U.S . DEPARTMENT OF THE INTERIOR 

U.S . GEOLOGICAL SURVEY 

Physical and Chemical Data on 

Sediments Deposited in the Missouri and 

the Mississippi River Flood Plains During 

the July Through August 1993 Flood 

Floods in the Upper Mississippi River Basin 1993 

Circular 1120-L 

~USGS


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PHYSICAL AND CHEMICAL DATA ON SEDIMENTS 

DEPOSITED IN THE MISSOURI AND THE MISSISSIPPI 

RIVER FLOOD PLAINS DURING THE JULY THROUGH 

AUGUST 1993 FLOOD 

By Gregg K. Schalk, Robert R. Holmes, Jr., and Gary P Johnson 

Floods in the Upper Mississippi River Basin, 1993 

U.S. GEOLOGICAL SURVEY CIRCULAR 1120-L 
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary 

U.S . GEOLOGICAL SURVEY 

Charles G. Groat, Director 

Any use of trade, product, or firm names in this 

publication is for descriptive purposes only and does 

not imply endorsement by the U.S . Government 

1998 

Library of Congress Cataloging in Publication Data 

Schalk, Gregg K., 1968-

Physical and chemical data on sediments deposited in the Missouri and the Mississippi River flood plains during the July through August 1993 flood / by Gregg K. Schalk, Robert R. Holmes, Jr., and Gary P Johnson. p. 62 cm. - (Floods in the upper Mississippi River basin, 1993; L) (U.S . Geological Survey circular ; 1120) Includes bibliographical references . Supt. of Docs. no. : 119.4/2 :1120-L ISBN 0-607-88279-4 

1 . River sediments-Mississippi River Valley. 2. River sediments-Missouri River Valley. 3. Floods-Mississippi River Valley. 4. Floods-Missouri River Valley. I . Holmes, Robert R., 1965- . II . Johnson, Gary P, 1969- . III . Title . IV. Series 

V. Series : U.S. Geological Survey circular ; 1120.
 GB1217.F58 1993 Ch. L [GB1399 .8] 551 .48'9'0977 s--dc21 [551 .3'54'0977]


97-49113 

CIP 

Free on application to the


U.S. Geological Survey


Branch of Information Services


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FOREWORD 

During spring and summer 1993, record flooding inundated much of the upper Mississippi River 

Basin. The magnitude of the damages-in terms of property, disrupted business, and personal traumawas unmatched by any other flood disaster in United States history. Property damage alone is expected to 

exceed $10 billion. Damaged highways and submerged roads disrupted overland transportation throughout the flooded region . The Mississippi and the Missouri Rivers were closed to navigation before, during, 

and after the flooding. Millions of acres of productive farmland remained under water for weeks during 

the growing season . Rills and gullies in many tilled fields are the result of the severe erosion that 

occurred throughout the Midwestern United States farmbelt. The hydrologic effects of extended rainfall 

throughout the upper Midwestern United States were severe and widespread. The banks and channels of 

many rivers were severely eroded, and sediment was deposited over large areas of the basin's flood plain. 

Record flows submerged many areas that had not been affected by previous floods . Industrial and agricultural areas were inundated, which caused concern about the transport and fate of industrial chemicals, 

sewage effluent, and agricultural chemicals in the floodwaters. The extent and duration of the flooding 

caused numerous levees to fail . One failed levee on the Raccoon River in Des Moines, Iowa, led to flooding of the city's water treatment plant. As a result, the city was without drinking water for 19 days . 

As the Nation's principal water-science agency, the U.S . Geological Survey (USGS) is in a unique 

position to provide an immediate assessment of some of the hydrological effects of the 1993 flood. The 

USGS maintains a hydrologic data network and conducts extensive water-resources investigations nation 

wide. Long-term data from this network and information on local and regional hydrology provide the 

basis for identifying and documenting the effects of the flooding. During the flood, the USGS provided 

continuous streamflow and related information to the National Weather Service (NWS), the U.S . Army 

Corps of Engineers, the Federal Emergency Management Agency (FEMA), and many State and local 

agencies as part of its role to provide basic information on the Nation's surface- and ground-water 

resources at thousands of locations across the United States . The NWS has used the data in forecasting 

floods and issuing flood warnings . The data have been used by the Corps of Engineers to operate water 

diversions, dams, locks, and levees . The FEMA and many State and local emergency management agencies have used USGS hydrologic data and NWS forecasts as part of the basis of their local flood-response 

activities . In addition, USGS hydrologists are conducting a series of investigations to document the 

effects of the flooding and to improve understanding of the related processes. The major initial findings 

from these studies will be reported in this Circular series as results become available. 

U.S . Geological Survey Circular 1120, Floods in the Upper Mississippi River Basin, 1993, consists of individually published chapters that will document the effects of the 1993 flooding. The series 

includes data and findings on the magnitude and frequency of peak discharges ; precipitation ; water-qual 

ity characteristics, including nutrients and man-made contaminants ; transport of sediment ; assessment of 

sediment deposited on flood plains ; effects of inundation on ground-water quality; flood-discharge volume; effects of reservoir storage on flood peaks ; stream-channel scour at selected bridges ; extent of floodplain inundation ; and documentation of geomorphologic changes. 

Charles G. Groat 

Dirctor 

Foreword III 
CONTENTS 

Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III 

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

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Description of Study Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Study Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Site Selection and Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Sampling Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

Laboratory Analytical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

Quality-Assurance Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Physical and Chemical Data on Sediments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Particle-Size Distribution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Moisture Content and Volatile Solids, Nutrient, and Carbon Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Selected Element Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Pesticide Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

Semivolatile Organic Compound Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

Summary and Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

References Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 

FIGURES 

1 . Map showing location of study area and sediment deposition sites sampled during September 1993 

in the Missouri and the Mississippi River flood plains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

2.4. Photographs showing: 

2. Silt and clay sediment deposited in the Missouri River flood plain near Hermann, Missouri, 

during the 1993 flood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

3. Sand dunes deposited in the Missouri River flood plain near St. Charles, Missouri, during 

the 1993 flood. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

4. Aerial photograph showing the Missouri River flood plain near Hartsburg, Missouri, November 1993 . 3 

TABLES 

1 . Selected data for sampling sites in the Missouri and the Mississippi River flood plains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2. Detection or reporting limits of analytical methods used for the determination of constituent 

concentrations in the less than 2-millimeter size fraction of postflood sediment samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

3. Detection limits and methods used for the determination of element concentrations in the less than 

62-millimeter size fraction of postflood sediment samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

4. Detection limits used for the determination of pesticide and semivolatile organic compound 

concentrations in the less than 2-millimeter size fraction of postflood sediment samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

5. Particle-size distribution of postflood sediment and preflood soil samples in the Missouri and the 

Mississippi River flood plains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 

6. Moisture content and volatile solids, nutrient, and carbon concentrations in the less than 2-millimeter 

size fraction of postflood sediment samples in the Missouri and the Mississippi River flood plains . . . . . . . . . . . 16 

7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of 

postflood sediment samples in the Missouri and the Mississippi River flood plains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 

8. Descriptive statistics of selected element and carbon concentrations in the less than 0.062-millimeter 

size fraction of postflood sediment samples in the Missouri and the Mississippi River flood plains . . . . . . . . . . . . 35 

9. Measured and expected concentrations of elements in standard reference material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 

10. Estimated pesticide concentrations in the less than 2-millimeter size fraction of postflood 

sediment samples in the Missouri and the Mississippi River flood plains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 

11 . Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction 

of postflood sediment samples in the Missouri River flood plain, sample set reagent spike, 

standard reference material, and surrogate samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 

12. Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of 

postflood sediment samples in the Mississippi River flood plain, sample set reagent spike, 

standard reference material, and surrogate samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 

13 . Tentatively identified compounds that were detected in the gas chromatography/mass 

spectrometry analysis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 

Contents V 
CONVERSION FACTORS AND VERTICAL DATUM


Multiply


millimeter (mm)


meter (m)


square meter (m'`)


kilometer (km)


kilogram (kg)


gram (g)


square kilometer (km')


By To obtain 

0.03937 inch 

3.281 foot 

10 .76 square foot 

0.6214 mile 

2.205 pound 

0.03527 ounce 

0.3861 square mile 

Temperature in degrees Celsius (°C) can be converted to degrees Fahrenheit (°F) as follows: 

Celsius temperature (°C) °F = 1.8°C + 32 Fahrenheit temperature (°F) 

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 . 

VI Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Physical and Chemical Data on Sediments Deposited 

in the Missouri and the Mississippi River Flood Plains 

j During the July through August 1993 Flood 

By Gregg K. Schalk, Robert R. Holmes, Jr., and Gary P Johnson 

Abstract 

In July and August 1993, Missouri and Mississippi River floodwaters overtopped or breached 

levees and inundated agricultural and urban areas 

in the flood plains . To assess the regional variability of quality of silt and clay sediments transported 

and deposited during inundation, sediment samples were collected in September 1993 at 25 sites 

in the Missouri and the Mississippi River flood 

plains . The samples were analyzed for physical 

properties and chemical constituents that included 

particle-size distribution, water content, volatile 

solids, nutrients, carbon, selected trace elements, 

pesticides, and semivolatile organic compounds 

for postflood sediment samples, and particle-size 

distribution for preflood soil samples . Pesticides 

were detected in samples from many of the sites, 

with alachlor detected in one sample at a concentration of 54 micrograms per kilogram. Many 

semivolatile organic compounds were detected in 

samples at several sites, with the concentration of 

fluoranthene in one sample at 270 milligrams per 

kilogram. Procedures for selecting sites, techniques developed for sampling, laboratory analytical methods, and quality-assurance sampling 

methods also are described. 

INTRODUCTION 

Peak discharges exceeded 100-year recurrence 

intervals at U.S . Geological Survey (USGS) streamflow-gaging stations on the Missouri and the Mississippi Rivers during July and August 1993 (Parrett and 

others, 1993). Floodwaters inundated the floodplain as 

a result of failed levees . Sediments transported by the 

floodwaters were deposited in varying thicknesses in 

these inundated areas. The deposited silt and clay sediments were thought to contain elevated concentrations 

of nutrients and trace elements. Also, because the 

floodwaters inundated various agricultural and urban 

areas, several pesticides and organic compounds were 

thought to have attached to silt and clay sediments that 

were mobilized and deposited downstream in the inundated flood plain. Large concentrations ofthese various 

constituents are of concern because of their potential 

effects on croplands and wildlife habitat in the flood 

plain. To obtain information that would be needed to 

address these concerns, the USGS conducted a study to 

assess the regional variability in the physical and chemical characteristics of silt- and clay-size (hereafter 

referred to as "silt and clay") sediments deposited in 

the Missouri and the Mississippi River flood plains . 

The study included determination of the presence of 

contaminants in the sediments and a comparison of 

particle-size distribution in postflood sediment and preflood soil at several locations. 

Purpose and Scope 

This report describes the sampling and analytical 

techniques, quality-assurance methods, and the results 

of analyses of sediment samples collected in September 1993 from 25 sites along the flood plains of the 

Missouri and the Mississippi Rivers . Data presented for 

the postflood sediment samples include particle-size 

distribution, water content, volatile solids, and concentrations of nutrients, carbon, other selected elements, 

pesticides, and semivolatile organic compounds. The 

particle-size distribution of preflood soil sampled 

beneath the postflood sediment samples also is presented . 

Introduction 1 
	90 

Description of Study Area 

The study area was the flood plains of the Missouri and the Mississippi Rivers that were inundated by 

floodwaters during the July through August 1993 

	8996° 95° 94" 93° 43" 

42° 

40° 

39° 

38° 

37° 

36° 

flood-a 560-river mile reach of the Missouri River 

from Nebraska City, Nebraska, to St. Louis, Missouri, 

and a 578-river mile reach of the Mississippi River 

from Dubuque, Iowa, to Cairo, Illinois (fig . 1) . These 

flood plains contain a series of levees constructed to 

92° 91 , , , 

_W1Sl:0:ti_S1N 

I0_IN0h, 

MS.9 

MO.2 CIGaries J~ '7 St, Louis 

MO.1 

100 MILES 

I I 

100 KILOMETERS 

Figure 1 . Location of study area and sediment deposition sites sampled during September 1993 in the Missouri and the 

Mississippi River flood plains . 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
withstand floodwaters from the rivers and their tributaries. The predominant land use in the flood plain is agriculture, interspersed with urban areas. Postflood 

sediment samples were collected along the flood plains 

at 25 sites. 

Deposition of silt and clay sediment in the flood 

plain generally was associated with "slack water" areas 

where floodwaters entered with little velocity and 

pooled . These areas commonly were located near the 

flood-plain side of the levee adjacent to the levee break 

where the flow paths separated. Silt and clay deposition 

was determined to be as much as 140 mm deep in the 

flood plain of the Missouri River near Hermann, Missouri (fig . 2) . 

Figure 2. Silt and clay sediment deposited in the Missouri 

River flood plain near Hermann, Missouri, during the 1993 

flood . The photograph was taken on September 7, 1993 . 

Although sites with sand deposition generally 

were not sampled, sand dunes as deep as 4 mwere 

observed near many levee breaks, such as those near St. 

Charles, Missouri (fig . 3) . Sand dunes along the flood 

plain near Hartsburg, Missouri, were as long as 3,000 

mand as high as 3 m (fig . 4) . 

STUDY METHODS 

For this study, 25 sites were selected to sample 

postflood sediment and preflood soil . Site selection and 

location techniques, sampling techniques, laboratory 

analytical methods, and quality-assurance samples are 

discussed in the following sections . 

Figure 3. Sand dunes deposited in the Missouri River flood 

plain near St. Charles, Missouri, during the 1993 flood . The 

photograph was taken on September 7, 1993. 

Figure 4. Aerial photograph showing the Missouri River flood plain near Hartsburg, Missouri, November 1993. The river 

length is about 20 kilometers. 

Study Methods 3 
Site Selection and Location 

Twelve sites along the Missouri River flood plain 

and 13 sites along the Mississippi River flood plain, in 

areas where substantial quantities of silt and clay were 

deposited during the 1993 flood, were selected for sampling. Approximate locations for the sampling sites initially were selected from topographic maps. The sites 

were located about 45 river miles apart-those on the 

Missouri River extending upstream from the junction 

ofthe Missouri and the Mississippi Rivers, and the sites 

along the Mississippi River beginning at Dubuque, 

Iowa, and extending to the junction of the Mississippi 

and the Ohio Rivers (fig . 1 ; table 1) . 

Exact locations for sampling were chosen on the 

basis of onsite reconnaissance, which was limited to 5 

river miles upstream or downstream from the initially 

selected approximate location . Factors considered in 

selection of the sampling location included the degree 

of disturbance, abundance of silt and clay, accessibility

of the location, and the type of preflood land use . The 

preferred land use was agricultural production fields . 

Areas of possible contamination as a result of human or 

animal activities were avoided. After visual inspection

of the surface of the silt and clay deposit, a hole was 

dug to permit inspection of the structure of the deposit 

and the total deposition depth (fig . 2) . Adeposition 

depth of at least 0.2 mwas required before a sample 

was collected. 

Table 1 . Selected data for sampling sites in the Missouri and the Mississippi River flood plains 

[MO, Missouri; MS, Mississippi] 

Latitude/longitude, Depth interval for postflood

Site

(fig. 1) station number secondsi sampled in feet mile2 in millimeters 3 

Missouri River flood-plain samples 

Mo. 1 384125090341401 384125.4 09-07-93 451 38 0-70 

0903414.2 

MO.2 384305091263301 384304.5 09-07-93 505 98 20-140 

0912632.9 

MO.3 383438092034301 383438.4 09-08-93 537 137 0-70 

0920343.2 

MO.4 385142092265701 385141 .6 09-08-93 570 176 0-30 

0922656.9 

385142092265702 385141.6 09-08-93 570 176 30-150 

0922656.9 

MO.5 391823092565401 391823.2 09-09-93 620 238 0-40 

0925654.2 

MO.6 391714093225301 391713.9 09-09-93 648 281 0-30 

0932252.9 

MO.7 391152094100401 391152.2 09-10-93 710 338 0-60 

0941003.6 

MO.8 391134094432401 391134.0 09-10-93 748 380 0-40 

0944324.2 

MO.9 393857095015401 393857.1 09-10-93 790 432 0-90 

0950154.1 

MO.10 395247095074001 395247.1 09-11-93 836 474 0-90 

0950740.1 

MO.11 401901095370101 401900.9 09-11-93 883 525 0-80 

0953700.6 

MO.12 404010095485601 404010.0 09-11-93 919 560 0-20 

no. U.S . Geological Survey in degrees, minutes, Date Elevation, River sediment samples, 

0954855.7 

4 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 1 . Selected data for sampling sites in the Missouri and the Mississippi River flood plains-Continued 

[MO, Missouri ; MS, Mississippi] 

Latitude/longitude, Depth interval for postflood 

Site no. U.S . Geological Survey in degrees, minutes, Date Elevation, River sediment samples, 

(fig . 1) station number secondsl sampled in feet mile2 in millimeters3 

Mississippi River flood-plain samples 

MS. 1 422840090381801 422839 .7 09-18-93 597 578 0-100 

0903818.2 

MS.2 420450090112601 420449 .9 09-18-93 585 536 0-40 

0901126.0 

MS.3 413026090363201 413026 .3 09-18-93 550 481 0-60 

0903631.8 

MS.4 411023091022301 411022 .8 09-19-93 537 435 0-40 

0910222.7 

MS.5 403851091142501 403851 .0 09-20-93 530 389 0-70 

0911424.6 

MS.6 400642091252201 400641 .5 09-20-93 483 341 0-20 

0912521 .5 

MS.7 393318091073101 393318 .2 09-21-93 458 291 0-60 

0910731 .1 

MS.8 390239090435901 390239 .3 09-21-93 440 245 0-20 

0904359.0 

MS.9 385224090123801 385223 .9 09-22-93 423 203 0-60 

0901237.9 

MS.10 381248090165601 381248 .1 09-22-93 395 148 0-20 

0901656.2 

MS.11 374532089404501 374532 .0 09-24-93 365 95 0-110 

0894044.9 

MS . 12 371745089302201 371744 .9 09-23-93 335 52 0-60 

0893021 .9 

MS . 13 370333089135201 370332 .8 09-23-93 315 10 0-20 

0891352.4 

'The first number listed is latitude ; the second number is longitude. 

`For the Missouri River, 0 river mile is at thejunction of the Missouri and the Mississippi Rivers; for the Mississippi River, 0 river mile is at the 

junction of the Mississippi and the Ohio Rivers . 

30 millimeter is the surface of the sediment deposition . 

Once the exact sampling site was selected, a 

hand-held global positioning system (GPS), accurate to 

within 30 m, was used to determine the latitude and 

longitude of the site . Latitude, longitude, USGS station 

number, description, date sampled, elevation of the 

site, the location in river miles with respect to either the 

Missouri River (MO prefix site numbers) or the Mississippi River (MS prefix site numbers), and the sedimentdeposition depth are given in table 1 . Elevations were 

determined to ± 3 mfrom 7.5-minute USGS topographic maps. River miles were determined to ±0.5 km 

from 7.5-minute USGS topographic maps . 

Sampling Techniques 

To collect a postflood sediment sample, a hole 

was dug to identify the interface between the postflood 

deposition and the preflood soil . The flood-deposited 

sediments were well consolidated, whereas the underlying, preflood soil typically had a "loose" structure 

and commonly contained roots and other organic 

debris . After digging the hole, the surface area was 

cleared of any organic debris . The vertical cut area was 

shaved with a clean plastic scraper to ensure no contamination . The plastic scraper, a plastic scoop, and 

latex gloves were used to collect a sample from the vertical cut. The sample was collected above the interface 

Study Methods 5 
in a 1-m2 area or less, depending on the quantity of sediment available. Ascoop of the sediment was collected 

at various points in the sample area . The sediment was 

composited, placed in a sample container, and immediately chilled. After sample collection, the plastic scrapers and scoops were cleaned and rinsed with deionized 

water, methanol, and organic-free water. No samples 

were collected where water had not receded from the 

area . One postflood sediment sample was collected at 

all sites except site MOA; at this site, two samples

mostly composed of sand were collected-one from 0 

to 30 mm and the other from 30 to 150 mm. 

Samples collected for moisture and carbon content and for concentrations of volatile solids, nutrients, 

pesticides, and semivolatile organic compounds were 

analyzed only in the less than 2-mm size fraction. 

Because the postflood sediment samples were determined onsite to have a particle diameter of less than 2 

mm, no samples were seived. 

After the postflood sediment samples were collected, preflood soil samples were collected for particle-size distribution . All flood deposition was removed 

from the sample area with a clean plastic scraper to the 

postflood deposition and preflood soil interface. Preflood soil samples were collected by using the same 

collection procedures used for the postflood sediment 

samples . 

Different sample containers were used for each 

analysis type. Samples for analysis of particle-size distribution were collected in a plastic bag and sealed . 

Samples for analysis of moisture content, volatile solids, nutrients, and carbon were collected in a widemouth polyethylene bottle with a plastic lid. Samples 

for analysis of pesticides and semivolatile organic compounds were collectedin a 1-L wide-mouth glass bottle 

with a Teflon-lined lid that had been baked at 450° C. 

Samples for analysis of other selected elements were 

collected in a wide-mouth plastic bottle with a Teflonlined lid. 

Laboratory Analytical Methods 

Samples for particle-size distribution were analyzed at the USGS laboratory in Rolla, Missouri. The 

following classification of particle-size diameter (Guy, 

1969) was used to describe material in this report : 

gravel, 2 to less than 64 mm; sand, 0.062 to less than 2 

mm; silt, 0.04 to less than 0 .062 mm; and clay, less than 

0.004 mm. Silt and clay material are considered to be 

fine grained; sand- and gravel-size (hereafter referred 

to as "sand and gravel") material are considered to be 

coarse . Samples that contained sand, silt, and clay 

material were analyzed by using a hydrometer, visual 

accumulation (VA) tube, and wet sieve (Guy, 1969) . 

Samples that contained mostly silt and clay material 

were analyzed by using a hydrometer as described by 

the U.S . Army Corps of Engineers (1970) . 

Samples for analysis of water content and concentrations of volatile solids, nutrients, and carbon in 

the less than 2-mm size fraction were analyzed at the 

USGS laboratory in Arvada, Colorado, by using analyt 

ical methods having detection or reporting limits listed 

in table 2 . 

Table 2. Detection or reporting limits of analytical methods used for the determination of constituent concentrations in the less 

than 2-millimeter size fraction of postflood sediment samples 

[Analysis done at the U.S . Geological Survey laboratory, Arvada, Colorado] 

Detection Detection 

or reporting or reporting 

Constituent limit Constituent limit 

Moisture content by dry weight, in percent. . 0.1 Solids, volatile, in milligrams per kilogram . . . . . . . 1 .0 

Nutrients, in milligrams per kilogram 

Nitrite plus nitrate as nitrogen . . . . . . . . . . . . . . . . . . . . . . 2.0 Ammoniaplus organic nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . 20 

Ammoniaas nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 Phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 

Carbon, in grams per kilogram 

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 Inorganic. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.1 

Pesticides, in micrograms per kilogram s 

Alachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6 Dieldrin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 .2 

Atrazine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.8 Metolachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 .6 

4,4'-DDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.0 Simazine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 .2 

Desethylatrazine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Trifluralin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 4.8 

6 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 2. Detection or reporting limits of analytical methods used for the determination of constituent concentrations in the less 

than 2-millimeter size fraction of postflood sediment samples-Continued 

[Analysis done at the U.S . Geological Survey laboratory, Arvada, Colorado] 

Detection Detection 

or reporting or reporting 

Constituent limit Constituent 

Semivolatile organic compounds, in micrograms per kilogram 

Acenaphthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Acenaphthylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Acridine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Anthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Anthraquinone. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Azo-benzene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[a]anthracene


Benzo[b]fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[k]fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[g, h. i]perylene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[a]pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Benzo[c]quinoline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,2'-Biquinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4-Bromophenyl phenyl ether. . . . . . . . . . . . . . . . . . . . . . . . . 

Butylbenzylphthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Cg-Alkyt-phenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9H-Carbazole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

bis(2-Chloroethoxy)methane . . . . . . . . . . . . . . . . . . . . . . . . 

bis(2-Chloroethyl)ether . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

bis(2-Chloroisopropyl)ether . . . . . . . . . . . . . . . . . . . . . . . . . . 

4-Chloro-3-methylphenol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Chloronaphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Chlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4-Chlorophenyl phenyl ether. . . . . . . . . . . . . . . . . . . . . . . . . 

Chrysene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorocyclopentadiene . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachloroethane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

lndeno[1,2,3-cd]pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Isophorone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Isoquinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1-Methyl-9H-fluorene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Methylanthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4,5-Methylenephenanthrene. . . . . . . . . . . . . . . . . . . . . . . . . 

1-Methylphenanthrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1-Methylpyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Naphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Nitrobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

n-Nitroso di-n-propylamine . . . . . . . . . . . . . . . . . . . . . . . . . 

10 

5.0 

10 

5.0 

20 

20 

10 

10 

10 

20 

10 

10 

20 

10 

10 

10 

10 

10 

10 

20 

30 

10 

10 

10 

10 

20 

20 

20 

10 

10 

10 

10 

20 

10 

10 

10 

10 

100 

40 

10 

p-Cresol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dibenzo[a,h]anthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dibenzothiphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Di-n-butylphthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,3-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,4-Dichlorobenzene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4-Dichlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Diethyl phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dimethylnaphthalene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,6-Dimethylnaphthalene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,6-Dimethylnaphthalene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

3,5-Dimethylphenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dimethyl phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4,6-Dinitro-2-methylphenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4-Dinitrophenol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,6-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

di-n-Octyl phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

bis(2-Ethylhexyl)phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Ethylnaphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9H-Fluorene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobenzene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobutadiene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

n-Nitrosodiphenylamine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Pentachloroanisol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Pentachloronitrobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Phenanthrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Phenanthridine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Phenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 

Pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Quinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,3,5,6-Tetramethylphenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2,4-Trichlorobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4,6-Trichlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,3,6-Trimethylnaphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4,6-Trimethylphenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

limit 

10 

20 

5.0 

10 

10 

10 

10 

20 

10 

10 

10 

10 

20 

10 

200 

300 

20 

50 

20 

10 

10 

5.0 

10 

10 

20 

10 

20 

30 

100 

5.0 

10 

10 

5 .0 

10 

30 

10 

20 

10 

30 

'Reporting limits are estimates (E.T . Furlong, U.S . Geological Survey, written commun., 1993). 

Study Methods 7 
Water content and volatile solids concentration were 

determined by using methods described in Fishman 

and Friedman (1989) . Nutrient samples were analyzed 

by using methods described in Fishman (1993) . Total 

and inorganic carbon samples were analyzed by using 

methods described in Wershaw and others (1987) . 

Organic carbon concentrations were computed by subtracting the inorganic carbon from the total carbon concentrations. 

The concentrations of selected elements and carbon in the less than 0.062-mm size fraction were determined at the USGS laboratory in Lakewood, Colorado, 

by using the methods described in Arbogast (1990) . 

Theconstituents analyzed and descriptions of the different methods of analysis for each constituent are 

listed in table 3. The total carbon concentration was 

determined by using methods described in Wershaw 

and others (1987) . 

Table 3. Detection limits and methods used for the determination of element concentrations in the less than 62-millimeter 

size fraction of postflood sediment samples 

[4N HCl, 4 normal hydrochloride acid ; mg/kg, milligrams per kilogram ; 0.1N HCI, 0.1 normal hydrochloric acid; ICP-AES, inductively coupled plasmaatomic emission spectrometry ; IR, infrared spectrometry ; n.a ., not analyzed ; HGAAS, hydride-generation atomic absorption spectrometry ; FAAS, flame 

atomic absorption spectrometry ; CVAAS, cold-vapor atomic absorption spectrometry ; DN, delayed neutron activation-methods presented in Arbogast (1990) . Analyzed at the U.S . Geological Survey laboratory, Lakewood, Colorado] 

Element 

Aluminum . . . . . . . . . . . . . . . . . . . . . . . . . 

Calcium . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 

Iron . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . 

Magnesium. . . . . . . . . . . . . . . . . . . . . . . . 

Phosphorus . . . . . . . . . . . . . . . . . . . . . . . . 

Potassium. . . . . . . . . . . . . . . . . . . . . . . . . . 

Sodium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Sulfur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Titanium . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Antimony . . . . . . . . . . . . . . . . . . . . . . . . . . 

Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Barium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . 

Bismuth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Cadmium. . . . . . . . . . . . . . . . . . . . . . . . . . . 

Cerium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Chromium . . . . . . . . . . . . . . . . . . . . . . . . . 

Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Europium . . .. . . . . . . . . . . . . . . . . . . . . . . 

Gallium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Gold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Holmium . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Lanthanum . . . . . . . . . . . . . . . . . . . . . . . . 

Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Lithium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Manganese . . . . . . . . . . . . . . . . . . . . . . . . 

Mercury. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Molybdenum . . . . . . . . . . . . . . . . . . . . . 

Method Total digestioni 

ICP-AES 0.005 percent by weight 

-do- .005 percent by weight 

-do- .02 percent by weight 

--lo- .005 percent by weight 

-do- .005 percent by weight 

-do- .01 percent by weight 

-do- .006 percent by weight 

IR4 .05 percent by weight 

ICP-AES .005 percent by weight 

HGAAS 0.2 mg/kg 

ICP-AES n.a . 

-do- 10 mg/kg 

HGAAS .2 mg/kg 

ICP-AES 1 mg/kg 

-do- 1 mg/kg 

-do- 10 mg/kg 

-do- 2 mg/kg 

FAASS .1 mg/kg 

ICP-AES 5 mg/kg 

-do- 2 mg/kg 

-do- 2 mg/kg 

-do- 2 mg/kg 

-do- 2 mg/kg 

-do- 4 mg/kg 

-do- 8 mg/kg 

-do- 4 mg/kg 

-do- 2 mg/kg 

-do- 4 mg/kg 

-do- 2 mg/kg 

-do- 4 mg/kg 

CVAAS4 .02 mg/kg 

ICP-AES 2 mg/kg 

Detection limit 

4N HCI 0.1 N HCI 

digestion 2 digestion3 

(mg/kg) (mg/kg) 

1 .3 1 .3 

1 .0 1.0 

.40 .40 

5.8 5.8 

12 .5 12 .5 

7.5 7.5 

2.5 2.5 

n.a. n.a. 

.25 .25 

n.a . n.a . 

6.3 6.3 

3.8 3.8 

.05 .05 

.10 .10 

.025 .025 

7.5 7.5 

.50 .50 

n.a . n.a. 

5.0 5 .0 

1.5 1 .5 

1.3 1 .3 

.25 .25 

n.a . n.a. 

n.a. n.a. 

n.a. n.a. 

n.a. n.a. 

.75 .75 

6.3 6.3 

.38 .38 

.63 .63 

n.a. .006 

1 .0 1 .0 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 3. Detection limits and methods used for the determination of element concentrations in the less than 62-millimeter 

size fraction of postflood sediment samples-Continued 

[4N HCI, 4 normal hydrochloride acid : mg/kg, milligrams per kilogram ; 0.1 NHCI, 0.1 normal hydrochloric acid ; ICP-AES, inductively coupled plasmaatomic emission spectrometry ; IR, infrared spectrometry ; n.a ., not analyzed; HGAAS, hydride-generation atomic absorption spectrometry ; FAAS, flame 

atomic absorption spectrometry ; CVAAS, cold-vapor atomic absorption spectrometry ; DN, delayed neutron activation-methods presented in Arbogast 

(1990) . Analyzed at the U.S . Geological Survey laboratory, Lakewood, Colorado] 

Element 

Neodymium . . . . . . . . . . . . . . . . . . . . . . 

Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Niobium . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Scandium . . . . . . . . . . . . . . . . . . . . . . . . . . 

Selenium . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Silver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Strontium . . . . . . . . . . . . . . . . . . . . . . . . . . 

Tantalum . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Thorium . . ., . . . . . . . . . . . . . . . . . . . . . . . . 

Tin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Tungsten . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Uranium . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Vanadium . . . . . . . . . . . . . . . . . . . . . . . . . . 

Ytterbium . . . . . . . . . . . . . . . . . . . . . . . . . . 

Yttrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Zinc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Zirconium . . . . . . . . . . . . . . . . . . . . . . . . . 

Carbon, total . . . . . . . . . . . . . . . . . . . . . 

Carbon, organic . . . . . . . . . . . . . . . . 

Carbon, carbonate 

as CO,. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Method 

-do­

-do­

-do­

-doHGAAS 

ICP-AES 

FAAS' 

ICP-AES 

-do­

-doDN 

ICP-AES 

-do­

-doDN 

ICP-AES 

-do­

-do­

-do­

-doCombustion4 

Difference4 

Titration4 

Total digestion) 

9 mg/kg 

3 mg/kg 

4 mg/kg 

2 mg/kg 

.2 mg/kg 

2 mg/kg 

.1 mg/kg 

2 mg/kg 

40 mg/kg 

6 mg/kg 

1 mg/kg 

5 mg/kg 

n.a . 

100 mg/kg 

.2 mg/kg 

2 mg/kg 

1 mg/kg 

2 mg/kg 

2 mg/kg 

n.a . 

.05 percent by weight 

.05 percent by weight 

.01 percent by weight 

Detection limit 

4N HCI O.1N HCI 

digestion 2 digestion 3 

(mg/kg) (mg/kg) 

n.a. n.a . 

1 .3 1 .3 

n.a. n.a . 

n.a. n.a . 

.05 .05 

0.50 0.50 

n.a . n.a. 

.025 .025 

n.a . n.a . 

n.a . n.a . 

n.a . n.a. 

10 10 

7.5 7.5 

n.a . n.a. 

n.a . n.a. 

.38 .38 

n.a . n.a. 

.25 .25 

.25 .25 

.63 .63 

n.a . n.a. 

n.a . n.a. 

n.a . n.a. 

'Concentrated hydrochloric, hydrofluoric, nitric, and perchloric acids.


`'Conditionally available fraction in the sediments.


;Available fraction in the sediments.


4Method presented in Arbogast (1990) .


5Method presented in O'Leary and Viets (1986) .


Selected pesticide and semivolatile organic compound concentrations were determined for all sites in 

the less than 2-mm size fraction at the Enseco Analyti 

cal Laboratory, Arvada, Colorado . A list ofconstituents 

and the detection limits is given in table 4. Samples for 

pesticides were analyzed by using U.S . Environmental 

Protection Agency (USEPA) method SW8080, and 

samples for semivolatile organic compounds were analyzed by using USEPA method SW8270 (U.S . Environmental Protection Agency, 1986) . 

Concentrations of selected pesticides and semivolatile organic compounds were determined for 15 of 

25 sites in the less than 2-mm size fraction at the USGS 

laboratory in Arvada. A list of constituents and the 

detection limits is given in table 2 . The detection limits 

for 4,4'-DDE (hereafter referred to in this report as 

"DDE") and dieldrin were lower than the limits used by 

the Enseco Analytical Laboratory. A different procedure was used by the USGS to analyze for the pesticides and semivolatile organic compounds. 

Study Methods 9 
Table 4. Detection limits used for the determination of pesticide and semivolatile organic compound concentrations in the 

less than 2-millimeter size fraction of postflood sediment samples 

[All detection limits in milligrams per kilogram . Analyzed at the Enseco Analytical Laboratory, Arvada, Colorado] 

Compound 

Aldrin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

alpha-BHC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

beta-BHC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

delta-BHC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

gamma-BHC (Lindane) . . . . . . . . . . . . 

Chlordane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


4,4'-DDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


4,4'-DDE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


4,4'-DDT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Dieldrin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Endrin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Endrin aldehyde . . . . . . . . . . . . . . . . . . . . . . . .


Endosulfan I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Acenaphthene . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Acenaphthylene . . . . . . . . . . . . . . . . . . . . . . . . .


Acetophenone . . . . . . . . . . . . . . . . . . . . . . . . . . .


4-Aminobiphenyl . . . . . . . . . . . . . . . . . . . . . .


Aniline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Anthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzidine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[a]anthracene . . . . . . . . . . . . . . . . . .


Benzo[b]fluoranthene . . . . . . . . . . . . . . . .


Benzo[k]fluoranthene . . . . . . . . . . . . . . . .


Benzoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


Benzo[g, h, i]perylene . . . . . . . . . . . . . . . . .


Benzo[a]pyrene . . . . . . . . . . . . . . . . . . . . . . . . .


Benzyl alcohol . . . . . . . . . . . . . . . . . . . . . . . . . .


4-Bromophenyl phenyl ether . . . .


Butylbenzylphthalate . . . . . . . . . . . . . . . .


4-Chloroaniline . . . . . . . . . . . . . . . . . . . . . . . . .


bis(2-Chloroethoxy)methane . . . .


bis(2-Chloroethyl)ether . . . . . . . . . . . . .


bis(2-Chloroisopropyl)ether . . . . . .


4-Chloro-3-methylphenol . . . . . . . . .


2-Chloronaphthalene. . . . . . . . . . . . . . . . .


2-Chlorophenol . . . . . . . . . . . . . . . . . . . . . . . . .


4-Chlorophenyl phenyl ether . . . .


1-Chloronaphthalene. . . . . . . . . . . . . . . . .


Detection limit Compound Detection limit 

Pesticides ) 

0.010 Endosulfan II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

.010 Endosulfan sulfate . . . . . . . . . . . . . . . . . . . . . . . . 

.010 Heptachlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

.010 Heptachlor epoxide . . . . . . . . . . . . . . . . . . . . . . 

.010 Methoxychlor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

.10 PCB, Aroclor 1016 . . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1221 . . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1232 . . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1242 . . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1248 . . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1254 . . . . . . . . . . . . . . . . . . . . . . 

.020 PCB, Aroclor 1260 . . . . . . . . . . . . . . . . . . . . . . . 

.010 Toxaphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Semivolatile organic compounds2 

0.50 

.50 

2.5 

2.5 

2.5 

.50 

5.6 

.50 

.50 

.50 

2.5 

.50 

.50 

1.0 

.50 

.50 

1.0 

.50 

.50 

.50 

.50 

.50 

.50 

.50 

2.5 

Chrysene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dibenzofuran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dibenzo[a,h]anthracene . . . . . . . . . . . . . . . 

Di-n-butylphthalate . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . 

1,3-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . 

1,4-Dichlorobenzene . . . . . . . . . . . . . . . . . . . . 

2,4-Dichlorophenol . . . . . . . . . . . . . . . . . . . . . . 

2,6-Dichlorophenol . . . . . . . . . . . . . . . . . . . . . . 

Diethyl phthalate . . . . . . . . . . . . . . . . . . . . . . . . . . 

p-Dimethylaminoazobenzene . . . . . . . 

7,12-Dimethylbenzo[a]anthracene 

2,4-Dimethylphenol . . . . . . . . . . . . . . . . . . . . . . 

Dimethyl phthalate . . . . . . . . . . . . . . . . . . . . . . . 

4,6-Dinitro-2-methylphenol . . . . . . . . . 

2,4-Dinitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . 

2,4-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . . 

2,6-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . . 

Di-n-octyl phthalate. . . . . . . . . . . . . . . . . . . . . . 

Diphenylamine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

bis(2-Ethylhexyl)phthalate . . . . . . . . . . . 

Ethyl methanesulfonate . . . . . . . . . . . . . . . . 

Fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Fluorene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobenzene . . . . . . . . . . . . . . . . . . . . . . 

0.020 

.020 

.010 

.010 

.10 

.10 

.10 

.10 

.10 

.10 

.10 

.20 

0.50 

.50 

.50 

.50 

.50 

.50 

.50 

.50 

2.5 

.50 

2.5 

2.5 

.50 

.50 

1.5 

1.5 

.50 

.50 

.50 

2.5 

.50 

2.5 

.50 

.50 

.50 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 4. Detection limits used for the determination of pesticide and semivolatile organic compound concentrations in the 

less than 2-millimeter size fraction of postflood sediment samples-Continued 

[All detection limits in milligrams per kilogram . Analyzed at the Enseco Analytical Laboratory, Arvada, Colorado] 

Compound Detection 

Hexachlorobutadiene . . . . . . . . . . . . . . . . 0.50 

Hexachlorocyclopentadiene . . . . . . .50 

Hexachloroethane . . . . . . . . . . . . . . . . . . . . . .50 

Indeno [l, 2, 3-cd]pyrene. . . . . . . . . . . . . .50 

Isophorone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

3-Methylcholanthrene . . . . . . . . . . . . . . . 2.5 

Methyl methanesulfonate. . . . . . . . . . 2.5 

2-Methylnaphthalene . . . . . . . . . . . . . . . . .50 

2-Methylphenol . . . . . . . . . . . . . . . . . . . . . . . . . .50 

4-Methylphenol . . . . . . . . . . . . . . . . . . . . . . . . . .50 

Naphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

1-Naphthylamine. . . . . . . . . . . . . . . . . . . . . . . 2.5 

2-Naphthylamine. . . . . . . . . . . . . . . . . . . . . . . 2.5 

2-Nitroaniline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

3-Nitroaniline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

4-Nitroaniline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

Nitrobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

2-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

it Compound Detection limit 

organic compoundsZ-Continued 

4-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

n-Nitrosodimethylamine . . . . . . . . . . . . . . . 2.5 

n-Nitrosodi-n-butylamine . . . . . . . . . . . . . 2.5 

n-Nitrosodi-n-propylamine . . . . . . . . . . . .50 

n-Nitrosodiphenylamine . . . . . . . . . . . . . . . .50 

n-Nitrosodiperidine . . . . . . . . . . . . . . . . . . . . . . 2.5 

Pentachlorobenzene . . . . . . . . . . . . . . . . . . . . . . 2.5 

Pentachloronitrobenzene . . . . . . . . . . . . . . 2.5 

Pentachlorophenol . . . . . . . . . . . . . . . . . . . . . . . . 1 .5 

Phenacetin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

Phenanthrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

Phenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50 

Pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 

1,2,4,5-Tetrachlorobenzene . . . . . . . . . . 2.5 

2,3,4,6-Tetrachlorophenol . . . . . . . . . . . . 2.5 

1,2,4-Trichlorobenzene . . . . . . . . . . . . . . . . .50 

2,4,5-Trichlorophenol. . . . . . . . . . . . . . . . . . . 1 .5 

2,4,6-Trichlorophenol. . . . . . . . . . . . . . . . . . . .50 

'Method SW8080 (U .S . Environmental Protection Agency, 1986). 

MMehhod SW8270 (U.S . Environmental Protection Agency, 1986). 

Quality-Assurance Samples 

Quality-assurance samples were collected and 

analyzed to determine the variability in sampling and 

analytical techniques . Replicate samples were col 

lected at sites MO.7, MS . 1, MS.7, and MS. 13 to determine the variability of sampling techniques . Duplicate 

samples were split from samples collected for analysis 

of concentrations of semivolatile organic compounds 

and selected elements to determine the variability in 

analytical techniques . 

Sample set reagent spikes were used to determine the accuracy of the analyses for pesticides and 

semivolatile organic compounds. During the gel per 

meation chromatography (GPC) process, pentachlorophenol (chlorophenols) may have been sorbed and 

desorbed, which caused low and variable recoveries, 

and degradation of hexachlorocyclopentadiene and 

hexachlorobutadiene likely occurred in the injection 

port of the gas chromatography/mass spectrometry 

(GC/MS) (E.T. Furlong, U.S . Geological Z-1 Survey, written commun., 1993) and affected the concentrations 

detected in the reagent spikes . 

The effect of the sample matrix and gross processing errors in samples collected for pesticides and 

semivolatile organic compounds can be monitored by 

the results of the surrogate compound recoveries . 

Selected surrogate compounds with chemical properties similar to some ofthe analytes of interest are added 

to each sample at the beginning of extraction . 

Standard reference materials (SRM) for elements, pesticides, and semivolatile organic compounds 

were analyzed to determine laboratory analytical accu 

racies . Analytical split analyses for the elemental SRM 

also were performed to determine precision of the 

analyses . 

Analysis of sample set blanks was performed for 

samples collected for pesticides and semivolatile 

organic compounds. Analysis of a blank determines if 

any interferences occurred during the analytical process of the sample set. No interferences were detected 

in any of the blanks for either sample set. 

Study Methods 1 1 
PHYSICAL AND CHEMICAL DATA ON 

SEDIMENTS 

The following sections present and summarize 

the results of analyses of particle-size distribution, 

water content, and the concentrations of nutrients, vol 

atile solids, carbon, other selected elements, pesticides, 

and semivolatile organic compounds in postflood sediment samples and the particle-size distribution of preflood soil samples. 

The mean and the standard deviation were computed for water content, volatile solids, nutrients, carbon, selected elements, and pesticides . The mean and 

the standard deviations were computed only for constituents detected in more than 50 percent of the samples . In those samples where the constituent concentration was less than the detection limit, one-half the 

detection limit was used to compute the mean and the 

standard deviation. 

Particle-Size Distribution 

The particle-size distribution data for the postflood sediment and preflood soil samples are presented 

in table 5. Because of the waythe sample sites were 

selected, the postflood sediment samples primarily are 

silt and clay except for the deeper sample from MOA, 

which contained 91.7 percent by weight sand. Postflood sediment samples that were greater than 50 percent by weight clay were from sites MO.3, MO.6, 

MO.8, MO.9, and MS .9 (fig . 1) and ranged from 52.3 

to 78 .2 percent by weight clay. All other postflood sediment samples ranged from 51 .5 to 87.7 percent by 

weight silt . The sample from MO. 1 had the lowest clay 

content of 8 .0 percentby weight . Sand in postflood sediment samples ranged from 0 percent by weight at 

MO.6 to 28.4 percent by weight at MS. 13. 

Samples of preflood soil were collected from 

areas of various land uses, which included agricultural 

production fields, vacant urban areas, vacant land, and 

levees . The preflood soil sample collected from the 

base of a levee at MS.5 had the highest gravel content-7 .5 percent by weight. Sand in preflood soil samples ranged from less than 1 to 82.5 percent by weight, 

silt content ranged from 9.0 to 85 .2 percent by weight, 

and clay content ranged from 1 .0 to 71 .5 percent by 

weight. 

Moisture Content and Volatile Solids, 

Nutrient, and Carbon Concentrations 

The data for moisture content and for concentrations of volatile solids, nutrients, and carbon for all 

samples in the less than 2-mm size fraction are pre 

sented in table 6 . Moisture content in the postflood sediment ranged from 7 to 51 percent by weight . Volatile 

solids concentrations ranged from 6,750 to 91,500 

mg/kg. The deeper sample from M0.4 had the smallest 

nutrient concentrations detected in all samples. The 

nitrite plus nitrate as nitrogen concentration of 140 

mg/kg in the MS. 12 sample was about three times 

larger than the concentrations from other sites. For all 

samples except MOA layer 2, total carbon was present 

predominantly as organic carbon . The total carbon concentration from this sample (2.5 g/kg) was an order of 

magnitude less than the concentration in other samples. 

Selected Element Concentrations 

Generally, as grain size decreases in bottom-sediment material, element concentrations increase 

(Horowitz, 1991, p. 16) . On the basis of this general 

correlation, postflood sediment samples were analyzed 

for concentrations of 12 selected elements in the silt 

and clay fraction . These data are listed in table 7, 

descriptive statistics are listed in table 8 (both follow 

"References Cited" section), and the results for SRM 

for elements are in listed table 9. 

Pesticide Concentrations 

Samples were analyzed for pesticides by two 

laboratories . The method and detection limit for the 

pesticides for samples analyzed at the Enseco Analyti 

cal Laboratory are listed in table 4 and at the USGS laboratory in Arvada are listed in table 2. No pesticides 

were detected by the Enseco Analytical Laboratory. 

Results of pesticide analyses by the USGS laboratory 

are listed in table 10. Some of the concentrations 

reported in table 10 are less than the detection or reporting limit listed in table 2 because pesticide concentrations were determined by a custom-USGS method that 

generally has lower detection limits . Only DDE and 

dieldrin were analyzed by both laboratories . 

Alachlor was detected in 14 samples; the highest 

concentration of 54 mg/kg was in the MS.5 sample . 

1 2 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 5. Particle-size distribution of postflood sediment and preflood soil samples in the Missouri and the Mississippi River flood plains 

[MO, Missouri ; MS, Mississippi ; -, no data. Analyzed at the U.S . Geological Survey sediment laboratory, Rolla, Missouri] 

Percentage of sample smaller than particle diameter


Particle diameter,


in millimeters


Site no. Gravel Sand Silt Clay 

(fig . 1) Sample type 8.0 4.0 2.0 1 .0 0.50 0.25 0.125 0.062 0.031 0.016 0.008 0.004 0.002 

Missouri River 

MO. 1 Postflood . . . . . . 100 100 100 100 99.4 99 .3 98.2 89 .4 60.4 30 .7 12 .3 8 .0 5 .0 

Preflood . .. . .. . 100 100 100 100 100 100 87.9 45 .0 42.9 27 .0 20.0 15 .2 -

MO.2 Postflood . . . .. . 100 100 100 100 100 100 99.4 95 .2 88 .4 70 .4 51 .1 39 .6 27 .3 

Preflood . . . . . . . 100 100 100 100 100 99 .6 99.2 97 .0 90.1 81 .6 64 .2 49 .2 37 .4 

MO.3 Postflood .. . .. . 100 100 100 100 100 100 99.8 99 .4 97.3 79 .9 63 .3 52 .3 38 .8 

Preflood . .. . .. . 100 100 100 100 100 98 .8 93 .3 89 .9 87.9 82 .1 72 .2 60.4 50 .6 

MO.4 Postflood t . . . . 

Postfloodt . . . . 

100 100 

100 99 .5 

100 

99 .2 

100 

98 .4 

100 99 .7 

93 .8 85 .6 

99.0 

24.9 

92 .4 

7 .5 

75 .6 31 .1 

.1 -

16 .6 

-

11 .8 11 .5 

- -

Preflood . . . . . . . 96.6 96 .1 95 .5 93 .9 89 .5 85 .6 76.0 54 .1 27 .3 16 .6 10 .3 8 .1 -

MO.5 Postflood. . . . . . 100 100 100 100 99 .7 99 .2 98 .9 98 .8 75 .0 67 .7 51 .5 38 .1 30.8 

Preflood . . . . . . . 100 100 100 100 100 96 .9 69 .7 36 .9 29 .1 15 .9 10 .8 7 .9 -

v MO.6 Postflood. . . . . . 100 100 100 100 100 100 100 100 99 .2 98 .1 92 .2 78 .2 57.2 

y 

d Preflood . . . . . . . 100 100 100 100 100 99.9 99 .8 99 .7 97 .2 95.6 93 .3 71 .5 53.3 

d 

a MO.7 Postflood . . . . . . 100 100 100 100 99 .9 99.5 99 .0 98 .8 94 .9 72 .6 52 .4 39 .7 29.1 

m Replicate . . . . . . 100 100 100 100 100 99.9 99 .6 98 .2 64 .0 38 .9 26 .6 20 .2 13 .5 

3. Split . .. . .. . . . . . . . 100 100 100 100 100 100 99 .8 97 .2 85 .2 43.4 30.7 23.9 21 .1 

d Preflood . . . . . . . 100 100 100 99 .6 99 .6 98.4 96 .5 84 .0 38 .8 32 .6 25 .2 16 .2 7.7 

v

m 

°' 0 

to 

MO.8 Postflood .. . . . . 

Preflood . .. . . . . 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

100 

98 .9 

100 

97 .9 

99 .9 

91 .8 

98 .3 

54 .0 

91 .7 

43.9 

78 .3 

26 .2 

60 .8 

22.8 

44.8

22.8 

2. 

MO.9 Postflood .. . .. . 100 100 100 100 100 100 99 .9 99 .9 96 .7 93.3 83 .6 66 .3 48.4 

H Preflood . .. . .. . 100 100 100 100 100 100 100 39 .2 23 .4 21 .4 18 .2 15 .2 13 .8 

i

W 
A Table 5. Particle-size distribution of postflood sediment and preflood soil samples in the Missouri and the Mississippi River flood plains-Continued 

[MO, Missouri ; MS, Mississippi ; -, no data. Analyzed at the U.S . Geological Survey sediment laboratory, Rolla, Missouri] 

m€

d 

3 Particle diameter, 

in millimeters 

a 

m Site no. Gravel Sand Silt Clay 

Percentage of sample smaller than particle diameter€

y (fig . 1) Sample type 8 .0 4.0 2.0 1 .0 0.50 0.25 0.125 0.062 0.031 0.016 0.008 0.004 0.002 

Missouri River-Continued 

w MO.10 Postflood . . . . . . 100 100 100 100 100 100 99.8 98 .5 86 .6 81 .3 64 .1 45 .2 33.1 

a Preflood . . . . . . . 100 100 100 100 99.1 97 .4 93 .6 81 .3 17 .3 14 .0 10 .4 3 .6 2.7 

A MO.11 Postflood . . . . . . 100 100 100 99.9 99 .9 99 .9 99 .8 99 .5 87.7 48.8 34 .1 24 .4 19 .1 

Preflood . .. . . . . 100 100 100 100 100 96 .6 87 .9 71 .1 62.0 50 .8 45.4 30 .4 25 .7 W 

y

O 

MO.12 Postflood .. . .. . 100 100 100 100 100 100 99 .9 99.5 85 .4 62.0 42.5 31 .3 22.6 

3a Preflood . .. . .. . 100 100 100 100 99 .6 98 .4 95 .5 91 .1 67.7 50.5 39.7 32 .1 25 .8 

O 

MS. 1 Postflood. . . . . . 100 100 100 100 

Mississippi River 

100 99 .8 99 .7 99.7 67.6 40.0 21 .0 12 .0 6.8 

w Replicate . . . . . . 100 100 100 100 100 100 99 .6 99.3 76.3 51 .5 32.0 24.4 11 .5 

w Preflood . . . . . . . 100 100 99 .1 99 .1 98 .5 98 .2 97 .7 97.2 72 .8 50.3 29.0 18 .2 7 .7 

T 

?o MS.2 Postflood. . . . . . 100 100 100 100 99.9 99.9 99 .8 99.8 95 .2 83.0 63.0 35 .4 9 .9 

Preflood . . . . . . . 100 100 99 .2 98 .6 95.7 93.7 91 .8 89.3 46 .5 25 .7 15 .8 15 .1 7 .8 

0 

C. MS.3 Postflood. . . . . . 100 100 100 100 99.9 99.6 99.0 94.6 71 .4 36.2 22.2 18 .9 12 .8 

m Preflood . . . . . . . 100 100 100 99 .6 97.8 96.8 95.7 94.6 71 .8 41 .2 24.7 14 .3 10 .1 

fB 

MS.4 Postflood . . . . . . 100 100 100 99 .6 98.4 97.4 97.0 96.9 92 .5 85 .1 53 .8 33.9 27 .0 

Preflood . . . . . . . 100 100 98 .6 92 .1 70.9 56.3 53.3 51 .2 48.6 44.0 34.3 23.1 15 .6 

MS.5 Postflood . . . . . . 100 100 100 99.4 97.8 96.9 96.6 96.4 96 .0 68 .1 63 .3 44.9 21 .9 

Preflood . . . . . . . 100 96 .9 92 .5 85 .0 34.6 26.2 19 .2 10.0 2 .8 1 .6 1 .2 1 .0 .9 

MS.6 Postflood . . . . . . 100 100 100 100 100 99.9 99.6 99 .2 98.8 84 .7 60 .8 33 .0 20.3 

Preflood . . . . . . . 100 100 100 99.5 98.7 98 .5 98 .3 98 .1 87 .1 79 .7 57 .3 33 .1 28.0 
Table 5. Particle-size distribution of postflood sediment and preflood soil samples in the Missouri and the Mississippi River flood plains-Continued 

[MO, Missouri ; MS, Mississippi ; -, no data. Analyzed at the U.S . Geological Survey sediment laboratory, Rolla, Missouri] 

Percentage of sample smaller than particle diameter 

Particle diameter, 

in millimeters 

d 

Site no. Gravel Sand Silt Clay 

(fig . 1) Sample type 8.0 4.0 2.0 1 .0 0.50 0.25 0.125 0.062 0.031 0.016 0.008 0.004 0.002 

Mississippi River-Continued 

MS.7 Postflood . . . . . . 100 100 100 100 100 99 .9 99.5 97.5 87 .0 52 .8 35 .5 23 .6 17 .8 

Replicate . . . . . . 100 100 100 100 99 .9 99 .9 98.9 98.9 96 .9 78 .3 56 .6 37.2 27 .5 

Preflood . . . . . . . . 100 100 99 .0 96.0 83 .6 72 .4 69.3 68 .5 66 .7 58 .3 45 .7 31 .1 23 .1 

MS.8 Postflood . . . . . . 100 100 100 99.5 99 .4 99 .2 98.8 98.3 91 .4 70.3 50 .1 31 .4 18 .1 

Preflood. . . . . . . . 100 100 100 99.7 98 .9 98 .7 98.1 97.0 76 .5 55 .7 33 .8 18 .1 11 .1 

MS.9 Postflood . . . . . . 100 100 100 100 100 100 100 99 .8 98 .6 97 .9 83 .5 62.7 44 .9 

Preflood . . . . . . . . 100 10 100 100 100 100 99.0 92.5 83 .4 73 .1 61 .7 51 .8 34 .7 

MS.10 Postflood . . . . . . 100 100 100 100 99 .8 99 .8 99.7 99.5 58 .4 32.2 21 .4 18 .2 15 .7 

Preflood . . . . . . . . 100 98.7 98 .5 98 .5 98 .5 97 .9 95.8 83 .4 71 .5 53 .3 35 .5 26.2 16 .6 

MS.11 Postflood . . . . . . 100 100 100 100 100 100 100 98 .7 75.2 57 .9 42 .0 32.6 25 .4 

Preflood . . . . . . . . 100 100 100 100 100 100 100 99 .9 94 .6 84.0 70 .7 58.6 45 .6 

MS.12 Postflood . . . . . . 100 100 100 100 100 100 99 .9 99 .9 89 .7 77.6 60 .1 45.1 35 .9 

Preflood . . . . . . . . 100 100 100 99 .9 99 .9 98 .9 87 .8 51 .6 31 .3 25 .7 22 .9 12 .1 10 .1 

MS.13 Postflood . . . . . . 100 100 100 100 100 100 100 71 .6 46 .6 27.2 15 .4 9.1 9 .1 

Replicate . . . . . . 100 100 100 100 100 100 100 78.2 66 .8 43 .2 32 .7 20.5 16 .0 

0 Preflood . . . . . . . . 100 100 100 100 100 1 00 99 .6 98 . 9 42 .4 30.9 18 .0 13 .7 10.4 

A 

3 'Layer 1, 0 to 30 millimeters .

ZLayer 2, 30 to 150 millimeters . 

v

m 

tv 

0 

rnm 

a

3

0

0 

N 
F

i 

Table 6. Moisture content and volatile solids, nutrient, and carbon concentrations in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri 

o and the Mississippi River flood plains 

m 

o+


0 [USGS, U.S . Geological Survey ; mg/kg, milligrams per kilogram ; N, nitrogen ; g/kg, grams per kilogram; MO, Missouri ; rep, replicate sample; MS, Mississippi ; -, no data. All analyses by the USGS
 0


laboratory, Arvada, Colorado, except as indicated] 

a 

Moisture content, 

in percent by weight Carbon 

r

N 

o Ammonia + 

USGS Enseco Solids, Nitrite + Ammonia organic Phosphorus, 

La Site no. labora- Analytical volatile nitrate as N as N nitrogen as total Total Organic Inorganic : (fig . 1) Date Time tory Laboratory (mg/kg) (mg/kg) (mg/kg) N (mg/kg) (mg/kg) (g/kg) (g/kg) (g/kg) 

3 Missouri River 

F1 

W	 M0.1 09-07-93 1040 26 29 28,700 9 3.9 800 440 11 8.4 2.6 

MO.2 09-07-93 1636 27 36 9,110 8 7.2 710 390 11 9.0 2.0 

MO.3 09-08-93 1125 30 36 74,600 20 5.2 2,300 760 23 22 .8 

e. 'MO.4 09-08-93 1605 37 28 68,400 18 6.3 1,900 760 21 20 1.0 

2M0.4 09-08-93 1610 7 8.3 6,750 7 3.2 70 210 25 .8 1.7 

3 

y 

y

y 

. MO.5 09-09-93 1315 35 23 46,000 41 7.5 1,100 620 51 50 

-a' MO.6 09-09-93 1820 37 26 73,800 33 6.8 2,100 750 21 20 

a 

MO.7 09-10-93 1000 26 24 34,500 16 7.6 1,200 560 13 12 1 .1 

MO.7 rep 09-10-93 1001 35 28 67,500 16 7.2 2,000 740 21 20 .9 

c MO.8 09-10-93 1415 38 32 65,000 23 4.2 2,100 740 18 16 1 .9 

0

d MO.9 09-10-93 1745 35 30 63,200 13 7.3 1,900 810 19 18 .6 

MO.10 09-11-93 1000 25 23 45,500 26 3.3 1,200 560 13 12 12 

MO.11 09-11-93 1415 26 33 32,700 30 13 940 560 12 10 1 .5 

MO.12 09-11-93 1730 30 36 30,600 31 14 800 550 14 11 2.6 

Mean 28 - 42,000 20 6.9 1,200 580 17 16 1 .5 

Standard deviation 8.2 - 22,000 10 3.5 670 180 12 12 .65 

Mississippi River 

MS. 1 09-18-93 1110 35 34 48,200 21 5 .8 2,200 680 24 22 2.3 

MS. 1 rep 09-18-93 1111 35 35 52,300 21 5 .3 2,000 660 22 20 2.3 

MS.2 09-18-93 1720 51 50 85,300 15 13 3,200 990 32 31 .8 

1.5 

1.3 

v 
Table 6. Moisture content and volatile solids, nutrient, and carbon concentrations in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri 

and the Mississippi River flood plains-Continued 

[USGS, U.S . Geological Survey ; mg/kg, milligrams per kilogram ; N, nitrogen; g/kg, grams per kilogram; MO, Missouri ; rep, replicate sample ; MS, Mississippi; -, no data . All analyses by the USGS 

laboratory, Arvada, Colorado, except as indicated] 

Moisture content, 

in percent by weight Carbon 

Ammonia + 

Site no. 

(fig . 1) Date Time 

USGS 

laboratory 

Enseco 

Analytical 

Laboratory 

Solids, 

volatile 

(mg/kg) 

Nitrite + 

nitrate as N 

(mg/kg) 

Ammonia 

as N 

(mg/kg) 

organic 

nitrogen as 

N (mg/kg) 

Phosphorus, 

total 

(mg/kg) 

Total 

(g/kg) 

Organic 

(g/kg) 

Inorganic 

(g/kg) 

Mississippi River-Continued 

a 

MS .3 09-19-93 1440 34 33 35,400 10 7.1 1,400 640 22 17 4.6 

MS .4 09-19-93 1845 50 48 91,500 19 8 .0 3,300 920 38 34 3 .6 

MS .5 09-20-93 0920 27 35 50,900 29 5 .6 1,600 690 18 16 1 .9 

MS.6 09-20-93 1730 48 51 64,900 15 60 2,600 790 25 25 .4 

MS .7 09-21-93 0940 48 42 77,600 14 8 .9 2,500 680 28 25 3 .0 

MS .7rep 09-21-93 0941 48 51 71,500 11 24 2,400 680 29 26 2.6 

MS .8 09-21-93 1545 26 28 43,000 47 9.7 1,400 310 15 14 1 .3 

MS .9 09-22-93 0830 32 33 50,900 44 6.2 1,300 610 14 12 2.4 

MS .10 09-22-93 1420 26 25 51,300 42 7.4 1,400 270 15 15 .2 

MS .11 09-24-93 0920 36 34 75,400 70 15 2,100 740 23 22 .9 

3 MS . 12 09-23-93 1120 31 33 71,700 140 24 1,900 850 21 20 .7 

w MS . 13 09-23-93 1525 28 28 27,500 39 7.8 1,700 460 10 8.3 1 .7 

m MS . 13 rep 09-23-93 1526 27 28 23,900 12 6.1 1,700 390 10 8.0 2.0 

Mean 36 - 60,000 39 14 2,000 660 22 20 1.8 

0 Standard deviation 9.6 - 20,000 35 15 680 220 78 7.4 1.3 

3


d Missouri and Mississippi Rivers


v
d
rt


c Mean 32 - 51,000 30 10 1,700 620 20 18 1.7 

Standard deviation 9.6 - 22,000 28 11 770 200 10 10 1.0 

'Layer 1, 0 to 30 millimeters. 

ZLayer 2, 30 to 150 millimeters. 

rtN 

J

V 
Table 9. Measured and expected concentrations of elements in standard reference material 

[GXR-2, U.S . Geological Survey (USGS) geochemical exploration sample ; GSD-6, geochemical reference sample from China; STD, standard deviation; 

wt . %, percent by weight; mg/kg, milligrams per kilogram ; -, no data ; ( ), concentration does not meet criteria for recommended concentrations ; L, 

detected at less than the lower reporting limit but not quantified ; AAS, atomic absorption spectrometry. All elements analyzed by inductively coupled 

plasma-atomic emission spectrometry unless otherwise noted. Analyzed at theUSGS laboratory, Lakewood, Colorado] 

GXR-2 concentrations GSD-6 concentrations 

Sodium

Split sample Split sample 

Element Unit Measured Measured Expected' STD1 Measured Measured Expected2 STD2 

Aluminum. . . . . . . .. . . . . . wt. % 6.3 6._5 18.57 0.06 7.6 7.6 7.49 

Calcium. . . . . . . . . . . .. . . . . . 

Iron . . .. . . . . . . . . . . . . . . .. . . . . . 

wt. % 

wt. % 

.91 .92 

1.9 1 .9 

.88 

1 .84 

.04 

.05 

2.8 2.8 

4.1 4.1 

2.77 

(4 .12) --

Magnesium . . . . . .. . . . . . 

Phosphorus . . . . . . .. . . . . . wt. % wt. % 

.79 .80 

.07 .07 

.88 

.068 

.02 

-

1 .8 1 .8 

.11 .11 

1 .81 

.10 -0.07 

Potassium . . . . . . . . .. . . . . . wt. % 1.4 1 .4 1 .36 .04 2.0 2.0 2.03 

. . . . . . . . . . . . .. . . . . . wt. % .59 .58 .54 .08 1 .7 1 .7 1 .71 -

Sulfur, total . . . . . .. . . . . . wt. % .051- .051- .0315 - .09 .10 ( .08) -

Titanium . . . . . . . . . . .. . . . . . wt. % .25 .25 .29 .O1 .40 .39 .46 .02 

Antimony . . . . . . . . .. . . . . . mg/kg 40 38 47 4 1 .6 1 .8 1 .25 .33 

Arsenic. . . . . . . . . . . . .. . . . . . mg/kg 24 23 21 4 15 16 13 .6 1 .5 

Arsenic, AAS. . .. . . . . . mg/kg 24 23 21 4 15 15 13 .6 1 .5 

Barium . . . . . . . . . . . . .. . . . . . mg/kg 2,200 2,200 2,210 160 310 310 330 40 

Beryllium . . . . . . . . .. . . . . . mg/kg 1.0 1 .0 1 .6 - 1 .0 1 .0 1 .7 .4 

Bismuth. . . . . . . . . . . .. . . . . . mg/kg IO .OL 10.01- .44 .1 IO.OL 10 .01- 5 .6 

Cadmium. . . . . . . . . .. . . . . . mg/kg 4.0 4.0 4.1 .04 2.OL 2.01- .43 .04 

Cadmium, AAS. . . . . . mg/kg 4.5 4.2 4.1 .04 .35 .39 .43 .04 

Cerium . . . . . . . . . . . . .. . . . . . mg/kg 50 50 50 - 70 67 68 8 

Chromium . . . . . . . .. . . . . . mg/kg 35 34 34 4 200 200 190 24 

Cobalt. . . . . . . . . . . . . . .. . . . . . mg/kg 10 9.0 9.0 1 .3 29 28 24 .4 3 

Copper. . . . . . . . . . . . . .. . . . . . mg/kg 82 84 70 6 410 410 383 18 

Europium . . . . . . . . .. . . . . . mg/kg 2.01- 2.01- .77 - 2.01- 2.OL 1.5 .13 

Gallium . . . . . . . . . . . .. . . . . . mg/kg 19 18 37 - 18 16 16 .7 .8 

Gold . .. . . . . . . . . . . . . . . . . . . . . mg/kg 8.01- 8.OL .046 1 .019 8.01- 8.OL - -

Holmium. . . . . . . . . . . . . . . . mg/kg 4.OL 4.OL - - 4.OL 4.OL ( .78) .17 

Lanthanum . . . . . . . . . . . . . mg/kg 27 29 25 3 38 37 39 8 

Lead . . . . . . . . . . . . . . . . . .. . . . . mg/kg 590 590 670 50 24 25 27 5 

Lithium . . . . . . . . . . . . . . . . . . mg/kg 64 63 48 - 44 44 40 2 

Manganese . . . . . . . . . . . . . mg/kg 1,000 1,000 980 40 970 970 970 60 

Mercury. . . . . . . . . . . . . . . . . . mg/kg 2.9 2.9 2.7 .6 .02 .02 .045 .008 

Molybdenum . . . . . . . . . . mg/kg 2.01- 2.01- 1 .5 .2 5.0 6.0 7.7 1 .2 

Neodymium . . . . . . . . . . . mg/kg 21 22 - - 32 30 33 6 

Nickel . . . . . . . . . . . . . . . . . . . . . mg/kg 19 19 20 4 84 83 78 7 

Niobium . . . . . . . . . . . . . . . . . mg/kg 10 11 9.0 - 12 11 12 4.6 

Scandium . . . . . . . . . . . . . . . mg/kg 6.0 6.0 7.2 - 16 16 17 1 .6 

Selenium . . . . . . . . . . . . . . . . mg/kg .7 .7 .57 .17 .3 .3 ( .3) .13 

Silver . . .. . . . . . . . . . . . . . . . . . . mg/kg 17 16 18 3 2.OL 2.OL .36 .04 

Silver, AAS . . . . . . . . . . . . mg/kg 19 19 18 3 .38 .36 .36 .04 

Strontium . . . . . . . . . . . . . . . mg/kg 160 160 152 16 280 280 266 28 

Tantalum . . . . . . . . . . . . . . . . mg/kg 40.OL 40.OL .78 - 40 .OL 40 .01- .72 .07 

Thorium . . . . . . . . . . . . . . . . . mg/kg 9.0 9.0 8.6 .2 9.0 8.0 9.0 2 

Tin. . . . . . . . . . . . . . . . . . . . . . .. . . mg/kg 5.OL 5.OL 1 .2 .4 5.OL 5.OL 2.8 1 

Uranium . . . . . . . . . . . . . . . . . mg/kg 100.OL 100.01- 1 .98 1 .25 l00.OL l00.OL 2.4 .5 

Vanadium . . . . . . . . . . . . . . . mg/kg 51 50 61 9 140 140 142 12 

Ytterbium. . . . . . . . . . . . . . . mg/kg 1 .0 1 .0 2 - 2.0 2.0 2.1 4 

Yttrium. . . . . . . . . . . . . . . . . . . mg/kg 15 15 19 - 20 20 20 .2 2.4 

Zinc . . . . .. . . . . . . . . . . . . . . .. . . mg/kg 550 550 460 30 140 140 144 10 

Carbon, total . . . . . . . . . . wt. % 2.9 2.8 2.5 .24 .93 .84 (1 .17) -

Carbon, organic. . . . . . wt. % 2.9 2.8 - - .40 .33 ( .62) -

Carbon, carbonate. . wt. % OIL .01 - - .53 .51 ( .55)

Carbon dioxide. . . . . . . wt. % .02 .04 - - 1 .9 1 .9 -

1 Gladney and others (1984) . 

2 Xie and Yan (1985) . 

18 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
22

Table 10. Estimated pesticide concentrations in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River flood 

plains 

[Concentrations in micrograms per kilogram . DDE, dichlorodiphenyldichloroethylene ; MO, Missouri ; <, less than ; -, no data ; dup, laboratory duplicate sample ; rep, field replicate sample ; blank, blank 

sample ; n.a ., not applicable ; MS, Mississippi. Analyzed at the U.S . Geological Survey laboratory, Arvada, Colorado] 

Site no. Desethyl­

(fig .1) Alachlor Atrazine 4,4'-DDE atrazine Dieldrin Metolachlor Simazine Trifluralin 

Missouri River 

MO. 1 2.0 4.2 <4.0 <1 .2 6.2 3.2 - 5.1 

MO.2 6.9 6.0 .65 <1 .2 7.1 5.1 - 5.5 

1 MO.4 .80 7.8 .77 <1 .2 4.4 3.3 - 4.8 

'MOA <3 .6 <6.8 <4.0 <1 .2 <3.2 <3.6 - <4.8 

-MOAdup <3 .6 <6.8 <4.0 <1 .2 <3.2 <3.6 - <4.8 

MO.5 3 .6 6.0 1 .6 <1 .2 3.9 4.2 - 5.1 

MO.7 4.6 6.0 2.5 <1 .2 5.6 4.4 - 6.0 

MO.7 rep 3 .8 4.6 3.6 <1 .2 5.2 3.5 - 7.6 

MO.8 18 10 .64 2.9 3.6 9.9 - 4.8 

MO.10 2.6 7.6 .36 <1 .2 2.5 6.8 - <4.8 

MO.11 12 9.5 .87 <1 .2 <3.2 5.6 - 5.4 

MO blank <3.6 <6.8 <4.0 <1 .2 <3.2 <3.6 - <4.8 

Mean 6.3 7.1 1 .2 n.a . 4.8 5.3 n.a. 4.9 

Standard deviation 5.9 2.0 .76 n.a . 1.6 2.2 n.a. 1 .1 

3 Mississippi River

CL 

MS . 1 9.5 <6.8 0.93 <1 .2 <3.2 3.4 6.4 <4.8 

3 MS . 1 rep 11 <6.8 <4.0 <1 .2 <3.2 4.1 6.4 <4.8 

MS.3 40 <6.8 1 .1 <1.2 <3.2 6.1 <3.2 <4.8 

d MS.5 54 9.1 .96 <1 .2 <3.2 7 .5 <3.2 4.9 

m MS.7 0 27 6.7 .94 <1.2 <3.2 4.3 <3.2 <4.8

MS.7 rep 2 6.8 1.2 <1 .2 <3.2 4.2. . <3.2 <4.8

a 

3 

m 

N 

ID 

v 

c 
3 

y 

O

N Table 10. Estimated pesticide concentrations in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River flood 

plains-Continued 

v 

°: [Concentrations in micrograms per kilogram DDE, dichlorodiphenyldichloroethylene ; MO, Missouri ; <, less than ; -, no data; dup, laboratory duplicate sample ; rep, field replicate sample ; blank, blank
 m
0 sample ; n.a., not applicable; MS, Mississippi. Analyzed at the U.S . Geological Survey laboratory, Arvada, Colorado]


to 

o. Site no. Desethyl3 (fig.1) Alachlor Atrazine 4,4'-DDE atrazine Dieldrin Metolachlor Simazine Trifluralin 

rn Mississippi River-Continued 

0 

MS.9 4.2 9.1 0.32 <1 .2 <3.2 4.1 <3 .2 5.9 

MS.11 3.2 5.1 <4.0 <1 .2 <3.2 2.9 <3 .2 <4.8 m 

a MS,11 dup 2,9 4.6 .69 <1 .2 <3.2 2.8 <3 .2 4.9 

.* MS. 13 <3 .6 4.2 .48 <1 .2 <3.2 1.9 <3 .2 18 

MS . 13 rep <3 .6 4. .. .47 <1 . . . <3.2 1 .9 <3 . .. 13 

0 

MS blank <3 .6 <6.8 <4.0 <1 .2 <3.2 <3.6 <3 .2 <4.8 

c 

10 Mean 20 5.8 .96 n.a . n.a. 4.3 n.a . n.a . 

°' Standarddeviation ')1 2.5 .54 n.a . n.a. 1 .9 n.a . n.a . 

0 

Missouri and Mississippi Rivers 

y

w Mean 13 6.5 1 .1 n.a . n.a. 4.8 n.a . n.a . 

' Standard deviation 16 2.2 .66 n.a . n.a. 2.1 n.a . n.a . a 

Standard reference material 

Measured <3 .6 <6.8 9.1 <1.2 <3.2 <3.6 <3.2 <4.8 

0

v 

Expected - - 9.71 - - - - - 0

c 

0. 'Layer 1, 0 to 30 millimeters. 

d Layer 2, 30 to 150 millimeters. 

N 3Noncertified concentration. 
Atrazine and DDE were detected in 13 samples . Desethylatrazine was detected only in one sample . Dieldrin was detected in seven samples, all of which were 

from the Missouri River flood-plain sites . Metolachlor 

was detected in 15 samples. The Missouri River floodplain site samples were not analyzed for simazine, and 

only one Mississippi River site (MS. 1) had a concentration that was larger than the detection or reporting 

limit. Trifluralin was detected in 10 samples. 

Semivolatile Organic Compound 

Concentrations 

Sediment samples were analyzed for semivolatile organic compounds by two laboratories . None of 

these compounds were detected by the Enseco Analyt 

ical Laboratory, which used USEPA analytical methods. However, the compounds were detected in the. 

same samples by the USGS laboratory in Arvada, 

which used analytical methods that have lower detection limits than the methods used by Enseco . Eight 

semivolatile organic compounds were detected in sediment samples from eight sites in the Missouri River 

flood plain (table 11, which follows the "References 

Cited" section) . Twenty-five semivolatile organic compounds were detected in samples from 7 sites in the 

Mississippi River flood plain (table 12, which follows 

the "References Cited" section) ; concentrations of the 

compounds detected in these samples ranged from 23 

l,tg/kg of 2,6-dimethylnaphthalene at MS.5 and MS. 1 I 

and 2-ethylnaphthalene at MS .3 to 270 [tg/kg of 

fluoranthene at MS.3 . The number of compounds 

detected per site ranged from 5 to 24. 

Identification of unknown organic compounds 

that were detected in the GC/MS analysis is presented 

in table 13, which follows the "References Cited" sec 

tion . The siloxane compound group is present in silicon-based grease in the sampling or laboratory 

equipment, but is not present in the sediment . In the 

Missouri River flood-plain samples, l l compounds and 

4 compound groups were identified, and in the Mississippi River flood-plain samples, 29 compounds and 7 

compound groups were identified . 

SUMMARY AND CONCLUSIONS 

Floodwaters inundated the Missouri and Mississippi River flood plains during July and August 1993 as 

a result of peak discharges that exceeded 100-year 

recurrence intervals at streamflow-gaging stations. 

Sediments transported by the floodwaters were deposited in varying thicknesses in the inundated areas. 

Because the sediments were thought to contain elevated concentrations of nutrients and trace elements, 

the U.S . Geological Survey collected sediment samples 

at 25 sites in the Missouri and the Mississippi River 

flood plains . The. samples were analyzed for physical 

properties and chemical constituents that included particle-size distribution, water content, volatile solids, 

nutrients, carbon, selected trace elements, pesticides, 

and semivolatile organic compounds. 

Postflood sediment samples consist primarily of 

silt and clay ; sand ranged from 0 to 28 .4 percent by 

weight in the samples. Moisture content ranged from 7 

to 51 percent by weight . Volatile solids concentrations 

ranged from 6,750 to 91,500 milligrams per kilogram . 

Total carbon was present predominantly as organic carbon in postflood samples . Several pesticides commonly 

applied to cropland were detected in samples from several sites. Alachlor was detected in 14 samples; the 

largest concentration detected was 54 micrograms per 

kilogram . Atrazine and 4,4'-DDE were detected in 13 

samples. Dieldrin was detected in seven samples, all 

from the Missouri River flood plain. Metolachlor was 

detected in 15 samples. Eight semivolatile organic 

compounds were detected in samples from 8 sites in 

the Missouri River flood plain; 25 semivolatile organic 

compounds were detected in samples from 7 sites in 

the Mississippi River flood plain. 

REFERENCES CITED 

Arbogast, B.F., ed., 1990, Quality assurance manual for the 

Branch of Geochemistry, U.S . Geological Survey : U.S . 

Geological Survey Open-File Report 90-668, 184 p. 

Fishman, M.J ., ed., 1993, Method of analysis by the U.S . 

Geological Survey National Water Quality Laboratory-Determination of inorganic and organic constituents in water and fluvial sediments: U.S . Geological 

Survey Open-File Report 93-125, 217 p. 

Fishman, M.J ., and Friedman, L.C ., eds., 1989, Methods for 

determination of inorganic substances in water and fluvial 

sediments: U.S . Geological Survey Techniques of Water 

Resources Investigations, book 5, chap . A1, 545 p. 

Guy, H.P., 1969, Laboratory techniques and methods for sediment analysis : U.S . Geological Survey Techniques of 

Water-Resources Investigations, book 5, chap. C1, 58 p. 

Gladney, E.S ., Burns, C.E ., and Roelandts, I., 1984, 1982 

compilation of elemental concentration data for the 

United States Geological Survey's geochemical exploReferences Cited 21 
ration reference samples GXR-1 to GXR-6: Geostandards Newsletter, v. 8, no. 2, p. 119-154. 

Horowitz, A.J ., 1991, A primer on sediment-trace element 

chemistry (2d ed.) : Chelsea, Mich., Lewis Publishers, 

136 pNational Institute of Standards and Technology, 1990, Certificate of analysis, standard reference material 1941 : 

Office of Standard Reference Materials, 11 p. 

O'Leary, R.M., and Viets, J.G., 1986, Determination of antimony, arsenic, bismuth, cadmium, copper, lead, molybdenum, silver, and zinc in geological materials by 

atomic absorption spectrometry using a hydrochloric 

acid-hydrogen peroxide digestion: Atomic Spectroscopy, v. 7, p. 4-8. 

Parrett, Charles, Melcher, N.B., and James, R.W, Jr., 1993, 

Flood discharges in the Upper Mississippi River Basin, 

1993: U.S . Geological Survey Circular 1120-A, 14 p. 

U.S .	 Army Corps of Engineers, 1970, Grain-size analyses, 

appen. V of Engineer manual-Laboratory soils testing, engineering and design : U.S . Army Corp of Engi 

neers, EM 1110-2-1906, 28 p. 

U.S .	 Environmental Protection Agency, 1986, Test methods 

for evaluating solid waste, v. 1B ofLaboratory manual 

physical/chemical methods (3d ed.) : Office of Solid 

Waste and Emergency Response, SW-846, p. 8080-

1-8080-27 and 8270-1-8270-34 . 

Wershaw, R.L., Fishman, M.J ., Grabbe, R.R., and Lowe, 

L.E., eds ., 1987, Methods for the determination of 

organic substances in water and fluvial sediments : U.S . 

Geological Survey Techniques of Water-Resources 

Investigations, book 5, chap. A3, 80 p. 

Xie, Xuejing, and Yan, Mingcai, 1985, Geochemical reference samples, drainage sediment GSD 1-8 from China: 

Geostandards Newsletter, v. 9, no. 1, p. 83-159. 

22 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
EXPLANATION OF TABLE 7 

ABBREVIATIONS AND REPORTING UNITS FOR CHEMICAL CONSTITUENTS AND NOTATIONS USED IN 

TABLE 

wt. % Percent by weight


mg/kg Milligrams per kilogram


4N HCl 4 normal hydrochloric acid (conditionally available fraction)


O.1N HCl 0.1 normal hydrochloric acid (available fraction)


AAS Atomic absorption spectrometry


CVAAS Cold-vapor atomic absorption spectrometry


DN Delayed neutron activation


�Carbon C02
 dioxide 

MO Missouri 

MS Mississippi 

rep Replicate sample 

dup Duplicate sample 

- No data 

N Not detected at the lower reporting limit 

L Detected at less than the lower reporting limit but not quantified 

All elements analyzed by inductively coupled plasma-atomic emission spectrometry except where noted. Analyzed at 

the U.S . Geological Survey laboratory, Lakewood, Colorado. 
a Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains 

rt 

Aluminum Calcium Iron Magnesium

O1 

Site no. Total 4N HCI OAN HCI Total 4N HCI OA N HCI Total 4N HCI OA N HCI Total 4N HCI 0 .1 N CI 

m 

a (fig . 1) (wt . %) (mg/kg) (mg/kg) (wt . %) (mg/kg) (mg/kg) (Wt. %) (mg/kg) (mg/kg) (Wt . %) (mg/kg) (mg/ g) 

Missouri River m 

m MO.1 5.1 4,300 360 1 .4 1,000 8,000 1 .8 8,600 620 0 .65 1,900 1,900 

MO.2 5 .7 5,500 480 1 .5 1,400 10,000 2 .3 11,000 860 .77 2,300 2,100 

'o MO.3 6.8 12,000 1,000 12 1,000 8,600 3 .4 19,000 1,600 .84 3,000 1,600 

1 MO.4 4.9 3,900 350 1 .2 760 7,000 1 .6 7,800 660 .51 1,500 1,400 

Z MOA 4.3 - - 2 .0 - - 2 .1 - - .79 - - 0. 

MO.5 5 .6 5,600 510 1 .1 820 7,600 2 .4 11,000 710 .57 1,700 1,200 

MO.6 7.9 9,100 1,400 1 .3 1,000 10,000 4 .3 15,000 1,900 1 .0 2,500 1,400 

MO.7 5 .3 5,600 430 1 .3 960 8,400 2 .0 9,900 850 .62 2,100 1,400 

ca MO.7 rep 5 .3 5,700 390 1 .3 1,000 7,800 1 .9 10,000 740 .59 2,200 1,300 W

0

c MO.7 rep 5 .3 4,900 400 1 .3 100 8,100 1 .9 9,100 730 .59 1,900 1,400 

d M0.8 7 .4 15,000 1,400 1 .1 1,100 8,700 3 .9 22,000 1,400 .92 3,400 1,600 

a MO.9 

MO.10 

7 .9 

5 .1 

19,000 

5,800 

1,300 

400 

1 .1 

1 .0 

1,200 

820 

8,700 

5,700 

4.3 

1 .8 

29,000 

10,000 

1,700 

650 

1 .0 

.54 

4,200 

2,000 

1,700 

1,200 

MO.11 5 .8 7,900 600 1 .2 1,000 7,600 2 .4 14,000 940 .69 2,700 1,500 

MO.12 5 .6 7,100 570 1 .3 1,200 8,400 2 .2 13,000 590 .71 2,700 1,700 N 

LA. 

Mississippi River 

N 

v, MS.1 5 .1 5,900 580 1 .4 810 7,900 2 .6 13,000 2,200 0.69 1,800 2,400 

7p MS. 1 rep 5 .1 5,600 610 1 .4 790 8,800 2 .5 13,000 2,100 .70 1,700 2,600 

MS.2 6 .6 10,000 980 1 .0 740 6,800 3 .7 20,000 2,100 .77 2,600 1,700 

0 MS.3 4.7 4,600 450 1 .7 1,200 10,000 2.0 10,000 1,400 .70 1,700 2,900 

0 

0' MS.4 5 .8 8,500 780 2 .0 1,300 15,000 3.1 17,000 1,600 .80 2,300 2,400 

Lb. 

N MS.6 

MS.7 

6 .1 

5.2 

6.0 

9,000 

6,000 

8,800 

710 

440 

790 

1 .0 

.8 

1 .5 

680 

440 

1,100 

7,000 

4,400 

12,000 

3 .0 

2.1 

3 .0 

16,000 

10,000 

17,000 

1,700 

650 

2,100 

.64 

.38 

.70 

2,000 

1,200 

2,200 

1,400 

450 

2,000 

MS.7 rep 5.9 8,000 740 1 .6 1,000 12,000 3 .0 15,000 2,000 .70 2,000 1,900 

MS.7 dup 5.9 7,500 730 1 .6 920 12,000 3 .0 14,000 1,800 .70 1,800 2,000 

MS.8 4.8 5,000 430 .9 430 5,300 1 .6 7,700 440 .38 960 780 

MS.9 5.9 8,100 480 1 .3 1,100 8,300 2 .4 15,000 700 .73 2 .900 1,600 

MS.10 4.6 4,300 320 .7 290 2,300 1 .5 7,000 430 .34 1,100 340 

MS.11 6.3 8,300 720 1 .3 1,100 9,300 2 .9 15,000 1,400 .77 2,500 1,700 

MS.12 6.7 10,000 940 1 .3 1,100 9,600 3 .7 18,000 1,700 .88 2,800 1,800 

MS.13 4.9 3,800 350 1 .3 890 7,400 1 .7 8,000 610 .57 1,600 1,800 

MS. 13 rep 4.8 4,100 390 1 .3 950 8,100 1 .7 8,500 620 .57 1,700 1,900 

MS. 1 dup 5 .1 5,600 560 1 .4 850 8,100 2 .5 13,000 1,900 .69 1,800 2,400 

MS. 13 dup 4.9 3,800 340 1 .3 970 7,100 1 .7 8,000 500 .58 1,600 1,700 
Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Phosphorus Potassium Sodium Sulfur, Titanium


total,


combus-


Site no. Total 4N HCI 0.1 N HCI Total 4N HCI OA N HCI Total 4N HCI 0.11N HCI tion Total 4N HCI


(fig . 1) (wt . %) (mg/kg) (mg/kg) (wt . %) (mg/kg) (mg/kg) (Wt . %) (mg/kg) (mg/kg) (Wt . %) (wt. %) (mg/kg)


OAN HCI 

(mg/kg) 

Missouri River 

MO.1 0.07 150 260 1 .8 420 7 .5N 1 .1 42 25 0.05L 0.25 89 0 .82


MO.2 .08 230 250 1 .8 620 75N .97 40 32 .05L .27 74 .79


MO.3 .10 500 130 1 .8 1,400 120 .74 54 51 .05L .30 120 1 .8


1 MOA .06 150 260 1 .7 290 7 .5N 1 .1 31 34 .05L .24 69 .91


ZMOA .09 - - 1 .6 - - 1 .2 - - .05L .57 - -

MO.5 .07 230 180 1 .7 440 7 .5N .89 30 43 .05L .26 61 .71


MO.6 .11 360 95 2.0 1,400 460 .47 35 61 .06 .31 64 2 .0


MO.7 .07 200 280 1 .9 700 7.5N 1 .1 35 26 .05L 24 90 .85


MO.7 rep

MO.7 dup 

.07 

.07 

160 

190 

300 

300 

1 .8 

1 .9 

750 

580 

7 .5N 1 .1 

7 .5N 1 .1 

38 

34 

24 

21 

.05L 

.05L 

.24 

24 

110 

78 

1 .4


1 .1


MO.8 .10 450 120 1 .9 1,800 290 .61 49 60 .05L .31 140 22


MO.9 .11 490 120 1 .9 2,400 300 .52 46 73 .05 .32 170 2 .5


MO.10 .06 170 260 1 .8 680 7 .5N 1 .1 38 25 .05L 24 89 1 .6


MO.11 .08 320 260 1 .9 1,100 7 .5N .99 41 32 .05L .25 120 1 .7


MO. 12 .08 210 280 1 .9 1,100 7 .5N 1 .1 58 54 .05L .23 120 1 .4


Mississippi River 

MS.1 0.10 450 180 1 .8 94 7 .5N 1 .0 28 28 0.05L 0.25 150 5 .2


MS.] rep 

MS. 1 dup

MS.2 

.09 

.09 

.14 

430 

480 

750 

190 

200 

140 

1 .8 

1 .7 

1 .8 

68 

64 

670 

7 .5N 1 .0 

7 .5N .98 

7 .5N .70 

25 

22 

27 

35 

33 

33 

.05 

.05 

.06 

.25 

24 

.30 

140 

120 

190 

4 .9 

3 .8


6 .5


MS.3 .08 360 190 1 .6 43 7 .5N 1 .0 16 16 .05L .25 110 3 .8


MS.4 .12 620 130 1 .7 430 7 .5N .74 22 30 .08 .28 170 4 .0


MS.5 .11 550 150 1 .6 550 7 .5N .69 17 13 .05 .28 1,100 2 .9


MS.6 .08 250 240 1 .6 390 7 .5N .80 9.5 6.7 .05L .28 57 1 .2


MS.7 .09 480 96 1 .7 490 7 .5N .74 20 33 .08 .29 150 5 .1


MS.7 rep .09 410 87 1 .7 400 7 .5N .76 20 32 .09 .26 130 5 .4


MS.7 dup 

MS.8 

.09 

.04 

430 

170 

86 

60 

1 .7 

1 .8 

340 

170 

7 .5N .76 

7 .5N .80 

21 

13 

43 

23 

.09 

.05L 

.25 

.25 

120 

58 

3 .8


1 .7


MS.9 .07 290 210 1 .9 1,100 7 .5N .94 49 33 .05L .27 120 1 .5


MS.10 .04 150 77 1 .8 430 7 .5N .96 19 20 .05L .26 89 2 .6


Ms. 11 .09 410 170 1 .8 940 7 .5N .81 32 32 .05 27 110 2 .0


MS.12 .11 530 130 1 .8 1,100 33 .66 37 44 .05 .32 120 2 .5


MS.13 .07 180 290 1 .7 220 7 .5N 1 .1 28 21 .05L .25 74 1 .3


MS. 13 rep .07 180 310 1 .7 270 7 .5N 1 .1 30 21 .05L 29 84 1 .4


MS. 13 dup .07 200 310 1 .7 210 7 .5N 1 .1 27 33 .05L .27 73 1 .3

Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

n 

Antimony Arsenic Barium 

0

' 

Total, Total, 4N HCl, O.1N HCl, 

Site no. AAS 4N HCI 0.1N HCI Total 4N HCl 0.1N HCl AAS AAS AAS Total 4N HCI 0.1N HCI 

m (fig . 1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

3 Missouri River m 

a 

0 Mo. 1 0.8 6.3N 6.3N IOL 3.8N 3 .8N 7.2 3.6 1.2 760 69 62 

0

0 MO.2 .8 6.3N 6.3N 10 3.8N 3 .8N 10 4.3 1.9 770 83 93 

MO.3 .9 6.3N 6.3N 14 3.8N 3 .8N 14 8.8 1 .5 760 100 140 

0 'MO.4 .5 6.3N 6.3N IOL 3.8N 3 .8N 6.4 2.9 1 .3 700 53 62 

'MO.4 .6 - - IOL - - 4.9 - - 1,100 - -

' MO.5 .7 6.3N 6.3N IOL 3.8N 3.8N 9.0 4.6 .9 670 61 94 

MO.6 1.1 6.3N 6.3N 18 6.9 3.8N 19 6.9 2.0 770 84 190 

MO.7 .9 6.3N 6.3N IOL 3.8N 3.8 8.2 3.3 1 .9 740 67 80 

w MO.7 rep .6 6.3N 6.3N IOL 3.8N 3.8N 8.0 3.5 1 .6 730 69 70 

0 MO.7 dup .8 6.3N 6.3N IOL 3.8N 3.8N 8.1 3.2 2.1 730 65 72 c 

d MO.8 1 .4 6.3N 6.3N 17 4.2 3.8N 16 9.4 1 .6 760 110 180 

' a MO.9 1 .2 6.3N 6.3N 22 3.9 3.8N 18 11 1 .8 750 120 190 

MO.10 .5 6.3N 6.3N IOL 3.8N 3.8 7.0 3 1 .7 710 70 72 

to MO.11 .8 6.3N 6.3N 10 4.0 3.8N 9.8 5.0 2.0 770 83 110 

MO.12 .7 6.3N 6.3N IOL 3.8N 3.8N 9.0 4.7 1 .6 790 81 88 

y

T). 

y Mississippi River 

v Ms. 1 0.4 6.3N 6.3N IOL 3 .8N 3.8N 6.4 3.1 1 .1 580 31 67 

7p MS. 1 rep 

MS. 1 dup 

.5 

.5 

6.3N 

6.3N 

6.3N 

6.3N 

IOL 

IOL 

3 .8N 

3 .8N 

3.8N 

3.8N 

6.0 

6.2 

2.9 

2.4 

1 .0 

1 .0 

580 

570 

30 

30 

70 

64 

MS.2 .7 6.3N 6.3N 11 3.8N 3.8N 11 2.7 1 .0 670 57 130 

0

0 

MS.3 1 .0 6.3N 6.3N IOL 3.8N 3.8N 4.9 2.1 .7 550 24 51 

MS.4 1 .0 6.3N 6.3N IOL 3.8N 3.8N 7.6 2.0 .7 600 44 98 

iu MS.5 .9 6.3N 6.3N 10 3.8N 3.8N 9.4 4.3 1 .0 650 63 130 

MS.6 .6 6.3N 6.3N IOL 3.8N 3.8N 5.0 1 .8 .6 590 39 110 

y MS.7 1 .0 6.3N 6.3N IOL 3.8N 3.8N 6.8 2.8 .6 610 58 110 

MS.7 rep .8 6.3N 6.3N IOL 3.8N 3.9 6.8 2.7 .7 610 60 92 

MS.7 dup .9 6.3N 6.3N 10L 3.8N 3.8N 6.5 1 .9 .6 610 63 90 

MS.8 .7 6.3N 6.3N 10L 3.8N 4.0 4.5 1 .6 .4 580 32 75 

MS.9 1.0 6.3N 6.3N 11 4.8 4.8 9.5 5.7 1.3 770 91 93 

MS.10 .5 6.3N 6.3N IOL 3.8N 3.8N 4.3 1 .7 .3 650 37 77 

Ms.] 1 1.1 6.3N 6.3N 13 3.8N 3.8N 11 4.0 1.7 720 85 120 

MS. 12 1 .3 6.3N 6.3N 15 3.8N 3.8N 14 6.3 1.4 720 91 140 

MS. 13 .7 6.3N 6.3N IOL 3.8N 3.8N 5 .6 2.2 1 .0 710 59 56 

MS. 13 rep .8 6.3N 6.3N IOL 3.8N 3.8N 5 .9 2.6 1.1 700 69 61 

MS. 13 dup .7 6.3N 6.3N IOL 3.8N 3.8N 5 .9 1 .4 1.0 710 62 54 
Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Beryllium Bismuth Cadmium Cerium 

Total, 

Site no. Total 4N HCI O.1N HCI Total 4N HCI O.1N HCI Total 4N HCI O.1N HCl AAS Total 4N HCI O.1N HCI 

(fig . 1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River 

MO. 1 1 .0 0.056 0.16 IOL 7.5N 7.5N 2L 0.5N 0.5N 0.56 59 5.ON 5.ON


MO.2 1 .0 .084 .24 IOL 7.5N 7.5N 2L .5N .5N .37 70 5.ON 5.ON


MO.3 2.0 .17 .45 IOL 7.5N 7.5N 2L .5N .5N .48 75 5 .ON 10


1 MOA 1 .0 .048 .15 IOL 7.5N 7.5N 2L .5N .5N .22 59 5.2 5.ON 

Z MOA 1 .OL - - IOL - - 2L - - .14 140 - -

MO.5 1 .0 .12 .28 IOL 7.5N 7.5N 2L .5N .5N .35 69 5.4 5.ON


MO.6 2.0 .20 .61 IOL 7.5N 7.5N 2L .5N .5N .56 70 5.ON 6.0


MO.7 1 .0 .084 .21 10L 7.5N 7.5N 2L .5N .5N .32 59 5.ON 5.ON


MO.7 rep 

MO.7 dup 

1 .0 

1 .0 

.083 

.060 

.19 

.20 

IOL 

10L 

7.5N 

7.5N 

7.5N 2L 

7.5N 2L 

.5N 

.5N 

.5N 

.5N 

.27 

.29 

57 

54 

5.ON 

5.ON 

5.9


5.ON


MO.8 2.0 .25 .53 IOL 7.5N 7.5N 2L .5N .5N .51 74 5.ON 6.3


MO.9 2.0 .25 .59 IOL 7.5N 7.SN 2L .5N .SN .50 79 5.ON 5.8


MO.10 1 .0 .089 .20 IOL 7.5N 7.5N 2L .5N .5N .25 60 5.ON 5.ON


MO.11 1 .0 .084 .27 IOL 7.5N 7.5N 2L .5N .SN .37 62 5.ON 5.ON


MO. 12 1 .0 .099 .24 IOL 7.5N 7.5N 2L .5N .5N .34 55 5.ON 5.ON


Mississippi River 

Ms. 1 1 .0 0.025N 0.22 IOL 7.5N 7.5N 2L 0.SN 0.SN 0.37 54 5.ON 7.5


MS. I rep 

MS. 1 dup 

MS.2 

1.0 

1 .0 

1 .0 

.025N 

.025N 

.064 

.24 

.23 

.43 

l OL 

IOL 

IOL 

7.SN 

7.5N 

7.5N 

7.SN 2L 

7.SN 2L 

7.SN 2L 

.5N 

.5N 

.5N 

.5N 

.5N 

.5N 

.40 

.37 

.40 

53 

51 

73 

5.ON 

5.ON 

5.ON 

7.3


5.ON


12


MS.3 1 .OL .025N .17 10L 7.SN 7.SN 2L .5N .5N .35 58 5.ON 5.ON


MS.4 1.0 .025N .33 10L 7.5N 7.5N 2L .SN .SN .66 62 5.ON 5.ON


MS.5 1.0 .063 .39 IOL 7.5N 7.5N 2L .5N .5N .27 67 5.ON 5.ON


MS.6 1.0 .092 .34 IOL 7.5N 7.5N 2L .5N .5N .25 67 6.7N 5.ON


MS.7 1.0 .059 .39 IOL 7.5N 7.5N 2L .5N .5N .49 64 5.ON 5.ON


MS.7 rep 1 .0 .053 .36 IOL 7.5N 7.5N 2L .5N .5N .52 61 5.ON 6.7


MS.7 dup 

MS.8 

1 .0 

1 .0 

.030 

.082 

.37 

.31 

IOL 

IOL 

7.5N 

7.5N 

7.5N 2L 

7.5N 2L 

.SN 

.5N 

.5N 

.5N 

.51 

.18 

65 

60 

5.ON 

5.4 

5.ON


12


MS.9 1 .0 .11 .26 10L 7.5N 7.5N 2L .SN .5N .35 63 5.ON 7.5


MS.10 1 .OL .061 .20 10L 7.5N 7.5N 2L .5N .55 .36 57 5.ON 12


MS.11 1 .0 .11 .37 IOL 7.5N 7.5N 2L .5N .5N .50 69 5.ON 5.ON


MS.12 2.0 .14 .46 IOL 7.5N 7.5N 2L .5N .5N .61 71 5.ON 10


MS.13 1 .0 .027 .16 IOL 7.5N 7.5N 2L .5N .5N 24 73 5.ON 5.ON


MS. 13 rep 1 .0 .026 .16 IOL 7.5N 7.5N 2L .5N .5N .26 73 5 .ON 5.ON


MS. 13 dup 1 .0 .040 .16 IOL 7.5N 7.5N 2L .5N .5N .25 76 5 .ON 5.3

y 

" Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

GalChromium Cobalt Copper 

o. 

Site no. 

(fig . 1) 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

OA N HCI 

(mg/kg) 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

0.1 N HCI 

(mg/kg) 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

OA N HCI 

(mglkg) 

Europium, 

total 

(mg/kg) 

lium, 

total 

(mg/kg) 

Gold, 

total 

(mg/kg) 

Holmium, 

total 

(mg/kg) 

Missouri River 

3 

0	 MO. 1 40 5 .2 1 .5N 8 1 .3 1 .7 11 3 .1 3 .5 2 .01- 11 8 .OL 4 .01-

MO.2 50 4.8 1 .5N 10 2 .6 1 .3N 17 4 .4 5 .7 2 .OL 12 8 .OL 4 .OL 

0 MO.3 65 9.6 1 .5N 15 3 .4 2 .2 25 8 .3 8 .6 2 .01- 16 8 .OL 4 .OL w 'MOA 35 4.1 1 .5N 8 2 .0 1 .6 10 2 .5 2 .7 2.01, 10 8 .OL 4 .OL co Z MOA 55 - - 7 - - 7 - - 2 .01, 10 8 .01- 4 .OL e. 

w MO.5 51 5 .1 1 .5N 11 2 .3 1 .8 15 4.8 4 .4 2.01- 14 8 .OL 4 .OL 

eo MO.6 82 7 .1 1 .5N 16 2 .3 3 .2 31 8 .2 10 2.01- 21 8 .01- 4 .OL

MO.7 41 4.9 15N 9 1 .7 1 .4 14 3.7 4 .7 2.01- 12 8 .OL 4 .OL 

MO.7 rep 42 5 .8 1 .5N 9 1 .8 1 .8 14 3.6 4 .1 2.01- 12 KOL 4 .OL

0 MO.7 dup 40 5 .6 15N 8 1 .5 1 .4 14 3.7 4 .2 2.OL 11 8 .OL 4 .OL c 

y MO.8 73 12 1 .5N 16 3 .6 2.7 29 11 8 .6 2.01- 19 8 .OL 4 .01-

a MO.9 81 13 1 .5N 17 3 .9 2.3 31 13 9 .4 2.01- 19 8 .01- 4.OL 

MO.10 40 6.5 1 .5N 9 1 .7 1 .4 12 4.1 3.6 2 .01- 11 KOL 4.OL m MO.11 47 6.7 1 .5N 11 3 .2 1 .3 17 6.2 4.9 2.OL 13 KOL 4.OL 

0 

MO.12 43 6.9 1 .5N 10 2 .9 2.0 16 6.2 4.2 2 .OL 13 8 .OL 4.OL 

y


'a MS. 1 50 9.3 1 .5N 11 2 .0 1 .3N 16 3 .2 4.8 2 .OL 11 KOL 4.01-

Iq MS. 1 rep

MS. 1 dup 

49 

48 

8.4 

9.3 

1 .5N 

1 .5N 

11 

11 

2 .2 

1 .9 

1 .3N 

1 .3N 

16 

16 

3 .2 

3 .4 

5 .3 

4.6 

2.OL 

2 .01-

l 1 

11 

KOL 

8 .OL 

4.OL

4.OL 

MS.2 67 11 1 .5N 15 2 .1 3 .0 25 7 .6 8 .4 2 .01- 16 8 .OL 4.OL 

0

0 

MS .3 43 6.8 1 .5N 8 N1 .3 1 .3 14 3 .9 5 .2 2.01- 10 8 .OL 4.OL

°' 

iv 

MS.4 

MS.5 

62 

60 

11 

8 .6 

1 .5N 

1 .5N 

12 

12 

2 .2 

2 .5 

1 .8 

1 .6 

21 

22 

6 .1 

6 .5 

6.4 

6.6 

2.OL 

2 .OL 

14 

13 

8 .OL 

8 .OL 

4.OL 

4.OL 

w MS.6 

MS.7 

47 

59 

6.6 

9 .5 

1 .5N 

1 .5N 

8 

12 

1 .7 

2 .1 

1 .3N 

2 .2 

17 

21 

4.8 

5 .6 

5 .1 

8 .1 

2 .OL 

2 .OL 

12 

13 

8 .OL 

8 .OL 

4.01-

4.OL 

MS.7 rep 57 9 .5 1 .7 12 2.5 2 .8 20 5.5 7 .5 2.01- 13 8 .01- 4.OL 

y Mississippi River


MS.7 dup 59 9 .2 1 .6 12 2 .5 2 .8 21 5.2 7 .2 2.01- 13 8 .OL 4.OL 

MS.8 40 6 .3 1 .5N 6 1 .4 1 .3N 15 4.0 4 .5 2.OL 11 8 .OL 4.OL 

MS.9 52 8 .5 1 .5N 11 2.9 2.2 18 6.6 5 .4 2.01, 14 8 .OL 4.OL 

MS.10 38 4 .2 1 .6 7 2.1 1 .7 14 3.3 3 .6 2.01, 9 8 .01, 4 .01-

Ms.11 59 8 .2 1 .5N 12 3 .1 2.5 21 6.5 7 .6 2.01- 15 8 .01- 4 .01-

MS.12 74 9 .6 1 .6 15 3 .3 3.4 26 7.7 9 .2 2.01- 19 8 .OL 4 .OL 

MS. 13 43 4.6 1 .5N 7 1 .7 1 .3 12 2.4 2 .6 2.01- 11 8 .OL 4 .OL 

MS. 13 rep 40 5 .2 1 .5N 8 1 .6 1 .3N 11 2.5 2 .6 2 .01- 11 8 .OL 4.OL

MS. 13 dup 40 4.8 1 .7 8 1 .6 1 .7 11 2.6 2 .8 2 .01- 11 8 .01- 4.OL 
Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Lanthanum Lead Lithium Manganese 

Site no. Total 4N HCI 0.1 N HCI Total 4N HCI OA N HCI Total 4N HCI OA N HCI Total 4N HCI 0.1 N HCI 

(fig .1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River 

Mo. 1 35 7.7 2.6 15 6.3N 6.3N 21 5.0 0.38N 430 84 210


MO.2 39 8.8 3.2 17 6.3N 9.2 26 6.1 .38N 650 120 380


MO.3 43 13 5.7 22 7.0 8.6 37 9.9 .38N 1 .100 370 560


1 MOA 2MOA 35 

78 

7.4 - 2.6 

- 16 

13 

6.3N 

- 6.3N - 19 

14 

4.4 

- .38N - 450 

500 

93 

-

240

-

MO.5 37 9.6 3.6 16 11 6.7 28 5.6 .38N 760 280 320


MO.6 40 10 6.2 24 12 10 46 9.0 .38N 1,300 330 720


MO.7 35 8.4 3.0 18 7.0 6.3N 22 5.6 .38N 490 89 280


MO.7 rep

MO.7 dup 

34 

33 

8.9 

8.1 

3.0 

3.3 

17 

16 

6.3N 

6.3N 

6.4 

6.3N 

22 

22 

5.4 

4.9 

.38N 

.38N 

460 

450 

94 

87 

240


250


MO.8 

MO.9 

44 

45 

16 

18 

6.1 

6.6 

24 

23 

9.8 

12 

9.5 

8.1 

41 

45 

11 

14 

.38N 

.38N 

1,300

1,200 

470 

490 

640


610


MO.10 36 9.7 3.2 15 7.4 6.9 21 5.0 .38N 450 180 180


MO. 11 36 11 3.9 15 7.3 6.8 25 6.7 .38N 820 380 320


MO.12 32 10 3.4 17 12 6.3N 23 6.5 .38N 770 330 320


Mississippi River 

Ms. 1 30 6.5 4.0 19 9.1 9.4 20 4.1 0.38N 1,100 400 510


MS. 1 rep

MS. 1 dup 

30 

29 

6.4 

6.7 

4.1 

3.9 

21 

21 

12 

6.3N 

8.5 

6.3N 

20 

20 

3.8 

4.3 

.38N 

.38N 

1,100 

1,100 

340 

360 

550


510


MS.2 

MS.3 

40 

33 

11 

5 .6 

6.7 

2.8 

22 

23 

11 

6.7 

14 

13 

31 

17 

7.2 

3.4 

.38N 

.38N 

1,400 

660 

280 

110 

870


330


MSA 

MS.5 

35 

39 

8.0 

11 

4.6 

5 .5 

23 

18 

15 

12 

11 

6.3N 

29 

30 

6.5 

6.2 

.38N 

.38N 

1,200 

970 

230 

380 

730


420


MS.6 38 9.9 4.4 16 7.9 6.3N 24 3.8 .38N 570 270 170


MS.7 

MS.7 rep 

36 

34 

9.4 

8.8 

6.0 

5 .7 

24 

21 

11 

13 

10 

9.9 

29 

29 

6.4 

6.1 

.38N 

.38N 

1,100 

1,000 

170 

150 

720


660


MS.7 dup 35 8.3 5 .6 22 6.3N 6.3N 29 5.6 .38N 1,000 140 670


MS

MS.8 35 8.1 4.8 19 17 6.3N 22 3.4 .38N 830 420 220


MS.9 36 12 3.8 18 12 6.3N 28 8.7 .38N 750 270 350


MS.10 33 5 .8 3 .3 21 17 6.3N 17 3.5 .38N 610 320 140


MS.11 40 11 5.3 22 6.3N 6.3N 31 7.6 .38N 970 280 530


MS.12 39 12 6.4 25 6.3N 6.3N 40 9.0 .38N 1,300 300 780


MS.13 41 7.0 2.9 16 6.3N 6.3N 19 3.9 .38N 640 220 260


MS. 13 rep 41 7.8 3.0 16 6.3N 6.3N 19 4.2 .38N 670 230 300
 . 13 dup 43 7.2 3.1 15 6.3N 6.3N 19 4.0 .38N 670 220 260

o Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Mercury (CVAAS) Molybdenum Neody- Nickel Scan­ cm 

0 mium, Niobium, dium, 

Site no. Total 0.1 N HCI Total 4N HCI 0.1 N HCI total Total 4N HCI OA N HCI total total 

(fig .1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) a 

3 Missouri River 

3 

0)	 MO. 1 0.02L 0.008 2.OL LON LON 26 18 6.0 4.0 10 6.0 

MO.2 .02L .006 2.OL LON LON 31 24 7.7 3.5 11 7.0 

'0 MO.3 .02 .010 2.01, 1 .5 LON 34 33 11 6.1 12 10 

y 1MOA .02L .006L 2.01, LON LON 27 16 5.4 3.0 10 5.0 

`MO.4 .02L - 2.OL - - 60 14 - - 16 6.0 0. 

a 

MO.5 .021, .006 2.OL 1 .1 LON 30 24 6.8 4.1 10 8.0 

MO.6 .03 .010 2.OL LON LON 34 40 8.3 7.3 13 13 

MO.7 .02L .006L 2.OL LON LON 30 20 6.4 3.6 10 6.0 

rn MO.7 rep .02L .006 2.OL LON LON 27 19 7.4 3.5 10 6.0 

0 MO.7 dup .02L .006L 2.OL 1 .1 LON 26 19 8.3 1.6 10 6.0 c 

m MO.8 .02 .006 2.OL LON LON 37 37 14 6.5 13 12 

MO.9 .02L .006 2.OL LON LON 36 42 16 6.4 15 13 

s m 

MO.10 

MO.11 

.02L 

.02L 

.006L 

.020L 

2.OL 

2.OL 

LON 

LON 

LON 

LON 

28 

29 

18 

25 

9.2 

11 

3.4 

3.8 

11 

10 

6.0 

7.0 

MO.12 .021, .060L 2.OL LON LON 25 22 11 4.3 10 7.0 

N

T


rn Mississippi River
 N


MS-1 0.03 0.008 2.OL LON LON 24 21 5.9 2.7 8.0 7.0 

1q MS. 1 rep .03 .008 2.OL LON LON 24 21 6.5 2.8 9.0 7.0 

a 

MS. 1 dup .03 .O1 2.OL LON LON 23 22 5.5 1 .3N 8.0 7.0 

MS.2 .04 .006 2.OL LON LON 31 33 11 5.6 12 10 

0 MS.3 .02L .006L 2.OL LON LON 28 20 7.8 1 .3N 8.0 6.0 

0 

o. MS.4 .04 .006 2.OL 1 .5 LON 28 28 8.6 1 .6 10 9.0 

2 MS.5 .02 .006L 2.OL 1 .7 LON 31 27 8.4 2.0 11 9.0 

0 MS.6 .02L .006L 2.OL 1 .4 LON 32 21 6.1 2.8 10 8.0 w MS.7 .02L .006 2.OL LON LON 29 27 8.9 2.1 11 9.0 

MS.7 rep .03 .006L 2.OL 1 .4 LON 28 27 8.0 2.9 10 9.0 

MS.7 dup .04 .O1 2.OL 1 .7 LON 29 28 7.2 2.7 10 9.0 

MS.8 .02L .006L 2.OL 1 .1 LON 30 18 4.7 2.5 10 7.0 

MS.9 .02L .006L 2.OL 1 .5 LON 30 25 11 2.8 11 8.0 

MS.10 .02L .006L 2.OL LON LON 26 15 5.9 1 .5 10 6.0 

MS.11 .02 .006L 2.OL 1 .1 LON 31 28 10 3.3 11 9.0 

MS.12 .03 .006 2.OL 1 .0 LON 34 36 12 5.1 14 11 

MS.13 .02L .006L 2.OL LON LON 32 17 4.7 1 .3N 10 6.0 

MS. 13 rep .02L .006L 2.OL 1 .1 LON 33 17 6.9 1 .3N 11 6.0 

MS. 13 dup .02L .006L 2.OL LON LON 26 16 4.8 1 .3N 10 6.0 
Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Selenium (AAS) Silver Strontium Tanta- Thorium 

Total, lum, Total, 

Site no. Total 4N HCI OA N HCI Total 4N HCI 0.1 N HCI AAS Total 4N HCI OA N HCI total Total DN 

(fig .1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River 

MO. 1 

MO.2 

0.3 

.5 

0.05L 

.05L 

0.05L 

.05L 

2 .OL 

2 .OL 

0.50N 

.50N 

0.50N 0.15 

.50N .17 

190 

180 

9.7 

11 

17 

24 

40L 

40L 

8 

10 

8 .9


10


MO.3 .8 .05L .05L 2 .OL .50N .50N .20 150 14 30 40L 11 14


'MOA 

Z MO.4 

.2 

.1 

.05L 

-

.051, 

-

2 .OL 

2 .OL 

.50N 

-

.50N .14 

- .11 

180 

220 

8 .1 

-

18 

-

40L 

40L 

9 

25 

8 .0


-

MO.5 .5 .06 .05L 2 .OL JON .50N .16 160 8 .7 25 40L 10 9 .1


MO.6 1 .0 .051, .05L 2.OL .50N .50N .17 140 12 46 40L 13 13


MO.7 .4 .051, .05L 2 .OL .50N .50N .17 180 10 23 40L 11 7.8


MO.7 rep 

MO.7 dup 

.3 

.3 

.05L 

.05L 

.05L 

.05L 

2 .OL 

2 .OL 

.50N 

.50N 

.50N .16 

.50N .16 

180 

180 

11 

10 

21 

22 

40L 

40L 

9 

9 

9 .6


12


MO.8 .8 .05L .05L 2.OL .50N .50N .17 140 15 35 40L 13 12


MO.9 1 .0 .05L .05L 2.OL .50N .50N .16 140 17 39 40L 13 11


MO.10 .3 .05L .05L 2 .OL .50N .50N .15 170 9.4 17 40L 9 8 .1


MO.11 .6 .05L .05L 2.OL .50N .50N .15 170 11 23 40L 9 10


MO.12 .5 .051, .05L 2 .OL .50N .50N .16 190 13 24 40L 8 7.3


Mississippi River 

MS.1 0.5 0.05L 0.05L 2.OL 0 .50N 0.50N 0.16 150 4.5 10 40L 8 7 .2


MS. 1 rep .5 .05L .05L 2.OL .50N JON .16 150 4.3 11 40L 8 7 .8


MS

MS.2 .8 .05L .05L 2.OL .50N .50N .16 120 6.3 13 40L 11 10


MS .3 .3 .05L .05L 2.OL .50N .50N .13 150 4.0 8 .8 40L 9 6 .9


MS.4 

MS .5 

.8 

.6 

.05L 

.05L 

.05L 

.05L 

2.01, 

2.OL 

.50N 

.50N 

JON 

.50N 

.21 

.16 

120 

110 

5 .6 

6.2 

15 

13 

40L 

40L 

9 

10 

8 .7


11


MS .6 .4 .05L .05L 2.01, .50N JON .15 120 4.2 9 .2 40L 9 12 

MS .7 .7 .05L .05L 2.OL .50N JON .22 120 6.3 15 40L 11 10 

MS .7 rep .7 .05L .05L 2.OL .50N .50N .20 120 5.9 14 40L 10 11 

MS.7 dup

MS.8 

.7 

.3 

.05L 

.05L 

.05L 

.05L 

2.OL 

2.01-

.50N 

JON 

.50N 

.50N 

.20 

.15 

120 

120 

5.7 

3 .4 

14 

8 .8 

40L 

40L 

9 

10 

11


9 .6


MS.9 .4 .051, .05L 2.OL JON .50N .17 170 14 23 40L 9 11


MS.10 .3 .05L .05L 2.OL JON .50N .13 140 4.5 7.5 40L 9 9 .2


MS.11 .6 .05L .05L 2.OL .50N JON .20 150 11 23 40L 12 12


MS.12 .8 .05L .05L 2.OL .50N .50N .23 140 11 24 40L 12 13


MS.13 .2 .05L .05L 2.OL .50N .50N .15 180 7 .3 13 40L 10 10


. 1 dup .5 .05L .05L 2.OL .50N .50N .19 150 4.3 10 40L 8 7 .9


MS. 13 rep .2 .05L .05L 2.OL .50N .50N .13 170 7 .7 14 40L 11 13


MS.] 3 dup .2 .051, .05L 2.01- .50N .50N .15 180 7.1 13 40L 10 13 
y

21 

N Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

m Tin Tungsten Uranium Vanadium Ytterc Total, bium,

Site no. Total 4N HCI OA N HCl 4N HCI OA N HCI Total DN Total 4N HCI OA N HCI total 

0. (fig .1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River 

Mo. 1 5.OL ]ON ION 7.5N 7.5N 100L 3 .1 63 12 3.2 2.0 

MO.2 5.OL ION ION 7.5N 7.5N 100L 3 .3 79 14 5.1 2.0 

e MO.3 5.OL ION ION 7.5N 7.5N 100L 3.7 110 26 8.4 2.0 

y 1 MOA 5.OL ION ION 7.5N 7.5N 100L 3.2 56 11 3.0 2.0 

a 'MO.4 5.OL - - - - 100L - 75 - - 3.0 

MO.5 5.OL ION ION 7.5N 7.5N TOOL 3.6 81 17 4.3 2.0 

m MO.6 

MO.7 

5.OL 

5 .OL 

ION 

ION 

ION 

ION 

7.5N 

7.5N 

7.5N 

7.5N 

100L 

100L 

3.5 

3.3 

140 

68 

20 

13 

10 

4.6 

3.0 

2.0 

w MO.7 rep 5 .OL ION ION 7.5N 7.5N TOOL 3.0 65 14 4.0 2.0 

p MO.7 dup 5 .OL ION ION 7.5N 7.5N IOOL 2.9 64 12 3.7 2.0
 c
1


y MO.8 5 .OL ION ION 7.5N 7.5N TOOL 3.7 130 33 8.6 2.0


0. MO.9 5.OL ION ION 7.5N 7.5N 100L 3.6 140 38 11 2.0 

3	 MO.10 5.OL ION ION 7.5N 7.5N 100L 3.3 64 14 4.7 2.0 

MO.11 5.OL ION ION 7.5N 7.5N 100L 3.3 83 19 5.1 2.0 

MO.12 5.OL ION ION 7.5N 7.5N 100L 2.8 75 18 3.7 2.0 

to Mississippi River 

'o . MS.1 5.OL ION ION 7.5N 7.5N 100L 2.6 63 13 4.3 1 .0 

7p MS. 1 rep 

MS. 1 dup 

5.OL 

5.OL 

ION 

ION 

ION 

ION 

7.5N 

7.5N 

7.5N 100L 

7.5N 100L 

2.5 

2.6 

63 

62 

13 

13 

4.5 

3 .7 

2.0 

2.0 

MS.2 5.OL ION ION 7.5N 7.5N 100L 3.2 100 23 9.5 2.0 

0

0 

MS .3 5.OL ION ION 7.5N 7.5N 100L 2.9 54 11 3.6 1 .0

N.

e. MS.4 5.OL ION ION 7.5N 7.5N 100L 2.8 83 17 6.4 2.0 

w MS.6 

MS.7 

5.OL 

5.OL 

ION 

ION 

ION 

ION 

7.5N 

7.5N 

7.5N 

7.5N 

100L 

100L 

3.1 

3.1 

65 

86 

12 

17 

6.5 

8.6 

2.0 

2.0 

MS.7 rep 5.OL ION ION 7.5N 7.5N 100L 2.9 83 16 8.1 2.0 

MS.7 dup 5.OL ION ION 7.5N 7.5N 100L 3.0 83 15 7.5 2.0 

MS.8 5.OL ION ION 7.5N 7.5N 100L 2.9 57 12 3.9 2.0 

MS.9 5.01, ION ION 7.5N 7.5N 100L 3.0 84 21 4.5 2.0 

MSAO 5.OL ION ION 7.5N 7.5N 100L 3.3 56 12 4.4 2.0 

MS.11 5.OL ION ION 7.5N 7.5N 100L 3.3 93 18 7.3 2.0 

MS.12 5.01, ION ION 7.5N 7.5N 100L 3.4 110 22 9.'2 2.0 

MS.13 5.OL ION ION 7.SN 7.SN 100L 3.7 57 11 2.2 2.0 

MS. 13 rep 5.01, ION ION 7.5N 7.SN 100L 4.0 60 12 2.1 2.0 

MS. 13 dup 5.OL ION ION 7.5N 7.5N 100L 3.9 59 11 2.2 2.0 

E MS.5 5.OL ION ION 7.5N 7.5N 100L 3.3 88 20 6.7 2.0 
Table 7. Concentrations of elements and carbon in the less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the Mississippi River 

flood plains-Continued 

Yttrium Zinc Zirconium Carbon (wt . %) 

Total, Organic, CarSite no. Total 4N HCI 0.11N HCI Total 4N HCl 0.1N HCI 4N HCI 0.1 N HCI combus- diff- bonate, 

(fig .1) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) tion erence titration 3 C02 

Missouri River 

MO. 1 19 4 .2 3 .6 51 32 6 .4 0.63N 0 .63N 0.80 0.51 0.29 1 .1


MO.2 21 5 .8 4.6 66 40 9.1 .63N .63N 1 .24 .91 .33 1 .2


MO.3 24 8 .5 6.7 96 64 15 .63N .63N 1 .53 1 .37 .16 .57


'MO.4 17 3 .8 3 .3 44 28 6 .5 .63N .63N .56 .35 .21 .77


2MO.4 28 - - 42 - - - - .61 .12 .49 1 .8


MO.5 19 5 .7 4.3 64 35 10 .63N .63N .98 .81 .17 .63


MO.6 25 7 .6 7 .5 130 53 18 .63N .63N 2 .38 2.27 .11 .39


MO.7 18 4.8 4.0 63 37 10 .63N .63N .92 .68 .24 .88


MO.7 rep

MO.7 dup 

18 

17 

5 .1 

4.8 

3 .6 

3.7 

57 

56 

37 

37 

9 .7 

8 .5 

.63N 

.63N 

.63N 

.63N 

.84 

.90 

.60 

.67 

.24 

.23 

.87


.86


M0.8 26 1 .0 7 .4 110 73 14 .63N .63N 1 .85 1 .73 .12 .43


MO.9 27 13 7 .9 120 86 13 .63N .63N 1 .90 1 .81 .09 .35


MO.10 19 5 .5 3 .7 50 36 5 .7 .63N .63N .78 .64 .14 .53


Mo.] 1 

MO.12 

19 

18 

6.9 

6.5 

4.7 

4.3 

70 

64 

54 

46 

8 .8 

8 

.63N 

.63N 

.63N 

.63N 

1 .19 

1 .19 

1 .02 

.97 

.17 

.22 

.62


.81


Mississippi River 

MS.1 16 3 .7 4.3 89 52 22 0 .63N 0.63N 1 .92 1 .65 0.27 0.97


MS. 1 rep 16 3 .6 4 .6 93 52 25 .63N .63N 2 .00 1 .73 .27 .98


MS

MS.2 22 7.0 6 .4 100 62 18 .63N .76 3 .10 2.98 .12 .45


MS.3 16 3.0 3 .5 67 38 17 .63N .66 1 .54 1 .09 .45 1 .6


MS.4 20 5.2 5 .2 120 66 30 .63N .63N 3 .30 2.86 .44 1 .6


MS.5 21 6.3 5 .6 83 51 12 .63N .63N 2 .13 2.01 .12 .42


MS.6 21 5.9 4 .3 65 39 7 .1 .90 .76 1 .29 1 .26 .03 .10


MS.7 21 5.8 6 .2 100 59 24 .63N .70 2 .39 2.08 .31 1 .1


MS.7 rep 20 5.4 5 .9 98 55 23 .63N 1 .1 2 .37 2.06 .31 1 .1


MS.7 dup 

MS.8 

20 

18 

5.1 

4.5 

5 .7 

4 .3 

99 

50 

53 

29 

25 

4.7 

.63N 

.63N 

.63N 

1 .8 

2 .54 

1 .34 

2.23 

1 .23 

.31 

.11 

1 .1


.42


MS.9 20 7 .2 4 .3 72 54 8 .7 .63N 1 .4 1 .07 .84 .23 .86


MS.10 15 3 .0 2 .5 44 32 4.4 .63N 2.4 1 .19 1 .18 .01 .05


MS.11 21 7 .0 5 .8 88 52 16 .63N .63N 1 .52 1 .31 .21 .79


MS.12 23 8 .0 6.8 110 62 19 .63N .80 1 .96 1 .76 .20 .72


. 1 dup 16 3 .8 4 .2 91 53 24 .63N .63N 1 .95 1 .68 .27 .99


MS.13 17 3 .7 3 .5 48 28 7.1 .63N .63N .70 .46 .24 .89


MS. 13 rep 19 3 .9 3 .7 49 31 8.6 .63N .63N .64 .38 .26 .94


MS. 13 dup 19 3 .9 3 .3 49 29 7.7 .63N 4.5 .70 .44 .26 .94


'Layer 1, 0 to 3 centimeters .


'
-Layer 2, 3 to 15 centimeters .


3Coulometrically titrated to compute carbonate carbon .

EXPLANATION OF TABLE 8 

ABBREVIATIONS AND REPORTING UNITS FOR CHEMICAL CONSTITUENTS AND NOTATIONS USED IN 

TABLE 

wt. % Percent by weight


mg/kg Milligrams per kilogram


4N HCl 4 normal hydrochloric acid (conditionally available fraction)


O.1N HCl 0.1 normal hydrochloric acid (available fraction)


AAS Atomic absorption spectrometry


CVAAS Cold-vapor atomic absorption spectrometry


DN Delayed neutron activation


MO Missouri


MS Mississippi


N Not detected at the lower reporting limit


L Detected at less than the lower reporting limit but not quantified


n.a . Not applicable


All elements analyzed by inductively coupled plasma-atomic emission spectrometry except where noted. Analyzed at the 

U.S . Geological Survey laboratory, Lakewood, Colorado. 

34 Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains 

Aluminum Calcium Iron Magnesium 

Descriptive 

statistics 

Total 

(wt. %) 

4N HCI 

(mg/kg) 

0.1N HCI 

(mg/kg) 

Total 4N HCI 0.1N HCI Total 

(wt. %) (mg/kg) (mg/kg) (wt. %) 

4N HCI 

(mg/kg) 

0.1N HCI 

(mg/kg) 

Total 

(wt. %) 

4N HCI 

(mg/kg) 

O.1N HCI 

(mg/kg) 

Missouri River flood-plain samples (12) 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 3,900 350 1 .0 760 5,700 1 .6 7,800 590 0.51 1,500 1,200 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .9 19,000 1,400 1 .5 1,400 10,000 4.3 29,000 1,900 1 .0 4,200 2,100 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 .1 8,400 730 1 .2 1,000 8,200 2 .7 14,000 1,000 .74 2,500 1,600 

Standard deviation . . . . . . . . . . . . . . . 1 .1 4,700 420 .14 180 1,200 1 .0 6,300 470 .17 770 270 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 12 12 12 12 12 12 12 12 12 12 12 12 

Mississippi River flood-plain samples (13) 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 .6 3,800 320 0.7 290 2,300 1 .5 7,000 430 0.34 960 340 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 .7 10,000 980 2.0 1,300 15,000 3 .7 20,000 2,200 .88 2,900 2,900 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .6 7,100 610 1 .2 860 8,100 2.6 13,000 1,300 .64 2,000 1,600 

Standard deviation . . . . . . . . . . . . . . . .74 2,200 220 .37 330 3,300 .75 4,400 660 .17 640 750 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 13 13 13 13 13 13 13 13 13 13 13 13 

Missouri and Mississippi River flood-plain samples (25) 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 .6 3,800 320 0.7 290 2,300 1 .5 7,000 430 0.34 960 3-10 

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 .9 19,000 1,400 2.0 1,400 15,000 4.3 29,000 2,200 1 .0 4,200 2,900 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .8 7,800 670 1 .2 940 8,200 2.6 14,000 1,200 .69 2,200 1,600 

Standard deviation . . . . . . . . . . . . . . . .95 3,600 330 .28 270 2,400 .86 5,300 580 .18 740 560 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 25 25 25 25 25 25 25 25 25 25 25 25 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Phosphorus 

4N HCI 

(m9/k9) 

Potassium 

4N HCI OANHCI Total 

(m9/k9) (mgtk9) (Wt. %) 

Sodium 

4N HCI 

(mg/kg) 

Sulfur, 

total, 

combustion 

(wt. %) 

Titanium 

4N HCI 

(mg/kg) 

m 

o 

0.1N HCI 

(m9/k9) a 

Descriptive 

statistics 

Total 

(wt. %) 

0.1N HCI 

(mglk9) 

Total 

(Wt. %) 

0.1N HCI 

(mg/kg) 

Total 

(wt. %) 

N 

Missouri River flood-plain samples (12)


7


yr Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .06 150 95 1 .7 290 7 .5N 0 .47 30 25 0.051, 0 .23 61 0.71


v


0 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 500 280 2.0 2,400 460 1 .1 58 73 .06 .32 170 2 .5


N 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .08 290 210 1 .8 1,000 n .a . .89 42 43 n.a . .27 100 1 .4 a 

3 

Standard deviation . . . . . . . . . . . . . . .018 130 73 .09 630 n .a . .24 8 .8 16 n.a . .032 34 .62 

Number of samples above 

w detection limit . . . . . . . . . . . . . . . . . . . N 

12 12 12 12 12 4 12 12 12 2 12 12 

w

c Mississippi River flood-plain samples (13) 

a Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.04 150 60 1 .6 43 7.5N 0.66 9 .5 6.7 0.051, 0.25 57 1 .2 

=rS

m Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 750 290 1 .9 1,100 33 1 .1 49 44 .08 .32 190 6 .5 

H

N

N 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .087 400 160 1 .7 510 n.a. .84 24 26 n .a. .27 120 3 .1

. Standard deviation . . . . . . . . . . . . . . .029 190 65 .10 360 n.a. .14 11 10 n .a. .022 41 1 .7 v 

v Number of samples above 

0 detec tion limit . . . . . . . . . . . . . . . . . . . 13 13 13 13 13 1 13 13 13 6 13 13 13


'r1 Missouri and Mississippi River flood-plain samples (25)
 O


O


o. Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .04 150 60 1 .6 43 7 .5N 0.47 9.5 6.7 0 .051, 0.23 57 0.71 

v 

N 

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . .14 750 290 2 .0 2,400 460 1 .1 58 73 .08 .32 190 6.5

Mean . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . .085 340 180 1 .8 790 n.a . .86 33 34 n.a. .27 110 2.3 

Standard deviation . . . . . . . . . . . . . . .024 170 72 .10 560 n.a . .19 13 16 n.a. .027 38 1 .5 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 25 25 25 25 25 5 25 25 25 8 25 25 25 

12 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Antimony Arsenic Barium 

Total, Total, 4N HCI, 0.1 N HCI, 

Descriptive 

statistics 

AAS 

(mg/kg) 

4N HCI 

(mg/kg) 

O.1N HCI 

(mg/kg) 

Total 4N HCI 0.1N HCI AAS 

(mg/kg) (mg/kg) (mg/kg) (mg/kg) 

AAS 

(mg/kg) 

AAS 

(mg/kg) 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

O.1N HCI 

(mg/kg) 

Missouri River flood-plain samples (12) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5 6 .3N 6.3N IOL 3 .8N 3.8N 6 .4 2 .9 0.9 670 53 62 

Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .4 6 .3N 6.3N 22 6 .9 3.8 19 11 2 .0 790 120 190 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 n .a. n.a. n.a . n .a . n.a. 11 5 .6 1 .6 740 82 110 

Standard deviation . . . . . . . . . . . . . . .27 n .a. n.a. n.a . n .a . n.a. 4 .4 2.7 .34 35 20 49 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 1'2 0 0 6 4 2 12 12 12 12 12 12 

Mississippi River flood-plain samples (13) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 6.3N 6.3N IOL 3 .8N 3 .8N 4 .3 1 .6 0.3 550 24 51 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .3 6.3N 6.3N 15 4.8 4.8 14 6 .3 1 .7 770 91 140 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 n.a . n.a. n.a. n.a . n.a. 7 .7 3 .1 .91 650 55 97 

Standard deviation . . . . . . . . . . . . . . .26 n.a . n.a. n.a. n.a . n.a. 3 .0 1 .5 .41 68 23 30 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 13 0 0 5 1 2 13 13 13 13 13 13 

Missouri and Mississippi River flood-plain samples (25) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.4 6.3N 6 .3N IOL 3 .8N 3 .8N 4.3 1 .6 0.3 550 24 51 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .4 6.3N 6 .3N 22 6.9 4.8 19 11 2.0 790 120 190 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 n.a. n .a . n.a. n.a. n .a . 9 .3 4 .4 1 .2 690 69 100 

Standard deviation . . . . . . . . . . . . . . .26 n.a. n .a . n .a. n.a. n .a . 4.1 2 .5 .52 74 25 40 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 25 0 0 11 5 4 25 25 25 25 25 25 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Beryllium Bismuth Cadmium Cerium 

Descriptive

statistics 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

0.1N HCI 

(mg/kg) 

Total 

(mg/kg) 

4N HCI 0.1 N HCI Total 

(mg/kg) (mg/kg) (mg/kg) 

4N HCI 

(mg/kg) 

OAN HCI 

(mg/kg) 

Total, 

AAS 

(mg/kg) 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

0.1N HCI 

(mg/kg) 

Missouri River flood-plain samples (12)

ID 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0.048 0 .15 IOL 7.5N 7 .5N 2.OL O.SN 0.5N 0.22 55 5 .ON 5.ON y 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 .25 .61 IOL 7.5N 7 .5N 2.OL .5N .5N .56 79 5 .4 10 

0 

0 Mean.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .3 .13 .33 n.a. n.a . n.a . n.a . n .a . n.a. .40 66 n.a. n.a. 

a Standard deviation . . . . . . . . . . . . . . . .5 .072 .17 n.a. n.a . n.a . n.a . n.a . n.a. .12 7.8 n.a. n.a. 

m Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 12 12 12 0 0 0 0 0 0 12 12 2 4 N

y

0 

c Mississippi River flood-plain samples 1131 -e 

°' Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .OL 0.025N 0.16 10L 7 .5N 7 .5N 2.0L O.SN 0.5N 0.18 54 5 .ON S .ON 0

c. 

a Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 .14 .46 IOL 7 .5N 7 .5N 2.OL .5N .55 .66 73 6.7 12 0 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .065 .31 n.a . n .a . n.a . n .a . n .a . n.a . .39 64 n.a. n.a. 

La 

y Standard deviation . . . . . . . . . . . . . . . .4 .041 .10 n.a . n .a . n .a . n .a . n .a . n.a . .14 6.2 n.a . n.a. 

detection limit . . . . . . . . . . . . . . . . . . . 11 10 13 0 0 0 0 0 1 13 13 2 6 

m 

Missouri and Mississippi River flood-plain samples (25) 

0

O

0 Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .OL 0.025N 0.15 IOL 7 .5N 7.5N 2.OL 0.5N 0.5N 0 .18 54 5 .ON 5 .ON 

Number of samples above 

v 

m. Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 .25 .61 IOL 7.5N 7.5N 2 .OL .5N .55 .66 79 6 .7 12 0

y Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .2 .099 .32 n.a . n.a. n .a. n.a. n.a. n .a . .39 65 n.a . n.a . 

Standard deviation . . . . . . . . . . . . . . . .45 .065 .13 n.a . n.a. n .a. n.a. n.a. n.a . .13 6 .9 n.a . n.a . 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 23 22 25 0 0 0 0 0 1 25 25 4 10 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Chromium Cobalt Copper Euro- HolDescriptive Total 4N HCI 

statistics (mg/kg) (mg/kg) 

0. N HCl 

(mg/kg) 

Total 4N HCI OANHCI Total 4N HCI 

(mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

OAN HCI 

(mg/kg) 

pium, 

total 

(mg/kg) 

- allium, total 

(mg/kg) 

Gold, 

total 

(mg/kg) 

mium, 

total 

(mg/kg) 

Missouri River flood-plain samples (12) 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4 .1 1 .5N 8 1 .3 1 .3N 10 2 .5 2.7 2 .01, 10 8 .OL 4.OL 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 13 1 .5N 17 3 .9 3 .'2 31 13 10 2 .OL 21 S .OL 4.OL 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 7 .2 n.a. 12 2 .6 1 .8 19 6.3 5.8 n.a. 14 n .a . n .a . 

Standard deviation . . . . . . . . . . . . . . . 17 2 .9 n.a. 3 .4 .83 .68 7 .8 3 .2 2 .6 n.a. 3 .6 n .a . n .a . 

Number of samples above 

detection limit. . . . . . . . . . . . . . . . . . . . 12 12 0 12 12 11 12 12 12 0 12 0 0 

Mississippi River flood-plain samples (13) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 4 .2 1 .5N 6 1 .3N 1 .3N 12 2.4 2 .6 2 .OL 9 8 .OL 4 .OL 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 11 1 .6 15 3 .3 3 .4 26 7 .7 9 .2 2 .OL 19 8 .OL 4 .OL 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 8 .0 n .a . 10 2 .1 1 .8 19 5 .2 6 .0 n .a. 13 n.a . n .a . 

Standard deviation . . . . . . . . . .2. . . . 11 .2 n .a . 3 .0 .72 .88 4.4 1 .8 2 .0 n .a. 2.7 n.a . n .a . 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . . 13 13 2 13 12 10 13 13 13 0 13 0 0 

Missouri and Mississippi River flood-plain samples (25) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.1 1 .5N 6 1 .3N 1 .3N 10 2 .4 2 .6 2 .OL 9 8 .OL 4 .OL 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 13 1 .6 17 3 .9 3 .4 31 13 10 2 .OL 21 8 .OL 4 .OL 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 7.5 n.a . 11 2.4 1 .8 19 5 .8 5 .9 n .a. 14 n.a . n.a . 

Standard deviation . . . . . . . . . . . . . . . 14 2 .5 n.a . 3 .2 .79 .78 6 .2 2 .6 2 .2 n .a. 3 .2 n.a . n.a . 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . . 25 25 2 25 24 21 25 25 25 0 25 0 0 
c Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

v

o; Lanthanum Lead Lithium Manganese d 

Descriptive Total 4N HCI 0.1N HCI Total 4N HCI 0.1N HCI Total 4N HCI 0.1N HCI Total 4N HCI 0.1N HCI 

N statistics (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

m 

a

3 Missouri River flood-plain samples (12) 

<D 

N Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 7.4 2.6 15 6.3N 6.3N 19 4.4 0 .38N 430 84 180 

v Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 18 6.6 24 12 10 46 14 .38N 1,300 490 720 O 

O Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 11 4.2 18 7.9 6.6 30 7 .4 n.a . 810 270 400

a 

Standard deviation . . . . . . . . . . . . . . . 4.1 3.3 1 .5 3.6 3.5 2.7 9 .9 2 .9 n.a . 340 150 180 

m Number of samples above 

H detection limit . . . . . . . . . . . . . . . . . . . . 12 12 12 12 9 8 12 12 0 12 12 12 

0 

C Mississippi River flood-plain samples (13) 

o. Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 5 .6 2.8 16 6.3N 6.3N 17 3 .4 0.38N 570 110 140 

O Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 12 6 .7 25 17 14 40 9 .38N 1,400 420 870 

y 

Mean. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 9 .0 4 .6 20 9 .9 n.a . 26 5.7 n.a. 930 280 460 

N

y. Standard deviation . . . . . . . . . . . . . . . 3 .3 2 .3 1 .3 3 .0 4 .9 n.a . 6.8 2.1 n.a. 280 88 250 v 

v Number of samples above 

detection limit . . . . . . . . . . . .. . .. . . . . 13 13 13 13 10 5 13 13 0 13 13 13 

T Missouri and Mississipp i River flood-plain samples (25)
 O


O


a Minimum. . . . . . . . .. . . . . .. . .. . .. . . . . . . . 30 5.6 2 .6 15 6.3N 6.3N 17 3 .4 0.38N 430 84 140
 v


LO. 

H Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 18 6.7 25 17 14 46 14 .38N 1,400 490 870

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 10 4.4 20 8 .9 n .a. 28 6 .6 n.a . 870 270 430 

Standard deviation . . . . . . . . . . . . . . . 3 .7 2.9 1 .4 3.4 4.3 n .a. 8 .5 2 .6 n.a . 310 120 220 

Number of samples above 

detection limit. . . . . . . . . . . . . . . . . . . . 25 25 25 25 19 13 25 25 0 25 25 25 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Scan- Mercury (CVAAS) Molybdenum Neody- Nickel mium, Niobium, dium,

statistics (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River flood-plain samples (12) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .021, 0.0061, 2 .OL LON LON 25 16 5.4 3 .0 10 5 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .03 .01 2 .OL 1 .5 LON 37 42 16 7.3 15 13 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . n .a. .008 n .a. n.a. n .a . 30 26 9.4 4 .7 11 8 .3 

Standard deviation . . . . . . . . . . . . . . . n.a. .007 n .a. n.a. n .a . 3 .9 9 .1 3.3 1 .5 1 .6 2 .9 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 3 7 0 2 0 12 12 12 12 1'2 12 

Mississippi River flood-plain samples (13) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .021, 0.0061, 2 .OL LON LON 24 15 4.7 1 .3N 8 6 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .04 .008 2 .OL 1 .7 LON 34 36 12 5 .6 14 11 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . n .a. n.a . n .a. .95 n .a . 30 24 8.1 2 .6 10 8 .1 

Standard deviation . . . . . . . . . . . . . . . n .a. n.a . n .a. .47 n .a . 2 .7 6 .3 2.5 1 .5 1 .6 1 .6 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 6 5 0 7 0 13 13 13 11 13 13 

Missouri and Mississippi River flood-plain samples (25) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .021, 0 .OO6L 2.OL LON LON 24 15 4.7 1 .3N 8 5 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .04 .01 2.OL 1 .7 LON 37 42 16 7 .3 15 13 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . n.a . n .a . n .a . n .a. n .a . 30 25 8.8 3 .6 11 8 .2 

Standard deviation . . . . . . . . . . . . . . . n.a . n .a . n.a . n .a. n .a . 3 .3 7 .7 2.9 1 .8 1 .6 2.3 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 9 12 0 9 0 25 25 25 23 25 25 

Descriptive Total O.1N HCl Total 4N HCI O.1N HCI total Total 4N HCl O.1N HCl total total 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Selenium (AAS) Silver Strontium TantaThorium 

Total, lum, Total, 

Descriptive Total 4N HCI 0.11N HCI Total 4N HCI 0.1 N HCI AAS Total 4N HCI OAN HCI total Total DN 

statistics (mg/kg) (mg/kg) (mg/kg) ( mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

C. Missouri River flood-plain samples (12) 3 ID 

w Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.2 0 .051, 0.051, 2.OL 0 .5N 0.5N 0.14 140 8.1 17 401, 8 7 .3 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .0 .06 .051, 2 .OL .5N .5N .20 190 17 46 401, 13 14 

O 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 n .a. n .a. n .a. n .a. n .a. .16 160 12 27 n .a. 10 9 .9 m 

O. 

3 Standard deviation . . . . . . . . . . . . . . . .3 n .a. n .a. n .a. n .a. n .a. .015 19 2.7 9 .1 n .a . 1 .9 2 .2 

m Number of samples above 

detection limit. . . . . . . . . . . . . . . . . . . . 12 1 0 0 0 0 12 12 12 12 0 12 12 N 

H 

O 

C Mississippi River flood-plain samples (13) 

°' Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .2 0 .051, 0 .051, 2 .OL 0 .5N 0.5N 0 .13 110 3 .4 7 .5 401, 8 6 .9 

o. 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 .051, .051, 2 .OL .5N .5N .23 180 14 24 401, 12 13 O 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 n.a . n .a. n .a. n .a. n .a. .17 140 6 .8 14 n.a . 9 .9 10 

C4. 

(a Standard deviation . . . . . . . . . . . . . . . .2 n.a . n .a. n .a. n .a. n .a. .033 22 3 .2 5 .8 n.a . 1 .2 1 .8 

a 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . . 13 0 0 0 0 0 13 13 13 13 0 13 13 

Missouri and Mississippi River flood-plain samples (25) 

O 

p. Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 .2 0.051, 0 .051, 2 .OL O.5N 0 .5N 0 .13 110 3 .4 7.5 401, 8 6.9 

v 

m. Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .0 .06 .051, 2 .OL .5N .5N .23 190 17 46 401, 13 14 

W 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 n .a . n.a . n.a . n.a . n.a . .17 150 9 .3 20 n.a . 10 10 

Standard deviation . . . . . . . . . . . . . . . .2 n .a . n.a . n.a . n .a . n .a . .026 25 3 .8 9.8 n .a . 1 .6 1 .9 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . . 25 1 0 0 0 0 25 25 25 25 0 25 25 

1 
Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Tin Tungsten Uranium Vanadium YtterTotal, bium, 

Descriptive Total 4N HCI OAN HCI 4N HCI 0.1N HCI Total DN Total 4N HCI 0.1N HCI total 

statistics (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) (mg/kg) 

Missouri River flood-plain samples (12) 

Minimum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7 .5N 7.5N 100L 2 .8 56 11 3 .0 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7 .5N 7 .5N 100L 3 .7 140 38 11 3 

Mean . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . n .a. n .a. n.a. n.a. n.a. n.a. 3 .4 91 20 6.0 2.1 

Standard deviation . . . . . . . . . . . . . . . n .a. n.a. n.a. n.a. n.a. n.a. .27 31 8 .6 2.8 .29 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 0 0 0 0 0 0 12 12 12 12 12 

Mississippi River flood-plain samples (13) 

Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7 .5N 7 .5N 100L 2 .6 54 11 2.2 1 

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7 .5N 7 .5N 100L 3 .7 110 23 9.5 2 

Mean .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . n .a. n .a . n.a. n .a . n.a. n.a. 3 .1 77 16 5 .9 1 .8 

Standard deviation . . . . . . . . . . . . . . . n .a. n .a . n.a. n .a . n.a. n.a. .29 19 4.5 2.3 .37 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 0 0 0 0 0 0 13 13 13 13 13 

Missouri and Mississippi River flood-plain samples (25) 

Minimum.. . .. . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7.5N 7 .5N 100L 2 .6 54 11 2.2 1 

Maximum . . .. . . . . . . . . . . . . . . . . . . . . . . . . 5 .OL ION ION 7.5N 7 .5N IOOL 3 .7 140 38 11 3 

Mean . . . . . . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . n .a . n.a . n.a . n .a . n .a. n.a. 3 .2 83 18 6.0 2.0 

Standard deviation . . . . . . . . . . . . . . . n .a . n.a . n.a . n .a . n .a. n.a. .30 26 6.8 2.5 .35 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 0 0 0 0 0 0 25 25 25 25 25 
a Table 8. Descriptive statistics of selected element and carbon concentrations in less than 0.062-millimeter size fraction of postflood sediment samples in the Missouri and the 

Mississippi River flood plains-Continued 

Yttrium Zinc Zirconium Carbon (wt. %) .. 

0

3 Descriptive 

statistics 

Total 

(mg/kg) 

4N HCI 

(mg/kg) 

O.1N HCI 

(mg/kg) 

Total 4N HCI 0.1N HCI 

(mg/kg) (mg/kg) (mg/kg) 

4N HCI 

(mg/kg) 

OAN HCI 

(mg/kg) 

Total, 

combustion 

Organic, 

difference 

Carbonate, 

titration 1 C02 

Q

2CD 

Missouri River flood-plain samples (12) 

N Minimum . . . . . . . . . . . .. . .. . . . . . . . . . . . . . 17 3 .8 3 .3 44 28 5.7 0.63N 0.63N 0.56 0.35 0.09 0.35 

v Maximum . . . . .. . .. . .. . . . . . . . . . . . . . . . . 27 13 7 .9 130 86 18 .63N .63N 2 .38 2 .27 .33 1 .2 0 

m Mean.. . .. . . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . 21 6 .9 5 .2 77 49 10 n .a . n.a . 1 .28 1 .09 .19 .69

Q 

Standard deviation . . . . . . . . . . . . . . . 3 .5 2 .6 1 .7 29 18 3 .8 n.a. n.a . .54 .59 .073 .27 =r 

Number of samples above 

N detection limit . . . . . . . . . . . . . . . . . . . 12 12 12 12 12 12 0 0 12 12 12 12

Mississippi River flood-plain samples (13) t 

at€ 3 Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.0 2 .5 44 28 4.4 0 .63N 0.63N 0.70 0.46 0.01 0 .05€ Q€

Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 8.0 6.8 120 66 30 .9 2 .4 3 .30 3.00 .45 1 .64 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5 .4 4 .8 80 48 15 n.a . .84 1 .8 1 .59 .21 .77 w 

0 Standard deviation . . . . . . . . . . . . . . . 2 .6 1 .7 1 .3 24 13 8 .0 n.a . .65 .77 .74 .14 .50 

-a 

- Number of samples above 

detection limit . . . . . . . . . . . . . . . . . . . 13 13 13 13 13 13 1 8 13 13 13 13 m 

?1 Missouri and Mississippi River flood-plain samples (25) 0€0€

Q Minimum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3 .0 2 .5 44 28 4.4 0.63N 0.63N 0 .56 0.35 0.01 0.05€ v 

" Maximum. . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 13 7 .9 130 86 30 .9 2.4 3 .3 2 .98 .45 1 .64 H 

Mean. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6 .2 5.0 78 48 12 n.a. n.a . 1 .6 1 .35 .20 .73 

Standard deviation . . . . . . . . . . . . . . . 3 .1 2 .3 1 .5 26 15 6.6 n.a. n .a . .71 .70 .11 .40 

Number of samples above 

detection limit . . . . . . . . . . . . . . . . . .. 25 25 25 25 25 25 1 8 25 25 25 25 

2Coulometrically titrated to compute carbonate carbon. 

c 

0 

3 
EXPLANATION OF TABLE 11 

ABBREVIATIONS AND REPORTING UNITS FOR CHEMICAL CONSTITUENTS AND NOTATIONS USED IN 

TABLE 

MO Missouri


SRM Standard reference material


dup Duplicate sample split in laboratory


rep Replicate sample


RS Reagent spiked sample, in percent recovery


MC Measured concentration


EC Expected concentration


STD Standard deviation


< Less than


- No data


Detections shown in bold. Analyzed at the U.S . Geological Survey laboratory, Arvada, Colorado. 

Table 11 45 
A 

Of Table 11 . Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri River flood plain, sample

set reagent spike, standard reference material, and surrogate samples 

m Site number (fig . 1) 

0 M0.4 

a Layer 2 MO.7 SRM 1941 

3

m Sam- Samy Compound NIOA MO.2 Layer 1 pie Dup M0.5 pie Rep MO.8 MO.10 M0.11 RS MC 'EC 1 STD 

Concentration, in micrograms per kilogram 0 

0 

Acenaphthene . . .. . . . . . . . . . . .. . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 62 <10 52 2 Q. 

' 

Acenaphthylene . . . . . . . . . . . .. . . . . . . . . . . 

Acridine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

<5 

<10 

58 

69 

260 

<10 

115 

-

10 

Anthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 70 370 202 42 

Anthraquinone. . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 80 390 - -

y 

c Azo-benzene . . . . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 66 <20 - -

Benzo[a]anthracene . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 49 <10 <10 <10 70 580 2550 79 

o+ Benzo[b]fluoranthene . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 68 720 2780 190 

c. Benzo[k]fluoranthene . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 74 520 2444 49 

s Benzo[g,h,i]perylene . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 66 360 2516 83 

m 

w€ Benzo[a]pyrene . . . . . . . . . . . . . . . . . . . . . . . 110 120 100 <10 <10 <10 <10 <10 <10 100 <10 68 780 `670 130 

Benzo[c]quinoline . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 75 <10 - -

w. 2,2'-Biquinoline . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 54 <20 - -

4-Bromophenyl phenyl ether . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 68 <10 - - Butylbenzylphthalate . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 78 <10 <10 <10 <10 63 <10 - - x 

C8-Alkyl-phenol . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 56 <10 - -

?~ 9H-Carbazole . . . . . . . . . . . . . . . . . . . . .. . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 75 <10 - -

°o 

a 

bis(2-Chloroethoxy)methane . . bis(2-Chloroethyl)ether . . . . . . . . . . . bis(2-Chloroisopropyl)ether. . . . 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

<10 

<10 

<20 

52 

55 

51 

<10 

<10 

<20 

-

-

-

-

0 4-Chloro-3-methylphenol . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 47 <30 

2-Chloronaphthalene. .. . . . . . . . . . . . . 2-Chlorophenol . . . . . . . . . . . . . . . . . . . . . . . 

4-Chlorophenyl phenyl ether . . Chrysene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

53 

<10 

<10 

<10 

50 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

60 

55 

67 

72 

<10 

<10 

<10 

660 

-

-

-

449 

p-Cresol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 52 <10 

Dibenzo[a,h]anthracene . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 107 <20 

Dibenzothiphene . . . . . . . . . . . . . . . . . . . . . <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 69 190 

Di-n-butylphthalate . . . . . . . . . . . . . . . . . 54 53 59 <10 <10 60 62 60 60 <10 <10 74 380 

1,2-Dichlorobenzene . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 61 <10 
Table 11 . Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri River flood plain, sample 

set reagent spike, standard reference material, and surrogate samples-Continued 

Site number (fig . 1) 

MO.4 

Layer 2 MO.7 SRM 1941 

Sam- SamCompound M0.1 MO.2 Layer 1 pie Dup M0.5 pie Rep MO.8 MO.10 MO.11 RS MC 1 EC 1 STD 

Concentration, in micrograms per kilogram-Continued 

1,3-Dichlorobenzene . . . . . . . . . . . . . . . 

1,4-Dichlorobenzene . . . . . . . . . . . . . . . 

2,4-Dichlorophenol . . . . . . . . . . . . . . . . . 

Diethyl phthalate. . . . . . . . . . . . . . . . . . . . . 

1,2-Dimethylnaphthalene. . . . . . . . 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

58 

49 

56 

70 

61 

<10 

<10 

<20 

<10 

110 

1,6-Dimethylnaphthalene . . . . . . . . 

2,6-Dimethylnaphthalene. . . . . . . . 

3,5-Dimethylphenol . . . . . . . . . . . . . . . . 

Dimethyl phthalate. . . . . . . . . . . . . . . . . . 

4,6-Dinitro-2-methylphenol . . . . 

<10 

<10 

<20 

<10 

<200 

<10 

<10 

<20 

<10 

<200 

<10 

<10 

<20 

<10 

<200 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 28 <10 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<200 <200 <200 <200 <200 <200 

<10 

<10 

<20 

<10 

<200 

<10 

22 

<20 

<10 

<200 

61 

60 

56 

66 

0 

280 

240 

<20 

<10 

<200 

-

198 

-

-

-

-

23 

-

-

-

2,4-Dinitrophenol. . . . . . . . . . . . . . . . . . . 

2,4-Dinitrotoluene . . . . . . . . . . . . . . . . . . 

2,6-Dinitrotoluene . . . . . . . . . . . . . . . . . . 

di-n-Octyl phthalate . . . . . . . . . . . . . . . . bis(2-Ethylhexyl)phthalate. . . . . . 

<300 

<20 

<50 

<20 

60 

<300 

<20 

<50 

<20 

79 

<300 

<20 

<50 

<20 

94 

<300 <300 <300 <300 <300 <300 

<20 <20 <20 <20 <20 <20 

<50 <50 <50 <50 <50 <50 

<20 <20 <20 <20 <20 <20 

<10 <10 96 91 81 66 

<300 

<20 

<50 

<20 

<10 

<300 

<20 

<50 

<20 

79 

0 

59 

58 

65 

64 

<300 

<20 

<50 

<20 

1,900 

2-Ethylnapthalene . . . . . . . . . . . . . . . . . . . 

Fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9H-Fluorene . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobenzene. . . . . . . . . . .. . . . . . 

Hexachlorobutadiene . . . . . . . . . . . . . . 

<10 

36 

<10 

<10 

<20 

<10 

39 

<10 

<10 

<20 

<10 

47 

<10 

<10 

<20 

<10 <10 <10 <10 <10 <10 

<5 <5 44 58 50 38 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 <20 <20 <20 <20 <20 

<10 

<5 

<10 

<10 

<20 

<10 

42 

<10 

<10 

<20 

58 

77 

64 

68 

61 

110 

950 

210 

<10 

<20 

-

`1,220 

104 

-

-

-

240 

5 

-

-

Hexachlorocyclopentadiene. . . . 

Hexachloroethane . . . . . . . . . . . . . . . . . . . 

Indeno[1,2,3-cd]pyrene . . . . . . . . . . . 

Isophorone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Isoquinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

<20 

<20 

<20 

<10 

<10 

<20 

<20 

<20 

<10 

<10 

<20 

<20 

<20 

<10 

<10 

<20 <20 <20 <20 <20 <20 

<20 <20 <20 <20 <20 <20 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 

<20 

<20 

<10 

<10 

<20 

<20 

<20 

<10 

<10 

34 

51 

52 

76 

54 

<20 

<20 

560 

<10 

<10 

-

'`569 

-

-

-

40 

-

-

1-Methyl-9H-fluorene . . . . . . . . . . . . . 

2-Methylanthracene . . . . . . . . . . . . . . . . 

4,5-Methylenephenanthrene . . . 

1-Methylphenanthrene . . . . . . . . . . . . 

1-Methylpyrene . . . . . . . . . . . . . . . . . . . . . . . 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<10 

<10 

<20 

<10 

<10 

<10 

<10 

<20 

<10 

<10 

68 

72 

73 

73 

74 

<10 

320 

260 

260 

340 

-

66 

-

109 

-

-

7 

-

6 

-
A	 Table 11 . Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Missouri River flood plain, sample 

set reagent spike, standard reference material, and surrogate samples-Continued 

v Site number (fig . 1) 

o M0.4


a Layer 2 MO.7 SRM 1941


Compound MO.1 MO.2 Layer 1 

Sample Dup MO.5 Sampie Rep MO.8 MO.10 MOA1 RS MC I EC 'STD 

v 

v

O 

Concentration, in micrograms per kilogram-Continued 

N 

Naphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 58 780 1,322 14 °- Nitrobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 52 <10 - 2-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 52 <100 - 4-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 0 <40 -

H 

n-Nitrosodiphenylamine . . . . . . . . . 

Pentachloroanisol . . . . . . . . . . . . . . . . . . . . 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

<10 

<20 

68 

73 

<10 

<20 

-

- Pentachloronitrobenzene . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 88 <30 - a 

3 

Pentachlorophenol . . . . . . . . . . . . . . . . . . 

Phenanthrene . . . . . . . . . . . . . . . . . . . . . . . . . . . 

<100 

<5 

<100 

<5 

<100 

31 

<100 

<5 

<100 

<5 

<100 

<5 

<100 

43 

<100 

36 

<100 

<5 

<100 

<5 

<100 

<5 

0 

71 

<100 

530 -2577 59 

w Phenanthridine . . . . . . . . . . . . . . . . . . . . . . . . Phenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

<10 

74 

55 

<10 

200 -

- --

n-Nitrosodi-n-propylamine . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 53 <10 -

y. Pyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 49 56 <5 <5 53 63 57 44 <5 50 76 890 2 1,080 200 

Quinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 58 <10 - - 2,3,5,6-Tetramethylphenol . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 56 <30 - -

1,2,4-Trichlorobenzene . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 60 <10 - - M 2,4,6-Trichlorophenol . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 15 <20 - - 0 2,3,6-Trimethylnaphthalene . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 62 230 - - a 2,4,6-Trimethylphenol . . . . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 53 <30 - - v 

3
N Surrogate samples, in percent recovery


Nitrobenzene-d5. . . . . . . . . . . . . . . . . . . . . . 33 55 20 29 39 48 54 40 60 14 73 31 32 

2-Fluorobiphenyl . . . . . . . . . . . . . . . . . . . . . 49 62 52 57 53 68 58 55 64 68 61 49 55 

Terphenyl-d14 . . . . . . . . . . . . . . . . . . . . . . . . . 52 69 65 62 53 77 60 61 66 68 64 52 59 

13enzo-E-pyrene-d12 . . . . . . . . . . . . . 87 97 75 70 64 114 95 92 108 87 102 74 71 

'National Institute of Standards and Technology (1990) . 

'Certified concentrations. 

This surrogate compound is addedjust before the gel permeation chromatography (GPC) step to monitor for GPC-specific losses (E .T. Furlong, U.S . Geological Survey, written commun., 19931. 

3 
EXPLANATION OF TABLE 12 

ABBREVIATIONS AND REPORTING UNITS FOR CHEMICAL CONSTITUENTS AND NOTATIONS 

USED IN TABLE 

MS Mississippi


SRM Standard reference material


rep Replicate sample


dup Duplicate sample split in laboratory


RS Reagent spike sample, in percent recovery


MC Measured concentration


EC Expected concentration


STD Standard deviation


< Less than


- No data


Detections shown in bold. Analyzed at the U.S . Geological Survey laboratory, Arvada, Colorado . 

Table 12 49 
c	 Table 12. Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Mississippi River flood plain, 

sample set reagent spike, standard reference material, and surrogate samples 

v

d Site number (fig . 1)

0

0 MS.1 MS.7 MSA 1 MS.13 SRM 

Sam- Sam- Sam- Sam3 Compound ple Rep MS.3 MS.5 pie Rep MS.9 pie Dup pie Rep RS MC 'EC 1 STD 

3 Concentration, in micrograms per kilogram N 

v Acenaphthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 34 <10 <10 <10 <10 <10 <10 <10 <10 67 <10 52 2 

0	 Acenaphthylene . . . . . . . . . . . . . . . . . . . . . . . . . . . <5 <5 48 <5 <5 <5 <5 <5 <5 <5 <5 65 280 115 10 

Acridine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 65 <10 - -

o. Anthracene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <5 <5 74 <5 <5 46 <5 <5 <5 <5 <5 69 410 02 42 

5 Anthraquinone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 89 <20 <20 <20 <20 <20 <20 <20 <20 76 400 - -

`° Azo-benzene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 66 <20 

Benzo[a]anthracene . . . . . . . . . . . . . . . . . . . . <10 <10 140 <10 67 63 <10 62 60 <10 <10 78 670 '550 79 

c Benzo[b]fluoranthene . . . . . . . . . . . . . . . . . . <10 <10 130 <10 84 <10 <10 76 75 <10 <10 56 760 2 780 190 

Benzo[k]fluoranthene . . . . . . . . . . . . . . . . . . <10 <10 100 <10 70 <10 <10 62 62 <10 <10 58 700 `444 49 d Benzo[g,h,i]perylene . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 20 260 `516 83 

a Benzo[a]pYrene . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 160 <10 <10 <10 <10 100 100 <10 <10 60 860 670 130 

Benzo[c]quinoline . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 72 <10 - -

2,2'-Biquinoline . . . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 63 <20 - -

H. 4-Bromophenyl phenyl ether. . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 68 <10 - -

Butylbenzylphthalate . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 85 88 <10 <10 <10 76 <10 - -

Cg-Alkyl-phenol . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 72 <10 

?q 9H-Carbazole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 72 190 

bis(2-Chloroethoxy)methane . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 71 <10 

T, bis(2-Chloroethyl)ether . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 66 <10 

o bis(2-Chloroisopropyl)ether . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 73 <20 0 

a 

4-Chloro-3-methylphenol. . . . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 52 <30 -

2. 2-Chloronaphthalene . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 65 <10 -

N	 2-Chlorophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 62 <10 -

4-Chlorophenyl phenyl ether. . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 67 <10 -

Chrysene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 180 <10 75 76 <10 69 68 <10 54 80 760 449 

p-Cresol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 64 <10 <10 <10 <10 <10 <10 <10 <10 66 <10 

Dibenzo[a,h]anthracene . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 29 <20 

Dibenzothiphene . . . . . . . . . . . . . . . . . . . . . . . . . <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 <5 69 210 

Di-n-butylphthalate . . . . . . . . . . . . . . . . . . . . . 60 71 87 65 77 69 65 72 64 68 77 76 460 

1,2-Dichlorobenzene . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 74 <10 
Table 12. Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Mississippi River flood plain, 

sample set reagent spike, standard reference material, and surrogate samples-Continued 

Site number (fig. 1) 

IVISA MS.7 MSA 1 MS.13 SRM 

Sam- Sam- Sam- SamCompound ple Rep MS.3 MS.5 pie Rep MS.9 pie Dup pie Rep RS MC 'EC 1 STD 

Concentration, in micrograms per kilogram-Continued 

1,3-Dichlorobenzene . . . . . . . . . . . . . . . . . . . 1,4-Dichlorobenzene . . . . . . . . . . . . . . . . . . . 

2,4-Dichlorophenol . . . . . . . . . . . . . . . . . . . . . 

Diethyl phthalate . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dimethylnaphthalene . . . . . . . . . . . . 

<10 <10 

<10 <10 

<20 <20 

<10 <10 

<10 <10 

<10 

<10 

<20 

<10 

19 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<10 <10 

<10 <10 

<20 <20 

<10 <10 

<10 <10 

66 

68 

62 

72 

66 

<10 

<10 

<20 

<10 

130 

1,6-Dimethylnaphthalene . . . . . . . . . . . . 

2,6-Dimethylnaphthalene . . . . . . . . . . . . 

3,5-Dimethylphenol . . . . . . . . . . . . . . . . . . . . . 

Dimethyl phthalate . . . . . . . . . . . . . . . . . . . . . . 

4,6-Dinitro-2-methylphenol . . . . . . . . 

<10 <10 

42 39 

<20 <20 

<10 <10 

<200 <200 

39 

58 

<20 

<10 

<200 

<10 <10 <10 <10 <10 <10 

23 50 52 29 23 25 

<20 <20 <20 <20 <20 <20 

<10 <10 <10 <10 <10 <10 

<200 <200 <200 <200 <200 <200 

<10 <10 

30 24 

<20 <20 

<10 <10 

<200 <200 

66 

66 

60 

66 

0 

310 

270 

<20 

<10 

<200 

-

198 

-

-

-

-

23 

-

-

-

2,4-Dinitrophenol . . . . . . . . . . . . . . . . . . . . . . . . 

2,4-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . 

2,6-Dinitrotoluene . . . . . . . . . . . . . . . . . . . . . . . 

Di-n-octyl phthalate. . . . . . . . . . . . . . . . . . . . . 

bis(2-Ethylhexyl)phthalate . . . . . . . . . . 

<300 <300 

<20 <20 

<50 <50 

<20 <20 

75 86 

<300 

<20 

<50 

<20 

220 

<300 <300 <300 <300 <300 <300 

<20 <20 <20 <20 <20 <20 

<50 <50 <50 <50 <50 <50 

<20 <20 <20 <20 <20 <20 

70 91 91 80 130 140 

<300 <300 

<20 <20 

<50 <50 

<20 <20 

74 73 

0 

62 

66 

61 

81 

<300 

<20 

<50 

<20 

2,300 

2-Ethylnaphthalene . . . . . . . . . . . . . . . . . . . . . . 

Fluoranthene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9H-Fluorene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobenzene . . . . . . . . . . . . . . . . . . . . . 

Hexachlorobutadiene . . . . . . . . . . . . . . . . . . . 

<10 <10 

54 57 

<10 <10 

<10 <10 

<20 <20 

23 

270 

47 

<10 

<20 

<10 <10 <10 <10 <10 <10 

45 78 85 43 67 67 

<10 <10 35 <10 <10 <10 

<10 <10 <10 <10 <10 <10 

<20 <20 <20 <20 <20 <20 

<10 <10 

49 53 

<10 <10 

<10 <10 

<20 <20 

65 

73 

66 

70 

65 

120 

1,000 

240 

<10 

<20 

-

`1 .220 

104 

-

-

-

240 

5 

-

-

Hexachlorocyclopentadiene . . . . . . . . 

Hexachloroethane . . . . . . . . . . . . . . . . . . . . . . . . 

<20 <20 

<20 <20 

<20 

<20 

<20 <20 <20 <20 <20 <20 

<20 <20 <20 <20 <20 <20 

<20 <20 

<20 <20 

63 

64 

<20 

<20 

-

-

-

-

Indeno[1,2,3-cd]pyrene . . . . . . . . . . . . . . . <20 <20 69 <20 <20 <20 <20 <20 <20 <20 <20 28 440 -'569 40

Isophorone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 66 <10 - -

Isoquinoline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 59 <10 - -

1-Methyl-9l-I-fluorene . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 68 <10 -

66 

-

2-Methylanthracene . . . . . . . . . . . . . . . . . . . . . <10 <10 83 <10 <10 <10 <10 <10 <10 <10 <10 70 360 7

4,5-Methylenephenanthrene. . . . . . . . <20 <20 60 <20 40 41 <20 <20 <20 <20 <20 69 270 - -

1-Methylphenanthrene . . . . . . . . . . . . . . . . <10 <10 53 <10 <10 <10 <10 <10 <10 <10 <10 70 280 109 6

1-Methylpyrene . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 72 390 - -

Naphthalene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 66 740 1,322 14 

Nitrobenzene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 68 <10 - -

2-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 66 <100 - -

4-Nitrophenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 <40 0 <40 - -

n-Nitrosodi-n-propylamine . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 64 <10 - -
Table 12. Concentrations of semivolatile organic compounds in the less than 2-millimeter size fraction of postflood sediment samples in the Mississippi River flood plain, 

sample set reagent spike, standard reference material, and surrogate samples-Continued 

d Site number (fig . 1) 

MS.1 MS.7 MSA 1 MS.13 SRM 

a Sam- Sam- Sam- Sam-€

3 Compound ple Rep MS.3 MS.5 pie Rep MS.9 pie Dup pie Rep RS MC 1 EC 1 STD€

m€

m Concentration, in micrograms per kilogram-Continued 

v 

n-Nitrosodiphenylamine . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 73 <10 - - cy Pentachloroanisol . . . . . . . . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 68 <20 - - Pentachloronitrobenzene . . . . . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 78 <30 - - Pentachlorophenol. . . . . . . . . . . . . . . . . . . . . . . <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 <100 0 <100 - - Phenanthrene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 <5 160 <5 46 46 <5 45 44 <5 <5 70 560 '577 59 

m Phenanthridine . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 71 <10 - -

rn Phenol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 65 210 - -

c Pyrene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 60 220 52 84 87 55 75 71 58 61 74 960 2 1,080 200 

Quinoline. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 67 <10 - - 2,3,5,6-Tetramethylphenol . . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 60 <30 

c. 1,2,4-Trichlorobenzene . . . . . . . . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 60 <10 

2,4,6-Trichlorophenol. . . . . . . . . . . . . . . . . . <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 <20 60 <20 

2,3,6-Trimethylnaphthalene . . . . . . . . <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 <10 16 <10 

W 2,4,6-Trimethylphenol . . . . . . . . . . . . . . . . . <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 <30 63 <30 

W 

Surrogate samples, percent recovery 

Nitrobenzene-d5 . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3 14 23 19 9.9 16 12 20 25 22 10 45 30 

2-Fluorobiphenyl . . . . . . . . . . . . . . . . . . . . . . . . . 55 51 52 38 54 55 45 48 46 53 54 54 55 

°o Terphenyl-d14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 62 63 45 59 67 64 64 60 64 71 58 64 

a Benzo-E-pyrene-d12 . . . . . . . . . . . . . . . . . . 87 84 93 66 92 96 82 90 91 89 92 65 67 

'National Institute of Standards and Technology (1990) . 

y '- Certified concentrations . 

3 This surrogate compound is added just before the gel permeation chromatography (GPC) step to monitor for GPC-specific losses (E .T. Furlong, U.S . Geological Survey, written commun., 1993). 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis 

[MO, Missouri ; MS, Mississippi; -, no established confidence level; >C,o, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum. Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Compound 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >CIO-C2o . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2O . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . 

Saturated hydrocarbon: CIO-C2o . . . . . . . . 

Confidence Estimated concentration, 

level in milligrams per kilogram 

Missouri River 

MO.1 

. . . . . . . . . . . . . 0.15 

. . . . . . . . . . . . . .16 

. . . . . . . . . . . . . .24 

. . . . . . . . . . . . . .26 

. . . . . . . . . . . . . .31 

. . . . . . . . . . . . . .38 

. . . . . . . . . . . . . .46 

. . . . . . . . . . . . . .54 

. . . . . . . . . . . . . .20 

. . . . . . . . . . . . . .29 

. . . . . . . . . . . . . .25 

. . . . . . . . . . . . . .17 

. . . . . . . . . . . . . .40 

MO.2 

. . . . . . . . . . . . . 0.15 

MO.3 

. . . . . . . . . . . . . 0.16 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . 

No compounds detected . . . . . . . . . . . . . . . . . . . . . 

No compounds detected . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

(4aS-cis)-2,3,4,4a,5,6,7,8-octahydro-1,1,4a,7-

tetramethyl-lH-benzocyclo-hepten-7-ol . . . . . . 1 .15 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .19 

. . . . . . . . . . . . . - .16 

MO.4 (layer 1) 

. . . . . . . . . . . . . 

MO.4 (layer 2) 

. . . . . . . . . . . . . 

MO.5 

. . . . . . . . . . . . . 0.14 

. . . . . . . . . . . . . .24 

. . . . . . . . . . . . . .62 

. . . . . . . . . . . . . 2.1 

. . . . . . . . . . . . . 4.1 

Table 13 53 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi; -, no established confidence level; >Czp, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration, 

Compound level in milligrams per kilogram 

MO.6 

Saturated hydrocarbon: C10-C,p . . . . . . . . . . . . . . . . . . . . 

(Z)-14-Methyl-8-hexadecen-l-ol . . . . . . . . . . . . . . . . . . 

Cyclododecanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9-Hexadecanoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexadecanoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

4,8,1,2-Trimethyl-3,7, 

11-tridecatrienenitrile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,p . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Methyl- l-hexadecanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexadecyl ester tetradecanoic acid . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,0 . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexadecyl ester Hxadecanoic acid . . . . . . . . . . . . . . . . 

- 0.15 

1 .16 

1 .19 

- .19 

- .65 

.37 

.87 

.89 

1 .18 

- .23 

- 9.1 

1 .22 

- .20 

1 .68 

- .20 

- .20 

1 .65 

MO.7 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0.51 

3-Ethyl-5-(2-ethylbutyl)-octadecane . . . . . . . . . . . . . . 1 .14 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .69 

M0.7 (replicate) 

Unknown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.39 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 

MO.8 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . - 0.26 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .21 

Hexadecanoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .34 

MO.9 

No compounds detected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

MO.10 

No compounds detected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi: -, no established confidence level; >C=p, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration, 

Compound level in milligrams per kilogram 

MO.11 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . - 0.14 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .14 

11-Diene selina-4(14) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .22 

MO.12 

No compounds detected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Mississippi River 

MS.1 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

2,4-Dimethyl-2-pentanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,O. . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dibromo-2-methyl-propane . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >CZ0. . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >Cz0. . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

MS.1 (replicate) 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

2,4-Dimethyl-2-pentanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >CZ0 . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >CZ0 . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

2,4-Dimethyl-2-pentanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . . 

MS.2 

1 6.0 

1 .21 

- .60 

- .28 

1 .18 

.40 

.32 

.82 

.37 

.24 

1 6.1 

1 .14 

- .54 

- .26 

- .28 

.20 

.34 

.47 

.59 

.26 

.35 

1 5.1 

1 .17 

- .49 

- .44 

- .16 

Table 13 55 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri MS, Mississippi; -, no established confidence level ; >C,p, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence 

Compound level 

MS.2^Continued 

1,2-Dibromo-2-methyl-propane . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C-,p . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >Cio . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >Cio . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1 

-

-

-

-

MS.3 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 1 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -

Saturated hydrocarbon: >Cio . . . . . . . . . . . . . . . . . . . . . . . . . -

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . 

Saturated hydrocarbon: >Cio . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2p . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2p . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Estimated concentration, 

in milligrams per kilogram 

0.16 

.14 

.68 

.26 

.22 

.34 

1.3 

.83 

.86 

.64 

.88 

.85 

.71 

5.1 

.58 

.69 

.84 

1 .1 

.56 

1 .5 

1 .4 

1 .1 

.34 

.34 

.43 

.34 

.40 

.49 

.85 

.73 

.39 

1.3 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi ; -, no established confidence level; >CGO, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum. Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Compound 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,p. . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >CZo . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Confidence Estimated concentration, 

level in milligrams per kilogram 

MS.4 

1.2 

.61 

.18 

1.4 

.49 

.86 

.68 

1 .7 

.58 

.57 

1 .1 

.53 

.70 

1.1 

.40 

1.1 

1.2 

.38 

1.5 

.40 

MS.5 

2-Methyl- 1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

Diisooctyl ester-1,2-benzenedicarboxlic 

acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,O . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,p . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,O . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1 5.0 

- 1 .3 

- .64 

- 1 .6 

- .52 

1 .41 

- .41 

- .75 

- .46 

- .56 

1 .8 

1 .1 

.82 

.75 

.53 

.49 

.88 

Table 13 57 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry

analysis-Continued 

[MO, Missouri; MS, Mississippi; -, no established confidence level; >C,o, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration,

Compound level in milligrams per kilogram 

MS.6 

2-Methyl-1,3-dioxolane-2-propanol. . . . . . . . . . . . . . . 

Saturated hydrocarbon: CIO-C,o . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1 3.9 

- .68 

- .77 

- 1 .6 

- 1 .5 

.65 

1 .7 

.75 

1 .2 

1 .1 

2.8 

1 .1 

1 .1 

.75 

1 .0 

1 .2 

.88 

.65 

1.8 

.97 

MS.7 

5-(Acetyloxy)-2-pentanone . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,,o . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

1,1'-Thiobis-dodecane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . . . . . . . . . . . . . 

Cyclic hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C2o . . . . . . . . . . . . . . . . . . . . . . . . . 

1 4.1 

- .39 

2 .64 

- .56 

- .93 

_ .22 

- .27 

1 .27 

- .92 

- .21 

.46 

.71 

.25 

.61 

.52 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi ; -, no established confidence level ; >CZ0, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration, 

Compound level in milligrams per kilogram 

MS.7-Continued 

Unsaturated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

MS.7 (replicate) 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >Czo . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon. . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . .. . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o. . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

MS.8 

2-Methyl- 1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

Saturated hydrocarbon: Clo-C,o. . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

0.67 

.25 

.64 

.28 

1 3.5 

- .20 

- .27 

- .34 

- 1.3 

.32 

.53 

.21 

.21 

.84 

.23 

.81 

.41 

.59 

.33 

.68 

.28 

.66 

.21 

1 6.2 

- .48 

- .57 

- .25 

- .31 

1.6 

1 .1 

.59 

1 .5 

.33 

Table 13 59 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry analysis-Continued 

[MO, Missouri ; MS, Mississippi; -, no established confidence level ; >C,p, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidence level" column), confident 

identification, whichmeans good agreement was observed between the unknown compound and a specific library spectrum. Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration,

Compound level in milligrams per kilogram 

MS.8-Continued 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . .. ., . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Ethyl ester, acetic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Methyl-1,3-dioxolane-2-propanol. . . . . . . . . . . . . . . 

2,4-Dimethyl-2-pentanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: CIO- C2o . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,o . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C-) o . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Aromatic hydrocarbon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., . ., ., 

4-(Acetyloxy)-2-butanone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

2-Methyl-1,3-dioxolane-2-propanol . . . . . . . . . . . . . . . 

2,4-Dimethyl-2-pentanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: C10- C20 . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

Unsaturated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

-do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

Oxygenated hydrocarbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

0.27 

.35 

.36 

.64 

.53 

.33 

.88 

.78 

.32 

MS.9 

1 0.14 

1 4.4 

1 .16 

- .20 

- .20 

.51 

.18 

.15 

.22 

.24 

.59 

.34 

.60 

MS.10 

1 0.16 

1 5.5 

1 .20 

- .32 

- .24 

.32 

.16 

.43 

.32 

.19 

.45 

.24 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi; -, no established confidence level; >CZO, more than 20 carbon molecular chain; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum ; 2 (in "Confidencelevel" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Confidence Estimated concentration, 

Compound level in milligrams per kilogram 

MS.11 

Saturated hydrocarbon: >GO. . . . . . . . . . . . . . . . . . . . . . . . . . 0.16 

(Z,E)-3,7,11-trimethyl-2,6,10-dodecatrien-l01 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 .18 

Saturated hydrocarbon: >C,o. . . . . . . . . . . . . . . . . . . . . . . . . . - .33 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .24 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .17 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - .34 

MS.12 

4-Methyl-, (Z)-2-pentene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: CIO-CoO. . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9-Hexadecenoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexadecanoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1-Methyl-4-(1-methylethyl)-cyclohexanol . . . . . 

5-Bromo-2,3-dimethyl-2-pentene . . . . . . . . . . . . . . . . . . 

[R- [(E,E)]-3,7,11,15-tetramethyl-6,10,14­

hexadecatrien- l-ol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C-,0. . . . . . . . . . . . . . . . . . . . . . . . . . 

1-(Ethenyloxy)-octadecane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C,O. . . . . . . . . . . . . . . . . . . . . . . . . . 

Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,2-Dimethyl ester 1,2,4-benzenetricarboxylic 

acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 

Alloaromadendrene. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . 

1 0.19 

_ .23 

- .33 

1 1.3 

1 1.7 

1 .14 

1 .16 

1 .23 

- .25 

1 .17 

.28 

.26 

1 .30 

1 .26 

MS.13 

2,4-Dimethyl-3-pentanone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: CIO-C,O. . . . . . . . . . . . . . . . . . . . . Siloxane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

9-Hexadecenoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Hexadecanoic acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

[R- [R,R-(E)] ]-3,7,11,15-tetramethyl-2-

hexadecen-l-o 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

3,7,11-Trimethyl-2,6,10-dodecatrien-1-o 1 . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . 

-do- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

[S-(Z) ]-3,7,11-trimethyl-1,6,10-dodecatrien3-ol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Saturated hydrocarbon: >C20. . . . . . . . . . . . . . . . . . . . . . . . . . (+)-6-methyl-2-(4-methyl-3-cyclohexen-l-yl)-

5-hepten-2-o l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1 0.13 

- .16 

- .34 

1 1 .4 

1 1 .5 

1 .14 

1 .22 

- .27 

- .20 

1 .38 

_ .28 

1 .30 

Table 13 61 
Table 13. Tentatively identified compounds that were detected in the gas chromatography/mass spectrometry 

analysis-Continued 

[MO, Missouri ; MS, Mississippi; -, no established confidence level ; >CZ0, more than 20 carbon molecular chain ; 1 (in "Confidence 

level" column), tentative identification based on an indication of a specific library spectrum; 2 (in "Confidence level" column), confident 

identification, which means good agreement was observed between the unknown compound and a specific library spectrum . Analyzed at 

the Enseco Analytical Laboratory, Arvada, Colorado] 

Compound 

MS.13 

Saturated hydrocarbon : >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

Octadecanal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

3,7,11-Trimethyl-2,6,10-dodecatrien-l-ol . . . . . . 

Saturated hydrocarbon : >C20 . . . . . . . . . . . . . . . . . . . . . . . . . 

--do-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

1,1'-ethylidenebis-cyclohexane . . . . . . . . . . . . . . . . . . . . . . 

5,6-dihydro-5,6-dihydroxy- .beta.-carotene . 

beta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . 

Sclareol . . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . 

Confidence Estimated concentration, 

level in milligrams per kilogram 

(replicate) 

- 0.19 

1 .16 

1 .21 

- .39 

- .35 

1 .19 

1 .31 

1 .51 

Data on Sediments Deposited in the Missouri and the Mississippi River Flood Plains