science 

uses

for a changing world

In cooperation with the North Dakota Department of Health

HYDROLOGIC SETTING AND GEOCHEMICAL CHARACTERIZATION 

OF FREE-PHASE HYDROCARBONS IN THE ALLUVIAL AQUIFER 

AT MANDAN, NORTH DAKOTA, NOVEMBER 2000

Water-Resources Investigations Report 01-4108

U.S. Department of the Interior 

U.S. Geological Survey

U.S. Department of the Interior 

U.S. Geological Survey

HYDROLOGIC SETTING AND GEOCHEMICAL CHARACTERIZATION 

OF FREE-PHASE HYDROCARBONS IN THE ALLUVIAL AQUIFER 

AT MANDAN, NORTH DAKOTA, NOVEMBER 2000

By Frances D. Hostettler, Colleen E. Rostad, Keith A. Kvenvolden, 

Geoffrey N. Delhi, Larry D. Putnam, Jonathan J. Kolak, Brian P. 

Chaplin, and Bryan D. Schaap

Water-Resources Investigations Report 01-4108

In cooperation with the North Dakota Department of Health

Bismarck, North Dakota 

2001
U.S. DEPARTMENT OF THE INTERIOR 

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY 

CHARLES G. GROAT, Director

Any use of trade, product, or firm names is for descriptive purposes only 

and does not imply endorsement by the U.S. Government.

For additional information write to:

District Chief 

U.S. Geological Survey 

Water Resources Division 

821 East Interstate Avenue 

Bismarck, ND 5 8501

Copies of this report can be purchased from:

U.S. Geological Survey 

Information Services 

Box 25286 

Denver, CO 80225-0286
CONTENTS

Abstract..................................................................................................................................................................................................... 1

Introduction.............................................................................................................................................."

Hydrologic setting.....................................................................................................................................

Climate................................................................................................-.......................................-......"

Hydrogeologic units............... ..............................."....."......"..............."................".....".........".............."................."...........".......7

Ground-water flow ....................................."..........""........................"................."..."......"...."."...."..""........".".........""..."...."""9

Spatial extent of free-phase hydrocarbons .................................."..................."..".........................."...."......"............................".........11

Geochemical characterization of hydrocarbons ......................................................"............."..............".."..........."...."....."...."........".17

Sampling methods..................................................

Analytical teclmiques.".....""...."...".."...."..............."........."................-^

Volatile analysis ................................................................................................................................. ...................."."..............18

Semivolatile analysis.".".......""........................"......""""."

Stable carbon isotope analysis.................................................................................................................................................. 19

Geochemical parameters from isotope and gas chromatographic/mass spectrometric data......................""............"......"..". 19

Liquid chromatographic/mass spectrometric analysis..............................................................................................................20

Analytical results........................"......................................................................."""......."".....".....................""......"...."..............20

Volatile components...................."....""".."................"....".......".........."....""........"""""........".""............"....................."...20

Semivolatile components..........................................................................................................................................................20

Stable carbon isotopes.........".................................................................."................".................."."......"........."..."...............25

Dyes........".........""..."....."".""........"""...."..""."."......"""."."........"."......""".."".."............"""""........"

Degradation analysis ................................................"....................................................."""......"........"........"..".."."".."...."........25

Characterization based on correlations .........".......""."............................."........"".............................".........."........."........"........33

Stable carbon isotopes....................................................

Parameter ratios ....................""..............."......"....."......""".""""....................""........"....."".."................................."......."33

Polycyclic aromatic hydrocarbons and alkylated derivatives ......"....""...................................................................................36

Volatile analysis .........--..... ..-..... .---..-- .-- ... ................................... ...... .. .-36

Dye analysis .-.-........-.-.-......-.-...--.......--...-..............--...-.-.- .-.-....-...................^

Electrospray analysis .""....................".................".............."".".."........."................."..."......................................................39

Summary and conclusions..-.--.-.......--.-.......---..............-..---.-.----.---...........-........-.-...-...-........... 

Chemical glossary for semivolatiles..........................".."................ ... . ................... .....................................................41

References...........................................""...........".........."..........."....................................................................-

Appendix A. Construction information for monitoring wells in study area..........................................................................................44

Appendix B. Total ion chromatograms from volatile analysis for RR40, HS#2, and ULR referencefoelsamples.--..-.......-.---------.-.-.........--.-.-...........-......-.-

Appendix C. Extracted ion chromatograms for m/z 57, characteristic of normal alkanes, from volatile 

analysis for RR40, HS#2, and ULR reference-fuel samples..."..... .... ..................................................... ..............................52

Appendix D. Concentrations, in micrograms per liter, of target volatile components...........................................................................56

Appendix E. Concentrations, in micrograms per liter, of detected target volatile components ..."........................................................64

Appendix F. Estimated concentrations, in micrograms per liter, of nontarget volatile components...................................................... 67

Appendix G. Total ion chromatograms and extracted ion chromatograms for m/z 83 from Semivolatile 

analysis...... ...... ................. ........................... ...........".........""....."....................................................................................69

Appendix H. Concentrations, in milligrams of polycyclic aromatic hydrocarbons per liter of product........................................ .. 95

Appendix I. Concentrations, in milligrams of selected polycyclic aromatic hydrocarbons per liter 

of product ........"... ........... ......"""...".......................................... ...................................................................................97

Appendix J. Stable carbon isotope ratio data from Zymax Forensics, San Luis Obispo, California................................................... 100

Appendix K. Flow injection/negative electrospray ionization mass spectra........................................................................................ 102

FIGURES

1. Map showing locations of study area, gaging stations, stage-measurement sites, and precipitation

station, Mandan, North Dakota....".".................................................................................................................................................3

2. Map showing locations of monitoring wells in study area, Mandan, North Dakota..........................................................................4

3. Map showing locations of monitoring wells in downtown area, Mandan, North Dakota..................................................................5

4. Map showing locations of monitoring wells from which light nonaqueous phase liquid samples

were collected, Mandan, North Dakota................................................... .....................................................................................6

iii
5. Diagram showing hydrogeologic section A-A', Mandan, North Dakota...........................................................................................8

6. Diagram showing geologic contact between bottom of silty clay or silty sand unit and top of

sand unit, Mandan, North Dakota.................................................................................................................................................... 10

7. Map showing water-table altitude, Mandan, North Dakota, June 29, 1992..................................................................................... 12

8. Graphs showing monthly precipitation, river stage, and water level in selected monitoring 

wells ...............................................................................................................................................

9. Map showing apparent light nonaqueous phase liquid thickness in selected monitoring wells, 

Mandan, Norm Dakota............................................^

10. Maps showing extent and apparent thickness of (A) light nonaqueous phase liquid, (B) light 

nonaqueous phase liquid in silty sand unit, and (C) light nonaqueous phase liquid in sand unit, 

Mandan, North Dakota......................................................................^

11. Graphs showing chemical components in RR40 reference-fuel sample............................,,,,., ,, ,m ... ~,.,..,,,,,.,........................... 24

12. Graphs showing extracted ion chromatograms for m/z 57, alkanes and isoprenoids, in approximate

sample degradation order .................................................................................................................................................................^^

13. Graphs showing electrospray ionization mass spectra of Unisol Red B50 additive in negative 

and positive modes............................................................................^

14. Map showing relative degradation from n-alkane profiles...............................................................................................................32

15. Map showing stable carbon isotope distribution..............................................................................................................................34

16. Map showing source-parameter value distribution..........................................................................................................................35

17. Map showing additive rndicator distribution.............................................^

TABLES

1. Mandan annual precipitation, 1951-2000 ......................................................................;...................................................................7

2. Mandan monthly precipitation, 1951-2000........................................................................................................................................7

3. Statistical summary of water-level altitudes (1990-2000) in selected monitoring wells surrounding 

light nonaqueous phase liquid......................................................................^

4. Ratios of concentrations of detected target components to 1,2,4-trimethylbenzene in light nonaqueous

phase liquid and selected reference-fuel samples ............................................................................................................................21

5. Ratios of selected nontarget components to 1,2,4-trimethylbenzene in light nonaqueous phase liquid

and selected reference-fuel samples.................................................................................................................................................22

6. Ratios of selected nontarget components related to fuel characterization in light nonaqueous phase

liquid and selected reference-fuel samples ......................................................................................................................................23

7. Geochemical parameters for light nonaqueous phase liquid samples, reference-fuel samples, and 

Restek standards..........................................................

8. Concentrations of Unisol Red B50 dye in light nonaqueous phase liquid samples, selected referencefuel samples, and additive samples ..................................................................................................................................................30

9. Relative intensities of masses from negative electrospray ionization mass spectra for light nonaqueous

phase liquid and selected reference-fuel samples ............................................................................................................................31

iv
Hydrologic Setting and Geochemical Characterization of Free-Phase 

Hydrocarbons in the Alluvial Aquifer at Mandan, North Dakota, 

November 2000

SyFrances D. Hostettler, Colleen E. Rostad, Keith A. Kvenvolden, Geoffrey N. Delin, Larry D. Putnam, Jonathan J. 

Kolak, Brian P. Chaplin, and Bryan D. Schaap

Abstract

Free-phase hydrocarbons are present in the alluvial aquifer at Mandan, North Dakota. A large contaminant 

body of the hydrocarbons [light nonaqueous phase liquid (LNAPL)] floats on the water table about 20 feet below 

land surface. The main LNAPL body is about 6 feet thick, and the areal extent is about 657,000 square feet. A 

study was conducted to describe the hydrologic setting and characterize the geochemical composition of the 

free-phase hydrocarbons in the alluvial aquifer.

Most of the study area is underlain by alluvium of the Heart River Valley that ranges in thickness from about 

25 to 109 feet. The alluvium can be divided into three stratigraphic units silty clay, silty sand, and sand and is 

underlain by shales and sandstones. Monitoring wells were installed prior to this study, to an average depth of 

about 29 feet.

Regional ground-water flow in the Heart River aquifer generally may be from west-northwest to eastsoutheast and is influenced by hydraulic connections to the river. Hydraulic connections also are probable 

between the aquifer and the Missouri River. Ground-water flow across the north boundary of the aquifer is 

minimal because of adjacent shales and sandstones of relatively low permeability. Recharge occurs from 

infiltration of precipitation and is spatially variable depending on the thickness of overlying clays and silts. 

Although the general water-table gradient may be from west-northwest to east-southeast, the flow directions can 

vary depending on the river stage and recharge events. Any movement of the LNAPL is influenced by the 

gradients created by changes in water-level altitudes.

LNAPL samples were collected from monitoring wells using dedicated bailers. The samples were 

transferred to glass containers, stored in the dark, and refrigerated before shipment for analysis by a variety 

of analytical techniques. For comparison purposes, reference-fuel samples provided by the refinery in Mandan 

also were analyzed. These reference-fuel samples included a current diesel fuel, a closely related but slightly 

broader refinery-cut fuel, a crude-oil composite, unleaded regular gasoline, and additives.

Four principal analytical techniques were used for geochemical characterization: Purge-and-trap gas 

chromatography/mass spectrometry (volatile components); capillary gas chromatography/mass spectrometry 

(semivolatile components); isotope ratio mass spectrometry (carbon isotopes; whole oils); and liquid 

chromatography/mass spectrometry with electrospray ionization (additives and other organic components). 

Volatile analytes included solvents, disinfection byproducts, halogenated hydrocarbons, and alkylbenzenes, 

including benzene, toluene, ethylbenzene, and meta-, para-, and orf/zo-xylenes. Semivolatile analytes included 

rt-alkanes, isoprenoid alkanes, cycloalkanes, and polycyclic aromatic hydrocarbons and related compounds 

(naphthalenes, phenanthrenes, and dibenzothiophenes and their alkylated derivatives). Of the additives, only the 

diesel-fuel additive with the red dye marker was amenable to electrospray ionization.

Results indicate the LNAPL consists of closely correlatable diesel fuel at various stages of degradation. All 

LNAPL samples contained the red dye marker for diesel fuel. None of the samples contained chlorinated 

solvents associated with industries such as drycleaning or automotive maintenance. Solvents such as acetone, 

dimethyl ether, and methylene chloride and the gasoline additives methyl-t-butyl ether (MTBE), ethyl-t-butyl
ether (ETBE), and t-amyl-methyl ether (TAME) were not found. With one possible exception, no evidence of a 

different diesel or other hydrocarbon fuel contribution was identified. At one site near the north edge of the main 

LNAPL body, evidence exists for traces of possible gasoline components in addition to the diesel fuel. The 

geochemical analysis of the LNAPL and correlations with other fuel products and additives strongly suggest 

episodic releases of a single, local-source, diesel fuel into the aquifer over an extended period of time.

INTRODUCTION

Ground-water contamination by crude oil and other petroleum-based hydrocarbons such as diesel fuel and gasoline is 

a widespread problem. Understanding the nature, transport, and fate of these organic contaminants is necessary to design 

appropriate, cost-effective remedial solutions at contaminated sites. Such understanding includes geochemical 

characterization of the specific contaminants involved as well as assessment of the hydrogeologic setting that affects their 

emplacement and transport.

Free-phase hydrocarbons related to petroleum are present in the subsurface at Mandan, N. Dak., in the Heart River 

Valley (ThermoRetec Consulting Corporation, 1999) (fig. 1). A large contaminant body of the hydrocarbons [also referred 

to in this report as light nonaqueous phase liquid (LNAPL)] exists beneath a railway yard and parts of the downtown area. 

The main free-phase body is about 6 feet thick and is floating on the water table about 20 feet below land surface.

Although the possibility of multiple input sources exists for any contaminant body, known input sources to at least part 

of the LNAPL body at Mandan are diesel-fuel spills from the railway yard and fueling areas south of Main Street (fig. 2) 

(Roberts, 2001). Chronic spillage of diesel fuel, thought to have occurred from 1953 to 1991, has resulted in an estimated 

subsurface accumulation of 1.5 to 3 million gallons of diesel product; recent recovery efforts by the railway have reclaimed 

.about 0.5 million gallons (Roberts, 2001). Other possible, but currently unsubstantiated, sources include gasoline, perhaps 

leaking from underground tanks at local consumer gasoline stations, and commercial solvents from a variety of local 

businesses. The commercial solvents may include automobile parts degreasers such as methylene chloride and 

trichloroethylene (TCE) or drycleaning solvents such as perchloroethylene (tetrachloroethylene) and 1,1,2-trichloro-1,2,2- 

trifluoroethane (Occupational Safety and Health Administration, 2001).

The Mandan site provides an opportunity for the U.S. Geological Survey to add to knowledge gained in previous 

studies of hydrocarbons in the subsurface. For example, long-term interdisciplinary research sponsored by the U.S. 

Geological Survey Toxic Substances Hydrology Program began in 1983 at a crude-oil spill site near Bemidji, Minn. That 

research focuses on physical, chemical, and biological processes controlling the migration and fate of petroleum 

hydrocarbon contaminants in a glacial outwash setting. This study at Mandan, conducted during 2000-01 by the U.S. 

Geological Survey in cooperation with the North Dakota Department of Health, focused on similar processes but involved 

hydrogeologic conditions in an alluvial setting.

The purposes of this study were to describe the hydrologic setting and characterize the geochemical composition of the 

free-phase hydrocarbons in the alluvial aquifer at Mandan. The study included descriptions of the hydrologic setting, the 

spatial extent of the LNAPL contaminant body, and the geochemical composition of the LNAPL. Any possible chemical 

contributors to the LNAPL body, consistent with possible local input sources, were considered in the analyses. 

Hydrocarbon compositions were differentiated insofar as possible between diesel fuel or fuels and gasoline components on 

the basis of guidelines in peer-reviewed literature. The study focused on the downtown area, including the railway yard 

and the east and west fueling areas (fig. 2). Most of the hydrogeologic data used for the study were collected during 1991- 

2000; LNAPL samples were collected in November 2000. The locations of monitoring wells in the study area are shown in 

figures 2 and 3, and the locations of monitoring wells from which LNAPL samples were collected are shown in figure 4. 

This report presents the results of this study.

The authors thank John Enz, North Dakota State Climatologist, and his assistant, Barbara Mahoney, who provided 

Mandan precipitation data. Thanks to Roger Schmid, Water Supply, Inc., Bismarck, N. Dak., for providing geologic logs 

and aquifer-test results for monitoring wells in the downtown Mandan area; Donna Rose, U.S. Geological Survey National 

Water Quality Laboratory, Denver, Colo., for analytical work and additional interpretation; and James Wald, Robert 

Lundgren, and Wayne Berkas, U.S. Geological Survey, for providing assistance with sampling and report preparation. 

Thanks also to Debbie Ludwick, Brian Blee, Drazen Samardzic, and Jeff Denmen, ThermoRetec Consulting Corporation,
100°54' 100°53'30

100°53' 100°52'30"

46°49'45"

46°49'30"

Base from ThermoRetec Consulting Corporation 

Cadd file 4438c11 s.2000 3 1 ,000

I I

2,000

I

3,000

I

4,000 5,0( 

I I

RH9,

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16, 2000, 

based on kriged LNAPL thicknesses

Abandoned oxbows and meanders 

Monitoring well and identifier

Figure 2. Locations of monitoring wells in study area, Mandan, North Dakota.
100°55'

46°50'

T. 139N. 

T.138 N.

46°471 300 =

Grant Marsh 

Memorial Bridge

06342500

World War One 

Memorial Bridge

Centennial

R. 182 W. R. 181 W. 

Base from U.S. Geological Survey 

Morton County, 1993

1/2 1

EXPLANATION

Alluvium (Heart River aquifer) 

Study area 

City of Mandan

R. 181 W. R. 180 W. 

SASKATCHEWAN MANITOBA

98° 49°

^06349000 Gaging station and number

A Stage-measurement site

325479 ^ Precipitation station and number

47° h

INDEX MAP

Figure 1. Locations of study area, gaging stations, stage-measurement sites, and precipitation station, Mandan, North Dakota.
100°53'45" 100°53'30"

46°49'45" 

46°49'30"

v-----""\\------ r -~A

L -Ar _\ rBase from ThermoRetec Consulting Corporation 

Cadd file 4438c11s, 2000

0

I_______L

500 

I

1,000 FEET

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) floating on water table, 

November 14-16, 2000, based on kriged LNAPL thicknesses

MW5R

 Monitoring well and identifier

Figure 3. Locations of monitoring wells in downtown area, Mandan, North Dakota.

Mandan, for their assistance in locating and sampling wells and for providing safety training. Burlington Northern Santa 

Fe Railway, Mandan, allowed access to their property; and BP Amoco Mandan Refinery, Mandan, provided samples of 

reference fuels and additives.

HYDROLOGIC SETTING

Climate

The semiarid climate of the study area includes large variations in temperature and precipitation. Temperatures range 

from summer highs of near 100°F (degrees Fahrenheit) to winter lows of -30°F. Soils begin to freeze in November, remain
100°53'45° 100°53'30°

460491 40"

WF11

46°49'30"

Base from ThermoRetec Consulting Corporation 

Cadd fHe 4438c11 s, 2000

500 

I_

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) floating on water table, 

November 14-16,2000, based on kriged LNAPL thicknesses

1,000 FEET 

I

MW2R Monitoring well and identifier

Figure 4. Locations of monitoring wells from which light nonaqueous phase liquid samples were collected, Mandan, North Dakota.
frozen from December through February, and begin to thaw in March. The hottest temperatures occur in July and August. 

For the 50 years from 1951 through 2000, the mean annual precipitation at the Mandan Experiment Station (U.S. 

Department of Commerce, Station #325479) (fig. 1), located about 1 mile southwest of the study area, was 16.61 inches 

(table 1). The minimum annual precipitation of 9.74 inches was recorded in 1973, and the maximum annual precipitation 

of 26.33 inches (about 2.7 times the 1973 total) was recorded in 1993. During 1991-2000 when most of the hydrogeologic 

data used in this study were collected, annual precipitation was about 3.4 inches above average. Monthly precipitation 

statistics for 1951-2000 (table 2) show the large variation that can occur in precipitation, especially in the early spring and 

summer.

Table 1. Mandan annual precipitation, 1951-2000

[Based on information from J. W. Enz and B. A. Mahoney, North Dakota State Climatologist office, written commun., 2000, 2001]

Years

1951-60

1961-70

1971-80

1981-90

1991-2000

Mean 

(inches)

16.24

16.00

15.00

15.77

20.05

Minimum 

(inches)

10.29

12.12

9.74

9.83

14.19

Maximum 

(inches)

21.76

23.34

19.06

25.52

26.33

1951-2000 16.61 9.74 26.33

Table 2. Mandan monthly precipitation, 1951-2000

[Based on information from J. W. Enz and B. A. Mahoney, North Dakota State Climatologist office, written commun., 2000, 2001]

Month

January

February

March

April

May

June

July

August

September

October

November

December

Mean 

(inches)

0.38

.37

.53

1.44

2.38

3.32

2.67

2.10

1.47

1.10

.53

.33

Minimum 

(inches)

0.01

.01

0

0

.28

.71

.20

.11

.19

0

0

.01

Maximum 

(inches)

0.96

1.62

2.02

6.36

6.81

6.56

13.43

6.09

4.67

5.81

1.96

.82

Hydrogeologic Units

Most of the study area is underlain by alluvium of the Heart River Valley (fig. 1) that ranges in thickness from about 25 

to 109 feet (Ackerman, 1980). This alluvium is about 1 mile wide from south to north near the study area and becomes 

wider toward the Missouri River. The alluvium is underlain by shales and sandstones and in some areas is overlain by fill 

material. The alluvium can be divided into three stratigraphic units-silty clay, silty sand, and sand (fig. 5). The monitoring 

wells in downtown Mandan were installed prior to this study (data from several contractors), to an average depth of about
North 

A

South A1

FEET 

1,650 -

1,645 -

1,640 -

HI

a

1

<

fcUJ 

LL

Z 1,630 -

UJ* 

Q

1,625 -

1,620 -

1,615 -

1,610

I

Silty sand

Fill

Silty clay

\ 

x

LNAPL thickness 

data not available 

for well MW42 C*-f

Sand

Trace of section shown in figure 9

250 

I

500 FEET

VERTICAL EXAGGERATION X 42 

EXPLANATION

Apparent light nonaqueous phase liquid (LNAPL) thickness, 

November 14-16, 2000

 - Approximate geologic contact

CDN

Q. Monitoring well and identifier

Screened interval 

^ Total depth

- 1,620

- 1,615

- 1,610

Figure 5. Hydrogeologic section A-A1 , Mandan, North Dakota.
29 feet below land surface (appendix A) using various methods. Because many geologists logged the wells, determining 

the continuity of geologic strata is tenuous.

The uppermost 0 to 6 feet of material is asphalt, concrete, or fill that consists of a heterogeneous mixture of gravel, 

sand, and silt. Underlying the fill is a silty clay unit that ranges in thickness from 2 to 21 feet. Average thickness of the 

unit is about 12 feet. Within the silty clay unit are very fine to medium-grained silty sand lenses that are as much as 8 feet 

thick. Many areas of the unit also have a fine sand fraction. Underlying the silty clay unit is a discontinuous fine to very 

fine silty sand unit that has an average thickness of about 6 feet where present. Interbedded within the silty sand unit are 

sand lenses that are as much as 4 feet thick and clay lenses that are 1 to 2 feet thick. This unit is most noticeably present 

beneath the area of Main Street, specifically near wells MW42, MW44 (fig. 5), MW5R, MW43, and MW45 (fig. 3), but is 

absent throughout about half the downtown area. Underlying the silty sand unit is a very fine to coarse-grained sand unit 

that ranges in thickness from 3 to 32 feet. The average thickness is about 13 feet, but many of the wells do not penetrate 

the entire thickness. Deeper parts of the unit consist of fine to coarse gravel.

The geologic contact between the bottom of the silty clay or silty sand unit and the top of the sand unit is shown in 

figure 6. Depth to the top of the sand unit ranges from less than 14 feet at wells CS1, MW13, MW40, MW41, PZ2, PZ4, 

PZ6 through PZ9, and PZ11 to greater than 20 feet at wells FR8, MW1R, MW5R, MW16, MW42, MW43, MW45 through 

MW48, RHl, RH2, and Wl. The less-than-14-feet zones are illustrated in figure 6 as relatively high areas and the greaterthan-20-feet zones as relatively low areas. Superimposed on the wire-frame diagram is the extent of the LNAPL floating 

on the water table and the extent of the LNAPL in the silty sand unit.

Unconfined conditions are presumed to prevail in most of the alluvial aquifer. Results of aquifer tests in the study area 

indicated the transmissivity of the sand unit ranges from 900 to 3,200 feet squared per day and the storage coefficient is 

0.03 (Soil Exploration Company, 1985; Roger Schmid, Water Supply, Inc., written commun., 2001). Based on a saturated 

thickness of 30 feet, the hydraulic conductivity ranges from about 30 to 110 feet per day. The upper value is similar to the 

value of 130 feet per day based on ground-water-flow model analyses (ThermoRetec Consulting Corporation, 1999). 

Based on sieve analyses, the hydraulic conductivity of the silty sand and sand units ranges from 0.1 to 7 feet per day (Soil 

Exploration Company, 1985). Estimates of specific yield for the sand unit range from 0.008 (ThermoRetec Consulting 

Corporation, 1999) to 0.38 (Soil Exploration Company, 1985). Based on regional data for the sand unit (Ackerman, 1980), 

the transmissivity ranges from 100 to 10,000 feet squared per day, the hydraulic conductivity ranges from 10 to 400 feet per 

day, and the storage coefficient is 0.0005 where the unit is confined by silty clay and 0.2 where the unit is unconfined. 

Hydraulic information is not available for the silty clay unit in the study area, but the typical range of hydraulic 

conductivity for silty clays is 0.001 to 10 feet per day (Freeze and Cherry, 1979).

Ground-Water Flow

Regional ground-water flow in the Heart River aquifer generally is reported to be from west-northwest to eastsoutheast (Ackerman, 1980) and is influenced by hydraulic connections to the river. Hydraulic connections also are 

probable between the aquifer and the Missouri River, located about three-fourths mile east of the study area. Ground-water 

flow across the north boundary of the aquifer probably is minimal because of adjacent shales and sandstones of relatively 

low permeability.

Recharge occurs from infiltration of precipitation and is spatially variable depending on the thickness of overlying 

clays and silts. Less overlying clay and silt allows more infiltration of precipitation. Recharge to the aquifer from the 

Heart and Missouri Rivers and discharge from the aquifer to the rivers depends on the relation between the altitudes of 

water levels in the aquifer and of stage in the rivers.

Water levels in the aquifer (Roger Schmid, Water Supply, Inc., written commun., 2001; Nic Winslow, ThermoRetec 

Consulting Corporation, written commun., 2001) change seasonally in response to river stages and precipitation. In the 

early spring, snowmelt runoff causes the stage in the Heart River to rise above the water level in the aquifer. Measurements 

made at highway bridge sites (fig. 1) during 1987 through 2000 indicate the stage can rise as much as 20 feet during peak 

spring runoff (James D. Wald, U.S. Geological Survey, written commun., 2001). Because the Heart River is to the west 

and south of the study area, the water level in the aquifer begins to rise to the west and south in response to rise in river 

stage. During the spring and early summer, when precipitation is highest, the water level in the aquifer rises as a result of
Contact between bottom of silty clay or silty 

sand unit and top of sand unit

No scale

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) floating on water table in 

silty sand unit, November 14-16, 2000, based on kriged LNAPL thicknesses

 Extent of LNAPL floating on water table, November 14-16, 2000, based on 

kriged LNAPL thicknesses

Figure 6. Geologic contact between bottom of silty clay or silty sand unit and top of sand unit, Mandan, North Dakota.

10
infiltration of precipitation. Greater infiltration of precipitation may occur in the south-central and southeast parts of the 

study area when runoff collects in abandoned oxbows and stream meanders (fig. 2).

Although the general water-table gradient may be from west-northwest to east-southeast (Radian International, 1999), 

the flow directions vary depending on the river stage and recharge events. Observed water-table altitudes shown in figure 7 

reflect the complex ground-water-flow system. On June 29, 1992, the water levels in the east and west fueling areas were 

at about the same altitude, and the water levels surrounding the LNAPL did not indicate flow directions that were clearly 

toward the east-southeast. Some of the monitoring wells in the south part of the study area had higher water-level altitudes 

than those in the north part of the study area.

Hydrographs for wells CS1, MW14, and MW16 (fig. 8), which are located southeast, northwest, and northeast of the 

LNAPL, respectively (fig. 7), show typical transient response in water levels. The water levels (1992-95) in well CS1 on 

the south are greater in the spring and summer than those in wells MW14 and MW16 on the north. The increase in water 

levels coincides with an increase in monthly precipitation (fig. 8). Precipitation during 1992 was slightly below average, 

and precipitation during 1993-95 was above average. The response to recharge from precipitation at the wells north of the 

LNAPL lags behind the response at the well south of the LNAPL, and the peak is somewhat less. The recharge response at 

well CS1 occurs before that in the north wells, possibly indicating more effective recharge to the south. In the winter, as 

recharge from infiltration decreases and stage in the Heart River declines, the water level at well CS1 declines, and groundwater-flow directions presumably trend more toward the east-southeast.

The transient response in aquifer water levels in the study area also is affected by the stage of the Missouri River in 

relation to the stage of the Heart River (U.S. Geological Survey, 1955-2000). Typically, peaks in streamflow in the 

Missouri River, which is controlled by releases from an upstream dam, do not coincide with spring runoff. This results in 

smaller differences between the stages of the Heart River near Mandan and the Missouri River at Bismarck during part of 

the year, most likely late summer and fall. When streamflow in the Missouri River is near 40,000 cubic feet per second, the 

stage of the river is about 1,630 feet above sea level 1 , which is about the same as the stage of the Heart River near the 

Highway 6 bridge when streamflow there is about 50 to 100 cubic feet per second. The stage record for October 1994 

through December 1995 (fig. 8) for the two rivers shows the relation between the stages during a period with above-average 

precipitation. The highest stage of the Heart River occurred in the early spring, but small rises also occurred as a result of 

storm events. The highest stages of the Missouri River generally coincide with the lowest stages of the Heart River. When 

differences between the river stages at the Highway 6 bridge and the Bismarck gage become less, the gradients that cause 

ground water to flow regionally toward the east-southeast are diminished.

A statistical summary of water-level altitudes (1990-2000) in selected monitoring wells surrounding the LNAPL 

(table 3) shows small differences in mean values. Seasonal changes in recharge and river stage likely produce seasonal 

variations in local ground-water-flow directions. The change in water level during the 1990's ranged from about 5 to 

10 feet and averaged about 7 feet for most wells. The mean water-level altitude ranged from 1,629.3 to 1,631.3 feet above 

sea level and, for most wells, was between 1,630.1 and 1,630.5 feet above sea level. The mean water-level altitudes in the 

three wells southeast of the LNAPL were greater than the mean for the well northeast of the LNAPL. Mean water-level 

altitudes for February generally were lower on the south and east sides of the LNAPL than on the north and west sides of 

the LNAPL. However, mean values for July were highest for the three wells southeast of the LNAP^,. Water-level 

altitudes, responding to changes in recharge and river stage, reflect a complex, temporally variable ground-water-flow 

pattern near the LNAPL.

SPATIAL EXTENT OF FREE-PHASE HYDROCARBONS

U.S. Geological Survey, ThermoRetec Consulting Corporation, and North Dakota Department of Health personnel 

measured LNAPL thicknesses in selected monitoring wells in downtown Mandan on November 14-16, 2000, using an

l Sea level: In this report, "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)~a geodetic datum derived from a 

general adjustment of the first-order level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.

11
100°54'30"

46°49'45"

46°49'30"

Base from ThermoRetec Consulting Corporation 

Cadd file 4438c11s, 2000 3 1 ,000

I

2,0 00 3,000 

I

4,000 5,0(

I I

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16, 2000, 

based on kriged LNAPL thicknesses

Abandoned oxbows and meanders

Monitoring wells. Identifier and water-table altitude 

shown for wells discussed in text. Datum is sea level

Greater than 1,630 feet

Greater than 1,629 feet and less than 1,630 feet 

Greater than 1,628 feet and less than 1,629 feet 

Less than 1,628 feet

Figure 7. Water-table altitude, Mandan, North Dakota, June 29, 1992.

12
15

UJ

o

Z 10

O

E.

o

UJ

cc

Q.

i i i i i i i i i i i I i i i i i i i i i i i I i i i i i i i i i i i | i i i i i i i r~rT~T

Monthly precipitation at 

Mandan Experiment Station

11111.11111.1.1.11 ili.iiiiiliiiiiilililili.il il ! li i.il il il 1111 ii

1,660

1,650

1,640

1,630

1,620 UJ

r~i T i i i i i i i | i i i i i i i 

River stage

 06349000 Heart River near Mandan, North Dakota, gaging station

 06342500 Missouri River at Bismarck, North Dakota, gaging station

w

UJ

8m 1,636

UJ 

UJ

i i i i i i i i i I i i i i i i 

Water level in selected monitoring wells

LU 

o

I

r 1-634

1,632

1,630

1,628

Well CS1 (southeast) 

Well MW14 (northwest) 

Well MW16 (northeast)

1,626 I I I I I I I I I I » I I I I i i i i i i i i I i i i i i i i i i i i |. ! i i i i | | | | | | 

JFMAMJJASONDJFMAMJJASONDJFMAMJJASONDJFMAMJJASOND 

1992 1993 1994 1995

Figure 8. Monthly precipitation, river stage, and water level in selected monitoring wells.

13
TableS. Statistical summary of water-level altitudes (1990-2000) in selected monitoring wells surrounding light nonaqueous phase liquid

[LNAPL, light nonaqueous phase liquid]

Well 

identifier

Yeerly

mean 

(feet 

above sea

level)

February

mean 

(feet 

above sea

level)

July

mean 

(feet 

above sea

level)

Maximum

(feet 

above sea

level)

Minimum

(feet 

above sea

level)

Change 

(feet)

Beginning date 

of record

Ending date 

of record

Number of 

measurements

Wl

CS1 

RH6 

RH7

MW9 

MW10 

MW11 

MW14

RH10

MW16

1,630.4 1,630.3

1,630.1

1,630.3

1,631.3

1,630.1

1,630.5

1,630.2

1,629.7

1,630.2

1,629.3

1,629.6

1,629.1

1,629.9

1,629.8

1,630.1

1,629.7

1,629.4

1,629.1

1,628.8

Monitoring well southwest of LNAPL

1,630.6 1,634.9 1,628.2 6.7 12/05/91 6/16/00 

Monitoring wells southeast of LNAPL

1,630.8 1,634.7 1,627.7 7.0 4/18/90 6/16/00

1,631.6 1,634.0 1,628.8 5.2 12/26/91 3/01/00

1,633.4 1,638.2 1,628.1 10.1 12/05/91 6/16/00

Monitoring wells north or northwest of LNAPL

1,629.7 1,634.1 1,627.3 6.8 1/10/90 6/17/00

1,630.8 1,634.7 1,627.8 6.9 1/10/90 6/17/00

1,630.6 1,634.4 1,627.4 7.0 1/10/90 6/16/90

1,629.7 1,633.8 1,627.1 6.7 4/17/90 6/16/00

Monitoring well east of LNAPL

1,630.0 1,634.1 1,628.3 5.8 12/26/91 6/16/00 

Monitoring well northeast of LNAPL

1,629.7 1,634.7 1,627.1 7.6 4/18/90 6/16/00

130

139

62

93

166

133

194

146

76

136

electric measuring device. The apparent LNAPL thickness in a well generally was different from the actual thickness in 

the aquifer (van Dam, 1967; Lenhard and Parker, 1990). The LNAPL in the aquifer is present not only as a lens of 

LNAPL-saturated sediment but is spread over a thicker mixing zone that contains air, LNAPL, and water in the pores. If 

the water .level rises, the apparent thickness in the well is likely to decrease. If the water level declines, the apparent 

thickness in the well is likely to increase. Although the apparent thickness in the well fluctuates, the total amount of 

LNAPL in the aquifer is not changed substantially by the water-level fluctuations.

Apparent LNAPL thicknesses are shown in figure 9. LNAPL was detected floating on the water table in about a 

657,000-square-foot area bounded approximately by 1st Street NW. on the north, Collins Avenue on the east, and 3rd 

Avenue NW. on the west (fig. 3). The southern extent is unclear because of the limited number of wells within the railway 

yard, but the LNAPL does not extend as far south as wells CS1 and RH7. In addition to the main LNAPL body, historic 

evidence (Roberts, 2001) and current recovery efforts (Burlington Northern Santa Fe Railway, 1999a through 1999d; 

2000a through 2000d) by the railway show several other hydrocarbon bodies exist, including beneath the east and west 

fueling areas, at well RH1 (the Roundhouse area), and at well PL4, where in 1987 a diesel-fuel pipeline directly from the 

local refinery was found to be leaking.

The extent of the LNAPL (fig. 10) was based on kriging of apparent LNAPL thicknesses in wells. The kriging was 

done with a linear variogram model and zero nugget effect. Kriging is a geostatistical gridding method used to produce 

contour surface plots from irregularly spaced data, and nugget is an interpolation and smoothing factor. The apparent 

LNAPL thickness was greatest near well MW44 (6.88 feet). The areas of greatest thickness appear to follow two 

directional trends-from near wells MW2R and MWI 7 to the east-northeast toward well MW7R and to the north-northwest 

toward wells MW44, MW45, and PZ6 (fig. 10A). The kriged LNAPL thicknesses shown in figure 10A do not always 

agree with the apparent thicknesses shown in figure 9 because of the inherent limitations of kriging.

Top and bottom altitudes of the LNAPL body were correlated with geologic information to evaluate the extent of 

LNAPL in the sand and overlying units. LNAPL floating on the water table occurred in all three units because the altitude 

of the geologic contacts between the units is variable. The LNAPL was primarily in the silty sand unit in the area that 

includes wells FR4, MW5R, MW8, MW43, MW45, MW47, and PZ6 (fig. 10B) and exclusively in the sand unit in the area

14
100°53'45" 100°53'30"

46049'45

46°49'30"

Base from ThermoRetec Consulting Corporation 

Cadd file 4438d 1s, 2000

0

I_______i

500 1,000 FEET

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) floating on water table, 

November 14-16,2000, based on kriged LNAPL thicknesses

A A1 Trace of section (See figure 5)

MW5R (0.56) Monitoring well and identifier. Number in parentheses is apparent LNAPL thickness,

in feet (Kurt Geiser, ThermoRetec Consulting Corporation, written commun., 2001)

Figure 9. Apparent light nonaqueous phase liquid thickness in selected monitoring wells, Mandan, North Dakota.

that includes wells EW2, FR2, MW7R, MW17, P1R, P5, and PZ4 (fig. 10C). The LNAPL was in both units in the

relatively small area that includes wells MW2R, MW44, and PZ2 (fig. 10C). The areal extent exclusively hi the silty sand

unit was about 278,000 square feet in November 2000, and the areal extent exclusively in the sand unit was about

351,000 square feet. The LNAPL is in the silty sand unit where the unit extends deepest below land surface (fig. 6). The

areal extent of the LNAPL in each unit changes with fluctuations hi the water table. As the water table declines, for

example, the extent of the LNAPL in the silty sand unit decreases and the extent hi the sand unit increases, causing a smear

zone.

15
PZ11

PZ13

MW12

MW16 

MW44

RH1

(A) Extent and apparent thickness of LNAPL

PZ11

PZ13

PZ9

MW16

CS1

RH1 

PZ11

PZ9

MW5I

RH7

CS1

RH1

(B) Extent and apparent thickness of LNAPL in silty sand unit

500 

I_

1,000 FEET 

__I

-6.0-

.MW7R

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) floating on water table in silty sand unit, November 14-16, 2000, based on kriged LNAPL thicknessesExtent of LNAPL floating on water table in silty sand and sand units, November 14-16, 2000, based on kriged LNAPL thicknesses

Extent of LNAPL floating on water table in sand unit, November 14-16, 2000, 

based on kriged LNAPL thicknesses

Extent of LNAPL floating on water table, November 14-16, 2000, based on kriged LNAPL thicknesses

Line of equal thickness of LNAPL floating on water table, November 14-16, 2000, 

based on kriged LNAPL thicknesses. Interval 1 foot

Monitoring well and identifier

(C) Extent and apparent thickness of LNAPL in sand unit

Figure 10. Extent and apparent thickness of (A) light nonaqueous phase liquid, (B) light nonaqueous phase liquid in silty sand unit, and (C) light nonaqueous 

phase liquid in sand unit, Mandan, North Dakota. (Note: The kriged thicknesses shown in this figure do not always agree with the apparent thicknesses shown in figure 9 because of the inherent limitations of kriging.)
LNAPL also was apparently present in the silty clay unit near well MW45 during November 2000. However, any 

LNAPL in this unit probably was located primarily in relatively thin sand lenses within the unit because silt and clay do not 

readily imbibe LNAPL fluids, particularly when saturated with water. The process by which LNAPL imbibition into the 

silty clay unit could occur is complex. A rising water table and the mounding of LNAPL near a source could have created 

a local zone of high pressure near the edge of the silty clay unit. This high pressure then could have forced the LNAPL into 

the sand lenses in the unit. The LNAPL also could have entered the silty clay unit if the porosity and permeability had been 

increased because of cracking or fracturing of the material. Fracturing could have occurred from anthropogenic activity at 

land surface or from alteration of the clay structure by the LNAPL. Soil cores would need to be collected and analyzed to 

evaluate the extent of fracturing and its effect on porosity and soil wettability.

The spatial extent of the LNAPL probably has been affected both by geology and transient ground-water-flow 

conditions. The LNAPL appears to be present mostly in the silty sand and sand units, which are the most permeable. Also, 

the LNAPL floats on the water table, which commonly is near the contact between the silty clay or silty sand unit and the 

sand unit. In areas where the silty clay unit extends below the water table, migration of the LNAPL probably has been 

inhibited or stopped. Because of changes in altitude of the water table, the effect of the silty clay unit could vary 

temporally. Furthermore,, changing hydrologic conditions can change water-table gradients, which affect the directions of 

LNAPL migration. The heterogeneous geology and the temporally varying water-table gradient across the study area 

complicates interpretations regarding migration of the LNAPL based on available data.

GEOCHEMICAL CHARACTERIZATION OF HYDROCARBONS

Hydrocarbons in fossil fuels occur as a complex mixture, which includes acyclic alkanes, cycloalkanes, olefins, and 

aromatics (Altgelt and Boduszynski, 1994). Acyclic alkanes, also called paraffins, include normal and isoparaffins-that is, 

straight-chain and branched-chain hydrocarbons. Cycloalkanes, also called naphthenes, are classified by the number of 

rings. Cycloalkanes can have five-membered rings (cyclopentanes) or six-membered rings (cyclohexanes) and most have 

side chains. Olefins, also called alkenes, have at least one double bond; although scarce in crude oil, olefins may occur in 

large amounts in lighter distillates from cracked refinery streams. Aromatics contain at least one benzene ring; poly cyclic 

aromatic hydrocarbons (PAHs) contain two or more fused benzene rings.

Gasoline and diesel fuel are two different refinery cuts, with gasoline a low boiling point distillation cut and diesel a 

mid-range cut. Hydrocarbons in gasoline are predominantly in the C3 to C\2 range. Hydrocarbons in diesel fuel are in the 

Cg to C25 range. The fuels contain very distinct distributions of hydrocarbon components although some overlap in 

components occurs at the distillation endpoint for gasoline and beginning for diesel. Important volatile components that 

differentiate gasoline from diesel fuel are isooctane (2,2,4-trimethylpentane) and aromatic hydrocarbons such as benzene, 

toluene, ethylbenzene, and xylene (BTEX), which are dominant in gasoline (Kaplan and others, 1997). Diesel fuel is 

characterized by a dominance of n-alkanes, seen in a chromatogram as a smooth, bell-shaped distribution pattern 

maximizing at about Cj 4 to C^. Within the given range of components in each of these two fuel classes, however, 

differences in relative amounts of specific components, such as alkylated PAHs, can occur. These differences are derived 

from the original crude-oil source from which the oils were produced and result in each oil having a unique chemical 

fingerprint.

Fuel additives are chemical components engineered to improve the performance of gasoline, diesel fuel, and other 

fuels. Performance benefits include octane (gasoline) and cetane (diesel) enhancement, emissions reduction, increased 

lubricity, storage stability, and the protection against deposits for fuel injectors, intake valves, and combustion chambers 

(Ethyl Corporation, 2001). Various petroleum products contain a variety of dyes, some federally mandated, to enable 

immediate distinction among fuel types such as gasoline (yellow), diesel (pink), and jet fuel (blue). Few dyes are pure, and 

sometimes mixtures of dyes are used (Youngless and others, 1985).

The most common approach to characterization and identification of a hydrocarbon spill in the environment is analysis 

by gas chromatography (GC) or gas chromatography/mass spectrometry (GC/MS) (Mansuy and others, 1997). This 

technique allows separation, identification, and quantification of the individual components of the fuel mixture. 

Correlations then are made on the basis of the molecular distribution of the aliphatic and aromatic hydrocarbons or specific 

biomarkers on a chromatogram (Wang and others, 1994). This type of analysis, along with several sampling and analytical

17
methods, was used to characterize the LNAPL in the alluvial aquifer at Mandan. Samples were analyzed for volatile and 

semivolatile components, stable carbon isotopes, additives, and dyes.

Sampling Methods

LNAPL samples were collected for chemical analysis from selected monitoring wells (fig. 4) on November 14-16, 

2000. The samples were collected using dedicated Teflon bailers and transferred to 1-liter glass containers by agitating the 

check-ball and allowing the liquid to flow from the bottom of the bailer into the glass container (modifications to this 

procedure at two sites are described in the next paragraph). The samples were placed in boxes and stored out of sunlight 

until being transferred to a locked refrigerator at the end of the day. Bailers were discarded after use. Samples were 

collected only from wells where LNAPL was readily collectible. Neither water in contact with the LNAPL nor sediment 

cores impacted (smeared) by the hydrocarbon product were targeted for sampling in this study. Sample PZ4 was received 

as an aqueous solution rather than free product and, therefore, was not included.

To ascertain whether sampling methodology affects reproducibility in the analysis of volatile components, samples 

were collected from wells WF11 and MW45 using several different methods. At well WF11, one sample was collected by 

releasing the check-ball with a glass pipet and allowing the liquid to flow from the bottom of the bailer. Another sample 

was collected by agitating the check-ball. The samples were labeled WF11 and WF11 A, respectively. At well MW45, one 

sample was collected by pouring the liquid from the top of the bailer, a second sample was collected by releasing the 

check-ball with a glass pipet and allowing the liquid to flow from the bottom of the bailer, and a third sample was collected 

by agitating the check-ball and allowing the liquid to flow from the bailer to the glass container. These samples were 

labeled MW45P, MW45B, and MW45, respectively.

Aliquots of the LNAPL samples were transferred from the 1-liter glass containers to 40-milliliter bottles using 25- 

milliliter glass pipets. A new pipet was used for each sample. The LNAPL remaining after subsampling was archived and 

kept in locked, dark, refrigerated storage. The aliquot samples were double bagged, sealed with duct tape, and shipped to 

the laboratory using chain-of-custody protocol.

Samples of a current diesel fuel (RR40), a broader refinery-cut fuel similar to diesel fuel (HS#2), a crude-oil composite 

(COC), unleaded regular gasoline (ULR), and additives (Nalco 5375A, Stadis 450, Para Flow 511, DCI6A, and Unisol 

Red B50) were received from the refinery in Mandan. Aliquots of each sample of reference fuels and additives also were 

transferred to 40-milliliter glass bottles using 25-milliliter glass pipets, double bagged, sealed with duct tape, and shipped 

to the laboratory using chain-of-custody protocol.

Finally, for comparison purposes, a sample of a diesel-fuel standard from a source completely unrelated to the Mandan 

reference-fuel samples was purchased from Restek Corporation, Bellefonte, Penn. Three solutions containing residues of 

the same fuel, weathered 25, 50, and 75 percent, also were purchased.

Analytical Techniques

Volatile Analysis

Purge-and-trap GC/MS was used to analyze the LNAPL and reference-fuel samples for volatile components. The 

analyses were done by the U.S. Geological Survey National Water Quality Laboratory, Denver, Colo., using modifications 

to Schedule 4054 (Connor and others, 1997). An aliquot of each sample was spiked into analyte-free reagent water at a 

dilution of 1:400,000 before analysis. The volatile analytes were similar to those listed hi the U.S. Environmental 

Protection Agency Method 524 target compound list (U.S. Environmental Protection Agency, 1995), which includes 

solvents, disinfection byproducts, halogenated hydrocarbons, and alkylbenzenes, and also included the BTEX suite 

(benzene, toluene, ethylbenzene, and meta-,para-, and ort/zo-xylenes). In addition, qualitative and semiquantitative data 

were generated for nontarget analytes. Ratios of target compounds selected for fuel characterization were calculated using 

concentrations from the quantitative data. Semiquantitative ratios of nontarget compounds identified by library matches 

were calculated on the basis of estimated concentrations where a relative response factor of 1 to the internal standard, 

fluorobenzene, was assumed.

18
Semivolatile Analysis

Capillary GC/MS was used to analyze the LNAPL and reference-fuel samples for semivolatile components. A 

Hewlett Packard 6890 gas chromatograph interfaced to a 5973 Mass Selective Detector equipped with a Merlin microinlet 

was maintained at 35°C (degrees Celsius) for 2 minutes and programmed at 5°C per minute to 315°C, holding for 

5 minutes. A DB-5MS 30-meter capillary column with a 0.25-millimeter inner diameter and a 0.25-micrometer bonded 

phase was used for the qualitative and quantitative analyses. Samples were analyzed as whole oils using 10 to 20 

milligrams of sample diluted to 5.0 milliliters in hexane. For PAH quantitation, appropriate deuterated internal standards 

were added. Five-point calibration curves were constructed and were linear over the calibration range investigated. An 

analytical reference standard (NIST SRM-1491, aromatic hydrocarbons) was analyzed before, halfway through, and after 

the suite of samples; analytes in the standard in all cases were within the acceptable range of the stated values. All 

compounds of interest, especially those used in correlations, were identified by comparison with known reference 

standards. Members of homologous series were identified by extracted ion (El) chromatograms of characteristic fragment 

ions. These series included n-alkanes [m/z 57 (mass-to-charge ratio)] and w-alkylated cyclohexanes (m/z 83; CHs). Ratios 

of selected components were calculated using either total ion chromatogram (TIC) peak heights (single analytes) or El 

chromatogram peak areas (alkyl PAH isomer families). These ratios and other relevant parameters are defined later. Bar 

graphs for the three most prominent PAH families (naphthalenes, phenanthrenes, and dibenzothiophenes from CO to C3) in 

the LNAPL and reference-fuel samples were constructed using quantitative data.

Stable Carbon Isotope Analysis

Isotope ratio mass spectrometry was used to analyze the LNAPL and reference-fuel samples for stable carbon isotopes 

(6 13C). The analyses were done by Zymax Forensics, San Luis Obispo, Calif. Analyses were done on whole oils, as bulk 

analyses. To assure accuracy, duplicate samples were analyzed for every 10 samples, and a National Bureau of Standards 

(NBS) oil sample also was analyzed.

Geochemical Parameters from Isotope and Gas Chromatographic/Mass Spectrometric Data

The following parameters were calculated from the isotope and GC/MS data:

(a) 8 C, the carbon isotopic composition of whole-oil residues useful for oil-source correlations and as an indication 

of systemic biodegradation (Peters and Moldowan, 1993; Stout and Lundegard, 1998).

(b) Pr/Ph, pristane/phytane a widely used source parameter (Peters and Moldowan, 1993) utilizing the two 

isoprenoids most common to fuel oils.

(c) «-C 17/Pr, n-Ci 7 alkane/pristane-used to track biodegradation (Kaplan and others, 1997; Stout and Lundegard, 

1998) because n-alkanes biodegrade faster than isoprenoids.

(d) n-Cmax--indicates the n-alkane or isoprenoid group at highest peak height in the El chromatograms for m/z 57.

(e) C1D/C1P, methyl dibenzothiophenes (m/z 198)/methyl phenanthrenes (m/z 192)--a source-discriminant ratio 

(Kaplan and others, 1997). This ratio and that in (f) compare common fuel components that contribute to the chemical 

fingerprint.

(f) C2D/C2P, dimethyl dibenzothiophenes (m/z 198)/dimethyl phenanthrenes (m/z 206)--a source-discriminant ratio 

(Kaplan and others, 1997; Bence and others, 1996). This ratio and that in (e) compare common fuel components that 

contribute to the chemical fingerprint.

(g) C1N/C2N, methyl naphthalenes (m/z 142)/dimethyl naphthalenes (m/z 156)-a source and weathering ratio 

(Kaplan and others, 1997) that helps differentiate sources within fuel types, when the fuel is unweathered, and indicates 

weathering progression (Cl loss occurs before C2) in weathered fuels.

(h) 1,2,4-TMB/2MN, l,2,4-trimethylbenzene/2-methyhiaphthalene~a diesel-fuel component ratio. Both analytes are 

prominent, moderately refractory, aromatic compounds.

19
Liquid Chromatographic/Mass Spectrometric Analysis

Liquid chromatography/mass spectrometry (LC/MS) was used to analyze the LNAPL, reference-fuel, and additive 

samples by both positive and negative electrospray ionization. All solvents used were ultraviolet (UV) HPLC grade. 

Using flow-injection analysis, 5 microliters of sample diluted with methanol was injected into an isocratic stream of 

methanol at 0.2 milliliter per minute. This method transferred the sample directly into the ion source. Samples were 

injected in duplicate every minute, in random order.

Additives received from the refinery were diluted in methanol for analysis. Upon addition to the solvent, the Nalco, 

Stadis, and Para Flow additives formed a bead, indicating they were practically insoluble. Upon mixing, the bead 

dissolved, but flakes precipitated out of solution. The DCI additive dissolved into a cloudy solution. Because of the 

sensitivity of the instrumentation and additive concentration relative to the samples, the additives were diluted once at 

1:1,000 and then again at 1:1,000 with methanol. The initial focus was on ionizing the additives effectively. Except for the 

Unisol Red B50 additive, dissolution into the methanol was poor. The additives also did not ionize well under either 

positive or negative electrospray ionization because most of the additives are composed solely of carbon- and hydrogenbased components (B. Devlin, Nalco/Exxon, oral commun., 2001), which do not respond to this ionization.

Samples were diluted for LC/MS analysis by adding 1 microliter of sample to 1,000 microliters of methanol. The 

samples were shaken well to mix and then refrigerated until analysis. Sample and standard solutions were analyzed 

unfiltered to eliminate bias from selective sorption onto filter media.

To investigate specific fuel types on the basis of dye additives used, the Unisol Red B50 sample provided by the 

refinery was analyzed by liquid chromatography/electrospray ionization/mass spectrometry (LC/ESI/MS). The sample 

was analyzed by negative ionization to optimize ionization conditions. Similar dyes were analyzed in case they had been 

used in the past. Reference standards of 10 similar solvent dyes were diluted to an appropriate concentration in methanol 

and analyzed to verify that ionization conditions were optimized to produce the deprotonated molecular ion without 

fragmentation or adduct formation. The Unisol Red B50 additive was diluted in methanol and hexane and analyzed for its 

UV spectrum using a CCD Array UV-Vis Spectrophotometer for comparison with literature values of the other dyes. 

Additive samples received from the refinery and LNAPL samples collected from the study area then were analyzed in 

quadruplicate. The polar or oxygenated species in the samples responded to this negative ionization method, but the 

aliphatic and aromatic components did not respond. The typical nonvolatility and thermal lability of dyes is not a 

limitation for this technique.

Analytical Results

Volatile Components

The LNAPL and reference-fuel samples were analyzed for volatile components to compare their respective 

compositions. TICs for the RR40, HS#2, and ULR reference-fuel samples are given in appendix B to enable visual 

comparison, and El chromatograms for m/z 57, characteristic of normal alkanes, are given in appendix C. Concentrations 

or nondetect notations for all target volatile components searched for in the LNAPL and selected reference-fuel samples 

are given (in order of increasing boiling point) in appendix D. Concentrations of only the detected target volatile 

components are given in appendix E. Estimated concentrations (based on a relative response factor of 1 to the internal 

standard, fluorobenzene) of nontarget volatile components (semiquantitative) are given in appendix F. Ratios of 

concentrations of detected target components (in order of increasing boiling point) to the major volatile component, 

1,2,4-trimethylbenzene (1,2,4-TMB), are given in approximate east-to-west order in table 4. Ratios of selected nontarget 

components to 1,2,4-TMB are given in table 5 for comparison. Ratios of selected nontarget components related to fuel 

characterization are given in table 6.

Semivolatile Components

The TIC from the semivolatile analysis of the RR40 reference-fuel sample is shown in figure 11 along with relevant 

chemical component El chromatograms. TICs from the semivolatile analyses of the LNAPL samples, selected referencefuel samples, and a Restek standard, RDF2-UN, are given in appendix G along with El chromatograms characteristic of

20
Table 4. Ratios of concentrations of detected target components to 1,2,4-trimethylbenzene in light nonaqueous phase liquid and selected reference-fuel s

[Based on analyses by U.S. Geological Survey; , no data]

Sample identifier

e ®

M ®

£ js

Ethylbenzene /n&p-Xylene

CD 

JS

6

CD

CD 

N

CD

.O

CD a.

= 0

§ 

fi-Propylbenzene

CD

e 

&

1,3,5-Trimethylben;

2-Ethyltoluene

CD

e

s

1,2,4-Trimethylben; sec-Butylbenzene

CD

_2 

o

a. 

o 

a.

o

V)

i.

CD

CD

1,2,3-Trimethylb

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

0.005

0.009 0.002

0.006

0.008

0.005

0.004

0.007 0.003

0.006

0.006

0.009 0.005

0.006 0.004

0.003 0.002

0.003 0.004

0.002

0.008

0.008

0.007

0.036 0.004

0.002 0.002

0.09

0.12

0.10

0.12

0.09

0.08

0.08

0.06

0.04

0.04

0.12

0.10

0.07

0.09

0.08

0.11

0.10

0.10

0.13

0.07

0.11

0.27

0.36

0.37

0.35

0.10

0.14

0.08

0.09

0.10

0.45

0.42

0.30

0.36

0.29

0.38

0.35

0.34

0.03

0.16

0.12

0.01

0.03

0.10

0.09

0.08

0.02

0.03

~

0.19

0.14

0.15

0.18

0.06

_

0.06

0.02

0.02

0.03

0.03

0.03

0.02

0.04

0.02

0.02

0.03

0.03

0.03

0.03

0.02

0.03

0.03

0.03

0.03

0.03

0.02

0.03

0.11

0.14

0.13

0.13

0.10

0.13

0.08

0.09

0.11

0.11

0.11

0.11

0.11

0.14

0.13

0.14

0.13

0.12

0.11

0.12

0.14

0.25

0.28

0.31

0.28

0.23

0.23

0.32

0.36

0.25

0.28

0.30

0.31

0.27

0.29

0.27

0.25

0.26

0.19

0.28

Reference-fuel

RR40

HS#2

ULR

0.024 0.239

0.019 0.232

1.030 3.874

0.16

0.17

0.68

0.61

0.57

2.53

0.29

0.28

0.94

0.03

0.05

0.04 0.06

0.13

0.16

0.17

0.24

0.26

0.28

0.08

0.13

0.21

0.18

0.15

0.23

0.15

0.02

0.21

0.23

0.17

0.16

0.21

0.21

0.19

0.04

0.03

0.03

0.25

0.22

0.19

samples

0.17

0.18

0.20

1 0.04

1 0.05

1 0.05

1 0.06

1 0.04

1 0.08

1 0.03

1 0.06

1 0.06

1 0.06

1 0.04

1 0.04

1 0.05

1 0.05

1 0.04

1 0.05

1 0.05

1 0.04

1 0.05

1 0.03

1 0.06

1 0.04

1 0.07

1 0.02

0.04

0.04

0.04

0.05

0.03

0.06

0.02

0.06

0.05

0.06

0.03

0.04

0.04

0.05

0.04

0.05

0.04

0.04

0.09

0.03

0.05

0.04

0.06

0.01

0.4

0.4

0.4

0.3

0.3

0.3

0.3

0.5

0.1

0.1

0.4

0.4

0.4

0.4

0.3

0.4

0.4

0.4

0.6

0.2

0.3

0.3

0.4

0.2
Table 5. Ratios of selected nontarget components to 1,2,4-trimethylbenzene in light nonaqueous phase liquid and selected reference-fuel samples 

[Based on analyses by U.S. Geological Survey; nc, not calculable]

Sample 

identifier

2-Methylheptane n-Undecane

1£3,4-Tetrahydronaphthalene

2-Methylnaphthalene 1-Methylnaphthalene 3-Methyloctane Methyl

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45"

MW45P

MW45B

FR4

MW8

MW7R

0.06

0.08

0.03

0.10

0.03

0.04

0.02

0.04

0.08

0

0.04

0.09

0.03

0.06

0.05

0.04

0.07

0.02

nc

0.02

0.03

0.87

nc

0.94

2.30

1.66

2.51

1.41

nc

2.60

2.80

1.45

nc

2.62

2.00

1.66

0.95

0.85

0.78

5.44

1.06

2.11

0.07

0.07

0.08

0.07

0.08

0.11

0.05

0.11

0.09

0.11

0.07

0.05

0.07

0.07

0.07

0.07

0.06

0.07

0.20

0.04

0.07

0.22

0.24

0.24

0.32

0.26

0.44

0.26

0.45

0.53

0.49

0.23

0.22

0.28

0.42

0.20

0.26

0.22

0.21

0.73

0.13

0.24

0.17

0.17

0.18

0.16

0.14

0.27

0.14

0.39

0.24

0.24

0.13

0.14

0.20

0.18

0.15

0.19

0.17

0.14

0.80

0.10

0.19

0.10

0.12

0.05

0.15

0.04

0.13

0.03

0.11

0.12

0.13

0.04

0.11

0.12

0.11

0.10

0.13

0.12

0.03

0.11

0.07

0.12

Reference-fuel samples

RR40

HS#2

ULR

0.06

0.09

0.05

2.72

4.15

0.25

0.14

0.12

0.004

1.33

0.51

0.01

0.84

0.28

0

0.13

0.25

0.04
Table 6. Ratios of selected nontarget components related to fuel characterization in light nonaqueous phase liquid and selected reference-fuel samples

[Based on analyses by U.S. Geological Survey; MC7,2-methylheptane; GH, /z-undecane; THN, 1,2,3,4-tetrahydronaphthalene; 2MN, 2-methylnaphthalene; MCg, 3-methy

trimethylcyclohexane; --, no data; E, east; SE, southeast; W, west]

o , Location or place .. , , 

Sample . .-., MC7/ C,,/ 

.. * from which sample . ' _" 

identifier . . / Cn THN was obtained "

THN/ 

2MN

MC7/ 

THN

MC7/ 

MCg

Cn/ 

MCg

Cn/ 

MCH

THN/ 

MCH

2MN/ 

MCH

MCg/ 

MCH

MC7/ 

TMCH

Light nonaqueous phase liquid samples

MW2R Railway yard 0.07 13

MW17 Railway yard

PZ2 Railway yard 0.03 12

P5 Railway yard 0.04 32

P1R Railway yard 0.02 22

EF1 Railway yard-E 0.01 22

PL4 Railway yard-SE 0.02 29

RH1 Railway yard-SE

WF11 Railway yard-W 0.03 29

WF11A Railway yard-W - 26

EW2 Railway yard 0.03 20

FR2 Railway yard

PZ6 North of Main Street 0.01 36

MW44 North of Main Street 0.03 27

MW43 North of Main Street 0.03 25

MW45 North of Main Street 0.04 14

MW45P North of Main Street 0.08 13

MW45B North of Main Street 0.03 11

FR4 North of Main Street -- 27

MW8 North of Main Street 0.02 27

MW7R North of Main Street 0.01 28

0.3

0.3

0.3

0.2

0.3

0.3

0.2

0.3

0.2

0.2

0.3

0.2

0.3

0.2

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.9

1.1

0.4

1.3

0.4

0.3

0.5

0.4

0.8

~

0.5

1.6

0.4

0.8

0.8

0.6

1.1

0.3

-

0.6

0.4

0.6

0.7

0.6

0.7

0.9

0.3

0.9

0.4

0.6

0.9

0.8

0.2

0.5

0.5

0.3

0.6

0.7

~

0.4

0.2

9

--

18

15

45

19

51

~

22

21

35

21

18

16

7

7

23

50

16

17

11

0

17

15

37

24

28

0

24

21

22

0

34

29

26

9

8

17

~

11

25

0.9

0.6

1.4

0.5

1.7

1.1

1.0

1.8

0.8

0.8

1.1

0.4

0.9

1.1

1.0

0.7

0.6

1.5

~

0.4

0.9

2.8

2.1

4.3

2.0

5.9

4.2

5.2

7.1

4.8

3.6

3.5

1.6

3.7

6.1

3.2

2.5

2.2

4.7

1.3

2.8

1.3

1.1

0.9

0.9

0.8

1.2

0.6

1.8

1.1

1.0

0.6

0.8

1.6

1.6

1.6

1.3

1.1

0.7

~

0.7

1.4

1.1

1.4

1.3

1.3

1.3

0.5

--

0.7

1.1

0

1.5

1.4

0.5

1.1

1.2

0.7

0.9

1.2

1.1

0.5

Reference-fuel samples

RR40 Refinery (current 

diesel fuel)

HS#2 Refinery (broader

refinery-cut fuel)

ULR Refinery (unleaded 

regular gasoline)

0.02

0.02

0.19

20

33

71

0.1

0.2

0.7

0.4

0.7

13.8

0.4

0.3

1.4

20

16

7

20

18

3

1.0

0.5

0

9.8

2.2

0.1

1.0

1.1

0.4

0.5

0.3

__
HI CO 

o

CL 

CO 

III

cc

TMB

17

15

14

13

C1N D2N

16

C3N

Pr

(A)

10 20 30 

RETENTION TIME, IN MINUTES

40 50

15

JuJL

(B)

N

i .^.^

C1N (C)

.1

C2N

I

C3N

j

III.,

n-ALKANES AND ISOPRENOIDS: m/z 57 NAPHTHALENES (N): m/z 128, 142, 156, 170

(D)

C1P

C3P

(E)

C1D

C2D

PHENANTHRENES (P): m/z 178, 192, 206, 220 DIBENZOTHIOPHENES (D): m/z 184, 198, 212, 226

Figure 11. Chemical components in RR40 reference-fuel sample: (A) Total ion chromatogram (numbers indicate 

n-alkane homologs;TMB, 1,2,4-trimethylbenzene; Pr, pristane; Ph, phytane); (B) extracted ion chromatograms for 

m/z 57 (Cmax shown); (C), (D), and (E) extracted ion chromatograms for polycyclic aromatic hydrocarbon families 

with C1 to C3 alkylation.

24
cyclohexanes for m/z 83. El chromatograms for alkanes for m/z 57 are shown in figure 12. Concentrations of PAHs in the 

LNAPL and reference-fuel samples and in the unweathered Restek standard, RDF2-UN, are given in appendix H, and bar 

graphs of PAH families are given in appendix I. Geochemical parameters from the semivolatile components are given in 

table 7.

Stable Carbon Isotopes

The LNAPL and reference-fuel samples were analyzed as whole oils for 5 13C. The 8 13C ratio data are given in 

appendix J, and averaged, rounded values are given in table 7.

Dyes

Response by a compound to either positive or negative ionization is very compound dependent. The Unisol Red B50 

additive, which contains a 2-naphthalenol phenyl azo alkyl derivative solvent dye, produced a strong negative ion at m/z 

339, implying a molecular weight of 340, as shown in figure 13A. The positive ion spectrum (fig. 13B) was much more 

complex than the negative spectrum and was dominated by hydrocarbons and sample artifacts. Under the same ionization 

conditions, samples containing the Unisol Red B50 additive would be expected to produce ions characteristic of the 

compound. Therefore, the LNAPL and reference-fuel samples were analyzed for dye components. The concentration hi 

each sample was based on the negative deprotonated molecular ion response of the Unisol Red B50 dye. Results of the 

analyses are given in table 8.

Initial full-scan analysis of the LNAPL samples in the positive mode produced peaks at nearly every mass because the 

hydrocarbons present ionized to produce a protonated molecular ion, a sodium adduct of the molecular ion, or both. The 

positive mode was, therefore, not applicable for specific compound analysis. The negative full-scan mass spectra from 

each sample are given in appendix K. The spectra are given numerically in table 9, with the most intense ions normalized 

to 100-percent intensity.

Degradation Analysis

The composition of a hydrocarbon oil product released into the environment begins to change almost immediately 

because of numerous biochemical and physical weathering processes (Kaplan and others, 1997). Physical weathering can 

include evaporation, water washing, or oxidation, and biochemical processes primarily involve microbial biodegradation 

(Hunt, 1996). Weathering, in general, removes the smaller, more volatile or more water soluble components. Microbial 

degradation removes components in a stepwise progression of chemical classes that is well documented in literature (for 

example, Kaplan and others, 1997). Straight-chain («-) alkanes, the dominant series of compounds in diesel fuel, are 

preferentially degraded first. Branched-chain alkanes, such as the ubiquitous isoprenoid family, and cyclic alkanes, such as 

the n-alkylated cyclohexane homologous series, are more refractory but next in the degradation succession. PAHs are 

removed sequentially in the order of increasing numbers of aromatic rings and alkyl substituents. For example, the tworinged naphthalenes degrade faster than the three-ringed phenanthrenes or dibenzothiophenes, and all of these PAHs with 

their alkylated derivatives degrade in the order CO>C 1 >C2>C3.

When a hydrocarbon body is analyzed, a profile of the components being degraded gives information on the state of 

weathering. In contrast, the components not yet degraded, whose profiles thus still hold the chemical fingerprint of the 

original hydrocarbon source, can be used for source correlations. Ratios using selected alkane and alkyl naphthalene, 

phenanthrene, and dibenzothiophene parameters commonly are used for these purposes (Kaplan and others, 1997; Bence 

and others, 1996).

The LNAPL samples from the various sites in this study appear, based on GC/MS analysis, to be closely related 

petroleum entities that are, however, at varying stages of degradation, probably related to their residence time in the aquifer. 

As discussed earlier, chronic spillage of diesel fuel into the subsurface is thought to have occurred from 1953 until 1991. 

Other contributions, if any, to the contaminant body are of unknown dates. The LNAPL in the samples is at a relatively 

early stage of degradation, impacting primarily the n-alkanes. The El chromatograms for the alkanes (m/z 57; fig. 12) 

show the varying stages of degradation in approximate order from freshest product to most-degraded (oldest) product. The

25
A. Freshest hydrocarbon product

9

,Lu II

°0

J

o

J, o1 ill

o

1

Pr

4

Ph 

jf y

RR40

,25

9

111

0

ro

I

0

I

o

1 ill

0

1

Pr

4

Ph 

||

PL4

1 < 25 j

> 

III III III

o

0

|

0

J

o

1 d,

o Pr 

|

Ph 

j|

WF11

22 

A a J

B. Older product with some fresh product

UJw 

o

CL 

CO 

UJ 

CC

PZ6 MW44 EF1

P5

CD:

EW2 FR2

Ph

ll

TIME

Figure 12. Extracted ion chromatograms for m/z 57, alkanes and isoprenoids, in approximate sample degradation order. [Carbon 

numbers of selected /j-alkane homologs shown; Pr, Ph, and o are pristane, phytane, and other (C-)3 to C-|6 and C-\Q) isoprenoids.]

26
C. Older product with no fresh product; isoprenoids becoming prominent

P1R MW7R

o o

MW8

HI

co 

O

Q. 

CO 

HI 

DC

MW43

o o

D. Oldest product; isoprenoids becoming dominant

0 O

MW2R RH1

TIME

Figure 12. Extracted ion chromatograms for m/z 57, alkanes and isoprenoids, in approximate sample degradation order-continued. 

[Carbon numbers of selected n-alkane homologs shown; Pr, Ph, and o are pristane, phytane, and other (C-|3 to C-je and C-\Q) 

isoprenoids.]

27
Table 7. Geochemical parameters for light nonaqueous phase liquid samples, reference-fuel samples, and Restek standards

[513C ratio data from Zymax Forensics, San Luis Obispo, California; remaining values based on analyses by U.S. Geological Survey; 613C, stable carbon isotopes; %o, per m

C17; /i-Cmax, n-alkane (#) or isoprenoid (ipr) suite maximum; CID, methyl dibenzothiophenes; CIP, methyl phenanthrenes; C2D, dimethyl dibenzothiophenes; C2P, dimet

C2N, dimethyl naphthalenes; 1,2,4-TMB, 1,2,4-trimethylbenzene (dominant C3-benzene); 2MN, 2-methylnaphthalene; ipr, suite of C13 , C14, C15 , C16, C18 , C19 (pristane), a

not calculable, --, no data]

Sample 

identifier

Location or place 

from which sample 

was obtained

513C

(%o)

Pr/Ph n-C17/Pr /i -Cmax C1D/C1P C2D/

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railway yard-southeast

Railway yard-west

Railway yard- west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

-28.6

-28.7

-28.6

-28.8

-29.1

-29.2

-29.6

-28.5

-29.0

-29.0

-28.7

-28.7

-28.6

-28.7

-28.4

-28.4

-28.3

-28.3

-28.3

-28.3

-28.8

1.2

1.3

1.2

1.2

1.2

1.2

1.3

1.3

1.3

1.3

1.3

1.3

1.2

1.2

1.2

1.3

1.3

1.2

1.2

1.2

1.2

0

0

0

1.5

0.17

0.91

4.5

0

3.0

2.9

0.83

0.83

3.6

3.3

0

0

0

0

0.21

0

0

10, ipr

ll>ipr

10>ipr

11>15

ll>ipr>15

15>12

15,17

ipr» 1 1

15

15

11»15

11>15

11>15

11>15

ll>ipr

ipr>10&ll

ipr>10&ll

ipr>10&ll

ll>ipr>15

ll>ipr

ll>ipr

0.80

0.79

0.75

0.81

0.88

0.82

0.90

0.80

0.84

0.84

0.82

0.90

0.74

0.75

0.75

0.75

0.75

0.75

0.74

0.75

0.74

0.9

0.8

0.8

0.9

0.9

0.9

0.9

0.9

0.9

0.9

0.8

1.0

0.8

0.8

0.8

0.8

0.8

0.8

0.8

0.

0.

Reference-fuel samples

RR40

HS#2

ULR

COC

Refinery

Refinery

Refinery

Refinery

-29.5

-29.4

-29.5

-29.7

1.5

1.4

nc

--

3.7

4.1

nc

~

15,17

13>11,17

8>»11

~

0.63

0.63

0

~

0.

0.

0

~

Restek standards

Diesel #2 (unweathered)

Diesel #2 (25-percent weathered)

Diesel #2 (50-percent weathered)

Diesel #2 (75-percent weathered)

Restek Corporation

Restek Corporation

Restek Corporation

Restek Corporation

~

~

~

2.5

2.5

2.4

1.9

0.97

0.96

0.96

0.91

15

15

16

18

0.12

0.12

0.12

0.12

0.

0.

0.

0.
*MSD1 SPC, time=1 .233 of NODAK\038C.D API-ES Negative

I.,,, I. , ..I Mill

\ f

aLi i ii ,1,1 

(A)

/ 

i j,ll Ij *l, li , , , , i, u , , , , ,

200 400 600 800 m/z

UI C/D

O 

Q. 

W 

LJJ 

DC

*MSD1 SPC,time=1.234of NODAK\038F.D API-ES Positive

JLi..LlliakH,lUlL

(B)

lUkikllLi, IllLL, .1 . l.ll

>

.....t. L

200 400 600 800 m/z

Figure 13. Electrospray ionization mass spectra of Unisol Red B5Q additive in (A) negative and (B) positive 

modes, (m/z, mass-to-charge ratio.)

spatial distribution of the relative degradation is shown in figure 14. The «-alkane distributions range from (a) the full 

diesel suite with C$ to 25 w-alkanes in a bell-shaped distribution with a Cmax at about Cj 5 to (b) an intermediate state of 

depletion of long-carbon-chain (high boiling point; high molecular weight; right end of chromatogram) members and a 

residual narrow distribution of short-carbon-chain (low boiling point; low molecular weight; left end of chromatogram) 

members with a CIQ or Cj i maximum to (c) the complete loss of n-alkanes, leaving isoprenoids as the dominant aliphatic 

components. This alteration pattern of the depletion of longer-chain w-alkanes and the accompanying relative increase of 

shorter-chain n-alkanes matches the pattern reported for a diesel-fuel spill at a large western United States petroleumoperating facility (Stout and Lundegard, 1998). A similar pattern also has been observed within the oil body in a recent reexamination of the oil accumulation at the well-studied Bemidji crude-oil spill site (F. Hostettler, U.S. Geological Survey, 

unpub. data) where anaerobic biodegradation is known to occur (Bekins and others, in press). Overall, the degradation

29
Table 8. Concentrations of Unisol Red B50 dye in 

light nonaqueous phase liquid samples, selected 

reference-fuel samples, and additive samples

[Data from U.S. Geological Survey; relative standard deviation for 

eight replicates was 33 percent; samples were diluted in duplicate 

and each analyzed in duplicate; fig/L, micrograms per liter; ND, not 

detected]

Sample identifier . _~

Light nonaqueous phase liquid samples

MW2R 52

MW17 16

PZ2 24

P5 36

P1R 16

EF1 33

PL4 1

RH1 44

WF11 28

WF11A 16

EW2 29

FR2 20

PZ6 14

MW44 15

MW43 20

MW45 33

MW45P 39

MW45B 30

FR4 45

MW8 23

MW7R 37

Reference-fuel samples

RR40

HS#2

ULR

Additive samples

Nalco 53 75 A

Stadis 450

Para Flow 511

DCI6A

53

20

ND

ND

ND

ND

ND

process at Mandan is quite slow as shown by the dominantly fresh product from well PL4 near the pipeline spill. The 

product from that well probably was deposited as long ago as 1987 when pipeline leakage was observed and stopped 

(Roberts, 2001). Thus, the product probably has been in the subsurface for at least 14 years but is still relatively 

undegraded.

At many sites, alkane patterns that have several maxima are evident. Older, partly degraded fuel has a CJQ or Cj j 

maximum, whereas fresher fuel input has the C}5 maximum, and a site where more than one maximum exists likely has 

experienced multiple episodic inputs of the same or closely related diesel fuels. The dominant maxima at each site are 

listed in table 7 along with the value for n-C17/Pr, which relates to the age of the diesel fuel (age here refers to the length of 

time the diesel fuel has been in the subsurface environment). Values of about 3 to 4 indicate fresh diesel fuel is present, and

30
Table 9. Relative intensities of masses from negative electrospray ionization mass spectra for light nonaqueous phase liquid and selected referencefuel samples

[Average of four analyses, normalized to 100-percent intensity; percent relative standard deviation is from eight replicate analyses of sample EW2; -, no data]

Mass

Sample identifier 107 121 166 180 194 195 208 209

EF1

PL4

RH1

WF11

WF11A

EW2 

EW2 

FR2 

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8 

MW7R

RR40 

HS#2 

ULR

Percent relative standard deviation

13

14

17

11

14

14

13

15

14

15

39

58

46

50

49

70

68

60

67

65

62

65

71

67

12 66

13 62

Reference-fuel samples

52

59

100 80

96

100

100

100

100

100

100

100

100

100

100

100

100

100

38

100

100

100

100

15

15

19

13

17

17

16

16

13

18

13

15

16

15

18

15

15

15

100

77

99

92

94

63

62

72

73

52

62

65

70

72

93

65

67

79

84

15

13

20

13

15

12

11

15

11

28

12

12

12

11

17

16

12

16

16

222

18

57

34

50

48

49

21

24

28

28

26

25

25

24

27

100

27

27

30

27

18

236

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

13

13

14

13

17

63

65

68

60

67

100

100

100

100

100

18

16

14

14

13

55

70

61

69

68

17

13

12

13

13

28

25

25

24

28

«

10

29

12

16

15

20

11

10

45

19

11

values near zero indicate no fresh diesel fuel is present and the product that is present is at least 20 years old (Christensen 

and Larsen, 1993). Given the degradation beyond loss of «-C17 shown in the chromatograms, much of the LNAPL in the 

samples could be considerably older than 20 years. Wells EW2, FR2, MW44, P5, and PZ6, in particular, near the center of 

the LNAPL (fig. 14) show some recent input of diesel fuel in addition to the older, more degraded product. The remainder 

of the wells in the main body contain LNAPL that is made up only of older product.

When «-alkanes are severely or completely degraded, the distribution pattern of the more refractory CHs can be used 

to verify the presence of diesel fuel (Kaplan and others, 1997). The distribution of the CHs for the LNAPL and referencefuel samples is given in appendix G in El chromatograms for m/z 83. These chromatograms show the product at all sites 

contains CHs from C7 to C22, the same range as in the RR40 reference-fuel sample from the refinery. With advancing 

biodegradation within the samples, a lower-range maximum begins to appear, as with the «-alkanes, but the degradation 

has not caused the high-end CHs to be lost. This ubiquitous presence and the prominence of the diesel-fuel range CHs is 

further evidence the LNAPL samples primarily are degraded diesel fuel.

31
100°53'45

46°49'40" 

46°49'30" 

Base from ThermoRetec Consulting Corporation 

Cadd file 4438d 1s, 2000

500 

I

1,000 FEE

__I

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16,2000, 

based on kriged LNAPL thicknesses

PZ2 SAMPLE IDENTIFI

Freshest hydrocarb

Older product with 

Older product with 

isoprenoids becom

Oldest product; iso

Figure 14. Relative degradation from w-alkane profiles.
Characterization Based on Correlations

To ascertain if the LNAPL at all sites is related, comparisons were made on the basis of stable carbon isotopes, several 

parameter ratios, PAHs and alkylated derivatives, and several analyses.

Stable Carbon Isotopes

The S13C values for the LNAPL and reference-fuel samples are given in table 7. The spatial distribution of the 

isotopes is shown in figure 15. If the railway used diesel fuel only from local sources when fueling at Mandan during 

1953-91, the 8 13C values for the current and older diesel fuels were expected to be similar. The values in table 7 have a 

narrow range (-29.7 to -28.3%o, from lighter to heavier) but are not identical. A correlation does exist, however, with the 

approximate age of the diesel fuel in the subsurface. The reference-fuel samples and sample PL4 from the pipeline spill 

were the lightest. Samples from the east and west fueling areas (separate accumulations from the main LNAPL body and 

presumably containing more recently spilled diesel fuel) and sample P1R (from the main LNAPL body) were the next 

lightest. Samples from the remaining wells in the main LNAPL body and from well RH1 (another small disconnected 

accumulation in the Roundhouse area) were at the heavier end of the range. Stout and Lundegard (1998) have shown that 

systematic biodegradation severely impacting the «-alkanes results in a steady enrichment of the residue in C, thus giving 

somewhat heavier 8 13C values. This relation was observed in the LNAPL samples. Therefore, the stable carbon isotope 

data are consistent with a common source for the hydrocarbons in the main LNAPL body.

Parameter Ratios

The values for the source parameters (Pr/Ph, C1D/C1P, C2D/C2P, and C1N/C2N) used in this study also are given in 

table 7. The Pr/Ph ratio was constant throughout the LNAPL samples but was slightly different for the RR40 and HS#2 

reference-fuel samples. The ratios were very different from those for the unrelated Restek diesel-fuel standards. This 

result indicates the chemical fingerprint of the current diesel fuel is quite close but nonetheless slightly different from that 

of the older diesel fuel hi the LNAPL body.

The ratios of refractory alkylated PAHs, namely C1D/C IP and C2D/C2P, confirm this result although they show some 

small areal differences within the main LNAPL body. The spatial distribution of the source-parameter values is shown in 

figure 16. The parameter values for the RR40 and HS#2 samples agree but were somewhat lower than the parameter values 

for samples from the main LNAPL body. Sample PL4 from the pipeline spill has been shown to contain the freshest spilled 

product, but the parameter values for that sample were at the opposite end of the range from those for the current diesel 

fuel. The parameter values for samples from the fueling areas and most of the railway yard were intermediate between 

those for'the reference-fuel samples and sample PL4. The parameter values for samples from wells north of Main Street 

and from well PZ2 have a narrow range and were lower than those for samples from the other downtown wells but still 

were intermediate between the values for the current diesel fuel and those for sample PL4. Note again that-a very 

significant difference exists between the parameter values for the LNAPL and reference-fuel samples and those for the 

Restek diesel-fuel standards analyzed for comparison (table 7).

The C1N/C2N ratio can have source and/or weathering implications, the latter depending on the stage of degradation 

of the product. The values for most of the LNAPL samples have a narrow range, 0.72 to 0.74, indicating the samples were 

very similar and the degradation progression has not reached the alkylated naphthalenes. Note that the values for the 

physically weathered Restek diesel-fuel standards rapidly decrease from 0.56 to 0, indicating that physical weathering has 

a substantial effect on this parameter. The LNAPL samples with values only slightly lower than 0.72 probably either have 

slight chemical-source-related differences or have undergone very mild weathering. The sample from well FR4 near the 

north edge of the main LNAPL body had a substantially lower value of 0.38, most likely indicating physical weathering in 

addition to biodegradation. Further evidence for this weathering is the TIC (appendix G) for that sample, which shows a 

loss of low-end components. The location of well FR4 near the north edge of the main body where the accumulation is 

relatively thin (figs. 9 and 10) increases the likelihood that physical weathering is causing this difference. The values of 

C1N/C2N for the RR40 and HS#2 samples differ slightly from each other, perhaps because of those samples being 

different refinery cuts, and again, were close but not identical to those for the LNAPL samples. All of this source 

correlation is consistent with an interpretation that the Mandan diesel products are closely related with minor chemicalfingerprint differences that likely reflect small changes in fuel composition over 50 years.

33
100°53'45B

46°49'40° 

WF11

46049<30d 

Base from ThermoRetec Consulting Corporation 

Cadd file 4438c11s, 2000

500 

I

1.000 FEET 

__I

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16,2000, 

based on kriged LNAPL thicknesses

SAMPLE IDENTIFIER

Number in parenthese

carbon isotope ratio, i

Lightest (-29.7 to -2

Next lightest (-29.2 

Heavier (-28.8 to-28

Heaviest (-28.5 to -2

Figure 15. Stable carbon isotope distribution.
100053'45a 100°53'30'

46°49'40° 

WF11

46°491 300 

Base from ThermoRetec Consulting Corporation 

Cadd file 4438d 1s, 2000

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16,2000, 

based on kriged LNAPL thicknesses

SAMPLE IDENTIFIER

Numbers in parenthes

and C2D/C2P (see tab

High end (0.88 to 0

Lower high (0.79 to 

Narrow (0.74 to 0.7

Refinery (0.63 to 0.

Figure 16. Source-parameter value distribution.
1,2,4-TMB (the dominant member of a suite of C3-benzenes) is a low-end component of diesel fuel. 1,2,4-TMB is 

present at substantially higher levels in lower-cut refinery fuels such as gasoline and kerosene. The 1,2,4-TMB/2MN ratio 

gives a relative value for the concentration of 1,2,4-TMB in comparison to 2-methylnaphthalene, a more refractory 

component of these fuels.

Diesel fuel, as used in railroad engines, commonly is amended with various additives to enhance performance or 

improve viscosity to prevent jelling in the winter. Some of these additives were enumerated previously, but another 

additive used in the past is EC5375A; this additive, as used at this railway location, contained mainly 1,2,4-TMB at 1 to 

5 percent (Nalco/Exxon Energy Chemicals, 1997). Diesel fuel also commonly is mixed, just before loading, with lowercut refinery products, especially kerosene, which also can be a source of enhanced 1,2,4-TMB. Use of any of these 

additives in the Mandan environment probably has varied seasonally and temporally, thus causing some variation in the 

chemical makeup of the diesel products and impacting the 1,2,4-TMB/2MN ratio. 1,2,4-TMB was present at varying 

levels in the LNAPL samples, and the range for the ratio is broader than the ranges for the source ratios discussed earlier 

that are not impacted by variable adulteration. However, distinct trends do occur in the data (table 7, fig. 17).

The value for 1,2,4-TMB/2MN was low for the RR40 sample, which should be free of additives. The value also was 

low for sample FR4, which probably was affected by weathering as previously discussed. The value was significantly 

higher for most other samples, including those from the fueling areas and from well PL4. Medium-low values occurred in 

samples from the east and west fueling areas, and medium values occurred in most samples from the main LNAPL body 

(fig. 17). Sample MW8 had a somewhat higher value, and the ULR reference-fuel sample, as expected, had a substantially 

higher value. The ubiquity of 1,2,4-TMB throughout the sample set, especially the relatively uniform value of the ratio in 

the main LNAPL body, supports its being an intrinsic part of similarly amended diesel-fuel input rather than being 

contributed by a separate contaminant source. The slightly higher value for sample MW8 suggests a possible trace of 

gasoline input.

Polycyclic Aromatic Hydrocarbons and Alkylated Derivatives

Bar graphs as graphic representations of PAH families [CO (parent), Cl, C2, and C3 for naphthalene, phenanthrene, 

and dibenzothiophene] commonly are used (Kaplan and others, 1997) to compare oil samples. Bar graphs for the LNAPL 

samples, the RR40 and HS#2 reference-fuel samples, and the Restek diesel-fuel standard, RDF2-UN, are given in 

appendix I. The patterns for the LNAPL samples and the RR40 and HS#2 samples are noticeably consistent, but the 

pattern for the Restek standard is noticeably different, especially for the phenanthrene and dibenzothiophene 

concentrations. Sample FR4, again, shows a pattern of slight loss of low-end components (naphthalenes), consistent with 

physical weathering, but the overall pattern fits with those of the other LNAPL samples. This result is additional strong 

evidence for a very similar or common source for the LNAPL samples and the current diesel fuel.

Volatile Analysis

Volatile analysis focuses on the compounds in the low range of the boiling-point spectrum. The presence of volatile 

components related to gasoline would be indicated by this analysis. General volatile content of the reference-fuel samples 

was typical of their respective types (appendix B). Generally, the RR40 and HS#2 reference-fuel samples had far fewer 

volatile components than the ULR reference-fuel sample.

In mass chromatograms for m/z 57, characteristic of alkanes (Philp, 1985), the RR40 sample shows peaks from «-Cg 

through «-Cj4 in a bell-shaped curve maximizing at n-C\Q and n-C\ \ (appendix C). The chromatogram for the HS#2 

sample was similar. In .contrast, the chromatogram for the ULR sample shows alkane peaks including n-C5 through n-C^ 

with a primary maximum at «-Cg and a lower maximum at n-C\ \. None of the LNAPL samples contained a Cg maximum, 

and only three samples~MW8, MW45, and MW45P~contained any traces of Cg. Most LNAPL samples maximized at nCIQ. Because the range of alkanes is limited within volatile analysis, results given in the semivolatile data, which show a 

more complete range, are more comprehensive.

Hydrocarbons were the only compounds detected in the target analysis which searches for a wide variety of selected 

compounds (appendix D). Except for styrene, which was detected in the ULR sample, the components detected in the 

RR40, HS#2, and ULR samples were the same; however, the components were detected in very different relative amounts,

36
100°53'45B 100°53'30"

46°49'40' 

WF11

46°49'30° 

Base from ThermoRetec Consulting Corporation 

Caddfile4438c11s, 2000

500 

I

1,000 FEE

__I

EXPLANATION

Extent of light nonaqueous phase liquid (LNAPL) 

floating on water table, November 14-16,2000, 

based on kriged LNAPL thicknesses

SAMPLE IDENTIFI

Numbers in parenth

1,2,4,-TMB/2MN (

Low (0.18; 0.27) 

Medium low (0.4

Medium (0.61 to 

High (0.98; 8.6)

Figure 17. Additive indicator distribution.
with low boiling point components dominant in the ULR sample and higher boiling point components in the RR40 and 

HS#2 samples. Solvents such as diethylether, acetone, methylene chloride, methyl-t-butyl ether (MTBE), ethyl-t-butyl 

ether (ETBE), and t-amyl-methyl ether (TAME) were not detected in any LNAPL samples. Halogenated hydrocarbons 

such as perchloroethylene (tetrachloroethylene) and l,l,2-trichloro-l,2,2-trifluoroethane associated with drycleaning 

(Occupational Safety and Health Administration, 2001) also were not detected.

The different sample-handling methods described previously for samples WF11 and WF11A and MW45, MW45B, 

and MW45P would have the greatest effect on the most volatile components such as benzene and toluene. However, the 

ratio of benzene to the most dominant component in the mixture, 1,2,4-TMB, was consistent in these two groups of 

samples (table 4). Therefore, differences in volatile component concentrations due to differences in sample-handling 

methods were minimal.

Ratios of the concentrations of the detected target components to the dominant component, 1,2,4-TMB, are given in 

table 4. The ratios for the ULR sample relative to those for the RR40 and HS#2 samples reflect the characteristics of 

gasoline in contrast to diesel fuel; the gasoline has greater amounts of the more volatile components (left side of table) and 

lesser amounts of the higher boiling point components (right side of table). The ratios of benzene to 1,2,4-TMB for the 

RR40 and HS#2 samples were 0.024 and 0.019, respectively, indicating that benzene was a minor component compared 

to 1,2,4-TMB. In the ULR sample, however, the ratio was greater than 1, indicating the concentration of benzene was 

approximately equal to that of 1,2,4-TMB. The ratios for all but one of the LNAPL samples were even lower than those 

for the RR40 and HS#2 samples, reflecting some loss of benzene through either water washing, volatilization, or 

biodegradation (Kaplan and others, 1996). However, sample MW8 had a slightly elevated ratio compared to the RR40 

and HS#2 samples and the remaining LNAPL samples, again suggesting a possible trace of gasoline components in this 

sample.

As shown by the ULR sample (table 4), BTEX components are dominant in gasoline. Generally, the ratios of the 

BTEX components for the RR40 and HS#2 samples were quite different from the ratios for the ULR sample (table 4). The 

ratios for the ULR sample were much higher than those for the RR40 and HS#2 samples. Values for the LNAPL samples 

were even lower than those for the reference-fuel samples. Again, these losses may be due to water washing, volatilization, 

or degradation (Kaplan and others, 1996). None of the BTEX components in the LNAPL samples were present at levels 

even close to those in the ULR sample.

Styrene, a unique component of the ULR sample, was not detected in the LNAPL samples or the RR40 and HS#2 

samples. However, styrene is one of the least stable components in gasoline mixtures. Therefore, its absence in the 

LNAPL samples is not confirmatory for lack of gasoline presence.

For the compounds with higher boiling points than 1,2,4-TMB, the ratios for the RR40 and HS#2 samples were greater 

than those for the ULR sample. Although some natural variability occurred in the data, the ratios for the LNAPL samples 

generally were similar to those for the RR40 and HS#2 samples.

Ratios of selected nontarget components to 1,2,4-TMB were greater for the RR40 and HS#2 samples than for the ULR 

samples (table 5), and the differences sometimes were appreciable. The ratios for undecane, n-Cn, a degradationvulnerable alkane, varied in the LNAPL samples but were not as low as the ratio for the ULR sample. This trend was true 

for most of the LNAPL samples. For several components, sample MW8 had the lowest ratio except for the ULR sample. 

Several of the components were not detected in sample FR4. Although some natural variability of the data occurred, the 

ratios for the LNAPL samples resembled those for the RR40 and HS#2 samples, not those for the ULR sample.

Ratios of selected nontarget components are given in table 6 to enable a comparison between the LNAPL and 

reference-fuel samples. Due to differences between gasoline and diesel fuel, few nontarget components were present in 

both fuel types. The ratios for the RR40 and HS#2 samples were very different from those for the ULR sample. Generally, 

the ratios for the LNAPL samples were similar to those for the RR40 and HS#2 samples.

The isooctane/methylcyclohexane (IsoC8/MCH) ratio is considered by Kaplan and others (1996) to be a characteristic 

gasoline ratio relating to octane rating. Isooctane in gasoline is, therefore, ubiquitous and, although degradable, is less 

easily degraded than the n-alkanes. Isooctane was not identified in the reference-fuel samples or in the LNAPL samples 

except for sample MW8, which likely had a trace; identification was somewhat tentative due to coeluting interferences.

38
The benzene/methylcyclohexane (Bz/MCH) ratio, which is similar to the water-washing ratio given in Kaplan and others 

(1996), was very different for the ULR sample than for the LNAPL, RR40, and HS#2 samples. The 2-methylheptane to 

undecane ratio, which is the ratio of a lower (more volatile) alkane to a higher one, was very low for the RR40 and HS#2 

samples and much greater for the ULR sample. Ratios for the LNAPL samples were less than half those for the ULR 

sample.

Generally, most ratios for the LNAPL samples were between those for the RR40 and HS#2 samples. The ratios for the 

ULR sample were distinctly different from those for the LNAPL samples. Many of the volatile components were not 

detected in sample FR4, which, as indicated earlier, appears to be more weathered than the other LNAPL samples. Volatile 

components related to gasoline, including 1,2,4-TMB, n-C6, benzene, and isooctane, were uniquely detected or found at 

slightly elevated levels in sample MW8.

Dye Analysis

The UV maximum of the Unisol Red B50 sample was compared to literature values for similar dyes (Green, 1990). 

The maximum, 518 nanometers (data not shown), was most similar to the maximums for Sudan Red B and Sudan IV. 

Between methanol and hexane, the solvent used essentially caused no change in the UV maximum of the Unisol Red B50 

sample. Under the ionization conditions used for LC/MS analysis, Sudan Red B and Sudan IV ionized well. Therefore, 

the same ionization conditions were assumed to be appropriate for the unknown component in the Unisol Red B50 sample.

All samples were analyzed by LC/MS for dye components. The red component in Unisol Red B50 was present in 

every sample except for the ULR reference-fuel and other additive samples (table 8). The RR40 reference-fuel sample had 

the highest concentration, at 53 micrograms per liter, and was followed by samples MW2R, FR4, and RH1. The lowest 

concentration, 1 microgram per liter, was in sample PL4. Although the concentrations were too random to discern a 

pattern, probably because of the chemical sensitivity of the dye, the presence of the dye is further evidence diesel fuel is 

present at all sites.

Alkyl disazonaphthol dyes, including Unisol Red B50, are toxic irritants and possible mutagens. These dyes and their 

degradation products (aromatic amines) have been shown to possess mutagenic and carcinogenic properties (Gregory, 

1986). These dyes are not light-fast and may degrade upon prolonged exposure to light. The Unisol Red B50 dye is not 

water soluble and, therefore, is not expected to dissolve into the nearby ground water.

Electrospray Analysis

When analyzed by LC/ESI/MS, the RR40 and HS#2 reference-fuel samples produced a pattern of alkyl moieties 

(table 9; appendix K) with peaks differing by 14 mass units. The compounds shown in these LC/ESI/MS spectra were 

most likely a series of homologous alkylated carbazoles; an authentic standard of carbazole (molecular weight 167) 

analyzed under similar conditions gave a peak corresponding to the lowest member of the series. These nitrogencontaining compounds are present in various petroleum products at very trace levels (Tissot and Welte, 1984). Due to the 

higher boiling point of carbazoles, they are not present in gasoline, and, thus, are not seen in the ULR reference-fuel 

sample chromatograms. Distributions of these compounds were very similar in the RR40, HS#2, and LNAPL samples, 

with minor differences in samples EF1 and FR4 only in the distribution of homologs from 0 to 4 carbons. Differences in 

sample FR4 probably are due to weathering as previously discussed.

The additive samples produced little response to LC/ESI/MS analysis. The ULR sample was distinctly different from 

all other samples; the major masses generated by the components in the ULR sample were not found in the remaining 

samples.

SUMMARY AND CONCLUSIONS

Free-phase hydrocarbons [light nonaqueous phase liquid (LNAPL)] are present floating on the water table in the 

alluvial aquifer at Mandan, North Dakota, over a subsurface area of about 657,000 square feet. The alluvium can be 

divided into three stratigraphic units-silty clay, silty sand, and sand~and is underlain by shales and sandstones. Although

39
the general water-table gradient may be from west-northwest to east-southeast, ground-water-flow directions can vary 

depending on the river stage and recharge events. Any movement of the LNAPL is influenced by the gradients created by 

changes in water-level altitudes. The thickness of the LNAPL body is about 6 feet.

To characterize geochemical composition, LNAPL samples were analyzed by purge-and-trap gas chromatography/ 

mass spectrometry (volatile components), capillary gas chromatography/mass spectrometry (semivolatile components), 

isotope ratio mass spectrometry (stable carbon isotopes), and liquid chromatography/mass spectrometry with electrospray 

ionization (additives and other organic components).

Characterization of the LNAPL samples by gas chromatography/mass spectrometry indicates the samples were all 

diesel product with a variable loss of «-alkanes from biodegradation. Bulk stable carbon isotope data suggest a 

biodegraded hydrocarbon fuel from a common source. Source-parameter ratios of the LNAPL components indicate an 

overall similarity among the samples, especially when compared with an unrelated diesel-fuel standard. However, slight 

differences exist in the chemical distribution within the samples, probably because of small variations hi refinery-fuel 

composition over a long period of local diesel-fuel usage. Very similar polycyclic aromatic hydrocarbon distributions in 

the LNAPL samples gives more evidence for a common source. The distribution of alkylated carbazoles shows a 

commonality of diesel-fuel components in samples throughout the downtown area. The red dye marker for diesel fuel is 

present in all LNAPL samples. These results, therefore, indicate the LNAPL body consists of closely correctable diesel 

fuel at various stages of degradation. None of the samples contained chlorinated solvents associated with industries such as 

drycleaning or automotive maintenance. Solvents such as acetone, dimethyl ether, and methylene chloride and the gasoline 

additives methyl-t-butyl ether (MTBE), ethyl-t-butyl ether (ETBE), and t-amyl-methyl ether (TAME) were not found. At 

one site near the north edge of the main LNAPL body, evidence exists for traces of possible gasoline components in 

addition to the diesel fuel. With this possible exception, no evidence of a different diesel or other hydrocarbon fuel 

contribution was identified. The geochemical analysis of the LNAPL and correlations with other fuel products and 

additives strongly suggest episodic releases of a single, local-source, diesel fuel into the aquifer over an extended period 

of time.

40
CHEMICAL GLOSSARY FOR SEMIVOLATILES

1. tt-alkanes CH3 (CH2 ) nCH3

e.g. n2. Isoprenoids

n=4-23 for n-C6-nC25 

= CH3 (CH2) 13 (CH3) or

Pristane (C19 ) 

Phytane (C20 )

Others: C13/ C14, C15, C16, C18

3. n-alkylated cyclohexanes

4. isooctane

5. PAH

naphthalene

R = H, CH3, C2H5 . . . C16H33

with 0,1, 2, 3 GI constituents:

CH,

e.g., Crnaphthalenes:

CH

phenanthrene

l-methylnaphthalene

2-methylnaphthalene

with 0,1, 2, 3 Ca constituents

dibenzothiophene with 0, l, 2/3 Ca constituents

CH

6. 1, 2, 4 - trimethylbenzene

CH

CH,

41
REFERENCES

Ackerman, D.J., 1980, Ground-water resources of Morton County, North Dakota: North Dakota State Water Commission County 

Ground-Water Studies 27, pt. Ill, and North Dakota Geological Survey Bulletin 72, pt. Ill, 51 p.

Altgelt, K.H., and Boduszynski, M.M., 1994, Composition and analysis of heavy petroleum fractions: New York, Marcel Dekker, 

495 p.

Bekins, B.A., Godsey, E.M., Warren, E., and Hostettler, F.D., in press, Microbial ecology of the vadose zone in the vicinity of residual 

crude-oil contamination: Abstract for American Geophysical Union Spring Meeting.

Bence, A.E., Kvenvolden, K.A., and Kennicutt, M.C., II, 1996, Organic geochemistry applied to environmental assessments of Prince 

William Sound, Alaska, after the Exxon Valdez oil spill A review: Organic Geochemistry, v. 24, p. 7-42.

Burlington Northern Santa Fe Railway, 1999a, Burlington Northern Santa Fe, Mandan, North Dakota, fact sheet: 2 p.

 1999b, Burlington Northern Santa Fe, Mandan, North Dakota, fact sheet #2, September, 1999: 2 p.

 1999c, Burlington Northern Santa Fe, Mandan, North Dakota, fact sheet #3, October, 1999: 2 p.

 1999d, Burlington Northern Santa Fe, Mandan, North Dakota, fact sheet #4, November, 1999: 2 p.

 2000a, Burlington Northern Santa Fe, Mandan, North Dakota, fact sheet #5, January, 2000: 1 p.

 2000b, BNSF recovery project, Mandan, North Dakota, information update #6: 2 p.

-2000c, BNSF recovery project, Mandan, North Dakota, information update #7: 2 p.

-2000d, BNSF recovery project, Mandan, North Dakota, information update #8: 2 p.

Christensen, L.B., and Larsen, T.H., 1993, Method for determining the age of diesel oil spills in the soil: Ground Water Monitoring and 

Remediation, v. 23, p. 142-149.

Connor, B.F., Rose, D.L., Noriega, M.C., Murtagh, L.K., and Abney, S.R., 1997, Methods of analysis by the U.S. Geological Survey 

National Water Quality Laboratory Determination of 86 volatile organic compounds in water by gas chromatography/mass 

spectrometry, including detections less than reporting limits: U.S. Geological Survey Open-File Report 97-829, 78 p.

Ethyl Corporation, 2001, Products: accessed March 2001 at URL http://www.ethyl.com/products/products_summ.html/ 

Freeze, R.A., and Cherry, J.A., 1979, Groundwater: Englewood Cliffs, New Jersey, Prentice-Hall, 604 p.

Green, F.J., 1990, The Sigma-Aldrich handbook of stains, dyes, and indicators: Aldrich Chemical Company, Milwaukee, Wisconsin, 

776 p.

Gregory, P., 1986, Dyes and pigments: v. 7, p. 45.

Hunt, J.M., 1996, Petroleum geochemistry and geology (2d ed.): W. H. Freeman and Company, 743 p.

Kaplan, I.R., Galperin, Y, Alimi, H., Lee, R.P., and Lu, S.T., 1996, Patterns of chemical changes during environmental alteration of 

hydrocarbon fuels: Groundwater Monitoring and Remediation, v. 16, no. 4, p. 113-124.

Kaplan, I.R., Galperin, Y, Lu, S.H., and Lee, R.P., 1997, Forensic environmental geochemistry Differentiation of fuel types, their 

sources and release time: Organic Geochemistry, v. 27, p. 289-317.

Lenhard, R.J., and Parker, J.C., 1990, Estimation of free hydrocarbon volume from fluid levels in monitoring wells: Ground Water, 

v. 28, no. 1, p. 57-67.

Mansuy, L., Philp, R.P., and Alien, J., 1997, Source identification of oil spills based on the isotopic composition of individual 

components in weathered oil samples: Environmental Science and Technology, v. 31, p. 3417-3425.

Nalco/Exxon Energy Chemicals, 1997, Material safety data sheet for product EC5375A: Sugarland, Texas, 8 p.

42
Occupational Safety and Health Administration, U.S. Department of Labor, 2001, Dry cleaning: accessed March 2001 at URL 

http://www.osha-slc.gov/SLTC/drycleaning/

Peters, K.E., and Moldowan, J.M., 1993, The biomarker guide: New Jersey, Prentice-Hall, 363 p. 

Philp, R.P., 1985, Fossil fuel biomarkers--Applications and spectra: New York, Elsevier, 294 p.

Radian International, 1999, Downtown Mandan subsurface investigation report-Burlington Northern and Santa Fe Railway Company: 

Radian International Report DCN:99. 228129.08, March 9, 1999, 30 p.

Roberts, Kris, 2001, Fuel recovery history, Mandan, North Dakota: North Dakota Department of Health; accessed March 2001 at URL 

http://www.health.state.nd.us/ndhd/presentations/mandannielspill/

Soil Exploration Company, 1985, Aquifer evaluation and proposed conceptual design fuel oil recovery system, Mandan, North Dakota: 

Soil Exploration Company Report #120-12493-A, 40 p.

Stout, S.A., and Lundegard, P.D., 1998, Intrinsic biodegradation of diesel fuel in an interval of separate phase hydrocarbons: Applied 

Geochemistry, v. 13, p. 851-859.

ThermoRetec Consulting Corporation, 1999, Supplemental design report, oil recovery using groundwater extraction, BNSF Railyard, 

Mandan, North Dakota: ThermoRetec Consulting Corporation December 30,1999, report to the Burlington Northern and Santa Fe 

Railway Company, 13 p.

Tissot, B.P., and Welte, D.H., 1984, Petroleum formation and occurrence: New York, Springer-Verlag, 699 p.

U.S. Environmental Protection Agency, 1995, Methods for determination of organic compounds in drinking water: EPA/600/R-95/131.

U.S. Geological Survey, 1955-2000, Water resources data, North Dakota, Water years 1954-1999: U.S. Geological Survey Water-Data 

Report, published annually.

van Dam, J., 1967, The migration of hydrocarbons in a water-bearing stratum, in Hepple, P., ed., The joint problems of the oil and water 

industries: London, The Institute of Petroleum Journal, p. 55-96.

Wang, Z., Fingas, M., and Sergy, G., 1994, Study of 22-year old Arrow oil samples using biomarker compounds by GC/MS: 

Environmental Science and Technology, v. 28, p. 1733-1746.

Youngless, T.L., Swansiger, J.T., Danner, D.A., and Greco, M., 1985, Mass spectral characterization of petroleum dyes, tracers, and 

additives: Analytical Chemistry, v. 57, p. 1894-1902.

43
APPENDIX A. Construction information for 

monitoring wells in study area

44
[Data from several contractors; , no data]

Site identifier

464929100532701

464937100525768

464937100525765

464940100523701

464939100524101

464940100523101

464941100523701

464940100523344

464939100523901

464938100523701

464934100532709

464934100532813

464934100532759

464933100533288

464933100532742

464932100532885

464933100532596

464937100533214

464933100533201

464925100542401

464928100530808

464930100531801

464939100523701

464931100533671

464932100533357

464933100532790

464933100532378

464935100533501

464935100532801

464936100532401

464938100533301

464939100532901

464941100533201

464939100533199

464939100533037

464946100533101

464941100533601

464937100531801

464932100533101

464933100533301

464932100533401

464934100533890

464935100533738

464937100533414

464934100533415

»i ii j .-n Date well Well identifier _^ . . constructed

CS1

DBT1

DBT2

EF1

EF4

EF5

EF6

EF7

EF8

EF9

EW1

EW2

EW3

EW4

FR1

FR2

FR3

FR4

FR5

FR6

FR7

FR8

FR9

MW1R

MW2R

MW3R

MW4R

MW5R MW6'

MW7R

MW8

MW9

MW10

MW11

MW12

MW13

MW14

MW16

MW17

MW18

MW20

MW40

MW41

MW42

MW43

04-13-1990

~

08-04-1997

04-18-1990

10-23-1991

10-24-1991

10-25-1991

11-18-1991

11-18-1991

11-19-1991

05-07-1999

05-07-1999

06-03-1999

06-03-1999

~

12-03-1986

12-02-1986

12-05-1986

11-12-1991

08-04-1992

_.

08-06-1992

08-07-1992

10-28-1986

10-29-1986

._

10-28-1986

04-16-1990

09-06-1984

04-17-1990

09-06-1984

09-06-1984

09-11-1984

-

--

04-17-1990

04-15-1990

04-15-1990

04-16-1990

11-14-1991

11-14-1991

10-25-2000

10-24-2000

10-24-2000

10-23-2000

Depth drilled 

(feet)

29.5

~

24.5

29.5

28

28

31

28

28

33

24.5

24.5

20

18

~

47

45

49

43

45

_.

40

40

40

30

._

30

29.5

19.5

29.5

19.5

21

21

~

~

29.5

30.1

30

31

40

40

28

28

28

28

Depth of well 

(feet)

29

-

-

29

28

26

26

27

27

33

24

24

18

18

--

45

41

42

41

43

..

35

36

.5

-

-

.5

.5

38.5

28

_

28

29.4

19

29.5

18

18.5

18.6

~

--

29.5

30

29

1

7

29.4

37

34

24

24

23

26

5

5

5

Depth of 

top of open 

interval 

(feet)

9.1

~

--

9.1

18

16

16

17

17

18

14

14

13.2

12.9

--

15

15.5

12

16

15

10

11

8.5

8

_

8

9.0

9

9.1

8

8.5

8.6

~

-

9.1

9.7

9.3

9

27

24

10

10

9

11.5

Depth of bottom Altitude of 

of open interval land surface 

(feet) (feet)

29.5

--

~

29.5

28

26

26

27

27

33

24

24

18

18

--

35

41.5

,647.7

,648

,648.54

,645.4

,649.1

,645.4

,647.9

,644.1

,646.1

1,650

1,646.3

1,647.2

1,647

1,647.7

1,646.5

1,646.9

1,646

42 1,645.6

36 1,648.1

35 1,645.3

..

25

31

1,648.4

1,645.6

1,650.3

38.5 1,647.2

28 1,647.6

_

28

29.4

,647.9

,646.6

19 1,646.8

29.5

18

18.5

18.6

~

--

29.5

30.1

29.7

29.4

37

34

24.5

24.5

23.5

26

,646.9

,645.7

,644.9

,645

,645.6

,645.3

,645.8

,646.3

,647

,647.4

,648

,648.77

,646.95

,646.62

,645.62

,647.18

45
[Data from several contractors; --, no data]

Site identifier

464934100533355

464936100533165

464937100532818

464935100532847

464933100533488

464932100532659

464933100532723

464933100532749

464933100532752

464934100532760

464930100530906

464929100530601

464929100531101

464930100530901

464929100530801

464928100530801

464926100530701

464931100530901

464933100533701

464933100533295

464934100532401

-

464936100533401

464937100532301

464938100532001

464938100533801

464939100532891

464940100532501

464940100531901

464939100533601

464941100533001

464930100531753

464931100531670

464930100531601

464931100531701

464933100531401

464932100532101

464930100532001

464927100531701

464929100531801

464934100531901

464931100531401

464930100534601

464924100542401

Well identifier

MW44

MW45

MW46

MW47

MW48

P1R

P2

P3

P4

P5

PL1

PL2

PL3

PL4

PL5

PL6

PL7

PL8

PZ1

PZ2

PZ3

PZ4

PZ5

PZ6

PZ7

PZ8

PZ9

PZ10

PZ11

PZ12

PZ13

PZ14

RH1

RH2

RH3

RH4

RH5

RH6

RH7

RH8

RH9

RH10

RH11

Wl

WF1

Date well 

constructed

10-23-2000

10-21-2000

10-21-2000

10-20-2000

10-19-2000

10-28-1986

10-28-1986

10-29-1986

11-10-1986

10-29-1986

11-07-1991

11-11-1991

11-11-1991

11-11-1991

11-11-1991

11-19-1991

11-21-1991

11-21-1991

12-16-1998

12-16-1998

12-15-1998

~

12-16-1998

12-16-1998

12-16-1998

12-16-1998

12-17-1998

12-16-1998

12-17-1998

12-17-1998

12-17-1998

04-13-1990

04-14-1990

04-13-1990

04-18-1990

11-05-1991

11-06-1991

11-06-1991

11-06-1991

11-19-1991

11-19-1991

11-20-1991

04-14-1990

04-12-1990

Depth drilled 

(feet)

28

26

26

26

26

30

40

30

28

30

30

28

28

28

28

28

28

28

24

24

24

~

24

24

24

24

23

24

24

24

24

31

29.5

31

29.5

26

26

26

26

31

31

27

29.5

32.5

Depth of well 

(feet)

24.5

22

24

21.5

25

27

37

28

28

28

26

27

27

27

27

27

25

26

24

24

24

-

24

24

24

24

23

24

24

24

24

29.5

29.1

29.4

29.5

24

25

25

25

30

30

26

29.2

32.3

Depth of 

top of open 

interval 

(feet)

10

7.5

9.5

7

10

7

7

8

8

8

16

17

17

17

17

17

15

15.5

14

14

~

14

~

14

14

14

14

13

14

14

14

14

9.7

8.7

9.1

9.1

12

10

15

15

15

15

16

8.8

9.8

Depth of bottom 

of open interval 

(feet)

24.5

22

24

21.5

25

27

37

28

28

28

26

27

27

27

27

27

25

26

24

24

24

~

24

24

24

24

23

24

24

24

24

29.5

29.1

29.4

29.5

24

25

25

25

25

26

29.2

32.3

Altitude of 

land surface 

(feet)

1,646.94

1,646.82

1,647.06

1,646.94

1,647.66

1,650.1

1,646.5

1,646.5

1,646.9

1,646.6

1,649.2

1,647.6

1,649.2

1,647.9

1,648.4

1,647.6

1,644.7

1,646.3

1,648.1

1,647.7

1,647.2

1,647.3

1,646.8

1,646.3

1,646.2

1,646.4

1,645.8

1,645.8

1,645.3

1,644.4

1,645.5

1,644.5

1,645.2

1,648.1

1,645

1,648

1,645.9

1,646.7

1,644.8

1,646.7

,645.1

,647

,645

,648.6

,653.8

46
[Data from several contractors; , no data]

Site identifier i» ii j »-c Date well Well identifier _^ t . constructed

Depth drilled 

(feet)

Depth of well 

(feet)

Depth of 

top of open 

interval 

(feet)

Depth of bottom 

of open interval 

(feet)

Altitude of 

land surface 

(feet)

464924100542198 WF2 04-12-1990 34.5 34 8.5 34 1,652.6

464926100542301 WF3 04-16-1990 29.5 29.5 9.1 29.5 1,649.8

464927100542301 WF4 10-25-1991 28 28 16 26 1,650

464926100542601 WF5 10-25-1991 27 26.5 16.5 26.5 1,648.5

464925100541801 WF6 10-30-1991 29 29 17 27 1,651.3

464923100542101 WF7 10-30-1991 30 27 17 27 1,651.7

464924100543001 WF8 10-31-1991 35 32.5 17.5 32.5 1,656.3

464923100542701 WF9 10-31-1991 32 29 17 29

464924100542201 WF10 11-20-1991 31 30 15 30

464925100542301 WF11 11-20-1991 28 27.5 15 27.5

464924100542701 WF12 11-20-1991 33 32 17 32

464925100542001 WF13 11-20-1991 30 30 15 30

,653.8 

,652.5 

,649.7

,653.2 

,651.9

47
APPENDIX B. Total ion chromatograms from volatile analysis 

for RR40, HS#2, and ULR reference-fuel samples

48
RESPONSE

Is)

Ethylbenzene 

&/>-Xylene m 

/7-Decane

1,2,4-Trimethylbenzene

«-Undecane

2-Methylnaphthalene - 
C/5 

fc 

O

j i u mil.. JIM

3 6 9 12 15 18 21 24 27 30 33 

TIME, IN MINUTES
LS

RESPONSE

«-Pentane

Toluene 

^ &/?-Xylene m 

1,2,4-Trimethylbenzene
APPENDIX C. Extracted ion chromatograms for m/z 57, characteristic of normal 

alkanes, from volatile analysis for RR40r HS#2, and ULR reference-fuel samples

52
es

RESPONSE
RESPONSE

tu-

<*»_

EC
ss

-r

RESPONSE

2-Methylbutane

3-Methylpentane

n. ON

Benzene
APPENDIX D. Concentrations, in micrograms per liter, 

of target volatile components

56
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated becau

Sample 

identifier

Location or place 

from which sample 

was obtained

Dichlorodifluorom ethane

Chlorom ethane

Vinylchloride

Bromom ethane

Chloro- Vinylethane bromide

Trichlorofluoromethane

Diethylether

1,1-Dichloroethene

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

RR40

HS#2

ULR

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railroad yard-southeast

Railway yard-west

Railway yard-west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

Refinery (current diesel

fuel)

Refinery (broader

refinery-cut fuel)

Refinery (unleaded

regular gasoline)

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

Reference-fuel samples

<80,000 <80,000

<80,000 <80,000

<80,000 <80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

-<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated becau

Sample Carbon 

identifier disulfide

3-Chloro-1- 

propene

Methylene 

chloride

Acrylonitrile

trans- Methyl-t-butyl 

1.2-dichloro- ether 

ethene (MTBE)

1,1-Dichloroethane

Di-isopropylether

Ethylt-butyl 

ether 

(ETBE)

2,2-Dichl

propan

Light nonaqueous phase liquid samples

MW2R <1 60,000

MW17 <1 60,000

PZ2 <1 60,000

P5 <1 60,000

P1R < 160,000

EF1 < 160,000

PL4 <1 60,000

RH1 <160,000

WF11 < 160,000

WF11A <1 60,000

EW2 < 160,000

FR2 <1 60,000

PZ6 <1 60,000

MW44 < 160,000

MW43 <1 60,000

MW45 <1 60,000

MW45P <1 60,000

MW45B <1 60,000

FR4 < 160,000

MW8 <1 60,000

MW7R <1 60,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<leH)6

<lef06

<le+06

<leH)6

<le+06

<le^06

<le+06

<lef06

<leK)6

<le+06

<leH)6

<leH)6

<lef06

<le+06

<leH)6

<le+06

<leH)6

<leH)6

<le+06

<leH-06

<leH)6

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000 

<80,000

<80,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

Reference-fuel samples

RR40 <1 60,000

HS#2 < 160,000

ULR < 160,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<le+06

<lef06

<le+06

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<80,00

<80,00

<80,00
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated beca

Sample 

identifier

BromochloromethaneMethylacrylonitrile

Tetrahydrofuran Chloroform

1,1.1-Trichloroethane

Carbon 1,1-Dichlorotetrachloride propene

Benzene

1.2-Dichlo

ethane

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<3.6eH)6

<3.6e4-06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6eH)6

<3.6ef06

<3.6e+06

<3.6e+-06

<3.6cH-06

<3.6e+06

<3.6ef06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<3.6e+06

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<40,000

840,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

E33,060

55,430

43,240

40,830

E34,160

El 3,790

40,020

<40,000

£24,450

20,230

56,030

45,370

£15,720

£13,940

£15,200

55,260

56,090

51,710

<40,000

252,000

£13,460

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

<80,00

Reference-fuel samples

RR40

HS#2

ULR

<40,000

<40,000

<40,000

<40,0000

<40,0000

<40,0000

<3.6ef06

<3.6e+06

<3.6e+06

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

44,480

74,420

17,390,000

<80,00

<80,00

<80,00
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated becau

§

Sample Dibromoidentifier methane

Methylmethacrylate

Bromodichloromethane

c/s-1 ,3-Dichloropropene

4-Methyl-2- 

pentanone

Toluene

frans-1,3- 

Dichloro 

propene

Ethyl 

methacrylate

1,1.2-Trichloroethane

Light nonaqueous phase liquid samples

MW2R 440,000

MW17 <40,000

PZ2 <40,000

P5 <40,000

P1R <40,000

EF1 <40,000

PL4 <40,000

RH1 <40,000

WF11 <40,000

WF11A <40,000

EW2 <40,000

FR2 <40,000

PZ6 <40,000

MW44 <40,000.

MW43 <40,000

MW45 <40,000

MW45P <40,000

MW45B <40,000

FR4 <40,000

MW8 <40,000

MW7R <40,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<280,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,0000

<40,000

E14,960

<40,000

<40,000

<40,000

<40,000

El 7,560

<40,000

<40,000

<40,000

£30,600

£28,490

Ell,510

£22,850

<40,000

<40,000

<40,000

<40,000

<40,000

£26,680

£12,410

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<240,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

Reference-fuel samples

RR40 <40,000

HS#2 <40,000

ULR <40,000

<280,000

<280,000

<280,000

<40,000

<40,000

<40,000

<80,000

<80,000

<80,000

<40,0000

<40,0000

<40,0000

450,800

902,500

65,430,000

<80,000

<80,000

<80,000

<240,000

<240,000

<240,000

<80,000

<80,000

<80,000
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated beca

Sample 

identifier

Dibromochloromethane1.2-Dibromoethane

Chlorobenzene

I.I.U-Tetrachloroethane

Ethylbenzene m & p-Xylene o-Xylene Styrene Bromoform

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

RR40

HS#2

ULR

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

542,200 712,400

773,300 1,690,000

705,100 2,517,000

628,800 1,957,000

624,400 2,336,000

305,400 359,300

461,500 768,800

252,400 324,100

165,800 383,600

159,300 369,100

744,000 2,887,000

704,500 3,028,000

396,600 1,676,000

508,700 1,932,000

597,800 2,271,000

758,900 2,631,000

755,800 2,634,000

696,100 2,451,000

<40,000 E50,780

908,400 1,128,000

395,300 683,600

Reference-fuel samples

305,900 1,147,000

673,700 2,220,000

11,540,000 42,770,000

42,180

206,000

664,600

456,000

559,400

56,920

153,000

<40,000

<40,000

<40,000

1,232,000

1,008,000

848,000

961,800

449,600

<40,000

<40,000

<40,000

<40,000

394,900

143,200

551,600

1,072,000

15,800,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

601,400

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated becau

Sample 

identifier

1,2,3-Trichloropropane

fra/is-1.4- 

Dichloro-2- 

butene

n-Propylbenzene

2-Chloro- 4-Chlorotoluene toluene1.3.5-Trimethylbenzene

2-Ethyltoluene

tert-Butylbenzene

1,2.4-Trimethylbenzene

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

<800,000

683,100

904,500

941,800

715,400

648,400

468,300

463,700

370,100

429,000

400,000

714,100

773,300

602,700

762,000

1,002,000

1,006,000

999,300

851,900

<40,000

767,800

692,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

856,000

1,581,000

1,957,000

1,636,000

1,853,000

852,200

1,304,000

<40,000

1,319,000

1,270,000

1,635,000

2,014,000

1,708,000

1,664,000

2,089,000

2,024,000

2,000,000

1,820,000

386,200

1,343,000

1,644,000

522,600

832,300

1,449,000

962,700

998,900

859,500

852,600

65,420

842,300

809,800

1,078,000

1,154,000

1,181,000

1,141,000

1,500,000

266,000

253,600

235,100

376,800

1,504,000

1,096,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

<80,000

6,253,000

6,292,000

6,984,000

5,318,000

6,622,000

3,736,000

5,610,000

4,212,000

4,060,000

3,556,000

6,421,000

7,195,000

5,639,000

5,402,000

7,809,000

6,990,000

7,421,000

7,200,000

1,479,000

6,924,000

5,777,000

Reference-fuel samples

RR40

HS#2

ULR

<80,000

<80,000

<80,000

<800,000

<800,000

<800,000

243,000

637,000

2,914,000

<40,000 <40,000

<40,000 <40,000

<40,000 <40,000

458,600

1,001,000

4,719,000

318,800

699,100

3,442,000

<80,000

<80,000

<80,000

1,886,000

3,884,000

16,890,000
[Elevated detection limits are due to 1:400,000 dilution of sample before purge-and-trap gas chromatographic/mass spectrometric analysis; <, less than; E, estimated beca

Sample 

identifier

1.4-Dichlorobenzene1.2.3-Trimethylbenzene

1.2-Dichlorobenzene

n-Butylbenzene

Hexachloroethane

1,2-Dibromo2-chloropropane

1.2,3.5-Tetramethylbenzene1.2,3.4-Tetramethylbenzene

U.4

Trichl

benz

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

2,610,000

3,073,000

3,051,000

1,764,000

2,441,000

1,198,000

1,771,000

2,293,000

576,100

561,300

2,574,000

3,191,000

2,397,000

2,458,000

2,868,000

3,143,000

3,051,000

2,884,000

889,300

1,914,000

2,138,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

<40,000

930,000

1,069,000

1,071,000

982,300

934,700

811,200

645,300

691,100

786,900

755,700

805,900

1,072,000

921,500

973,300

1,206,000

1,238,000

1,249,000

964,000

<226,200

757,200

1,065,000

<1 60,000

<1 60,000

< 160,000

<1 60,000

<1 60,000

< 160,000

<1 60,000

<1 60,000

< 160,000

<1 60,000

<1 60,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

<1 60,000

< 160,000

<1 60,000

<1 60,000

<1 60,000

<1 60,000

< 160,000

<1 60,000

<1 60,000

<1 60,000

<1 60,000

<1 60,000

< 160,000

< 160,000

< 160,000

<1 60,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

3,198,000

3,120,000

3,103,000

3,073,000

3,287,000

3,043,000

2,553,000

3,213,000

2,984,000

2,808,000

2,609,000

3,287,000

2,646,000

2,558,000

3,097,000

3,325,000

3,175,000

2,729,000

2,267,000

2,790,000

2,956,000

2,157,000

2,184,000

2,111,000

2,125,000

2,169,000

1,804,000

1,480,000

2,500,000

1,721,000

1,798,000

1,808,000

2,198,000

1,749,000

1,893,000

2,024,000

2,425,000

2,116,000

1,966,000

1,652,000

1,818,000

1,954,000

<80,

<80,0

<80,0

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

<80,

Reference-fuel samples

RR40

H#2

ULR

<40,000

<40,000

<40,000

744,100

1,742,000

3,860,000

<40,000

<40,000

<40,000

251,900

660,600

812,,800

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

< 160,000

1,010,000

1,522,000

2,390,000

1,156,000

2,372,000

1,071,000

<80,

<80,

<80,
APPENDIX E. Concentrations, in micrograms per liter, 

of detected target volatile components

64
[nd, not detected; BTEX, benzene, toluene, ethylbenzene, and xylene; , no data]

Sample 

identifier

Location or place 

from which sample 

was obtained

Benzene Toluene Ethylbenzene m & p-Xylene o-Xylene Styrene

Isopropylbenzene

n-Propylben

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railway yard-southeast

Railway yard- west

Railway yard-west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

33,060

55,430

43,240

40,830

34,160

13,790

40,020

nd

24,450

20,230

56,030

45,370

15,720

13,940

15,200

55,260

56,090

51,710

nd

252,000

13,460

nd

14,960

nd

nd

nd

nd

17,560

nd

nd

nd

30,600

28,490

11,510

22,850

nd

nd

nd

nd

nd

26,680

12,410

542,200

773,300

705,100

628,800

624,400

305,400

461,500

252,400

165,800

159,300

744,000

704,500

396,600

508,700

597,800

758,900

755,800

696,100

nd

908,400

395,300

712,400

1,690,000

2,517,000

1,957,000

2,336,000

359,300

768,800

324,100

383,600

369,100

2,887,000

3,028,000

1,676,000

1,932,000

2,271,000

2,631,000

2,634,000

2,451,000

50,780

1,128,000

683,600

42,180

206,000

664,600

456,000

559,400

56,920

153,000

nd

nd

nd

1,232,000

1,008,000

848,000

961,800

449,600

nd

nd

nd

nd

394,900

143,200

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

nd

151,100

204,500

199,500

172,000

157,800

132,800

96,390

103,200

113,300

109,000

173,400

181,200

136,000

165,700

200,400

224,800

223,800

194,600

nd

163,900

167,200

683,10

904,50

941,80

715,40

648,40

468,30

463,70

370,10

429,00

400,00

714,1

773,3

602,7

762,0

1,002,0

1,006,0

999,3

851,9

nd

767,8

692,0

Reference-fuel samples

RR40

HS#2

ULR

Refinery (current diesel

fuel)

Refinery (broader

refinery-cut fuel)

Refinery (unleaded

regular gasoline)

44,480

74,420

17,390,000

450,800

902,500

65,430,000

305,900

673,700

11,540,000

1,147,000

2,220,000

42,770,000

551,600

1,072,000

15,800,000

nd

nd

601,400

62,590

198,600

1,047,000

243,0

637,0

2,914,0
[nd, not detected; BTEX, benzene, toluene, ethylbenzene, and xylene; , no data]

Sample 

identifier

Location or place 

from which sample 

was obtained

1.2,4-Trimethylbenzene

sec-Butylbenzene

p-lsopropyltoluene

1,2,3-Trimethylbenzene

n-Butylbenzene

1.2,3.5-Tetramethylbenzene

U,3,4

methyl

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railway yard-southeast

Railway yard-west

Railway yard-west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

6,253,000

6,292,000

6,984,000

5,318,000

6,622,000

3,736,000

5,610,000

4,212,000

4,060,000

3,556,000

6,421,000

7,195,000

5,639,000

5,402,000

7,809,000

6,990,000

7,421,000

7,200,000

1,479,000

6,924,000

5,777,000

270,500

327,900

320,800

302,200

261,600

280,700

155,100

254,100

233,100

225,000

249,900

320,200

267,000

296,400

344,400

382,000

381,000

299,800

78,840

218,600

330,100

250,400

281,100

274,700

258,400

230,900

236,100

136,400

259,900

210,400

202,100

214,400

267,300

241,900

250,600

291,600

319,100

314,900

254,600

131,500

199,300

283,100

2,610,000

3,073,000

3,051,000

1,764,000

2,441,000

1,198,000

1,771,000

2293,000

576,100

561,300

2,574,000

3,191,000

2,397,000

2,458,000

2,868,000

3,143,000

3,051,000

2,884,000

889,300

1,914,000

2,138,000

930,000

1,069,000

1,071,000

982,300

934,700

811,200

645,300

691,100

786,900

755,700

805,900

1,072,000

921,500

973,300

1,206,000

1,238,000

1,249,000

964,000

nd

757,200

1,065,000

3,198,000

3,120,000

3,103,000

3,073,000

3,287,000

3,043,000

2,553,000

3,213,000

2,984,000

2,808,000

2,609,000

3,287,000

2,646,000

2,558,000

3,097,000

3,325,000

3,175,000

2,729,000

2,267,000

2,790,000

2,956,000

2,15

2,18

2,11

2,12

2,16

1,80

1,48

2,50

1,72

1,79

1,80

2,19

1,74

1,89

2,02

2,42

2,11

1,96

1,65

1,81

1,95

Reference-fuel samples

RR40

HS#2

ULR

Refinery (current diesel

fuel)

Refinery (broader

refinery-cut fuel)

Refinery (unleaded

regular gasoline)

1,886,000

3,884,000

16,890,000

83,280

277,200

347,600

74,010

244,700

174,100

744,100

1,742,000

3,860,000

251,900

660,600

812,800

1,010,000

1,522,000

2,390,000

1,15

2,37

1,07
APPENDIX F. Estimated concentrations, in micrograms 

per liter, of nontarget volatile components

67
[--, no data]

o>

09

Sample 

identifier

Location or place 

from which sample 

was obtained

2-Methylheptane Undecane

1Z3.4- 

Tetra hydronaphthalene

2-Methylnaphthalene

1-Methylnaphthalene

3-Methyl

octane

Light nonaqueous phase liquid samples

MW2R ~ " ' ------

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railway yard-southeast

Railway yard-west

Railway yard-west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

352,300

522,300

228,500

513,400

215,100

133,800

135,300

189,300

311,700

~

246,000

632,300

167,400

320,700

411,000

284,100

531,600

168,500

~

166,900

175,300

5,417,000

~

6,538,000

12,230,000

10,980,000

9,370,000

7,888,000

~

10,560,000

9,955,000

9,327,000

-

14,770,000

10,790,000

12,940,000

6,632,000

6,288,000

5,600,000

8,049,000

7,371,000

12,190,000

413,000

456,900

529,500

386,000

510,600

419,000

276,000

480,300

370,200

387,100

468,900

394,400

406,000

404,300

507,600

466,000

467,600

504,300

296,000

276,400

431,400

1,348,000

1,518,000

1,667,000

1,691,000

1,753,000

1,643,000

1,455,000

1,899,000

2,163,000

1,740,000

1,454,000

1,589,000

1,594,000

2,268,000

1,592,000

1,785,000

1,658,000

1,544,000

1,080,000

877,800

1,401,000

1,077,000

1,050,000

1,241,000

872,200

929,700

1,019,000

794,700

1,662,000

960,800

852,000

844,000

976,200

1,141,000

953,200

1,194,000

1,305,000

1,250,000

979,200

1,181,000

709,100

1,108,000

608,600

784,900

366,600

789,200

242,200

481,800

155,100

477,800

487,600

472,800

265,900

812,600

701,600

589,500

814,300

909,200

868,800

242,300

159,700

467,000

705,900

Reference-fuel samples

RR40 ~ " " " ------

HS#2

ULR87

Refinery (current diesel

fuel)

Refinery (broader

refinery-cut fuel)

Refinery (unleaded

regular gasoline)

108,400

340,000

829,700

5,133,000

16,130,000

4,287,000

258,400

481,500

60,140

2,504,000

1,984,000

90,250

1,590,000

1,104,000

40,460

251,200

983,000

608,900
APPENDIX G. Total ion chromatograms (top figures) and extracted ion 

chromatograms (bottom figures) for m/z 83 from semivolatile analysis

69
0) 

(/>

o

Q. 

</> 

0) 

DC

TIC

Time

m/z83

Numbers = homologs in w-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

70
0) 

</>

c 

o

Q. 

0) 

0) 

CC

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

71
o

</>

c 

o

Q. 

(/> 

0)

cc

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

72
0) 

(0

c 

o

Q. 

(/> 

0) 

DC

FR4

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

73
0) 

(/>

o

Q.

0)

0)

oc

I 13 14 15

HS#2

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

74
0) 

0)

c 

o

Q. 

</> 

0) 

DC

TIC

Time

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

75
C1N

C2N

MW2R

TMB

0) 

0)

c 

o

Q. 

0) 

0)

cr

TIC

10 11 12 13 14

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

76
0) 

0)

o

Q. 

(/) 0) 

DC

Time

TIC

13 14 15

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

77
0) 

0)

c 

o

Q. 

CO 

0) 

DC

MW44

TMB

TIC

Time

m/z83

Numbers = homologs in w-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

78
0) 

0)

c 

o

Q. 

(0 

0) 

OC

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

79
0) (/)

c 

o

Q. 

(0 

0) 

DC

Time

TIC

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

80
0) 

</>

c 

o

Q. 

(0 

0) 

DC

Time

TIC

10 11 12 13 14

m/z83

Numbers = homologs in /i-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

81
0) 

0)

o

Q. 

(0 

0) 

DC

TIC

Time

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

1MB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

82
o

(0

c 

o

Q. 

</> 

0)

cc

TIC

10

Time

m/z83

Numbers = homologs in n-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr - pristane; Ph == phytane. >

83
0)

w

c 

o

Q. 

0) 

O 

DC

Time

TIC

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

84
o

</>

c 

o

Q. 

0) 

0)

oc

TIC

Time

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

85
O 

(0

O

Q. 

(0 

0)

oc

15 16 17

18 PL4

Pr

19

Ph

20

21

22

23

24

25

TIC

Time

m/z83

Numbers = homologs in w-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

86
0) 

(/>

o

Q. 

(/) 

O 

CC

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

87
0) 

(0

c 

o

Q. 

0) 

0) 

DC

12 C1N

TMB

L .iA... AJi

PZ6

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

88
0) 

(0

o

Q. 

<0 

0

cr

TIC

13

14 115

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

89
O 

(ft

o

Q. 

(ft 

<D 

QC

C1N C2N

LJ.1 JU 111.

RH1

TMB

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

90
RR40

TMB

TIC

Time

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

91
0) 

0)

o

Q.

Toluene

ULR

Xylenes

n

TMB

C1N 

N n C2N

L i n

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

TMB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

92
0) 

(0

o

Q. 

0) 

0)

or

WF11

12

11

1MB

TIC

Time

m/z83

Numbers = homologs in H-alkane series (top) and alkylcyclohexane series (bottom). 

1MB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

93
0) 

0)

o

Q. 

(0 

0) 

QC

WF11A

12

11

1MB

TIC

Time

m/z83

Numbers = homologs in «-alkane series (top) and alkylcyclohexane series (bottom). 

1MB = 1,2,4-trimethylbenzene; N, C1N, C2N, C3N = naphthalene series; 

Pr = pristane; Ph = phytane.

94
APPENDIX H. Concentrations, in milligrams of polycyclic 

aromatic hydrocarbons per liter of product

95
Sample 

identifier

Location or place 

from which sample 

was obtained

1,2,4- 

Trimethylbenzene

.. ... 2-Methyl- Naphthalene ... . 

r naphthalene

1 -Methylnaphthalene

OL. a. Dibenzo- Phenanthrene ... . thiophene

Light nonaqueous phase liquid samples

MW2R

MW17

PZ2

P5

P1R

EF1

PL4

RH1

WF11

WF11A

EW2

FR2

PZ6

MW44

MW43

MW45

MW45P

MW45B

FR4

MW8

MW7R

RR40

 HS#2

ULR

COC

RDF2-UN

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard

Railway yard-east

Railway yard-southeast

Railway yard-southeast

Railway yard-west

Railway yard-west

Railway yard

Railway yard

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

North of Main Street

Refinery (current diesel

fuel)

Refinery (broader

refinery-cut fuel)

Refinery (unleaded

regular gasoline)

Refinery (crude-oil

composite)

Restek Corporation

6,828

8,132

9,112

5,968

7,140

4,720

6,608

5,024

4,412

4,700

9,196

9,540

7,244

7,140

9,408

8,368

8,724

8,676

1,580

8,816

7,212

1,984

3,888

17,912

3,656

2,487

2,928

3,652

3,960

3,136

3,264

2,684

3,380

2,264

2,792

2,972

3,404

3,248

3,160

3,160

3,728

3,820

3,764

3,816

396

3,012

3,336

Reference-fuel samples

1,864

1,820

1,900

408

Restek standard

1,137

8,236

10,076

10,788

8,956

9,004

7,564

8,588

7,876

7,684

8,240

9,768

9,176

8,736

8,908

9,936

10,584

10,504

10,620

4,004

8,124

9,832

9,220

7,484

1,892

1,088

3,904

5,092

6,036

6,468

5,436

5,372

4,704

4,924

5,472

4,472

4,780

5,728

5,476

5,344

5,372

5,972

6,372

6,292

6,360

3,420

5,064

5,952

5,808

4,776

1,004

852

2,391

1,260

1 ,356

1,612

1

1

1

,184

,132

,196

1,240

1,400

1,208

1,304

1

1

,196

,108

,388

,520

,652

,316

,364

,292

,560

,432

,364

,416

,324

,436

,372 1,420

,320 1,448

,560 1

,472

,440

,484

,412

1,488

1

2

1

,580

,588

,572

,588

,472

,508

,372 1,488

,164 1 ,808

,528 1,292

120

252

523

0

392

230

96
APPENDIX I. Concentrations, in milligrams of selected 

polycyclic aromatic hydrocarbons per liter of product

97
12000

10000

8000

6000

4000

2000

0

MW2R

16000

14000

12000

10000

8000

6000

4000

2000

0

MW17

COC1C2C3COC1C2C3COC1C2C3 COC1C2C3COC1C2C3COC1C2C3

16000

14000

12000

10000

8000

6000

4000

2000

0

PZ2

COC1C2C3COC1C2C3COC1C2C3

14000

12000

10000

8000

6000

4000

2000

0

P5

COC1C2C3COC1C2C3COC1C2C3

naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes 

phenanthrenes phenanthrenes phenanthrenes phenanthrenes

Iu_ 

O

cc

|

14000

12000

10000

8000

6000

4000

2000

0

P1R

COC1C2C3COC1C2C3COC1C2C3

12000

10000

8000

6000

4000

2000

0

EF1

IliLii

COC1C2C3COC1C2C3COC1C2C3

12000

10000

8000

6000

4000

2000

0

PL4

COC1C2C3COC1C2C3COC1C2C3

12000

10000

8000

6000

4000

2000 

0

.

1

RH1 

I

;

;

Jllhll..

COC1C2C3COC1C2C3COC1C2C3

naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes 

phenanthrenes phenanthrenes phenanthrenes phenanthrenes

12000

10000

8000

6000

4000

2000

0

WF11

COC1C2C3COC1C2C3COC1C2C3

12000

10000

8000

6000

4000

2000

0

WF11A

IliL.ii

COC1C2C3COC1C2C3COC1C2C3

14000

12000

10000

8000

6000

4000

2000

0

EW2

15000

10000

5000 

FR2

COC1C2C3COC1C2C3COC1C2C3 COC1C2C3COC1C2C3COC1C2C3

naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes naphthalenes ' ' dibenzothiophenes 

phenanthrenes phenanthrenes phenanthrenes phenanthrenes

98
CONCENTRATION, IN MILLIGRAMS PAH PER LITER OF PRODUCT
APPENDIX J. Stable carbon isotope ratio data from 

Zymax Forensics, San Luis Obispo, California

100
[Isotope ratio data for samples submitted by U.S. Geological Survey, Menlo Park; 813C, stable carbon isotopes; %o, per mil; --, no data]

Zymax identifier

22763-1 

22763-2S 

22763-3 

22763-4 

22763-5

22763-6 

22763-7 

22763-8 

22763-9 

22763-10

22763-11 

22763-12 

22763-13 

22763-14 

22763-15

22763-16 

22763-17 

22763-18 

22763-19 

22763-20

22763-21

22763-22 

22763-23 

22763-24 

22763-25

22763-26

NBS OIL STANDARD 

NBS OIL STANDARD-DUPLICATE

Sample identifier

Light nonaqueous phase liquid samples

MW2R 

MW17 

PZ2 

P5 

P1R

EF1 

PL4 

RH1 

WF11 

WF11A

EW2 

FR2 

PZ6

MW44 

MW43

MW45 

MW45P 

MW45B 

FR4 

MW8

MW7R

Reference-fuel samples

RR40 

HS#2 

ULR 

COC

NSC

Quality-assurance samples

813C(%o)

-28.57 

-28.67 

-28.62 

-28.80 

-29.05

-29.19 

-29.60 

-28.50 

-29.02 

-28.96

-28.71 

-28.68 

-28.58 

-28.74 

-28.36

-28.41 

-28.30 

-28.32 

-28.31 

-28.30

-28.84

-29.52 

-29.43 

-29.52 

-29.72

-29.64

-29.82 

-29.78

Whole oil

613C (%o) Duplicate

-28.69

--

-28.77

-

-28.78

--

--

--

101
APPENDIX K. Flow injection/negative electrospray ionization mass spectra

102
RR40:

100000-

80000 -

60000 -

40000 -

20000 -

o-

*MSD1 SPC, time=2.263 of NODAK2\044D.D API-ES Negative

M I , ll III III ill II

,0)^' Max: 106104

3^

^

Li

'

^

f> -b

^ 

Ullli'Ll. i li , ill, 1,1 , ,, i , i Inn i , 1 , , , ,

200 400 600 800 m/2

HS#2:

*MSD1 SPC, time=7.287 of NODAK2\044D.D API-ES Negative

-

80000 -

-

60000 -

40000 -

20000 -

-

0-

J

U

I Ll,lll£

N

JF

.\

>°T Max: 95760

f

\

Z>

t

fill iiJ!

f

V

<?

<&

\ ^

1 lililillllll li ll i , n I i i ,1, i I i i i , i 1 1 ,

I I i 1 1 II 1 1 I 1 1 1 1 1 1 1 

200 400 600 ' 800 m/z

103
Unleaded Regular:

16000^

14000-

12000^

10000^

8000 J

6000-^ 

4000- 

2000 J

0-

*MSD1

^

SPC, time=1 1.324 of NODAK2\044D.D API-ES Negative

A \

5s ' Max: 17504 

\

<f

Cj

^^fif^^J ^ ^ fc, ^v ^

II III II II II II , II

200 400 600 800 m/z

Nalco 5375A:

*MSD1

~

2250^

2000^ 

1750^

1500-| 

1250-^

1000-^

750-^

500 -_

SPC, time=3.251 of NODAK2\044LD API-ES Negative

\

v

,

^

A(

\

N

0%

^ Max: 2448

r^y

t

^ ,

< '

/N

^ $

f

05

#'

^

/

(£ f

/

%

5

c

^

^

^'

200 400 600 800 m/2

104
Stadis 450:

*MSD1 SPC, time=8.305 of NODAK2\044LD API-ES Negative

6000-

5000-

4000-

3000- 

2000- 

1000- 

1()0

s*

^J

*V

si

N

V

r 

$

°0

200

V

i

f

v^ 'p$> 

300

s

^

V

J

jj?' Max: 6389

^

Q

400 500 600 700 800 m/2

Para Flow 511:

*MSD1 SPC, time=1 0.309 of NODAK2\044LD API-ES Negative

2000-

1800-

1600- 

1400- 

1200-

1000-

800-

600-

> 

r

N^

<?' ^

N*

 v*

^ <??

\

y 

/ 

-i

#

^

.

^

/

^

200 4C

a^5 

oCf' Max: 2121

tS

y

?)

&'

^

*

)0 600

f'

^

sS5

0)^

i i i i

800 m/2

105
DCI 6A:

10000-

8000-

6000-

4000-

2000-

0-

*MSD1

i

SPC, time=4.267 <

^

c

?s

£

b

^

200

1

Df NODAK2\044K.D API-ES Negative

09?' Max: 10294

V

°?

^

V^'

pf^ ^<f ^ ^ #* ^ ^ ^

ll 1 1

400 600 800 m/2

Unisol Red B50:

12000-

10000-

8000-

6000-

4000-

2000-

*MSD1

II

SPC, time=7.287 of NOD

«

^

^

111

/

^

"9*

AK2V044K.D API-ES Negative

b 

O?' Max: 12706

^

f

200

^

4C)0

b

ti

V3 '

.0>

i

*

*V

V*^ #>,^ ^>^ ^

600 800 m/2

106
MW2R:

70000 -_

60000 -_

50000 '-J 

40000 -_

30000 -_

20000 -^ 

10000^

o^

*MSD1 SPC, time

^

i J i nil ilii

^

od

i=1 9.398 of NODAK2\044E.D API-ES Negative

^' Max: 70480

\

^

^'V0' ^ ^

^i'l'JlV:,!;,^! 1 ,,,!! 1;!.1 ,;!,!!:! '.III!.,! nM^nUlJliiJiih Ml , i ,i ,, i Ii i

1 00 200 300 400 500 600 700 m/z

MW17:

80000 -

60000 -

40000 -

20000 - 

0-

*MSD1 SPC, tirm

i n I i I i ii i ll

100 2

3=18.381 of NODAK2\044E.D API-ES Negative

\

^OT' Max: 93288

\C

U

 ^

s

 ) '

\^'

LlllllLllllJI, U I Jhh N, I , I , , ,l. , ,,!:, 

00 300 400 500 600 700 800 m/z

107
PZ2:

100000-

80000 -

60000 -

40000 -

20000 -

o-

*MSD1 SPC, time=22.419 of NODAK2\044D.D API-ES Negative

N!

,, , ' ]

^

I

Ui

,0)^' Max: 101376

is

j

IlLl iilLldl -11 II ill 111 UN, 1, ll In h M 1 ii in i i 1 1 1 ,,,.,, , , I

200 400 600 800 m/z

P5:

*MSD1 SPC, time=1 5.362 of NODAK2\044G.D API-ES Negative

60000 -

50000 -j

40000 -

30000 -

20000 -_

10000-

-

i il ll, nil liMill

N

^

J

.N

No)>' Max: 65000

?

I,

r^p

^^

i

^

* ^ V* ^

Jj.iijjliJ?^, , , , , . ,,, , ,

i > i > | i i i | i i > 200 400 600 800 m/z

108
P1R:

"

80000 i

70000 -m

60000 -_

50000 -j

40000 -_

30000 -

20000 -j

10000^

0^

*MSD1 SPC, time=25.455 of NODAK2\044D.D API-ES Negative

^

ll i.iidlki

^

SP

itli

2

^' Max: 86864

Gu

i

^

^ ^ ^

«l llllllllllllll lllll ll.llllllllllll III M 1 ll III II I ll i 1 1 1 1 1 1 1 1 1

00 400 600 800 m/2

EF1:

*MSD1 SPC, time=7.288 of NODAK2\044J.D API-ES Negative

70000 -_

60000 -_

50000 -_

40000 -_

30000 -J

20000 -_

10000-J

o^ 1, 1 1 III

1

xq

«

^c

Llliiill

\

^J5 ' Max: 71800

«/"v

 )

tv

$'

" ^V,>

iiiyi^iJiU jliiiiiih ihii iisiiiiiiiiu tii iii iihii u H i 1 1, 1 1« in 1 1 1 i ii i in \ i in i i

200 400 600 800 m/2

109
PL4:

*MSD1 SPC, time=1 5.362 of NODAK2\044D.D API-ES Negative

80000 -_

70000 -_

60000 -_

50000 -_

40000 -_

30000 -_

20000 -_

10000^

0-

(

<>

, ,,1L

10^' Max: 79784

>

^

3

^

\

} ^ofc? ^

i ll II raliliiiiJl! mil ii ul i i i i i i 1 1 i i i i i i

200 400 600 800 m/z

RH1:

*MSD1 SPC, time=1 2.325 of NODAK2\044E.D API-ES Negative

25000 -

20000 -

15000-

10000-

5000-

0-

200

* *

400

Max: 25880

600 800 m/2

110
WF11:

70000 -_

60000 -j

50000 -_

40000 -_

30000 -j 

20000 - 

10000^

o^

*MSD1 SPC, time=1 6.378 of NODAK2\044H.D API-ES Negative

i inn i iii i

4

«

^ Max: 74487

?

A

V

^ S

^' 'V

^ M ^' *> Mil $'

1 U

200 400 600 800 m/2

WF11A:

*MSD1 SPC, time=4.253 of NODAK2X044J.D API-ES Negative

70000 -

'-_

60000 -

50000 -

40000 -

30000 -

20000 -

10000-

0- , ii I il

\

^

"

^

SP

il

^Of > Max: 68576

^O

^

i

V

,1

lill

-P

 ^

v ^ | f^y^

i i

ill IIJlllllllL III llilllllllll 1 ,1 ill III h ill All 1 i 1 1 1 III 1 n l II 1 II n 1 In i || ,|

200 400 600 800 m/2

111
EW2:

*MSD1 SPC, time=7.286 of NODAK2\044H.D API-ES Negative

80000 -j

70000 ^

60000 -j

50000 -_

40000 -

30000 -j

20000 -_ 

10000^

J

^

HI liimli

N

JP 

II

^' Max: 79224

£>

f

\

^

i

/

<tf?

**> *

1 v"5

lllk III 1,11(1 lijlilj il 1 il ,,l,lil m , , ill , ,1 n I . 1

200 400 600 800 m/2

FR2:

70000 -

60000 -

50000 -

40000 -

30000 J

20000 - 

10000 J

0-

*MSD1 SPC, tim

v<

$

, ,u

«v

III

e=13.342 of NODAK2\044H.D API-ES Negative 

>o^' Max: 68680

^

<

V

\

^

llLllltililllli ll.llJlhln .In 1 i ink 1 i n 1 i 1 , i

200 400 600 800 m/2

112
PZ6:

*MSD1 SPC, time=7.301 of NODAK2\044E.D API-ES Negative

80000 -_ 

70000 -_

60000 -_

50000 -jj

40000 -j

30000 -_

20000 -_

10000-

o^

N^

,. i 1 1 1,1 ini jin

N

3'

N'

-°

\

,«

[JIll,

*' Max: 79256

^v

^ to>

\ V ^1

1 V

III IIHiNlilill lilll I I H mi III lln n ii i 1 1 I i . ii i I 1 1 i, i iii ii

100 200 300 400 500 600 700 m/2

MW44:

*MSD1 SPC, time=1 8.399 of NODAK2\044F.D API-ES Negative

120000-

100000-

80000 -

.

60000 -

40000 -

-

-

20000 -

.

o-

^y

, Li

100

N

^

Nk

,! 

No-

^

v

^CT' Max: 117224

^>

\

 ^

s

V

n

'j\

rV

\

lllllklJlllllllll 

f

till ill. Ill 1, Inlll 1,1 t, 1,1 1 1 I,, 1 , ., 1 ,,,,,,,, , , , ,

200 300 400 500 600 700 800m/2

113
MW43:

100000-

80000 -

60000 -

40000 -

20000 -

o-

*MSD1 SPC, time=1 2.343 of NODAK2\044F.D API-ES Negative

f

.,., m >l,il,!, i

^

\aly

^ Max: 101472

V .

\°

kll,

^

^

_; ^ ,Ci ^ <^j' ^

Jll Lll«yi ill ,\,.ll, lh III ill i ,ilni m, ,li 1, 1 , , , i MI . , i . , , I , 1 ill i i

100 200 300 400 500 600 700 m/z

MW45:

*MSD1 SPC, time=1.231 of NODAK2\044G.D API-ES Negative

100000-

80000 -

60000 -

40000 -

20000 -

0-

.\

M

.LtlliiUtiLiUilLiJlliil,!,, niLJi,,,, I,

100 200 300______400

Max: 106336

500 600 700 800 m/z

114
MW45P:

100000-

80000 -

60000 -

40000 -

20000 -

o-

*MSD1 SPC, tirm

^

i JLLl

IP

llh

j=1 2.342 of NODAK2\044G.D API-ES Negative

^ Max: 111585

"V

^

J,,

^

x

"0

klllllLllllUllI, lll.ll.t<lhJmlll II i.i 1 , 1 1 n .11 1 , 1 . Ill 1 in , i I , ,

200 400 600 800 m/2

MW45B:

*MSD1 SPC,

120000-

100000-

80000 -

60000 -

40000 -

20000 - 

0- 1 , , 1,

time=7.287 of NODAK2V044G.D API-ES Negative

^

( 

t>

c

L

^' Max: 133120

^

1

1

3

x

200 400 600 800 m/2

115
FR4:

*MSD1 SPC, time=1.232of NODAK2\044F.D API-ES Negative

30000 :

25000 :

20000 -_

15000-

10000-

5000-

°~

^

> mi

r

 {'

4

III

ffi Max: 32864

f

']/ N.

K ^

V

N\ ^

1 If ill if^^^^^^V ^

illli^ i niiiiililliMMilin i ih ii i i i

200 400 600 800 m/2

MW8:

60000 -

50000 :

40000 -

30000 -

20000 -| 

10000-

o^

*MSD1 SPC, time=1.276of NODAK2\044E.D API-ES Negative

c

l

i I ll hill I III

^' Max: 62616

"V

:,^N J

Itiliil in llHilil UH i HI, ul Ii i i ii 111 1 ii i i iii ii

100 200 300 400 500 600 700 800 m/2

116
MW7R:

*MSD1 SPC, t me=7.288 of NODAK2\044F.D API-ES Negative

120000-

100000-

80000 -

60000 -

40000 -

20000 -

1C

>$

 ,!, 

>

III!

\

^ Max: 118304

i!.,

4>

fe\

li ill, ll,IU,l,llllul II, Jill Jl ll I , Lll, I ,! I, I 1 , , , 1 1 . , 1 I , 1 1

)0 200 300 400 500 600 700 800 m/z

Methanol background:

*MSD1 SPC, time=1 4.344 of NODAK2\044D.D API-ES Negative

8000-

6000-

4000-

2000-

o- 1

f

N*

^

200

r

^' Max: 9418

f

d?

I

400 600 800 m/z

117

 (r U.S. GOVERNMENT PRINTING OFFICE: 2001 673-086 / 51006 Region No. 8