con

c. (u

g/

< DL

1.E+03

1.E+04

1.E 05

entane

Vapo

1.E+01

1.E+02

Trim

ethylpe

1.E+00‐10 0 10 20 30 40 50 60

224 T

Distance between soil vapor probe and contamination (ft.)

March 27, 2012

33

METHANE vs. BENZENE VAPOR

1 E+08Methane vs. Benzene Vapor ‐ LNAPL (all)

SiteSource

typeFacility

type

CH4 < 20% LEL (1% V/V)

CH4 > 20% LEL (1% V/V)

CH4 > 100% LEL (5% V/V)

Al d L UST Y

1.E+05

1.E+06

1.E+07

1.E+08

c.(ug/m3)

Alameda L UST YesCoachella L Refinery YesHuntington Beach L UST YesNewport Beach L/D UST YesFormer Chevron Stn L/D UST YesPaulsboro L/D Terminal YesGas & Go #7 L/D UST Yes

1.E+02

1.E+03

1.E+04

Vapo

r Co

nc

Gas & Go # / US esHal's Chevron L/D UST Yes#102 Chevron L/D UST YesSanta Clara L/D UST Yes7-Eleven #23387 L UST YesMilo L/D UST YesCF #1803 L/D UST YesB i k L/D UST Y

1.E‐01

1.E+00

1.E+01

Ben

zene

V Berwick L/D UST YesLeeds L/D UST YesSouth Portland L/D UST YesPortland-Forest_Ave L/D UST YesCF #1839 L/D UST YesSaco L/D UST YesLewiston L/D UST Yes

0.0001 0.001 0.01 0.1 1 10 100Methane (%)

Lewiston L/D UST YesNorth Windham L/D UST YesAugusta D UST YesNorth Battleford L/D UST Yes

March 27, 2012

34

PAULSBORO, NJ (Roggemans, 2002)

Building

Area 1AMethod 1: 19’-8 = 11’Method 2: 19 – (12+8)/2 = 9’

Site D19’-8 = >11’

0

Feet Below Grade Area 2

(Site D)

Area 1A

Method 2: 19 (12+8)/2 9

0

5519.6 % 19.1 %

24’

10340,000

38,000

Sand Soil

240,000

5 5

390,000

3.5 %

1.0 %

19.2 %

6.0 %

19.5 %

11.0 %

8’

12’19’

Benzene in GW 9,600 ug/L to

LNAPL

20

160,000500,000 630,0001.0 %6.0 % 6.1 %

16’

DATA ANALYSIS

Primary Chemicals EvaluatedBenzene, Xylenes, yHexaneMADEP fractions (C5-8, C9-12 aliphatics, C9-10

ti ) & TPHaromatics) & TPH2,2,4-Trimethylpentane (iso-octane)Fixed gases (O2 CO2 CH4)Fixed gases (O2, CO2, CH4)

Scenarios EvaluatedDissolved (all facilities but mostly UST)( y )LNAPL (UST only)LNAPL (all facilities)

March 27, 2012

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U S EPA P t l H d b VU.S. EPA Petroleum Hydrocarbon …iavi.rti.org/attachments/WorkshopsAndConferences/02_Hers_Truesdale...Methane ggg generated from gasoline containing ethanol