Concentration of Selected Sulfonylurea,

Sulfonamide, and Imidazolinone Herbicides,

Other Pesticides, and Nutrients in 71 Streams,

5 Reservoir Outflows, and 25 Wells in the

Midwestern United States, 1998

Water-Resources Investigations Report 00–4225

U.S. Department of the Interior

U.S. Geological Survey
U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 00–4225

Concentration of Selected Sulfonylurea,

Sulfonamide, and Imidazolinone Herbicides,

Other Pesticides, and Nutrients in 71 Streams,

5 Reservoir Outflows, and 25 Wells in the

Midwestern United States, 1998

By W.A. Battaglin, E.T. Furlong, and M.R. Burkhardt

Denver, Colorado

2001
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

The use of firm, trade, and brand names in this report is for identification purposes only and does

not constitute endorsement by the U.S. Geological Survey.

For additional information write to: Copies of this report can be purchased

U.S. Geological Survey

Information Services

Box 25286

Federal Center

Denver, CO 80225

from:

District Chief

U.S. Geological Survey

Box 25046, Mail Stop 415

Denver Federal Center

Denver, CO 80225–0046
CONTENTS III

CONTENTS

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

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

Purpose and Scope....................................................................................................................................................... 3

Herbicide Properties .................................................................................................................................................... 3

Previous Investigations and Expected Concentrations ................................................................................................ 4

Acknowledgments ....................................................................................................................................................... 5

Methods ................................................................................................................................................................................. 5

Sampling Sites ............................................................................................................................................................. 5

Sampling Schedule and Procedure .............................................................................................................................. 8

Analytical Methods...................................................................................................................................................... 19

Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides .............................................................................. 19

Other Pesticides and Degradates........................................................................................................................ 20

Nutrients, Physical Properties, and Discharge................................................................................................... 20

Quality Assurance........................................................................................................................................................ 20

Sample Collection.............................................................................................................................................. 20

Analytical Methods............................................................................................................................................ 23

Quality-Assurance Samples for Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides........................... 24

Quality-Assurance Samples for Other Herbicides............................................................................................. 26

Duplicate Analysis of Selected Herbicides........................................................................................................ 26

Occurrence of Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides .......................................................................... 28

Streams ........................................................................................................................................................................ 28

Reservoir Outflows ...................................................................................................................................................... 46

Ground Water............................................................................................................................................................... 46

Occurrence of Other Pesticides.............................................................................................................................................. 47

Streams ........................................................................................................................................................................ 47

Reservoir Outflows ...................................................................................................................................................... 50

Ground Water............................................................................................................................................................... 51

Occurrence of Nutrients and Physical Properties .................................................................................................................. 79

Streams ........................................................................................................................................................................ 79

Reservoir Outflows ...................................................................................................................................................... 96

Ground Water............................................................................................................................................................... 97

Herbicides in Pre-Emergence and Post-Emergence Stream and Reservoir Outflow Samples .............................................. 97

Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides Relative to Atrazine and Metolachlor...................................... 109

Conclusions............................................................................................................................................................................ 120

References Cited.................................................................................................................................................................... 120

FIGURES

1. Graph showing estimated acres of corn, soybeans, and wheat treated with selected sulfonylurea,

sulfonamide, and imidazolinone herbicides, 1998–98, in 11 Midwestern States........................................................ 2

 2. Graph showing EC50 concentrations in micrograms per liter for selected herbicides on five

aquatic plants ............................................................................................................................................................... 4

3–5. Maps showing:

3. Location and associated basin for the nine stream sites with large drainage areas .............................................. 8

4. Location and associated basin for the 62 stream and 5 reservoir sites with smaller

drainage areas ....................................................................................................................................................... 9

5. Location of the 25 well sites................................................................................................................................. 12

6. Diagram showing sample preparation steps for analysis of sulfonylurea, sulfonamide, and

imidazolinone herbicides............................................................................................................................................. 19
IV CONTENTS

7–13. Graphs showing:

7. Recoveries of 16 sulfonylurea, sulfonamide, and imidazolinone herbicides from

27 reagent water samples spiked at 0.050 or 0.10 microgram per liter .......................................................... 25

8. Differences between herbicide concentrations in 28 pairs of unspiked laboratory duplicate

natural-water samples ..................................................................................................................................... 26

9. Recoveries of 16 sulfonylurea, sulfonamide, and imidazolinone herbicides from 28 surfaceand ground-water samples spiked at 0.10 microgram per liter. The recoveries are corrected

for the ambient water herbicide concentration................................................................................................ 27

10. Differences between herbicide concentrations in 21 pairs of unspiked field duplicate naturalwater samples.................................................................................................................................................. 28

11. Percent differences between herbicide concentrations reported by the National Water Quality

Laboratory and concentrations reported by the Organic Geochemistry Research Laboratory for

177 surface- and ground-water samples.......................................................................................................... 29

12. Differences between herbicide concentrations reported by the National Water Quality Laboratory

and concentrations reported by the Organic Geochemistry Research Laboratory for 177 surfaceand ground-water samples .............................................................................................................................. 29

13. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations and percent detections

at or above the method reporting limit of 0.01 microgram per liter in 133 stream samples........................... 42

14–16. Maps showing:

14. Spatial distributions of imazethapyr concentrations in: (A) pre-emergence samples from

small stream and reservoir outflow sites, (B) pre-emergence samples from large river sites,

(C) post-emergence samples from small stream and reservoir outflow sites, and (D) postemergence samples from large river sites ....................................................................................................... 43

15. Spatial distributions of flumetsulam concentrations in: (A) pre-emergence samples from

small stream and reservoir outflow sites, (B) pre-emergence samples from large river sites,

(C) post-emergence samples from small stream and reservoir outflow sites, and (D) postemergence samples from large river sites ....................................................................................................... 44

16. Spatial distributions of nicosulfuron concentrations in: (A) pre-emergence samples from

small stream and reservoir outflow sites, (B) pre-emergence samples from large river sites,

(C) post-emergence samples from small stream and reservoir outflow sites, and (D) postemergence samples from large river sites ....................................................................................................... 45

17–24. Graphs showing:

17. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in eight reservoir

outflow samples............................................................................................................................................... 47

18. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in 25 groundwater samples.................................................................................................................................................. 51

19. Pesticide and pesticide degradate (2,6-diethylaniline to fonofos) concentrations and percent

detections at or above the method detection limit in 134 stream samples...................................................... 79

20. Pesticide and pesticide degradate (lindane to trifluralin) concentrations and percent detections

at or above the method detection limit in 134 stream samples ....................................................................... 79

21. Herbicide and herbicide degradate concentrations and percent detections at or above the

method reporting limit in 141 midwestern stream samples ............................................................................ 97

22. Concentrations of atrazine in samples collected from midwestern streams and reservoir

outflows in relation to: (A) imazethapyr, (B) flumetsulam, and (C) nicosulfuron .......................................... 118

23. Concentrations of metolachlor in samples collected from midwestern streams and reservoir

outflows in relation to: (A) imazethapyr, (B) flumetsulam, and (C) nicosulfuron .......................................... 119

24. Ratios of imazethapyr, flumetsulam, and nicosulfuron concentrations to atrazine and metolachlor

concentrations in pre- and post-emergence stream and reservoir outflow samples ........................................ 119
CONTENTS V

TABLES

1. Common names, trade names, and manufacturers for pesticides analyzed for in this study.................................. 6

2. Surface-water sampling sites .................................................................................................................................. 10

3. Ground-water sampling sites and sample type, number, and date of collection..................................................... 13

4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from

surface-water sites................................................................................................................................................... 14

5. Method of determination or analysis and reporting limits for physical properties and chemical

compounds in water samples .................................................................................................................................. 21

6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from

71 midwestern streams and 5 midwestern reservoirs ............................................................................................. 30

7. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations

in 133 water samples from 71 midwestern streams................................................................................................ 42

8. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations

in eight water samples from the outflow of five midwestern reservoirs ................................................................. 46

9. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples collected

from 25 midwestern wells....................................................................................................................................... 48

10. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in

25 water samples from 25 midwestern wells.......................................................................................................... 50

11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water

samples from 70 midwestern streams and 5 midwestern reservoirs....................................................................... 52

12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from

70 midwestern streams and 5 midwestern reservoirs ............................................................................................. 62

13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples

from 70 midwestern streams and 5 midwestern reservoirs..................................................................................... 72

14. Statistical summary of 46 pesticide and pesticide degradate concentrations in 134 water samples

from 71 midwestern streams................................................................................................................................... 78

15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern

reservoirs................................................................................................................................................................. 80

16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and

5 midwestern reservoirs .......................................................................................................................................... 90

17. Statistical summary of 23 herbicide and herbicide degradate concentrations in 141 water samples

from 71 midwestern streams................................................................................................................................... 96

18. Statistical summary of 46 pesticide and pesticide degradate concentrations in 10 water samples

from five midwestern reservoir outflows ................................................................................................................ 98

19. Statistical summary of 13 herbicide and 10 herbicide degradate concentrations in 10 water

samples from five midwestern reservoir outflows .................................................................................................. 99

20. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in

water samples collected in 1998 from 23 midwestern wells .................................................................................. 100

21. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples

from 23 midwestern wells....................................................................................................................................... 102

22. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples

from 23 midwestern wells....................................................................................................................................... 104

23. Statistical summary of 46 pesticide and pesticide degradate concentrations in 23 water samples

from 23 midwestern wells....................................................................................................................................... 105

24. Concentrations of 13 herbicides in water samples from 25 midwestern wells....................................................... 106

25. Concentrations of 10 herbicide degradates in water samples from 25 midwestern wells ...................................... 108

26. Statistical summary of 13 herbicide and 10 herbicide degradate concentrations in 25 water

samples from 25 midwestern wells......................................................................................................................... 109
VI CONTENTS

27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and

outflow from five midwestern reservoirs................................................................................................................. 110

28. Statistical summary of nutrient, field, and discharge data in water samples from 71 midwestern

streams..................................................................................................................................................................... 115

29. Statistical summary of nutrient, field, and discharge data in water samples from five midwestern

reservoir outflows.................................................................................................................................................... 115

30. Concentrations of nutrients and field data for water samples from 25 midwestern wells ...................................... 116

31. Statistical summary of nutrient and field data in water samples from 25 midwestern wells .................................. 117

32. Statistical summary of selected herbicide concentrations and discharge in pre-emergence and postemergence water samples from midwestern streams and reservoir outflows.......................................................... 117

33. Median of differences between post-emergence and pre-emergence concentrations of selected herbicides

and Wilcoxon signed-rank test results..................................................................................................................... 118
Abstract 1

Abstract

Sulfonylurea (SU), sulfonamide (SA),

and imidazolinone (IMI) herbicides are recently

developed herbicides that function by inhibiting

the action of a key plant enzyme, stopping

plant growth, and eventually killing the plant.

These compounds generally have low mammalian

toxicity, but crop and non-crop plants demonstrate

a wide range in sensitivity to SUs, SAs, and

IMIs, with over a 10,000-fold difference in

observed toxicity levels for some compounds.

SUs, SAs, and IMIs are applied either pre- or

post-emergence to crops commonly at 1/50th

or less of the rate of other herbicides. Little is

known about their occurrence, fate, or transport

in surface water or ground water in the United

States.

To obtain information on the occurrence

of SU, SA, and IMI herbicides in the Midwestern

United States, 214 water samples were collected

from 76 surface-water and 25 ground-water

sites in 1998. These samples were analyzed for

16 SU, SA, and IMI herbicides by using highperformance liquid chromatography/mass

spectrometry. Samples also were analyzed for

46 pesticides and pesticide degradation products

and 13 herbicides and 10 herbicide degradates.

At least 1 of the 16 SUs, SAs, or IMIs was

detected at or above the method reporting limit of

0.010 microgram per liter (μg/L) in 83 percent of

133 stream samples. Imazethapyr was detected

most frequently (69 percent of samples), followed

by flumetsulam (65 percent of samples) and nicosulfuron (53 percent of samples). At least one

SU, SA, or IMI herbicide was detected at or above

the method reporting limit in 6 of 8 reservoir

samples and 5 of 25 ground-water samples. SU,

SA, and IMI herbicides occurred less frequently

and at a fraction (often 1/50th or less) of the

concentrations of other herbicides such as atrazine. Acetochlor, atrazine, cyanazine, and metolachlor were all detected in 95 percent or more of

136 stream samples.

INTRODUCTION

 During the last 20 years, low application

rate herbicides have been developed that act by

inhibiting the action of a key plant enzyme, which

stops plant growth and eventually causes plant death.

Sulfonylurea (SU), sulfonamide (SA), and imidazolinone (IMI) herbicides are three classes of compounds

that share this mode of action (Whitcomb, 1998;

Meister, 1999). Crops that can be treated with SU, SA,

and IMI herbicides include barley, corn, cotton, durum

wheat, rice, canola, peanuts, soybeans, sugar beets,

spring wheat, and winter wheat. Some compounds

also are approved for use on Conservation Reserve

Program acreage and for noncropland weed

control.

The amount of cropland in the Midwestern

United States treated with SU, SA, and IMI herbicides

nearly tripled between 1990 and 1997. The total

Concentration of Selected Sulfonylurea, Sulfonamide,

and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and

25 Wells in the Midwestern United States, 1998

By W.A. Battaglin, E.T. Furlong, and M.R. Burkhardt
2 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

0

10

20

30

40

50

60

70

MILLIONS OF ACRES

90 91 92 93 94

YEAR

95 96 97 98

Imidazolinones

Sulfonamides

Sulfonylureas

corn, soybean, and wheat acreages on which nine SUs,

one SA, and two IMIs were applied in 11 Midwestern

States (Illinois, Indiana, Iowa, Kansas, Kentucky,

Minnesota, Missouri, Nebraska, Ohio, South Dakota,

and Wisconsin) from 1990 through 1998 are shown in

figure 1 (U.S. Department of Agriculture, 1991–99).

In 1997, more than 66 million acres were treated

with one of the 12 herbicides. For comparison, in

the same 11-State area, atrazine, a triazine herbicide,

was used on 41 million acres of corn; metolachlor, a

chloroacetanilide herbicide, was used on 23 million

acres of corn and soybeans; and glyphosate, an amino

acid derivative, was used on 16 million acres of corn,

soybeans, or wheat. In 1998, only 45 million acres of

cropland were treated with one of the 12 low application rate herbicides, while 43 million acres were

treated with atrazine, 21 million acres were treated

with metolachlor, and 29 million acres were treated

with glyphosate (U.S. Department of Agriculture,

1999).

Although applied over comparable areas as

triazine or chloroacetanilide herbicides, SU, SA, and

IMI herbicides are frequently applied after crops have

emerged, and at low rates (typically less than 25 grams

active ingredient per hectare). These application rates

are commonly 1/50th or less of the rates for triazine or

chloroacetanilide herbicides (typically more than

1,200 grams per hectare). Hence, the total amount of

SU, SA, and IMI herbicides applied annually is small

compared to the amount of triazines and chloroacetanilides applied. For example, in 1997 in the 11-State

area, an estimated 22,390 tons of atrazine, 23,680 tons

of metolachlor, and 5,660 tons of glyphosate were

applied to cropland, while the total estimated use

of the nine SUs, one SA, and two IMIs was only

1,200 tons (U.S. Department of Agriculture, 1998).

In 1998, an estimated 23,770 tons of atrazine,

20,760 tons of metolachlor, and 12,450 tons of

glyphosate were applied to cropland, while the estimated use of the nine SUs, one SA, and two IMIs was

only 676 tons (U.S. Department of Agriculture, 1999).

Little was known about the occurrence, fate,

or transport of SUs, SAs, and IMIs in the hydrologic

systems in the United States. To gain a better understanding of the occurrence of these herbicides, a

Cooperative Research and Development Agreement

(CRADA) between the U.S. Geological Survey

(USGS) and DuPont Agricultural Products was initiated in 1997. Battaglin and others (1998b) provided

a complete description of this CRADA. The overall

objective of the CRADA was to determine if and at

what concentrations selected SUs, SAs, and IMIs

occur in surface- and ground-water resources of

the Midwestern United States. Specific objectives

included:

• Developing an analytical method for selected

SUs, SAs, and IMIs.

• Conducting a reconnaissance to determine the

environmental occurrence of SU, SA, and

IMI herbicides in surface water and ground

water.

• Determining the frequency of detection and

concentration distributions of SU, SA, and

IMI herbicides relative to those of selected

other herbicides.

Figure 1. Estimated acres of corn, soybeans, and wheat

treated with selected sulfonylurea, sulfonamide, and imidazolinone herbicides, 1998–98, in 11 Midwestern States.
INTRODUCTION 3

These specific hypotheses were tested:

• The frequency of detections and concentrations of

SU, SA, and IMI herbicides were significantly

less than those of other herbicides that are applied

in greater total amounts.

• The frequency of detections and concentrations of

SU, SA, and IMI herbicides were greater in postemergence runoff samples than in pre-emergence

runoff samples.

• The frequency of detections and concentrations

of SU, SA, and IMI herbicides were greater in

streams and reservoirs than in ground water.

• The frequency of detections and concentrations

of SU, SA, and IMI herbicides were greater in

smaller watersheds that are predominantly agricultural than in larger watersheds that have more

diverse land use and land cover.

Purpose and Scope

The purpose of this report is to describe

analytical and data-collection methods and qualityassurance procedures and present data on selected SU,

SA, and IMI herbicides, other pesticides, nutrients,

and streamflow for samples collected in the spring and

summer of 1998. These data are only adequate to identify the occurrence of selected SU, SA, IMI, and other

pesticides during spring and summer runoff events in

Midwestern streams and in ground water in parts of

Iowa and Illinois. More data would be needed to estimate annual mean concentrations of detected analytes

or to ensure that analytes that were not detected are not

present at other times of the year.

Herbicide Properties

The soil half-lives of SUs, SAs, and IMIs generally range from 1 to 25 weeks depending on soil type,

soil pH, and temperature. Their water solubilities

range from 6 to 40,000 milligrams per liter (mg/L).

The water solubilities of SUs are dependent on water

pH. SUs degrade by chemical hydrolysis and microbial activity. SUs degrade faster in warm, moist, low

pH soils with low organic content (DuPont, 1998).

IMIs degrade by microbial activity and photolysis.

IMIs degrade faster in warm, moist, low organic soils

(Goetz and others, 1990).

SUs, SAs, and IMIs act upon a key plant

enzyme (acetolactate synthase) that is not found in

mammals or other animals. These herbicides are

reported to have very low toxicities in animals

(Brown, 1990; Meister, 1999). Terrestrial and aquatic

plants demonstrate a wide range in sensitivity to SUs,

SAs, and IMIs (Peterson and others, 1994; Whitcomb,

1998) with over a 10,000-fold difference in observed

toxicity levels for some compounds. EC50 concentrations are measures of compound toxicity. An EC50 is

the concentration in water of a compound that causes

a 50-percent reduction in a chosen plant characteristic

for which a toxicity endpoint exists. For example,

EC50s for algae can be calculated from laboratory

tests measuring biomass development in the presence

of varying compound concentrations. EC50 values

for selected SU, SA, IMI, and other herbicides on

five aquatic plants are shown in figure 2 (Fahl and

others, 1995; U.S. Environmental Protection Agency,

2000; Sabater and Carrasco, 1997; Fairchild and

others, 1997; Wei and others, 1998; C.J. Peter, DuPont

Agricultural Products, written commun., 1999). The

EC50 values plotted are for green algae (Selenastrum

capricornutum), duckweed (Lemna gibba), blue-green

algae (Anabaena flos-aquae), freshwater algae (Scenedesmus costatum), and freshwater diatom (Navicula

pelliculosa). In some cases, EC50 values from more

than one test on the same plant species are included.

EC50 values for several herbicides range over three

orders of magnitude. The EC50 data plotted in figure 2

support the hypothesis that an individual concentration

of 0.1 μg/L (microgram per liter) in water is an acceptable baseline for non-target aquatic plant toxicity.

SUs, SAs, and IMIs are active at very low

concentrations. They can cause reduced yields in some

crop rotations, even when only 1 percent or less of the

originally applied material remains. Some of these

herbicides have demonstrated residual phytotoxicity to

rotation crops such as corn, sunflowers, sugar beets,

and dry beans (Anderson and Humburg, 1987; Curran

and others, 1991). The labels of some of these herbicides restrict the planting of certain rotational crops.

Fletcher and others (1993) indicated that spray drift

containing SUs at concentrations less than 1 percent
4 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

of the recommended application rate may adversely

impact fruit tree yields. Felsot and others (1996)

suggested that the appearance of chlorotic spots on

crops in south-central Washington is a result of exposure to low levels of SU herbicides from precipitation

and not from direct spray drift. However, Obrigawitch

and others (1998) questioned the validity of Fletcher’s

findings and the results of other studies (Al-Khatib and

others, 1992; Curran and others, 1991) that based their

findings on short-term plant-response assessments.

Obrigawitch and others (1998) found that a treatment

rate of 0.1 gram of the most active SU ingredient

per hectare (0.00009 pound per acre) represents a

“threshold dose” and would be unlikely to reduce the

yields of even the most sensitive non-target plants.

Previous Investigations and Expected

Concentrations

Detections of SUs, SAs, and IMIs in water

collected from environmental settings have been

rare, and the few reported detections have been

at nanogram per liter concentrations (Bergstrom,

1990; Michael and Neary, 1993; D’Ascenzo and

others, 1998; Okamoto and others, 1998; Steinheimer

and others, 2000; Battaglin and others, 2000).

Bensulfuron

Chlorimuron

Chlorsulfuron

Flumetsulam

Halosulfuron

Imazapyr

Imazaquin

Imazathapyr

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Trisulfuron

Triflusulfuron

Acetochlor

Atrazine

Metolachlor

CONCENTRATION, IN MICROGRAMS PER LITER

0.01 1.0 100 10,000 1,000,000

Green algae

Duckweed

Bluegreen algae

Freshwater diatom

Freshwater algae

EXPLANATION

Figure 2. EC50 concentrations in micrograms per liter for selected herbicides on five aquatic

plants.
METHODS 5

However, several studies indicate that some SU, SA,

and IMI herbicides may leach beyond the active root

zone and enter ground-water or surface-water systems

(Anderson and Humburg, 1987; Bergstrom, 1990;

Flury and others, 1995; Veeh and others, 1994). Once

in ground water or surface water, some SUs, SAs,

and IMIs will tend to persist as the parent compound

while others will tend to hydrolyze (Dinelli and others,

1997; Harvey and others, 1985). A study by Afyuni

and others (1997) indicated that between 1.1 and

2.3 percent of an applied SU was lost in runoff during

a simulated rainfall event 24 hours after herbicide

application.

Because of their low application rates and low

overall use amounts, SU, SA, and IMI herbicides were

expected to occur at below part-per-billion concentrations in most water resources. One also can assume,

based upon their chemical characteristics, application

rates, and acres treated, that individual SU, SA, and

IMI herbicides would be expected to occur in surface

or ground water at 1 to 0.1 percent or less of the

concentration of the more commonly used triazine

herbicides. The USGS measured concentrations of

11 common herbicides and 2 herbicide metabolites

in samples from 52 midwestern streams during runoff

events that occurred soon after herbicide application

in 1989, 1990, 1994, and 1995 (Goolsby and others,

1994; Scribner and others, 1998). Median atrazine

concentration for the 4 years of data ranged from 5.5

to 10.9 μg/L; median cyanazine concentrations ranged

from 1.3 to 2.7 μg/L; and median metolachlor concentrations ranged from 1.7 to 2.5 μg/L. Maximum

concentrations for these three compounds for the

4 years ranged from 10.6 to 108 μg/L. Thus, one

could expect to observe SU, SA, and IMI herbicides

in midwestern streams during post-application runoff

events at concentrations ranging from 0.001 to

0.1 μg/L. Further, one could expect maximum concentrations of SU, SA, and IMI herbicides to range from

0.01 to 1.0 μg/L (Battaglin and others, 1998a). The

concentrations of triazine herbicides observed in

ground water (Kolpin and others, 1994) are generally

one to two orders of magnitude less than those

observed in streams during post-application runoff.

Hence, one would expect that SU, SA, and IMI

concentrations would seldom exceed 0.01 μg/L in

ground water.

Acknowledgments

Mariel Rodriguez, C. John Peter, Michael

Duffy, and Dayan Goodnough of DuPont Agricultural

Products provided information and insights regarding

the environmental and analytical chemistry of the

herbicides investigated. Samples for this study were

collected by USGS employees from Illinois, Indiana,

Iowa, Kansas, Kentucky, Minnesota, Missouri,

Nebraska, Ohio, and Wisconsin and analyzed

by USGS employees at the National Water Quality

Laboratory (NWQL) in Lakewood, Colorado, and the

USGS Laboratory in Lawrence, Kansas. The authors

are grateful for comments by Michael Duffy, DuPont,

and reviews by Tom Leiker, Donald Goolsby, and

John Flager of the USGS.

METHODS

The study involved collection of more

than 200 samples during a 1998 reconnaissance.

Samples were collected in the spring and early

summer from streams, large rivers, reservoir outflows,

and wells, sometimes in conjunction with USGS

National Stream Quality Accounting Network

(NASQAN) (Hooper and others, 1997) and National

Water-Quality Assessment (NAWQA) (Leahy and

Thompson, 1994) activities. All reconnaissance

samples were analyzed for 16 SU, SA, and IMI herbicides (table 1) using high-performance liquid chromatography coupled with mass spectrometry. This

custom analytical method has an estimated method

reporting limit (MRL) of 0.010 μg/L for all analytes

and is fully described by Furlong and others (2000).

All samples also were analyzed for 69 other pesticides

or degradates.

Sampling Sites

Samples were collected from 71 sites on

free-flowing streams in the Upper Mississippi,

Missouri, and Ohio River basins (figs. 3 and 4,

table 2). Fifty-two of the surface-water sites have

been studied in previous Midcontinent Herbicide

Initiative (MHI) investigations (Thurman and others,

1992; Goolsby and others, 1994; Scribner and others,
6 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 1. Common names, trade names, and manufacturers for pesticides analyzed for in this study (data from Larson and

others, 1997; Meister, 1999)

Common name Chemical class Trade names Primary bulk producer(s)

Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides

bensulfuron methyl sulfonylurea Londax DuPont

chlorimuron ethyl sulfonylurea Classic, Preview DuPont

chlorsulfuron sulfonylurea Glean, Telar, Finesse DuPont

flumetsulam sulfonamide Broadstrike, Preside, Scorpion, Python Dow AgroSciences

halosulfuron methyl sulfonylurea Battalion, Manage, Permit, Sempra Monsanto, Nissan

imazapyr imidazolinone Arsenal, Chopper, Lightning BASF

imazaquin imidazolinone Scepter, Detail, Squadron BASF

imazethapyr imidazolinone Pursuit, Lightning, Contour BASF

metsulfuron methyl sulfonylurea Allie, Ally, Escort, Finesse, Canvas DuPont

nicosulfuron sulfonylurea Accent, Basis Gold, Celebrity+ DuPont

primisulfuron methyl sulfonylurea Beacon, Tell, Exceed Novartis

prosulfuron sulfonylurea Peak, Exceed Novartis

sulfometuron methyl sulfonylurea Oust DuPont

thifensulfuron methyl sulfonylurea Pinnacle, Canvas, Basis, Reliance, Harmony DuPont

triasulfuron sulfonylurea Amber, Graminon Forte Novartis

triflusulfuron methyl sulfonylurea Upbeet DuPont

Other Pesticides and Degradates

acetochlor chloroacetamide Harness, Field Master, Surpass Monsanto, Zeneca

alachlor acetanilide Lasso, Partner, Lariat, Bronco, Freedom Monsanto, Crystal

2,6-diethylaniline alachlor degradate

atrazine triazine AAtrex, Gesaprim, Bicep Novartis

deethylatrazine atrazine degradate

azinphos-methyl organophosphate Guthion, Gusathion Bayer

benfluralin (Benefin) dinitroaniline Balan Dow AgroScience

butylate thiocarbamate Sutan + Micro Flo

carbaryl carbamate Sevin, Sevimol Aventis

carbofuran carbamate Furadan FMC

chlorpyrifos organophosphate Dursban, Empire Dow AgroSciences

cyanazine triazine Bladex BASF

dacthal chlorobenzoic acid Dacthal Zeneca

diazinon organophosphate Basudin, Knoxout Novartis, Cleary Chemical

dieldrin organochlorine Dieldrex (discontinued, 1991) Shell

disulfoton organophosphate Disyston, Furmin AL Bayer, Novartis

EPTC thiocarbamate Eptam, Eradicane Zeneca

ethalfluralin dinitroaniline Sonalan Dow AgroScience

ethoprophos organophosphate Chipco, Mocap Aventis

fonofos organophosphate fonofos Zeneca

lindane organochloride Sevidol Aventis

linuron urea Lorox, Metolin DuPont

malathion organophosphate Malatox, Malixol Helb USA, Aventis

metolachlor chloracetanilide Dual, Pennant, Derby, Bicep Novartis

metribuzin triazine Contrast, Turbo, Sencor, Lexone, Canopy Bayer, DuPont

molinate thiocarbamate Ordram Zeneca

napropamide amide Devrinol United Phosphorus

parathion organophosphate not registered for use in U.S. BASF
METHODS 7

Other Pesticides and Degradates—Continued

parathion methyl organophosphate Bladan, Metacide Bayer

pebulate thiocarbamate Tillam Zeneca

pendimethalin dinitroaniline Accotab, Herbadox, Stomp BASF, Scotts

phorate organophosphate Geomet, Thimet, Granutox BASF

prometon triazine Pramitol Novartis

propachlor acetanilide Ramrod Monsanto

propanil amide Surcopur, Cedar Porpanil Bayer, Cedar Chemical

propargite sulfite ester Comite, Omite, Ornamite Uniroyal Chemical

propyzamide (also pronamide)amide Kerb, Rapier Rohm and Haas, United Phosphorus

simazine triazine Gesatop, Princep, Derby Novartis

tebuthiuron urea Spike Dow AgroScience

terbacil urea Sinbar DuPont

terbufos organophosphate Contraven, Counter BASF

thiobencarb thiocarbamate Bolero, Saturn, Bigturn, Tobosa Kumiai Chemical, Sanonda,

Crystal Inter-America

tri-allate thiocarbamate Far-Go, Buckle Monsanto

trifluralin dinitroaniline Treflan, Trilin, Tri-Scept Dow AgroScience, Griffin

alpha-HCH organochlorine degradate of BHC, not sold for use in U.S. Hooker Chemical

cis-Permethrin pyrethroid Ambush, Prelude, Dragon, Permit, Outflank,

Astro, Flee, Ancothrin

BASF, FMC, Zeneca, Sanonda,

Helb USA

Other Herbicides and Degradates

acetochlor chloroacetamide Harness, Field Master, Surpass Monsanto, Zeneca

acetochlor ESA acetochlor degradate

acetochlor oxanilic acid acetochlor degradate

alachlor acetanilide Lasso, Partner, Lariat, Bronco, Freedom Monsanto, Crystal

alachlor ESA alachlor degradate

alachlor oxanilic acid alachlor degradate

ametryn triazine Evik, Gesapaz, Crisatrina Monsanto, Crystal

atrazine triazine AAtrex, Gesaprim, Bicep Novartis

deethylatrazine atrazine degradate

deisopropylatrazine atrazine degradate

hydroxy-atrazine atrazine degradate

cyanazine triazine Bladex BASF

cyanazine-amide cyanazine degradate

metolachlor chloracetanilide Dual, Pennant, Derby, Bicep Novartis

metolachlor ESA metolachlor degradate

metolachlor oxanilic acid metolachlor degradate

metribuzin triazine Contrast, Turbo, Sencor, Lexone, Canopy Bayer, DuPont

prometon triazine Pramitol Novartis

prometryn triazine Cotton-Pro, Caparol, Gesagard Novartis, Griffin

propachlor acetanilide Ramrod Monsanto

propazine triazine Prozinex Makhteshim-Agan

simazine triazine Gesatop, Princep, Derby Novartis

terbutryn triazine Ternit, Terbutrex Crystal, Makhteshim-Agan

Table 1. Common names, trade names, and manufacturers for pesticides analyzed for in this study (data from Larson and

others, 1997; Meister, 1999)—Continued

Common name Chemical class Trade names Primary bulk producer(s)
8 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

MONTANA

NORTH

DAKOTA

SOUTH

DAKOTA

WYOMING

COLORADO

KANSAS

IOWA

ILLINOIS

INDIANA OHIO

WEST

VIRGINIA

MICHIGAN

PENNSYLVANIA

MINNESOTA

MISSOURI

TENNESSEE

KENTUCKY

WISCONSIN

NEBRASKA

58

45

13

23

17

46

12

42 52

0 100 200 300 MILES

0 100 200 300 KILOMETERS

12

13

17

23

42

45

46

52

58

Illinois River at

 Valley City, Illinois

Mississippi River below

 Grafton, Illinois

Mississippi River at

 Clinton, Iowa

Iowa River at Wapello,

 Iowa

Wabash River at New

 Harmony, Indiana

Ohio River at Cannelton

 Dam, Kentucky

Platte River at Louisville,

 Nebraska

Sampling data

Basin name and number

EXPLANATION

Mississippi River at

 Hastings, Minnesota

Minnesota River near

 Jordan, Minnesota

105° 95°

45°

40°

85°

1998). These sites were selected from the set

of 150 sites sampled in 1989 using a stratified

random method (Scribner and others, 1993). The

sampling strategy used was not designed to produce

an unbiased estimate of herbicide occurrence in all

midwestern streams; rather, the intent was to target

higher risk areas while still capturing the variability

of the entire population. Samples also were collected

at 19 NASQAN or NAWQA sites. Figure 3 shows

locations and associated basins for the sites with

the nine largest drainage areas. The drainage

areas for these sites ranged from 12,499 to

171,300 square miles, and the median drainage

area was 37,050 square miles. Figure 4 shows locations and associated basins for the other 62 sites on

free-flowing streams. Drainage areas for these sites

ranged from 77.7 to 10,400 square miles, and the

median drainage area was 655 square miles.

Samples also were collected just downstream

from five reservoirs (table 2) at locations that had been

sampled in a previous investigation (Coupe and others,

1995; Scribner and others, 1996). The locations and

associated basins for these sites area also are shown

in figure 4. Drainage areas for these sites ranged from

298 to 9,628 square miles.

Ground-water samples were collected from

25 wells in Iowa and Illinois (fig. 5, table 3). Twenty

samples are from a network of municipal wells in Iowa

that are part of the Iowa Ground Water Monitoring

(IGWM) program (Detroy and others, 1988; Kolpin

and others, 1997). Wells from this network have been

sampled systematically since 1982. The depths to the

top of the well screen for the 20 sampled wells ranged

from 6 to 83 meters with 16 of the 20 being less than

20 meters. Five samples are from observation wells in

the Lower Illinois NAWQA study unit (Warner and

Schmidt, 1994). These five wells were all less than

8 meters deep.

Sampling Schedule and Procedure

Two samples were collected at each surfacewater and reservoir site, and one sample was collected

at each ground-water site in 1998. The first surfacewater samples were collected after pre-emergence

herbicides were applied (May or June) and following a

precipitation event that produced a significant increase

in streamflow. These samples will be referred to as

pre-emergence runoff samples. These samples are

comparable to the “post-application” samples

Figure 3. Location and associated basin for the nine stream sites with large drainage areas.
METHODS 9

54 60 56

57

55

62 61

49

50

51

59

53

31

11

25 8 24

21

22

19

18

16 75

76 4

73

6

36 35

71

64 65

66 70

69

68

67 63

72

37

33

38

39

40

41

34

10

9

1

15 2

3

14

7

27 5

26

20

47

48

43

44

74

32

30

29

28

NORTH DAKOTA

SOUTH DAKOTA

NEBRASKA

KANSAS

MINNESOTA

MISSOURI

ILLINOIS

INDIANA

KENTUCKY

IOWA

WISCONSIN

MICHIGAN

OHIO

Missouri River

Mississippi River

Ohio

River

0 100 200 MILES

0 100 200 KILOMETERS

45°

40°

95° 85°

1–Vermillion River, Lake Vermillion, IL

2–Bonpas Creek at Browns, IL

3–Little Wabash River at Carmi, IL

4–S. Branch Kishwaukee River, Fairdale, IL

5–Iroquois River near Chebanse, IL

6–Dupage River near Shorewood, IL

7–Illinois River at Marseilles, IL

8–Spoon River at London Mills, IL

9–Sangamon River near Monticello, IL

10–Sangamon River at Riverton, IL

11–LaMoine River at Colmar, IL

14–Kaskaskia River near Cowden, IL

15–Shoal Creek near Breese, IL

16–Turkey River at Spillville, IA

18–Wapsipinicon River near Tripoli, IA

19–Wapsipinicon River at Independence, IA

20–Iowa River near Rowan, IA

21–Old Mans Creek near Iowa City, IA

22–Wolf Creek near Dysart, IA

24–N. Skunk River near Sigourney, IA

25–Skunk River at Augusta, IA

26–Des Moines River at Fort Dodge, IA

27–Raccoon River at Van Meter, IA

28–Little Sioux River, Correctionville, IA

29–Maple River at Mapleton, IA

30–Boyer River at Logan, IA

31–Chariton River below Rathbun Lake, IA

32–Nishnabotna River above Hamburg, IA

33–Whitewater River near Alpine, IN

34–Blue River at Fredericksburg, IN

35–Mississinewa River, Mississinewa Lake, IN

36–Eel River near Logansport, IN

37–Wildcat Creek near Jerome, IN

38–Wildcat Creek near Lafayette, IN

39–White River near Nora, IN

40–Sugar Creek near Edinburgh, IN

41–E. Fork White River near Bedford, IN

43–Cottonwood River near New Ulm, MN

44–Little Cobb River near Beauford, MN

47–Des Moines River at Jackson, MN

48–Rock River at Luverne, MN

49–Black Vermillion River, Frankfort, KS

50–Big Blue River, Tuttle Creek Lake, KS

51–Delaware River near Muscotah, KS

53–Nodaway River near Graham, MO

54–North Dry Creek near Kearney, NE

55–Maple Creek near Nickerson, NE

56–Salt Creek at Roca, NE

57–Wahoo Creek at Ithaca, NE

59–Big Nemaha River, Falls City, NE

60–W. Fork Big Blue River, Dorchester, NE

61–Big Blue River at Barneston, NE

62–Little Blue River near Fairbury, NE

63–Clear Creek near Rockbridge, OH

64–Scioto River near Prospect, OH

65–Olentangy River at Claridon, OH

66–Olentangy River, Delaware Lake, OH

67–Big Darby Creek at Darbyville, OH

68–Scioto River at Higby, OH

69–L. Miami River near Oldtown, OH

70–Mad River at Eagle City, OH

71–Tiffin River at Stryker, OH

72–Auglaize River at Ft. Jennings, OH

73–Root River at Racine, WI

74–St. Croix River, St. Croix Falls, WI

75–Wisconsin River at Muscoda, WI

76–Rock River at Afton, WI

Stream sampling site

Reservoir sampling site

Sampling site name

EXPLANATION

Figure 4. Location and associated basin for the 62 stream and 5 reservoir sites with smaller drainage areas.
10 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 2. Surface-water sampling sites

[mi2, square miles; dd, degrees; mm, minutes; ss, seconds]

Site no.

(figs. 3, 4)

Station

identification

no.

Site name Site

type

Drainage

area

(mi2)

Latitude

(ddmmss)

Longitude

(ddmmss)

Illinois

1 03338890 Vermillion River below Lake Vermillion Dam, IL reservoir 298 400924 873906

2 03378000 Bonpas Creek at Browns, IL stream 228 382311 875832

3 03381495 Little Wabash River at Carmi, IL stream 3,088 380532 880922

4 05439500 S. Branch Kishwaukee River near Fairdale, IL stream 387 420639 885402

5 05526000 Iroquois River near Chebanse, IL stream 2,091 410032 874927

6 05540500 Dupage River near Shorewood, IL stream 324 413120 881135

7 05543500 Illinois River at Marseilles, IL stream 8,259 411937 884303

8 05569500 Spoon River at London Mills, IL stream 1,072 404232 901653

9 05572000 Sangamon River near Monticello, IL stream 550 400151 883520

10 05576500 Sangamon River at Riverton, IL stream 2,618 395034 893252

11 05584500 LaMoine River at Colmar, IL stream 655 401945 905355

12 05586100 Illinois River at Valley City, IL stream 26,743 394212 903843

13 05587455 Mississippi River below Grafton, IL stream 171,300 385805 902542

14 05592100 Kaskaskia River near Cowden, IL stream 1,330 391350 885033

15 05594000 Shoal Creek near Breese, IL stream 735 383635 892940

Iowa

16 05411600 Turkey River at Spillville, IA stream 177 431228 915656

17 05420500 Mississippi River at Clinton, IA stream 85,600 414650 901507

18 05420680 Wapsipinicon River near Tripoli, IA stream 343 425010 921526

19 05421000 Wapsipinicon River at Independence, IA stream 1,048 422749 915342

20 05449500 Iowa River near Rowan, IA stream 429 424536 933723

21 05455100 Old Mans Creek near Iowa City, IA stream 201 413623 913656

22 05464220 Wolf Creek near Dysart, IA stream 299 421506 921755

23 05465500 Iowa River at Wapello, IA stream 12,499 411041 911055

24 05472500 N. Skunk River near Sigourney, IA stream 730 411803 921216

25 05474000 Skunk River at Augusta, IA stream 4,303 404513 911640

26 05480500 Des Moines River at Fort Dodge, IA stream 4,190 423022 941204

27 05484500 Raccoon River at Van Meter, IA stream 3,441 413202 935659

28 06606600 Little Sioux River at Correctionville, IA stream 2,500 422820 954749

29 06607200 Maple River at Mapleton, IA stream 669 420925 954835

30 06609500 Boyer River at Logan, IA stream 871 413833 954657

31 06903900 Chariton River near below Rathbun Lake Dam, IA reservoir 549 404922 925322

32 06810000 Nishnabotna River above Hamburg, IA stream 2,806 403757 953732

Indiana

33 03275000 Whitewater River near Alpine, IN stream 529 393423 850927

34 03302800 Blue River at Fredericksburg, IN stream 283 382602 861131

35 03327000 Mississinewa River below Mississinewa Lake Dam, IN reservoir 808 404324 855727

36 03328500 Eel River near Logansport, IN stream 789 404655 861550

37 03333450 Wildcat Creek near Jerome, IN stream 146 402629 855508

38 03335000 Wildcat Creek near Lafayette, IN stream 794 402626 864945

39 03351000 White River near Nora, IN stream 1,219 395435 860620

40 03362500 Sugar Creek near Edinburgh, IN stream 474 392139 855951

41 03371500 E. Fork White River near Bedford, IN stream 3,861 384610 862430

42 03378500 Wabash River at New Harmony, IN stream 29,234 380755 875625
METHODS 11

Minnesota

43 05317000 Cottonwood River near New Ulm, MN stream 1,300 441729 942624

44 05320270 Little Cobb River near Beauford, MN stream 130 435948 935430

45 05330000 Minnesota River near Jordan, MN stream 16,200 444135 933830

46 05331580 Mississippi River near Hastings, MN stream 37,050 444448 925108

47 05476000 Des Moines River at Jackson, MN stream 1,250 433710 945910

48 06483000 Rock River at Luverne, MN stream 425 433915 961203

Kansas

49 06885500 Black Vermillion River at Frankfort, KS stream 410 394103 962615

50 06887000 Big Blue River below Tuttle Creek Lake Dam, KS reservoir 9,628 391516 963608

51 06890100 Delaware River near Muscotah, KS stream 431 393117 953157

Kentucky

52 03303280 Ohio River at Cannelton Dam, KY stream 97,000 375358 864220

Missouri

53 06817700 Nodaway River near Graham, MO stream 1,380 401208 950407

Nebraska

54 06770195 North Dry Creek near Kearney, NE stream 77.7 403828 990656

55 06800000 Maple Creek near Nickerson, NE stream 369 413339 963227

56 06803000 Salt Creek at Roca, NE stream 167 403929 963955

57 06804000 Wahoo Creek at Ithaca, NE stream 273 410840 963210

58 06805500 Platte River at Louisville, NE stream 85,370 410055 960928

59 06815000 Big Nemaha River at Falls City, NE stream 1,339 400208 953545

60 06880800 W. Fork Big Blue River, Dorchester, NE stream 1,192 404352 971038

61 06882000 Big Blue River at Barneston, NE stream 4,447 400240 963512

62 06884000 Little Blue River near Fairbury, NE stream 2,350 400654 971013

Ohio

63 03157000 Clear Creek near Rockbridge, OH stream 89 393518 823443

64 03219500 Scioto River near Prospect, OH stream 567 402510 831150

65 03223000 Olentangy River at Claridon, OH stream 157 403458 825920

66 03225500 Olentangy River below Delaware Lake Dam, OH reservoir 393 402118 830402

67 03230500 Big Darby Creek at Darbyville, OH stream 534 394202 830637

68 03234500 Scioto River at Higby, OH stream 5,131 391244 825150

69 03240000 L. Miami River near Oldtown, OH stream 129 394454 835553

70 03267900 Mad River at Eagle City, OH stream 310 395751 834954

71 04185000 Tiffin River at Stryker, OH stream 410 413016 842547

72 04186500 Auglaize River at Fort Jennings, OH stream 332 405655 841558

Wisconsin

73 04087240 Root River at Racine, WI stream 190 424505 874925

74 05340500 St. Croix River at St. Croix Falls, WI stream 6,240 452425 923849

75 05407000 Wisconsin River at Muscoda, WI stream 10,400 431153 902636

76 05430500 Rock River at Afton, WI stream 3,340 423633 890414

Table 2. Surface-water sampling sites—Continued

[mi2, square miles; dd, degrees; mm, minutes; ss, seconds]

Site no.

(figs. 3, 4)

Station

identification

no.

Site name Site

type

Drainage

area

(mi2)

Latitude

(ddmmss)

Longitude

(ddmmss)
12 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

IOWA

MISSOURI

ILLINOIS

24 23

19

10

11

12

9

6

13

14

15

22

21

25

20

17

18

7

1 2

3

4

5

16

8

40°

0

0 100 200 KILOMETERS

100 200 MILES

95° 90°

Missouri River

Mississippi River

Des Moines River

Illinois River

Ohio River

Illinois

1—LUS1–4

2—LUS1–14

3—LUS1–26

4—LUS2–9

5—LUS2–22

Iowa

6—Blockton 1

7—Fort Madison 4

8—Shambaugh 3

9—Nodaway 4

10—Silver City 3

11—Carson (5), 3

12—Cumberland 1

Iowa

13—Fontanelle 5

14—Menlo 3

15—Carlisle 5

16—Newton 3

17—Belle Plaine 4

18—Cedar Rapids S6

19—Vail 1

20—Marshalltown 8

21—Boone 20

22—Boxholm 2

23—Holstein 3

24—Kingsley 1

25—Sheffield 2

Ground-water sampling site

EXPLANATION

Figure 5. Location of the 25 well sites.
METHODS 13

collected in 1989, 1990, 1994, and 1995 from many of

the stream sites (Goolsby and others, 1994; Scribner

and others, 1998). The second surface-water samples

were collected after post-emergence herbicides were

applied (June or July), again following a precipitation

event that produced runoff and an increase in streamflow. These samples will be referred to as postemergence runoff samples. Samples collected at

current NASQAN stations and the reservoir samples

were collected 2–3 weeks after the first surface-water

samples were collected from nearby sites. The second

NASQAN and reservoir samples were collected

2–3 weeks after the second surface-water samples

were collected from nearby sites. Ground-water

samples were collected in June, July, or August. The

dates of sample collection and discharge on the date of

sample collection (for surface-water sites) are given in

tables 3 and 4.

Table 3. Ground-water sampling sites and sample type, number, and date of collection

[dd, degrees; mm, minutes; ss, seconds; W1, well sample from round 1; WD, duplicate well sample]

Site no.

(fig. 5)

Site

name

Depth to

top of well

screen,

in feet

Latitude

(ddmmss)

Longitude

(ddmmss)

Sample

type

Sample

no.

Date of

sample

collection

Illinois

1 LUS1–4 15.5 410502 893925 W1 SU–11 05/19/1998

2 LUS1–14 24.0 404603 885635 W1 SU–7 05/18/1998

WD SU–10 05/18/1998

3 LUS1–26 8.33 403759 884226 W1 SU–118 06/18/1998

4 LUS2–9 12.50 401327 890252 W1 SU–111 06/15/1998

5 LUS2–22 7.66 395853 883644 W1 SU–121 06/18/1998

Iowa

6 Blockton 1 271 403659 942853 W1 SU–184 07/23/1998

7 Fort Madison 4 147 403745 911747 W1 SU–182 07/22/1998

8 Shambaugh 3 30 403906 950150 W1 SU–186 07/24/1998

9 Nodaway 4 36 405632 945344 W1 SU–185 07/23/1998

10 Silver City 3 60 410656 953802 W1 SU–198 07/31/1998

WD SU–199 07/31/1998

11 Carson (5), 3 28 411501 952513 W1 SU–200 07/31/1998

12 Cumberland 1 155 411622 945209 W1 SU–188 07/27/1998

13 Fontanelle 5 39 411727 943740 W1 SU–183 07/23/1998

14 Menlo 3 20 412852 942751 W1 SU–193 07/29/1998

15 Carlisle 5 30 413040 932905 W1 SU–187 07/27/1998

16 Newton 13 45 413913 930700 W1 SU–71 06/03/1998

17 Belle Plaine 4 42 415417 921801 W1 SU–70 06/02/1998

18 Cedar Rapids S6 65 420005 914312 W1 SU–211 08/25/1998

WD SU–212 08/25/1998

19 Vail 1 32 420336 951156 W1 SU–137 06/23/1998

20 Marshalltown 8 223 420405 925456 W1 SU–72 06/02/1998

21 Boone 20 63 420451 935613 W1 SU–190 07/28/1998

22 Boxholm 2 49 421025 940630 W1 SU–189 07/25/1998

WD SU–191 07/25/1998

23 Holstein 3 54 422915 953235 W1 SU–139 06/25/1998

24 Kingsley 1 37 423537 955839 W1 SU–138 06/25/1998

25 Sheffield 2 27 425341 931325 W1 SU–192 07/29/1998
14 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]

Site no.

(figs. 3, 4)

Site

name

Sample

type

Sample

no.

Date of

sample

collection

Daily mean

discharge,

in cubic feet

per second

Illinois

1 Vermillion River below Lake Vermillion Dam, IL R1 SU–98 06/10/1998 494

RD SU–103 06/10/1998 494

R2 SU–177 07/16/1998 162

2 Bonpas Creek at Browns, IL S1 SU–43 05/23/1998 834

S2 SU–166 07/07/1998 499

3 Little Wabash River at Carmi, IL S1 SU–33 05/23/1998 9,340

S2 SU–175 07/09/1998 4,020

4 S. Branch Kishwaukee River near Fairdale, IL S1 SU–29 05/20/1998 1,620

S2 SU–195 07/29/1998 61

5 Iroquois River near Chebanse, IL S1 SU–99 06/10/1998 1,340

SD SU–101 06/10/1998 1,340

S2 SU–168 07/08/1998 8,490

SD SU–170 07/08/1998 8,490

6 Dupage River near Shorewood, IL S1 SU–100 06/09/1998 284

SD SU–102 06/09/1998 284

S2 SU–194 07/29/1998 166

SD SU–196 07/29/1998 166

7 Illinois River at Marseilles, IL S1 SU–113 06/12/1998 36,800

S2 SU–176 07/09/1998 21,600

8 Spoon River at London Mills, IL S1 SU–25 05/20/1998 1,270

SB SU–26 05/20/1998 1,270

S2 SU–160 07/01/1998 1,780

9 Sangamon River near Monticello, IL S1 SU–35 05/23/1998 836

S2 SU–201 08/05/1998 268

10 Sangamon River at Riverton, IL S1 SU–44 05/26/1998 6,800

S2 SU–174 07/09/1998 4,070

11 LaMoine River at Colmar, IL S1 SU–27 05/21/1998 939

S2 SU–142 06/29/1998 2,320

SD SU–143 06/29/1998 2,320

12 Illinois River at Valley City, IL S1 SU–120 06/18/1998 49,700

S2 SU–207 08/12/1998 21,700

13 Mississippi River below Grafton, IL S1 SU–60 06/02/1998 172,000

S2 SU–116 06/15/1998 267,000

14 Kaskaskia River near Cowden, IL S1 SU–30 05/20/1998 1,400

S2 SU–169 07/08/1998 2,700

15 Shoal Creek near Breese, IL S1 SU–32 05/22/1998 768

SD SU–34 05/22/1998 768

S2 SU–167 07/08/1998 761
METHODS 15

Iowa

16 Turkey River at Spillville, IA S1 SU–64 06/02/1998 181

S2 SU–109 06/12/1998 534

17 Mississippi River at Clinton, IA S1 SU–55 05/27/1998 56,600

S2 SU–155 07/01/1998 101,000

18 Wapsipinicon River near Tripoli, IA S1 SU–54 05/27/1998 595

SB SU–125 06/20/1998 1,300

S2 SU–126 06/20/1998 1,300

19 Wapsipinicon River at Independence, IA S1 SU–56 05/29/1998 2,570

S2 SU–110 06/12/1998 4,560

20 Iowa River near Rowan, IA S1 SU–65 06/02/1998 1,570

S2 SU–129 06/23/1998 3,770

21 Old Mans Creek near Iowa City, IA S1 SU–93 06/10/1998 209

S2 SU–147 06/30/1998 840

22 Wolf Creek near Dysart, IA S1 SU–87 06/10/1998 1,060

SD SU–88 06/10/1998 1,060

S2 SU–128 06/22/1998 3,630

23 Iowa River at Wapello, IA S1 SU–53 05/27/1998 13,400

S2 SU–127 06/19/1998 37,200

SD SU–132 06/19/1998 37,200

24 N. Skunk River near Sigourney, IA S1 SU–21 05/21/1998 1,140

S2 SU–95 06/10/1998 1,810

25 Skunk River at Augusta, IA S1 SU–45 05/26/1998 15,600

S2 SU–122 06/18/1998 14,400

26 Des Moines River at Fort Dodge, IA S1 SU–8 05/16/1998 7,880

S2 SU–108 06/12/1998 5,190

SD SU–114 06/12/1998 5,190

27 Raccoon River at Van Meter, IA S1 SU–9 05/17/1998 6,330

S2 SU–89 06/10/1998 9,160

28 Little Sioux River at Correctionville, IA S1 SU–42 05/27/1998 1,400

S2 SU–123 06/18/1998 2,760

29 Maple River at Mapleton, IA S1 SU–59 05/29/1998 891

S2 SU–90 06/09/1998 889

SS SU–97 06/09/1998 889

30 Boyer River at Logan, IA S1 SU–31 05/22/1998 1,070

S2 SU–96 06/09/1998 2,890

31 Chariton River near below Rathbun Lake Dam, IA R1 SU–69 06/04/1998 868

R2 SU–148 06/29/1998 812

32 Nishnabotna River above Hamburg, IA S2 SU–124 06/17/1998 53,700

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]

Site no.

(figs. 3, 4)

Site

name

Sample

type

Sample

no.

Date of

sample

collection

Daily mean

discharge,

in cubic feet

per second

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites—

Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]
16 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana

33 Whitewater River near Alpine, IN S1 SU–47 05/26/1998 727

S2 SU–162 07/08/1998 652

SD SU–213 07/08/1998 652

34 Blue River at Fredericksburg, IN S1 SU–50 05/27/1998 447

S2 SU–163 07/08/1998 490

35 Mississinewa River below Mississinewa Lake Dam, IN R1 SU–83 06/09/1998 210

R2 SU–164 07/09/1998 1,540

36 Eel River near Logansport, IN S1 SU–18 05/21/1998 701

SB SU–20 05/21/1998 701

S2 SU–152 06/30/1998 688

37 Wildcat Creek near Jerome, IN S1 SU–19 05/21/1998 126

S2 SU–151 06/30/1998 563

38 Wildcat Creek near Lafayette, IN S1 SU–22 05/20/1998 883

S2 SU–150 07/01/1998 1,130

39 White River near Nora, IN S1 SU–51 05/28/1998 1,260

S2 SU–149 07/01/1998 1,780

40 Sugar Creek near Edinburgh, IN S1 SU–46 05/26/1998 1,610

S2 SU–178 07/20/1998 1,490

41 E. Fork White River near Bedford, IN S1 SU–52 05/28/1998 14,300

S2 SU–161 07/06/1998 6,050

42 Wabash River at New Harmony, IN S1 SU–57 05/27/1998 66,000

SD SU–58 05/27/1998 66,000

S2 SU–136 06/23/1998 170,000

Minnesota

43 Cottonwood River near New Ulm, MN S1 SU–49 05/26/1998 525

S2 SU–180 07/21/1998 673

SD SU–181 07/21/1998 673

44 Little Cobb River near Beauford, MN S1 SU–12 05/18/1998 166

S2 SU–208 08/17/1998 2.8

45 Minnesota River near Jordan, MN S1 SU–13 05/19/1998 10,100

S2 SU–135 06/26/1998 12,000

46 Mississippi River at Hastings, MN S1 SU–14 05/20/1998 21,600

SD SU–15 05/20/1998 21,600

S2 SU–206 08/11/1998 8,770

47 Des Moines River at Jackson, MN S1 SU–48 05/26/1998 339

S2 SU–210 08/24/1998 267

48 Rock River at Luverne, MN S1 SU–130 06/24/1998 60

S2 SU–131 06/25/1998 161

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]

Site no.

(figs. 3, 4)

Site

name

Sample

type

Sample

no.

Date of

sample

collection

Daily mean

discharge,

in cubic feet

per second

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites—

Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]
METHODS 17

Kansas

49 Black Vermillion River at Frankfort, KS S1 SU–1 05/05/1998 80

S2 SU–107 06/09/1998 162

50 Big Blue River below Tuttle Creek Lake Dam, KS R1 SU–74 06/03/1998 3,610

R2 SU–197 07/29/1998 89

51 Delaware River near Muscotah, KS S1 SU–2 05/05/1998 111

S2 SU–105 06/10/1998 100

SB SU–106 06/10/1998 100

Kentucky

52 Ohio River at Cannelton Dam, KY S1 SU–75 06/04/1998 78,400

SD SU–214 06/04/1998 78,400

S2 SU–173 07/07/1998 146,000

Missouri

53 Nodaway River near Graham, MO S1 SU–119 06/18/1998 5,030

S2 SU–209 08/19/1998 282

Nebraska

54 North Dry Creek near Kearney, NE S1 SU–28 05/22/1998 83

S2 SU–76 06/08/1998 37

55 Maple Creek near Nickerson, NE S1 SU–37 05/21/1998 208

SD SU–38 05/21/1998 208

S2 SU–79 06/08/1998 705

56 Salt Creek at Roca, NE S1 SU–6 05/15/1998 470

S2 SU–94 06/10/1998 148

57 Wahoo Creek at Ithaca, NE S1 SU–5 05/15/1998 118

S2 SU–78 06/08/1998 495

58 Platte River at Louisville, NE S1 SU–39 05/22/1998 22,300

SD SU–40 05/22/1998 22,300

S2 SU–77 06/09/1998 28,900

59 Big Nemaha River at Falls City, NE S1 SU–41 05/26/1998 333

S2 SU–80 06/8/1998 438

60 W. Fork Big Blue River, Dorchester, NE S1 SU–36 05/23/1998 247

S2 SU–82 06/10/1998 231

61 Big Blue River at Barneston, NE S1 SU–4 05/15/1998 1,110

S2 SU–104 06/09/1998 1,170

62 Little Blue River near Fairbury, NE S1 SU–3 05/12/1998 261

S2 SU–81 06/08/1998 239

Ohio

63 Clear Creek near Rockbridge, OH S1 SU–86 06/10/1998 36

S2 SU–145 06/30/1998 84

64 Scioto River near Prospect, OH S1 SU–63 06/02/1998 128

S2 SU–141 06/29/1998 1,040

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]

Site no.

(figs. 3, 4)

Site

name

Sample

type

Sample

no.

Date of

sample

collection

Daily mean

discharge,

in cubic feet

per second

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites—

Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]
18 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Samples were collected using protocols that

are identical to those used for the collection of

samples for low levels of other dissolved organic

compounds (Shelton, 1994). The equal-widthincrement sampling method was used for all stream

and reservoir outflow samples except on some large

rivers where equal-discharge-increment sampling

was used (Edwards and Glysson, 1988). All equipment was precleaned with a Liquinox/tap-water

solution, rinsed with tap water, deionized water, and

then methanol, and air dried. All samples were

filtered through 0.7-μm pore-size heat-cleaned

Ohio—Continued

65 Olentangy River at Claridon, OH S1 SU–85 06/09/1998 13

S2 SU–157 06/29/1998 3,770

SB SU–156 06/29/1998 3,770

66 Olentangy River below Delaware Lake Dam, OH R1 SU–84 06/09/1998 34

R2 SU–153 07/01/1998 3,210

RD SU–154 07/01/1998 3,210

67 Big Darby Creek at Darbyville, OH S1 SU–62 06/03/1998 208

S2 SU–140 06/29/1998 11,400

68 Scioto River at Higby, OH S1 SU–73 06/04/1998 2,620

S2 SU–165 07/08/1998 5,030

69 L. Miami River near Oldtown, OH S1 SU–92 06/10/1998 97

S2 SU–144 06/30/1998 191

70 Mad River at Eagle City, OH S1 SU–91 06/10/1998 228

S2 SU–146 06/30/1998 454

71 Tiffin River at Stryker, OH S1 SU–66 06/01/1998 98

SD SU–67 06/01/1998 98

S2 SU–172 07/07/1998 40

72 Auglaize River at Fort Jennings, OH S1 SU–117 06/17/1998 670

S2 SU–171 07/08/1998 751

Wisconsin

73 Root River at Racine, WI S1 SU–61 06/01/1998 98

S2 SU–204 08/03/1998 5.3

74 St. Croix River at St. Croix Falls, WI S1 SU–68 06/03/1998 4,220

S2 SU–205 08/05/1998 1,690

75 Wisconsin River at Muscoda, WI S1 SU–133 06/16/1998 12,900

S2 SU–202 08/07/1998 8,890

SD SU–203 08/07/1998 8,890

76 Rock River at Afton, WI S1 SU–134 06/17/1998 2,140

S2 SU–179 07/21/1998 1,830

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]

Site no.

(figs. 3, 4)

Site

name

Sample

type

Sample

no.

Date of

sample

collection

Daily mean

discharge,

in cubic feet

per second

Table 4. Collection dates, sample types, sample numbers, and daily mean discharge for samples from surface-water sites—

Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample]
METHODS 19

glass-fiber filters using an aluminum-plate filter

holder and a ceramic-piston fluid-metering pump

with all Teflon tubing into precleaned 1-liter or

125-milliliter amber glass bottles. Samples

were immediately chilled and shipped on ice

from the field to the USGS National Water Quality

Laboratory (NWQL) in Lakewood, Colo., and

USGS Organic Geochemistry Research Laboratory

(OGRL) in Lawrence, Kansas, within 2 days of

collection.

Analytical Methods

Sulfonylurea, Sulfonamide, and Imidazolinone

Herbicides

An analytical method was developed by

researchers at the NWQL that is an extension and

improvement of the high-performance liquid chromatography/mass spectrometry (HPLC/MS) method by

Rodriguez and Orescan (1998). Briefly, the method

consists of isolation of the analytes of interest from

approximately 1 liter of water (precisely measured)

using two stacked solid-phase extraction cartridges.

After isolation, the cartridges are dried and the

analytes eluted using acidified acetone. The analytes

are then concentrated and solvent exchanged into

1 mL of 10 percent acetonitrile and 90 percent water.

The sample processing procedure is shown schematically in figure 6.

HPLC/MS analysis is performed using a

Hewlett Packard 1100 series HPLC, coupled to a

Hewlett Packard LC/MSD. Electrospray ionization,

operated in the positive ion mode, is used to ionize

the analytes. Selected-ion monitoring is used to maximize sensitivity. External standard calibration curves

are developed using a minimum of five standards.

The linear range of the method is from 0.005 to

0.5 μg/L. Three ions (1 quantitation, 2 confirmation)

are monitored for each compound. For confirmed

identification of analytes, the relative ion abundances

for the detection must be within 20 percent of average

response for standards, as well as have the correct

relative retention time (within 0.1 minute). Detected

analytes that do not meet one criterion are reported

as estimates (E on tables 6–10). Details of this analytical methods are provided by Furlong and others

(2000).

Concentrations were quantified by comparing

the sum of the three integrated ion peaks from an environmental sample to the sum of the integrated ion

peaks from a calibration curve. Five-point external

calibration curves for concentrations between 0.005 to

0.500 μg/L were produced for the 16 target analytes

(Furlong and others, 2000). A substantial fraction of

the reported concentrations are flagged with an “E.”

All concentrations below the estimated reporting limit

of 0.010 μg/L or above the upper limit of 1.0 μg/L

are flagged with an “E,” which indicates the qualitative

Figure 6. Diagram showing sample preparation steps for analysis of sulfonylurea, sulfonamide, and imidazolinone

herbicides.

Surface or

ground water

Field

infiltration

Overnight

shipment on ice

to laboratory

Sample pumped

at 10 milliliters per

minute through dual

strong anion

exchange (upper)

and ploymeric

solid-phase

extraction

cartridges

pH adjusted to 3

with acetic acid

1

liter

1

liter

Chemical and

nitrogen drying

Isolated herbicides

eluted with 1 percent

acetic acid in acetone

Solvent

exchange

and

volume

reduction

Final

extract
20 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

identification of the compound within a 20-percent

acceptance criterion. An “E” qualifier for concentrations within the analytical range of the method indicates that the relative abundance of a secondary or

tertiary ion fell outside the 20-percent acceptance

criterion, likely due to a co-extracted interference.

Other Pesticides and Degradates

All samples were analyzed for several other

classes of pesticides. Samples were analyzed at the

NWQL for 46 pesticides and pesticide degradates by

capillary-column gas chromatography/mass spectrometry (GC/MS) with selected-ion monitoring using

methods described by Zaugg and others (1995).

The compounds analyzed are listed under “Other

Pesticides and Degradates” in table 1. This analytical

method has method detection limits (MDLs) that

range from 0.001 to 0.018 μg/L (table 5). The

compounds analyzed include selected triazine, acetanilide, and thiocarbamate herbicides and carbamate,

organophosphate, and organochloride insecticides.

A complete discussion of data reporting procedures,

MDLs, MRLs and “E” coded data values is given by

Childress and others (1999).

All samples were analyzed at the OGRL for

13 herbicides and 10 herbicide degradates. The

13 herbicides and 3 of the degradates were analyzed

by GC/MS with selected-ion monitoring (Zimmerman

and Thurman, 1999). The other seven degradates were

analyzed by high-performance liquid chromatography

(HPLC) with diode-array detection following solidphase extraction on C18 cartridges (Ferrer and others,

1997a, 1997b; Kalkhoff and others, 1998; Hostetler

and Thurman, 1999). The analytical method has an

MRL of 0.05 μg/L for the 13 herbicides and 3 degradates, and 0.20 μg/L for the other 7 degradates

(table 5). The compounds analyzed are listed under

“Other Herbicides and Degradates” in tables 1 and 5.

Nutrients, Physical Properties, and Discharge

All samples were analyzed for nutrient

concentrations including nitrate plus nitrate, nitrite,

ammonia, ammonia plus organic nitrogen, orthophosphate, and total phosphorus. The samples

were analyzed by automated colorimetric procedures (Fishman and Friedman, 1989) at the NWQL.

Method reporting limits for nutrients are given

in table 5. Specific conductance, pH, and water

temperature were measured at the time samples

were collected. Water discharge normally was

measured with current meters. These measurements were used to confirm or adjust a rating for

converting stream stage to water discharge. At

most sites, estimates of daily mean discharge for

the period of sample collection were calculated

and are available in the USGS NWIS-W data base

(U.S. Geological Survey, 2000). The daily mean

discharge estimates at all surface-water sites

on the dates of sample collection are given in

table 4.

Quality Assurance

Because this study involved application of a new

custom analytical method for the SU, SA, and IMI

herbicide, a significant effort was put forth to ensure

the quality of the results. This included the collection

and(or) processing of extra samples in the field and in

the laboratory. Also, there are duplicate analyses of

some herbicides such as atrazine and metolachlor for

nearly every sample (one from NWQL and one from

OGRL).

Sample Collection

Quality-assurance (QA) samples were collected

at selected sites to provide information on the variability and bias of the measured SU, SA, and IMI

concentrations. A total of 26 field QA samples were

collected in the field. These samples consist of

21 concurrent duplicates (CD), which are two samples

collected as closely as possible in time and space but

processed, handled, and analyzed separately; and

5 field blanks (FB), which are blank solutions that are

subject to the same aspects of sample collection, field

processing, preservation, transportation, and laboratory handling as the environmental samples. Concurrent duplicates were submitted blindly to the USGS

NWQL, whereas field blanks were identified as such.

Field QA samples were only collected and processed

for the SU, SA, and IMI analysis.
METHODS 21

Table 5. Method of determination or analysis and reporting limits for physical properties and chemical compounds in water

samples

[μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; ft3/s, cubic feet per second]

Property or compound Method of analysis Reporting limit

Sulfonylurea, sulfonamide, and imidazolinone herbicides Method reporting limit

(μg/L)

bensulfuron methyl high-performance liquid chromatography/

electrospray ionization-mass spectrometry

following solid phase extraction

0.010

chlorimuron ethyl do. do.

chlorsulfuron do. do.

flumetsulam do. do.

halosulfuron methyl do. do.

imazapyr do. do.

imazaquin do. do.

imazethapyr do. do.

metsulfuron methyl do. do.

nicosulfuron do. do.

primisulfuron methyl do. do.

prosulfuron do. do.

sulfometuron methyl do. do.

thifensulfuron methyl do. do.

triasulfuron do. do.

triflusulfuron methyl do. do.

Property or compound Method of analysis Reporting limit

Other pesticides and degradates Method detection limit

(μg/L)

2,6-diethylaniline gas chromatography/mass spectrometry

following solid phase extraction

0.003

acetochlor do. .002

alachlor do. .002

atrazine do. .001

azinphos-methyl do. .001

benfluralin do. .002

butylate do. .002

carbaryl do. .003

carbofuran do. .003

chlorpyrifos do. .004

cyanazine do. .004

dacthal do. .002

deethylatrazine do. .002

diazinon do. .002

dieldrin do. .001

disulfoton do. .017

EPTC do. .002

ethalfluralin do. .004

ethoprophos do. .003

fonofos do. .003

lindane do. .004

linuron do. .002
22 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

malathion do. 0.005

metolachlor do. .002

metribuzin do. .004

molinate do. .004

napropamide do. .003

parathion do. .004

parathion methyl do. .006

pebulate do. .004

pendimethalin do. .004

phorate do. .002

prometon do. .018

propachlor do. .007

propanil do. .004

propargite do. .013

propyzamide do. .003

simazine do. .005

tebuthiuron do. .010

terbacil do. .007

terbufos do. .013

thiobencarb do. .002

tri-allate do. .001

trifluralin do. .002

alpha-HCH do. .002

cis-permethrin do. .005

p,p'-DDE do. .006

Property or compound Method of analysis Reporting limit

Other pesticides and degradates Method detection limit

(μg/L)

acetochlor gas chromatography/mass spectrometry

following solid phase extraction

(GC/MS)

0.05

acetochlor ESA high-performance liquid

chromatography/mass spectrometry

following solid phase extraction

(HPLC/MS)

.20

acetochlor OA do. .20

alachlor GC/MS .05

alachlor ESA HPLC/MS .20

alachlor OA do. .20

ametryn GC/MS .05

atrazine do. .05

deethylatrazine do. .05

deisopropylatrazine do. .05

hydroxy-atrazine HPLC/MS .20

cyanazine GC/MS .05

cyanazine-amide do. .05

Property or compound Method of analysis Reporting limit

Other pesticides and degradates Method detection limit

(μg/L)

Table 5. Method of determination or analysis and reporting limits for physical properties and chemical compounds in water

samples—Continued

[μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; ft3/s, cubic feet per second].
METHODS 23

Analytical Methods

Full-scan electrospray ionization mass spectra

were collected for each SU, SA, and IMI compound

using a Hewlett Packard Series 1100 LC/MSD. Fragmentation conditions were optimized so a minimum of

two, and typically three, ions were formed for each

analyte. The presence of all three ions and their relative abundances were used to confirm identification.

The sum of the three signals was used for maximum

detectability and quantitation. Two criteria were used

to verify compound detections. The chromatographic

retention time for a peak observed in a sample chromatograph was compared to the retention times of the

target analytes observed in a standard chromatograph.

After this initial criterion was met, identification was

confirmed by comparing the relative abundances of the

three ions measured in the sample chromatograph to

known relative abundances of a user-generated library

reference spectrum produced from a pure standard.

If the library spectra and the sample spectra did

not match within 20 percent, then the presence of

the compound was not confirmed. In some instances,

qualified identification and concentration estimates

were made, reflecting the effect of matrix interference

on the ability of the analyst to identify SU, SA, and

IMI herbicides at the low end of the concentration

range. For example, if an unknown sample peak retention time matched that of one of the target analytes,

two of the three ions were present, and the relative

abundances of the two ions were within 20 percent

of the average response for standards, the detection

was flagged with an “E” to indicate it was a qualified

metolachlor do. 0.05

metolachlor ESA HPLC/MS .20

metolachlor OA do. .20

metribuzin GC/MS .05

prometon do. .05

prometryn do. .05

propachlor do. .05

propazine do. .05

simazine do. .05

tebutryn do. .05

Property or compound Method of analysis Reporting limit

Nutrients, physical properties, and discharge Method reporting limit

water temperature (degrees Celsius) thermometer 0.10 degree

specific conductance conductance meter 1.0 μS/cm

pH pH meter .10 units

ammonia as N colorimetric methods .02 mg/L

ammonia plus organic N do. .10 mg/L

nitrite as N (mg/L) do. .01 mg/L

nitrite plus nitrate as N do. .05 mg/L

dissolved phosphorus as P do. .006 mg/L

orthophosphate as P do. .01 mg/L

dissolved organic carbon as C do. .33 mg/L

daily mean discharge current meter or rating curve .01 ft3/s

Property or compound Method of analysis Reporting limit

Other pesticides and degradates Method detection limit

(μg/L)

Table 5. Method of determination or analysis and reporting limits for physical properties and chemical compounds in water

samples—Continued

[μg/L, micrograms per liter; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; ft3/s, cubic feet per second]
24 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

identification and concentration estimate. This qualification was required in those cases where the second

confirming ion was produced in low (less than

10 percent) relative abundances under normal

HPLC/MS conditions.

These criteria are equivalent to those

used in an EPA-approved HPLC/MS method

(Method 8321A; U.S. Environmental Protection

Agency, 1996a), where the relative abundances of

two to four ions, at the appropriate retention time,

are used to qualitatively identify targeted analytes.

Although the ionization technique (thermospray

ionization) used in this EPA-approved method

differs from that used in this study, the ionization

techniques are similar in that simpler spectra are

produced than those typically produced by the

more common electron-impact ionization-gas

chromatography/mass spectrometry (EI-GC/MS),

necessitating a minimum of two, rather than three,

ions for qualitative identification. Some researchers

have successfully used the detection of a single ion,

typically a protonated parent molecule, at the

appropriate retention time to identify pesticides and

other polar contaminants (Ferrer and others, 1997a,

1997b; LaCorte and Barcelo, 1996). This is often

the result of the inability of a molecule to be fragmented under electrospray ionization conditions

and the desire to improve sensitivity. Tandem mass

spectrometry follow-up is typical. In this study, the

large number of samples precluded routine reanalysis, so controlled in-source fragmentation was

used (Crescenzi and others, 1997; Rodriguez and

Orescan, 1998; Vollmer and Wilkes, 1996). In practice, the capillary exit voltage is varied during the

chromatographic separation, fragmenting different

SU, SA, and IMI herbicides at optimal voltages,

producing a minimum of two, and typically three,

characteristic fragments for each compound.

However, since several of the herbicides studied

elute closely to each other, the voltage applied to

the capillary exit was a compromise value for

several compounds. The net result is that for some

compounds, a tertiary ion would be produced at low

relative abundance (5 to 10 percent) and occasionally would not be detected in the presence of background ion signal. In these cases, an estimated

(“E”) flag also was used.

The quality control of the analytical methods

used by the USGS NWQL are given in Zaugg and

others (1995). The quality control of the analytical

methods used by the USGS OGRL for this study

are given in Zimmerman and Thurman (1999) and

Hostetler and Thurman (1999).

Quality-Assurance Samples for Sulfonylurea,

Sulfonamide, and Imidazolinone Herbicides

Samples were analyzed in 27 sets, and instrumental and method QA samples were analyzed with

each set. Long-term instrument stability was indicated in analysis of 75 calibration verification

samples analyzed over the course of the study. Verification sample concentrations for each compound

were set at 0.10 μg/L. The average measured

concentration for individual target analytes ranged

from 0.093 to 0.101 μg/L. The average standard

deviation for the 16 target analytes in 75 calibration

verification samples was 0.006 μg/L.

The quality of method performance is indicated by the recovery calculated from the results of

27 set spikes, one analyzed with each set during the

study. The recoveries for the 16 target analytes are

shown in figure 7. The medians of the recoveries

range from 39 to 92 percent, and the average of the

medians is 73 percent. The standard deviations of

recoveries range from 14 to 26 percent and average

20 percent. Some of this variability is the result

of multiple instruments and operators and the use

of automated and manual sample preparation.

The lowest and most variable recoveries were

chlorsulfuron, halosulfuron methyl, prosulfuron,

triflusulfuron methyl, and primisulfuron methyl,

compounds that were not frequently detected in

this study.

Twenty-eight unspiked laboratory duplicate

samples were analyzed to estimate method precision at ambient herbicide concentrations and in the

presence of interferences. The duplicate samples

were made from the second of two 1-liter bottles of

water that were collected for SU, SA, and IMI

herbicide analysis at each site. Some duplicates

were analyzed within a single sample set and others

in two separate sets. Differences for each pair are

calculated as the concentration in the sample minus
METHODS 25

150

100

50

0

COMPOUND RECOVERY, IN PERCENT

Imazapyr

Nicosulfuron

Imazaquin

Triflusulfuron methyl

Primisulfuron methyl

Chlorimuron ethyl

Prosulfuron

Sulfometuron methyl

Triasulfuron methyl

Bensulfuron methyl

Halosulfuron methyl

Chlorsulfuron

Metsulfuron methyl

Thifensulfuron methyl

Imazethapyr

Flumetsulam

EXPLANATION

Percentile

Maximum

Minimum

95th

75th

25th

5th

50th (median)

the concentration in the duplicate sample. For this

analysis, concentrations that are reported as less

than the MRL were set to 0.005 μg/L, which allows

computation of a difference value when only one

of the sample pair has a reported concentration.

The number (n) of sample pairs with at least

one reported concentration for each herbicide is

shown in figure 8. Forty-five of the 112 concentration pairs have only one reported concentration;

in 11 of those pairs, the reported concentration is

less than the MRL. Most differences are less than

0.050 μg/L, and only a few differences are greater

that 0.10 μg/L (fig. 8).

In addition to unspiked duplicates, 28 randomly

selected samples were spiked at 0.10 μg/L and

analyzed to help determine the magnitude of possible

matrix enhancement. The results (fig. 9) indicate that

there was apparent matrix enhancement of recovery

that varied by compound. This effect was isolated

as a matrix effect by spiking sample extracts after

processing and observing the same enhancements

as when the sample was spiked prior to analysis.

The largest enhancements were for metsulfuron

methyl, thifensulfuron methyl, and triasulfuron.

In most cases, compound recoveries were

enhanced by a factor of 1.5 or less (Furlong

and others, 2000).

There were no detections above 0.010 μg/L

of the 16 SU, SA, and IMI herbicides in the five

field blank samples. This suggests that field sample

handling and processing were not likely to cause

contamination of the samples.

Twenty-one unspiked concurrent field duplicate samples were analyzed to estimate method

precision at ambient herbicide concentrations in the

presence of sample collection and sample water

interferences. Differences for each pair are calculated as the concentrations in the sample minus the

concentration in the duplicate sample. Again,

concentrations that are reported as less than the

MRL are set to 0.005 μg/L. The number of sample

pairs with at least one reported concentration is

Figure 7. Recoveries of 16 sulfonylurea, sulfonamide, and imidazolinone herbicides from 27 reagent water samples

spiked at 0.050 or 0.10 microgram per liter (from Furlong and others, 2000, fig. 3).
26 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

(n=0)

(n=12)

(n=2)

(n=21)

(n=4)

(n=4)

(n=17)

(n=23)

(n=3)

(n=14)

(n=0)

(n=2)

(n=5)

(n=4)

(n=1)

(n=0)

Bensulfuron

Chlorimuron

Chlorsulfuron

Flumetsulam

Halosulfuron

Imazapyr

Imazaquin

Imazethapyr

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Triasulfuron

Triflusulfuron

–0.15 –0.10 –0.05 0

DIFFERENCE, IN MICROGRAMS PER LITER

0.05 0.10 0.15

shown in figure 10. Sixteen of the 62 concentration

pairs had only one reported concentration; in 8 of

those pairs, the one reported concentration was less

than the MRL. Most differences were less than

0.020 μg/L (twice the MRL), and only one difference was greater that 0.040 μg/L (fig. 10), which

indicates that the reproducibility of analytical

results is quite good and that sample-collection

procedures did not introduce a large amount of error

into the results.

Quality-Assurance Samples for Other Herbicides

Twenty-eight unspiked laboratory duplicate

(LD) samples were analyzed by the USGS OGRL

to estimate method precision at ambient herbicide

concentrations and in the presence of interferences

for results from their laboratory. These duplicate

samples were made from extra 125-milliliter bottles

of water that were collected at each site. These

data are not analyzed here, but results from these

LD samples and from six concurrent field duplicate

samples and one field blank sample are included

in the tables of OGRL results (tables 15, 16, 24,

and 25).

Duplicate Analysis of Selected Herbicides

Nearly every sample was analyzed for eight

herbicides by both the NWQL and the OGRL. This

allows for a unique opportunity to compare results

from these two laboratories. Percent differences

(PD) were calculated for each pair of concentrations as the difference between the values (NWQL

– OGRL) divided by the mean of the two values,

expressed as a percentage. For this calculation,

concentrations reported by the NWQL that are less

than 0.05 μg/L, including those that are less than

the MDL, are set equal to 0.05 μg/L, the MRL of

results from the OGRL, and concentrations reported

by the OGRL as less than 0.05 μg/L (not detected)

also are set equal to 0.05 μg/L.

Analysis of the PD’s of sample pairs where

one or both have a reported concentration greater

than or equal to 0.05 μg/L (not an assigned value of

0.05 μg/L) indicate that the concentrations reported

by the NWQL for acetochlor, alachlor, atrazine,

cyanazine, metolachlor, prometon, and simazine all

tend to be higher than those reported by the OGRL

(fig. 11). The median of the percent differences for

metribuzin were not significantly different from

zero. The majority of the percent differences were

between –25 and +50 percent. These differences

may result from the different methodologies used

by the two laboratories. The laboratories use

different sample size: 1,000-milliliter nominal for

the NWQL and 125 milliliter nominal for the

OGRL. Also, the OGRL processes its calibration

standards through the sample extraction and isolation procedure, resulting in an inherent processing

correction in the calibration curves. The NWQL

develops its calibration curves from standards that

have not been processed through the extraction and

isolation procedure. The NWQL dilutes sample

Figure 8. Differences between herbicide concentrations

in 28 pairs of unspiked laboratory duplicate natural-water

samples (n is number of concentration pairs).
METHODS 27

extracts for calculating concentrations that are

greater than 4 μg/L, which may result in greater

analytical error, particularly for concentrations

that are greater than 20 μg/L.

Differences for each concentration pair

were calculated as the concentration in the

NWQL sample minus the concentration in the

OGRL sample. The same sample pairs used in

the above calculation of PDs are used for this

calculation. The number (n) of sample pairs

with one or more reported concentrations (equal

to or greater than 0.05 μg/L) and differences

between laboratory results are shown in figure 12.

Fifty percent of the 697 differences are 0.12 μg/L

or less, and only 5 percent of the differences

are larger than 3.2 μg/L. Paired difference

tests were used to determine if the observed

differences between herbicide concentrations

are statistically significant. Because the distributions of herbicide concentrations are positively

skewed, the non-parametric Wilcoxon signed-rank

test (Helsel and Hirsch, 1992) was used. The

following hypothesis is tested:

Null Hypothesis. Concentrations reported

by the NWQL are not significantly different from

concentrations reported by the OGRL (median of

differences = 0).

Alternate Hypothesis. Concentrations reported

by the NWQL are significantly different from concentrations reported by the OGRL (median of differences

not equal to 0).

Results indicate that the null hypothesis can

be rejected (p < 0.05) for acetochlor, atrazine, alachlor,

cyanazine, metolachlor, prometon, and simazine.

For these seven herbicides, the NWQL concentrations

all tended to be larger than the OGRL concentrations.

The largest median difference is for metolachlor

(0.25 μg/L), followed by atrazine (0.19 μg/L) and

acetochlor (0.08 μg/L).

Figure 9. Recoveries of 16 sulfonylurea, sulfonamide, and imidazolinone herbicides from 28 surface- and ground-water

samples spiked at 0.10 microgram per liter. The recoveries are corrected for the ambient water herbicide concentration

(from Furlong and others, 2000, fig. 5).

300

250

200

RECOVERY, IN PERCENT 150

100

50

0

–50

Imazapyr

Imazethapyr

Flumetsulam

Nicosulfuron

Imazaquin

Thifensulfuron methyl

Metsulfuron methyl

Chlorsulfuron

Sulfometuron methyl

Triasulfuron

Bensulfuron methyl

Halosulfuron methyl

Prosulfuron

Chlorimuron ethyl

Triflusulfuron methyl

Primisulfuron methyl

EXPLANATION

Percentile

Maximum

Minimum

95th

75th

25th

5th

50th (median)
28 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

–0.05 –0.025 0 0.025 0.05 0.075 0.10

DIFFERENCE, IN MILLIGRAMS PER LITER

(n=0)

(n=8)

(n=0)

(n=12)

(n=1)

(n=2)

(n=9)

(n=15)

(n=0)

(n=10)

(n=0)

(n=1)

(n=1)

(n=3)

(n=0)

(n=0)

Bensulfuron

Chlorimuron

Chlorsulfuron

Flumetsulam

Halosulfuron

Imazapyr

Imazaquin

Imazethapyr

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Triasulfuron

Triflusulfuron

The number of comparisons that can be made

between results from the two laboratories is to some

degree limited by the higher MRL of results from

the OGRL. For compounds that tend to occur at

higher concentrations, the limitation is small. For

example, the NWQL reported 158 concentrations

in 167 analyses for atrazine at or above the MDL

of 0.001 μg/L, whereas the OGRL reported 156

concentrations in 176 analyses at or above the MRL

of 0.05 μg/L. The effects of the reporting limit

difference is more pronounced for compounds that

occur frequently at low concentrations, such as

prometon. The NWQL reported 68 concentrations

at or above the MDL of 0.018 μg/L in 169 analyses

for prometon, whereas the OGRL reported only

12 concentrations in 176 analyses at or above the

MRL of 0.05 μg/L.

OCCURRENCE OF SULFONYLUREA,

SULFONAMIDE, AND IMIDAZOLINONE

HERBICIDES

Streams

 Stream sample collection began in May

and was completed in August 1998. Results from

133 stream samples are given in table 6. A statistical summary of these results is given in table 7. At

least one of the 16 SU, SA, or IMI herbicides was

detected in 111 (83 percent) of stream samples. The

detection frequencies reported are for samples with

concentrations at or above the method reporting

limit (MRL), currently 0.010 μg/L. Imazethapyr

was the most frequently detected compound. It

was detected in 92 or 69 percent of these samples.

Flumetsulam was detected in 87 (65 percent) of

the samples. Nicosulfuron was detected in 70

(53 percent) of the samples. Imazaquin was

detected in 44 (33 percent) of samples and chlorimuron ethyl was detected in 41 (31 percent) of

samples. Chlorsulfuron, halosulfuron methyl,

imazapyr, prosulfuron, sulfometuron methyl, and

thifensulfuron methyl were detected at concentrations at or above the MRL in 7 (5 percent) or fewer

of the samples. Bensulfuron methyl, metsulfuron

methyl, primisulfuron methyl, triasulfuron, and

triflusulfuron methyl were not detected at or above

the MRL in any stream sample.

The distributions of concentrations of the

target analytes in 133 samples are summarized in

figure 13. In some cases, estimated concentrations

are reported that are below the MRL. These concentrations are not counted as detections at or above the

MRL in table 7 but are used in the calculation of

summary statistics (the boxplots themselves and

percentile values in table 7). All non-detects are

treated as zeros in the calculation of percentile

values. The sum of SU, SA, and IMI concentrations

exceeded 0.50 μg/L in less than 10 percent of

stream samples.

The spatial distribution of concentrations for

three compounds, imazethapyr, flumetsulam, and

nicosulfuron, are shown in figures 14, 15, and 16,

respectively. In these figures, the drainage basins

Figure 10. Differences between herbicide concentrations in 21 pairs of unspiked field duplicate naturalwater samples (n is the number of concentration pairs).
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 29

–150 –100 –50 0

PERCENT DIFFERENCE

50 100 150

(n=58)

(n=17)

(n=52)

(n=139)

(n=109)

(n=145)

(n=62)

(n=117)

Simazine

Prometon

Metribuzin

Metolachlor

Cyanazine

Atrazine

Alachlor

Acetochlor

EXPLANATION

Percentile

Maximum

Minimum

95th

75th

25th

5th

50th (median)

(n=117)

(n=62)

(n=145)

(n=109)

(n=137)

(n=52)

(n=17)

(n=58)

Acetochlor

Alachlor

Atrazine

Cyanizine

Metolachor

Metribuzin

Prometon

Simazine

–10 –50 5

DIFFERENCE, IN MICROGRAMS PER LITER

10 15 20

EXPLANATION

Percentile

Maximum

Minimum

95th

75th

25th

5th

50th (median)

Figure 11. Percent differences between herbicide concentrations reported by the National

Water Quality Laboratory and concentrations reported by the Organic Geochemistry

Research Laboratory for 177 surface- and ground-water samples (n is the number of concentration pairs).

Figure 12. Differences between herbicide concentrations reported by the National Water Quality

Laboratory and concentrations reported by the Organic Geochemistry Research Laboratory for

177 surface- and ground-water samples (n is the number of concentration pairs).
30 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr

Illinois

1 Vermillion River below Lake

Vermillion dam, IL

06/10/98 R1 SU–98 <0.010 <0.010 <0.010 0.054 <0.010 <0.010

06/10/98 RD SU–103 Sample not analyzed (duplicate bottle for SU–98)

07/16/98 R2 SU–177 Sample not analyzed (both bottles broken)

2 Bonpas Creek at Browns, IL 05/23/98 S1 SU–43 Sample ruined in laboratory

07/07/98 S2 SU–166 <.010 .014 <.010 .020 <.010 <.010

3 Little Wabash River at Carmi, IL 05/23/98 S1 SU–33 <.010 .093 <.010 .074 <.010 <.010

07/09/98 S2 SU–175 Sample not analyzed (both bottles broken)

4 S. Branch Kishwaukee River near

Fairdale, IL

05/20/98 S1 SU–29 <.010 <.010 <.010 <.010 <.010 <.010

07/29/98 S2 SU–195 <.010 <.010 <.010 <.010 <.010 <.010

5 Iroquois River near Chebanse, IL 06/10/98 S1 SU–99 <.010 E.005 <.010 E.020 <.010 <.010

06/10/98 SD SU–101 Sample not analyzed (duplicate bottle for SU–99)

07/08/98 S2 SU–168 <.010 .017 <.010 .065 <.010 <.010

07/08/98 SD SU–170 <.010 .024 <.010 .082 E.015 <.010

6 Dupage River near Shorewood, IL 06/09/98 S1 SU–100 <.010 <.010 <.010 <.010 <.010 <.010

06/09/98 SD SU–102 Sample not analyzed (duplicate bottle for SU–100)

07/29/98 S2 SU–194 <.010 <.010 <.010 <.010 <.010 <.010

07/29/98 SD SU–196 <.010 <.010 <.010 <.010 <.010 <.010

7 Illinois River at Marseilles, IL 06/12/98 S1 SU–113 <.010 E.012 <.010 .039 <.010 <.010

07/09/98 S2 SU–176 Sample not analyzed (both bottles broken)

8 Spoon River at London Mills, IL 05/20/98 S1 SU–25 <.010 .079 <.010 .030 <.010 <.010

05/20/98 SB SU–26 <.010 <.010 <.010 <.010 <.010 <.010

07/01/98 S2 SU–160 <.010 .026 <.010 .029 <.010 <.010

9 Sangamon River near Monticello, IL 05/23/98 S1 SU–35 <.010 <.010 <.010 <.010 <.010 <.010

08/05/98 S2 SU–201 <.010 <.010 <.010 .017 <.010 <.010

10 Sangamon River at Riverton, IL 05/26/98 S1 SU–44 <.010 .025 <.010 .067 <.010 <.010

07/09/98 S2 SU–174 <.010 .012 <.010 .035 E.057 <.010

11 LaMoine River at Colmar, IL 05/21/98 S1 SU–27 <.010 .268 <.010 .058 <.010 <.010

06/29/98 S2 SU–142 <.010 .032 <.010 .038 <.010 <.010

06/29/98 SD SU–143 <.010 .034 <.010 .044 <.010 <.010

12 Illinois River at Valley City, IL 06/18/98 S1 SU–120 <.010 E.019 <.010 .068 <.010 <.010

08/12/98 S2 SU–207 <.010 <.010 <.010 .013 <.010 <.010
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 31

and 5 midwestern reservoirs

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl

Illinois—Continued

1 <0.010 0.053 <0.010 E0.021 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

Sample not analyzed

Sample not analyzed

2 Sample not analyzed

.053 .045 <.010 .066 <.010 .018 <.010 <.010 <.010 <.010

3 .133 .031 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

4 <.010 .016 <.010 E.013 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

5 <.010 .045 <.010 .013 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

.019 .407 <.010 .052 <.010 <.010 <.010 <.010 <.010 <.010

E.025 .417 <.010 .079 <.010 E.010 <.010 E.009 <.010 <.010

6 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

7 E.010 .105 <.010 .057 <.010 <.010 .018 <.010 <.010 <.010

Sample not anlayzed

8 <.010 .066 <.010 .036 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.015 .097 <.010 .066 <.010 <.010 <.010 <.010 <.010 <.010

9 <.010 .059 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.014 <.010 .013 <.010 <.010 <.010 <.010 <.010 <.010

10 E.007 .099 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.018 .130 <.010 .020 <.010 <.010 <.010 <.010 <.010 <.010

11 .109 .106 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.014 .034 <.010 .095 <.010 <.010 <.010 E.007 <.010 <.010

.017 .037 <.010 .096 <.010 <.010 <.010 <.010 <.010 <.010

12 <.010 .089 <.010 .054 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.020 <.010 .010 <.010 <.010 <.010 <.010 <.010 <.010
32 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Illinois—Continued

13 Mississippi River below Grafton, IL 06/02/98 S1 SU–60 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

06/15/98 S2 SU–116 <.010 <.010 <.010 .049 <.010 <.010

14 Kaskaskia River near Cowden, IL 05/20/98 S1 SU–30 <.010 <.010 <.010 <.010 <.010 <.010

07/08/98 S2 SU–169 <.010 <.010 <.010 .033 <.010 <.010

15 Shoal Creek near Breese, IL 05/22/98 S1 SU–32 <.010 .141 <.010 .070 <.010 <.010

05/22/98 SD SU–34 <.010 .135 <.010 .072 <.010 <.010

07/08/98 S2 SU–167 <.010 .176 <.010 .084 <.010 <.010

Iowa

16 Turkey River at Spillville, IA 06/02/98 S1 SU–64 <.010 <.010 <.010 .025 E.008 <.010

06/12/98 S2 SU–109 <.010 <.010 <.010 .036 E.017 <.010

17 Mississippi River at Clinton, IA 05/27/98 S1 SU–55 <.010 <.010 <.010 <.010 <.010 <.010

07/01/98 S2 SU–155 <.010 <.010 <.010 .025 <.010 <.010

18 Wapsipinicon River near Tripoli, IA 05/27/98 S1 SU–54 <.010 <.010 <.010 .019 <.010 <.010

06/20/98 SB SU–125 <.010 <.010 <.010 <.010 <.010 <.010

06/20/98 S2 SU–126 <.010 .010 <.010 .060 <.010 <.010

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 <.010 <.010 <.010 .019 <.010 <.010

06/12/98 S2 SU–110 <.010 <.010 <.010 .100 E.009 <.010

20 Iowa River near Rowan, IA 06/02/98 S1 SU–65 <.010 <.010 <.010 E.014 <.010 <.010

06/23/98 S2 SU–129 <.010 <.010 <.010 E.084 <.010 <.010

21 Old Mans Creek near Iowa City, IA 06/10/98 S1 SU–93 <.010 <.010 <.010 E.026 E.013 <.010

06/30/98 S2 SU–147 <.010 E.008 <.010 .021 <.010 <.010

22 Wolf Creek near Dysart, IA 06/10/98 S1 SU–87 <.010 <.010 <.010 .122 <.010 <.010

06/10/98 SD SU–88 <.010 <.010 <.010 E.024 <.010 E.004

06/22/98 S2 SU–128 <.010 <.010 <.010 E.220 <.010 E.004

23 Iowa River at Wapello, IA 05/27/98 S1 SU–53 <.010 <.010 <.010 E.012 <.010 <.010

06/19/98 S2 SU–127 <.010 <.010 <.010 E.085 <.010 <.010

06/19/98 SD SU–132 <.010 <.010 <.010 .090 <.010 <.010

24 N. Skunk River near Sigourney, IA 05/21/98 S1 SU–21 <.010 <.010 <.010 E.360 <.010 <.010

06/10/98 S2 SU–95 <.010 <.010 <.010 .187 <.010 <.010

25 Skunk River at Augusta, IA 05/26/98 S1 SU–45 <.010 <.010 <.010 .127 <.010 <.010

06/18/98 S2 SU–122 <.010 <.010 <.010 .184 <.010 <.010

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 33

Illinois—Continued

13 <0.010 0.027 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

.052 .049 <.010 .028 <.010 <.010 <.010 <.010 <.010 <.010

14 <.010 .059 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.017 .084 <.010 .021 <.010 <.010 <.010 <.010 <.010 <.010

15 <.010 .011 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.034 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.013 .016 <.010 .034 <.010 <.010 <.010 <.010 <.010 <.010

Iowa—Continued

16 <.010 .024 <.010 .043 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .061 <.010 .044 <.010 <.010 <.010 <.010 <.010 <.010

17 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .018 <.010 .022 <.010 <.010 <.010 <.010 <.010 <.010

18 <.010 .035 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .369 <.010 .119 <.010 <.010 <.010 E.010 <.010 <.010

19 <.010 <.010 <.010 .021 <.010 <.010 <.010 <.010 <.010 <.010

E.004 .236 <.010 .096 <.010 <.010 <.010 <.010 <.010 <.010

20 E.003 .018 <.010 E.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.130 <.010 E.110 <.010 <.010 <.010 <.010 <.010 <.010

21 <.010 .019 <.010 .027 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .070 <.010 .132 <.010 <.010 <.010 <.010 <.010 <.010

22 <.010 E.073 <.010 .103 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.058 <.010 .064 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.180 <.010 E.160 <.010 <.010 <.010 <.010 <.010 <.010

23 <.010 E.007 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.063 <.010 E.073 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .079 <.010 .082 <.010 <.010 <.010 <.010 E.005 <.010

24 <.010 E.025 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .183 <.010 .062 <.010 <.010 <.010 <.010 <.010 <.010

25 .010 .060 <.010 E.013 <.010 <.010 <.010 <.010 <.010 <.010

E.008 .119 <.010 .097 <.010 <.010 <.010 <.010 <.010 <.010

and 5 midwestern reservoirs—Continued

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl
34 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Iowa—Continued

26 Des Moines River at Fort Dodge, IA 05/16/98 S1 SU–8 <0.010 <0.010 <0.010 0.096 <0.010 <0.010

06/12/98 S2 SU–108 <.010 <.010 <.010 .062 <.010 <.010

06/12/98 SD SU–114 <.010 <.010 <.010 .060 <.010 <.010

27 Raccoon River at Van Meter, IA 05/17/98 S1 SU–9 <.010 <.010 <.010 <.010 <.010 <.010

06/10/98 S2 SU–89 <.010 <.010 <.010 E.015 <.010 <.010

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 <.010 <.010 <.010 <.010 <.010 <.010

06/18/98 S2 SU–123 <.010 <.010 <.010 E.011 <.010 <.010

29 Maple River at Mapleton, IA 05/29/98 S1 SU–59 <.010 <.010 <.010 .062 <.010 <.010

06/09/98 S2 SU–90 <.010 <.010 <.010 <.010 <.010 <.010

06/09/98 SS SU–97 Sample ruined in laboratory

30 Boyer River at Logan, IA 05/22/98 S1 SU–31 <.010 <.010 <.010 <.010 <.010 <.010

06/09/98 S2 SU–96 <.010 <.010 <.010 <.010 <.010 <.010

31 Chariton River below Rathbun

Lake Dam, IA

06/04/98 R1 SU–69 <.010 <.010 <.010 E.006 <.010 <.010

06/29/98 R2 SU–148 <.010 <.010 <.010 <.010 <.010 <.010

32 Nishnabotna River above

Hamburg, IA

06/17/98 S2 SU–124 <.010 E.009 <.010 .032 <.010 <.010

Indiana

33 Whitewater River near Alpine, IN 05/26/98 S1 SU–47 <.010 .084 <.010 .020 <.010 <.010

07/08/98 S2 SU–162 <.010 .037 <.010 .069 <.010 <.010

07/08/98 SD SU–213 <.010 .053 <.010 .070 <.010 <.010

34 Blue River at Fredericksburg, IN 05/27/98 S1 SU–50 <.010 <.010 <.010 <.010 <.010 <.010

07/08/98 S2 SU–163 Sample not analyzed (both bottles broken)

35 Mississinewa River below

Mississinewa Lake Dam, IN

06/09/98 R1 SU–83 <.010 <.010 <.010 .054 <.010 <.010

07/09/98 R2 SU–164 <.010 .080 <.010 .116 <.010 <.010

36 Eel River near Logansport, IN 05/21/98 S1 SU–18 <.010 E.300 <.010 <.010 <.010 <.010

05/21/98 SB SU–20 <.010 <.010 <.010 <.010 <.010 <.010

06/30/98 S2 SU–152 <.010 .011 <.010 .034 <.010 <.010

37 Wildcat Creek near Jerome, IN 05/21/98 S1 SU–19 <.010 E.050 <.010 E.071 <.010 <.010

06/30/98 S2 SU–151 <.010 .028 <.010 .169 <.010 <.010

38 Wildcat Creek near Lafayette, IN 05/20/98 S1 SU–22 <.010 <.010 <.010 E.010 <.010 <.010

07/01/98 S2 SU–150 <.010 .018 <.010 .117 <.010 <.010

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 35

Iowa—Continued

26 <0.010 0.134 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

<.010 .044 <.010 .015 <.010 <.010 <.010 <.010 <.010 <.010

E.002 .039 <.010 .012 <.010 <.010 <.010 <.010 <.010 <.010

27 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.063 <.010 E.018 <.010 <.010 <.010 <.010 <.010 <.010

28 <.010 E.011 <.010 E.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .080 <.010 .019 <.010 <.010 <.010 <.010 <.010 <.010

29 <.010 .077 <.010 .266 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .034 <.010 .047 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

30 <.010 .083 <.010 .094 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .033 E.007 .021 <.010 <.010 <.010 <.010 <.010 <.010

31 <.010 <.010 <.010 E.006 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

32 E.007 .105 <.010 .093 <.010 <.010 <.010 <.010 <.010 <.010

Indiana—Continued

33 .217 .038 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.018 .073 <.010 .025 <.010 <.010 <.010 <.010 <.010 <.010

.019 .068 <.010 .033 <.010 <.010 <.010 E.007 <.010 <.010

34 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

35 .072 .050 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.126 .099 <.010 .043 <.010 <.010 <.010 <.010 <.010 <.010

36 E1.100 E.690 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.021 .061 <.010 .041 <.010 <.010 <.010 <.010 <.010 <.010

37 E.160 E.088 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.034 .046 <.010 .015 <.010 <.010 <.010 <.010 <.010 <.010

38 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.046 .101 <.010 .023 <.010 <.010 <.010 <.010 <.010 <.010

and 5 midwestern reservoirs—Continued

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl
36 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana—Continued

39 White River near Nora, IN 05/28/98 S1 SU–51 <0.010 0.062 <0.010 0.059 <0.010 <0.010

07/01/98 S2 SU–149 <.010 .043 <.010 .109 <.010 <.010

40 Sugar Creek near Edinburgh, IN 05/26/98 S1 SU–46 <.010 .070 <.010 <.010 <.010 <.010

07/20/98 S2 SU–178 Sample not analyzed (both bottles broken)

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 <.010 .081 <.010 .118 <.010 <.010

07/6/98 S2 SU–161 <.010 .035 <.010 .025 <.010 <.010

42 Wabash River at New Harmony, IN 05/27/98 S1 SU–57 <.010 .040 <.010 <.010 <.010 <.010

05/27/98 SD SU–58 <.010 .033 <.010 <.010 <.010 <.010

06/23/98 S2 SU–136 <.010 <.010 <.010 .116 <.010 <.010

Minnesota

43 Cottonwood River near

New Ulm, MN

05/26/98 S1 SU–49 <.010 <.010 <.010 <.010 <.010 <.010

07/21/98 S2 SU–180 <.010 <.010 <.010 .032 <.010 <.010

07/21/98 SD SU–181 <.010 <.010 <.010 E.035 <.010 <.010

44 Little Cobb River near

Beauford, MN

05/18/98 S1 SU–12 <.010 <.010 <.010 <.010 <.010 <.010

08/17/98 S2 SU–208 <.010 <.010 <.010 .016 <.010 <.010

45 Minnesota River near Jordan, MN 05/19/98 S1 SU–13 <.010 <.010 <.010 .013 <.010 <.010

06/26/98 S2 SU–135 <.010 <.010 <.010 .057 <.010 <.010

46 Mississippi River at Hastings, MN 05/20/98 S1 SU–14 <.010 <.010 <.010 <.010 <.010 <.010

05/20/98 SD SU–15 <.010 <.010 <.010 <.010 <.010 <.010

05/20/98 S2 SU–206 <.010 <.010 <.010 E.009 <.010 <.010

47 Des Moines River at Jackson, MN 05/26/98 S1 SU–48 <.010 <.010 <.010 <.010 <.010 <.010

08/24/98 S2 SU–210 <.010 <.010 <.010 .345 <.010 <.010

48 Rock River at Luverne, MN 06/24/98 S1 SU–130 <.010 <.010 <.010 E.008 <.010 <.010

06/25/98 S2 SU–131 <.010 <.010 <.010 .022 <.010 <.010

Kansas

49 Black Vermillion River at

Frankfort, KS

05/05/98 S1 SU–1 <.010 <.010 <.010 <.010 <.010 <.010

06/09/98 S2 SU–107 <.010 <.010 <.010 .014 E.011 <.010

50 Big Blue River below Tuttle

Creek Lake Dam, KS

06/03/98 R1 SU–74 <.010 <.010 E.023 <.010 <.010 <.010

07/29/98 R2 SU–197 <.010 E.004 <.010 E.021 <.010 <.010

51 Delaware River near Muscotah, KS 05/05/98 S1 SU–2 <.010 <.010 <.010 <.010 <.010 <.010

06/10/98 S2 SU–105 <.010 E.007 <.010 <.010 <.010 <.010

06/10/98 SB SU–106 <.010 <.010 <.010 <.010 <.010 <.010

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 37

Indiana—Continued

39 0.120 0.027 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

.045 .035 <.010 .017 <.010 <.010 <.010 <.010 <.010 <.010

40 .136 .031 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

41 .161 .073 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.055 .047 <.010 .026 <.010 .022 <.010 <.010 <.010 <.010

42 .051 .046 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.041 .030 <.010 <.010 <.010 <.010 .012 <.010 <.010 <.010

<.010 .082 <.010 .045 <.010 <.010 <.010 <.010 E.005 <.010

Minnesota—Continued

43 <.010 .018 <.010 E.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .026 <.010 .034 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.028 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

44 <.010 .015 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .021 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

45 <.010 .017 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .114 <.010 .059 <.010 <.010 <.010 <.010 <.010 <.010

46 <.010 E.005 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.003 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 .010 <.010 <.010 <.010 <.010 <.010 <.010

47 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.025 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

48 <.010 E.100 <.010 E.006 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .117 <.010 .042 <.010 <.010 <.010 <.010 <.010 <.010

Kansas—Continued

49 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.774 E.006 <.010 <.010 <.010 E.008 <.010 <.010 <.010 <.010

50 E.011 <.010 <.010 .011 <.010 <.010 <.010 <.010 <.010 <.010

E.021 E.013 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

51 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.049 .043 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

and 5 midwestern reservoirs—Continued

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl
38 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Kentucky

52 Ohio River at Cannelton Dam, KY 06/04/98 S1 SU–75 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

06/04/98 SD SU–214 <.010 .014 <.010 <.010 <.010 <.010

07/07/98 S2 SU–173 <.010 <.010 <.010 E.010 <.010 <.010

Missouri

53 Nodaway River near Graham, MO 06/18/98 S1 SU–119 <.010 <.010 <.010 .020 <.010 <.010

08/19/98 S2 SU–209 <.010 <.010 <.010 <.010 <.010 <.010

Nebraska

54 North Dry Creek near Kearney, NE 05/22/98 S1 SU–28 <.010 <.010 <.010 .045 <.010 <.010

06/08/98 S2 SU–76 <.010 <.010 <.010 .035 <.010 E.006

55 Maple Creek near Nickerson, NE 05/21/98 S1 SU–37 <.010 <.010 <.010 .055 <.010 <.010

05/21/98 SD SU–38 <.010 <.010 <.010 .051 <.010 <.010

06/08/98 S2 SU–79 <.010 <.010 <.010 .112 <.010 .016

56 Salt Creek at Roca, NE 05/15/98 S1 SU–6 <.010 <.010 <.010 .019 <.010 <.010

06/10/98 S2 SU–94 <.010 .054 <.010 <.010 E.013 <.010

57 Wahoo Creek at Ithaca, NE 05/15/98 S1 SU–5 <.010 <.010 <.010 <.010 <.010 <.010

06/08/98 S2 SU–78 <.010 .010 <.010 .025 <.010 .072

58 Platte River at Louisville, NE 05/22/98 S1 SU–39 <.010 <.010 <.010 <.010 <.010 <.010

05/22/98 SD SU–40 <.010 <.010 <.010 <.010 <.010 <.010

06/09/98 S2 SU–77 <.010 <.010 <.010 <.010 <.010 <.010

59 Big Nemaha River at Falls City, NE 05/26/98 S1 SU–41 <.010 <.010 <.010 <.010 <.010 <.010

06/08/98 S2 SU–80 <.010 <.010 <.010 .052 <.010 <.010

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 <.010 <.010 <.010 .128 <.010 <.010

06/10/98 S2 SU–82 Sample ruined in laboratory

61 Big Blue River at Barneston, NE 05/15/98 S1 SU–4 <.010 <.010 <.010 <.010 <.010 <.010

06/9/98 S2 SU–104 <.010 .036 <.010 .033 .053 .022

62 Little Blue River near Fairbury, NE 05/12/98 S1 SU–3 <.010 <.010 <.010 <.010 <.010 <.010

06/08/98 S2 SU–81 <.010 .012 <.010 .064 <.010 <.010

Ohio

63 Clear Creek near Rockbridge, OH 06/10/98 S1 SU–86 Sample ruined in laboratory

06/30/98 S2 SU–145 <.010 .013 <.010 .018 <.010 <.010

64 Scioto River near Prospect, OH 06/02/98 S1 SU–63 <.010 .081 <.010 <.010 <.010 .010

06/29/98 S2 SU–141 <.010 .044 <.010 .030 <.010 E.018

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 39

Kentucky—Continued

52 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.013 <.010 <.010 .012 <.010 <.010 <.010 <.010 <.010 <.010

Missouri—Continued

53 <.010 .052 <.010 .065 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Nebraska—Continued

54 <.010 .144 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.028 .078 <.010 .037 <.010 E.011 <.010 <.010 <.010 <.010

55 .071 .051 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

E.061 .040 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.234 .161 <.010 .025 <.010 <.010 <.010 <.010 <.010 <.010

56 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.033 E.022 <.010 E.039 <.010 E.027 <.010 <.010 <.010 <.010

57 <.010 .213 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .028 <.010 .050 <.010 <.010 <.010 <.010 <.010 <.010

58 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

E.021 .030 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 .150 <.010 E.010 <.010 <.010 <.010 <.010

59 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

E.066 .122 <.010 .161 <.010 <.010 <.010 <.010 <.010 <.010

60 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

61 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.045 .021 <.010 .030 <.010 E.036 .014 <.010 <.010 <.010

62 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.063 <.010 <.010 <.010 <.010 E.009 <.010 <.010 <.010 <.010

Ohio—Continued

63 Sample not analyzed

E.009 <.010 <.010 .017 <.010 E.008 <.010 <.010 <.010 <.010

64 .512 .026 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.266 .314 <.010 .075 <.010 <.010 <.010 <.010 <.010 <.010

and 5 midwestern reservoirs—Continued

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl
40 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Ohio—Continued

65 Olentangy River at Claridon, OH 06/09/98 S1 SU–85 <0.010 <0.010 <0.010 <0.010 E0.005 E0.005

06/29/98 S2 SU–157 <.010 .023 <.010 .013 <.010 <.010

06/29/98 SB SU–156 <.010 <.010 <.010 <.010 <.010 <.010

66 Olentangy River below Delaware,

Lake Dam, OH

06/09/98 R1 SU–84 Sample ruined in laboratory

06/29/98 R2 SU–153 <.010 .048 <.010 .023 <.010 <.010

07/01/98 RD SU–154 <.010 .044 <.010 .022 <.010 <.010

67 Big Darby Creek at Darbyville, OH 06/03/98 S1 SU–62 <.010 E.006 <.010 .021 <.010 <.010

06/29/98 S2 SU–140 <.010 .013 <.010 .048 <.010 <.010

68 Scioto River at Higby, OH 06/04/98 S1 SU–73 <.010 .022 <.010 .014 <.010 <.010

07/08/98 S2 SU–165 <.010 .041 <.010 .030 <.010 E.004

69 L. Miami River near Oldtown, OH 06/10/98 S1 SU–92 <.010 <.010 <.010 E.007 <.010 <.010

06/30/98 S2 SU–144 <.010 .015 <.010 .033 <.010 <.010

70 Mad River at Eagle City, OH 06/10/98 S1 SU–91 <.010 <.010 E.013 <.010 <.010 <.010

06/30/98 S2 SU–146 <.010 .021 <.010 <.010 <.010 <.010

71 Tiffin River at Stryker, OH 06/01/98 S1 SU–66 <.010 E.006 <.010 .020 <.010 <.010

06/01/98 SD SU–67 <.010 E.006 <.010 .021 <.010 <.010

07/07/98 S2 SU–172 Sample not analyzed (both bottles broken)

72 Auglaize River at Fort Jennings, OH 06/17/98 S1 SU–117 <.010 <.010 <.010 E.290 <.010 <.010

07/08/98 S2 SU–171 <.010 .067 <.010 .110 E.067 <.010

Wisconsin

73 Root River at Racine, WI 06/01/98 S1 SU–61 <.010 <.010 <.010 <.010 <.010 E.008

08/03/98 S2 SU–204 <.010 <.010 <.010 <.010 <.010 <.010

74 St. Croix River at

St. Croix Falls, WI

06/03/98 S1 SU–68 <.010 <.010 <.010 <.010 <.010 <.010

08/05/98 S2 SU–205 <.010 <.010 <.010 <.010 <.010 <.010

75 Wisconsin River at Muscoda, WI 06/16/98 S1 SU–133 <.010 <.010 <.010 E.009 <.010 <.010

08/07/98 S2 SU–202 <.010 <.010 <.010 <.010 <.010 <.010

08/07/98 SD SU–203 <.010 <.010 <.010 <.010 <.010 <.010

76 Rock River at Afton, WI 06/17/98 S1 SU–134 <.010 <.010 <.010 .020 <.010 <.010

07/21/98 S2 SU–179 <.010 <.010 <.010 .041 <.010 <.010

Table 6. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples from 71 midwestern streams

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site

no.

(figs. 3, 4)

Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

Bensulfuron

methyl

Chlorimuron

ethyl

ChlorsulfuronFlumetsulam

Halosulfuron

methyl

Imazapyr
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 41

Ohio—Continued

65 <0.010 E0.014 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

.032 .072 <.010 .049 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

66 Sample not analyzed

.103 .158 <.010 .091 <.010 <.010 <.010 <.010 <.010 <.010

.098 .167 <.010 .089 <.010 <.010 <.010 <.010 <.010 <.010

67 .068 <.010 <.010 E.012 <.010 <.010 <.010 <.010 <.010 <.010

.025 <.010 <.010 .022 <.010 <.010 <.010 <.010 <.010 <.010

68 .030 <.010 <.010 E.009 <.010 <.010 <.010 <.010 <.010 <.010

E.084 .083 <.010 .060 <.010 <.010 <.010 <.010 <.010 <.010

69 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

E.008 <.010 <.010 E.008 <.010 <.010 <.010 <.010 <.010 <.010

70 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.007 <.010 .012 <.010 <.010 <.010 <.010 <.010 <.010

71 <.010 E.007 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 E.006 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Sample not analyzed

72 E.410 .044 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

.206 .062 <.010 .040 <.010 E.009 <.010 .015 <.010 <.010

Wisconsin—Continued

73 <.010 E.024 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

74 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

75 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 E.007 <.010 <.010 <.010 <.010 <.010 <.010

76 <.010 E.008 <.010 E.009 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .020 <.010 .029 <.010 <.010 <.010 <.010 <.010 <.010

and 5 midwestern reservoirs—Continued

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site

no.

(figs. 3, 4)

Concentration,

in micrograms per liter

ImazaquinImazethapyr

Metsulfuron

methyl

Nicosulfuron

Primisulfuron

methyl

Prosulfuron

Sulfometuron

methyl

Thifensulfuron

methyl

Triasulfuron

Triflusulfuron

methyl
42 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Bensulfuron

Chlorimuron

Chlorsulfuron

Flumetsulam

Halosulfuron

Imazapyr

Imazaquin

Imazethapyr

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Triasulfuron

Triflusulfuron

Sum of analytes

0%

32%

1%

62%

5%

4%

32%

69%

0%

51%

0%

5%

2%

1%

0%

0%

82%

0.001 0.010 0.10

CONCENTRATION, IN MICROGRAMS PER LITER

1.0 10

associated with the stream (and reservoir outflow)

sampling sites are shaded according to the herbicide

concentrations in the associated samples. The difference in concentration between pre- and postemergence samples is notable for all three of these

compounds. In general, the occurrence of imazethapyr

at concentrations greater than 0.10 μg/L appears to be

more widespread than flumetsulam or nicosulfuron.

Nicosulfuron concentrations tend to be lower than

flumetsulam or imazethapyr except in the postemergence samples from the large stream sites

(fig. 16D). The difference between pre- and postemergence concentrations for these three compounds

is not as distinct as the difference between pre- and

post-application concentrations of alachlor, atrazine,

or cyanazine observed in previous investigations

(Goolsby and others, 1994; Goolsby and Battaglin,

1995). The difference in concentrations between

smaller agricultural watersheds and larger watersheds

that have more diverse land use also is evident in

figures 14, 15, and 16. The concentration of one of

these three herbicides exceeds 0.10 μg/L in 43 of

369 values (11.7 percent) in samples from stream or

reservoir outflow sites in smaller watersheds but only

in 3 of 54 values (5.5 percent) in samples from the

nine sites on streams of larger watersheds.

Table 7. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in 133 water samples

from 71 midwestern streams (concentrations in micrograms per liter)

[<, less than; E, estimate]

Herbicide

Method

reporting limit

(MRL)

Number at

or above

MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

bensulfuron methyl 0.010 0 <0.010 <0.010 <0.010 <0.010 <0.010

chlorimuron ethyl .010 41 <.010 <.010 .013 .081 E.300

chlorsulfuron .010 1 <.010 <.010 <.010 <.010 E.013

flumetsulam .010 87 <.010 .020 .057 .128 E.360

halosulfuron methyl .010 7 <.010 <.010 <.010 E.011 E.067

imazapyr .010 5 <.010 <.010 <.010 E.006 .072

imazaquin .010 44 <.010 <.010 .021 .217 E1.11

imazethapyr .010 92 E.005 .028 .073 .183 E.690

metsulfuron methyl .010 0 <.010 <.010 <.010 <.010 E.007

nicosulfuron .010 70 <.010 .010 .039 .110 .266

primisulfuron methyl .010 0 <.010 <.010 <.010 <.010 <.010

prosulfuron .010 6 <.010 <.010 <.010 E.009 .036

sulfometuron methyl .010 2 <.010 <.010 <.010 <.010 .018

thifensulfuron methyl .010 2 <.010 <.010 <.010 <.010 .015

triasulfuron .010 0 <.010 <.010 <.010 <.010 E.005

triflusulfuron methyl .010 0 <.010 <.010 <.010 <.010 <.010

Sum of all 16 analytes .010 111 .027 .128 .237 .560 2.10

Figure 13. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations and percent

detections at or above the method reporting limit

of 0.01 microgram per liter in 133 stream samples.
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 43

Pre-emergence samples

Post-emergence samples

A

C

B

D

0

0 100 200 KILOMETERS

100 200 MILES

0

0 100 200 300 KILOMETERS

100 300 MILES 200

0

0 100 200 300 KILOMETERS

100 300 MILES 200

0

0 100 200 KILOMETERS

100 200 MILES

Imazethapyr concentration,

 in micrograms per liter

Sampling point

EXPLANATION

Not analyzed

Less than 0.01

0.01 to 0.05

0.051 to 0.1

More than 0.1

Figure 14. Spatial distributions of imazethapyr concentrations in: (A) pre-emergence samples from small stream and

reservoir outflow sites, (B) pre-emergence samples from large river sites, (C) post-emergence samples from small stream

and reservoir outflow sites, and (D) post-emergence samples from large river sites.
44 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Pre-emergence samples

Post-emergence samples

A

C

B

D

0

0 100 200 300 KILOMETERS

100 300 MILES 200

0

0 100 200 300 KILOMETERS

100 300 MILES 200

Flumetsulam concentration,

 in micrograms per liter

Sampling point

EXPLANATION

Not analyzed

Less than 0.01

0.01 to 0.05

0.051 to 0.1

More than 0.1

0

0 100 200 KILOMETERS

100 200 MILES

0

0 100 200 KILOMETERS

100 200 MILES

Figure 15. Spatial distributions of flumetsulam concentrations in: (A) pre-emergence samples from small stream and

reservoir outflow sites, (B) pre-emergence samples from large river sites, (C) post-emergence samples from small stream

and reservoir outflow sites, and (D) post-emergence samples from large river sites.
OCCURRENCE OF SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES 45

0

0 100 200 KILOMETERS

100 200 MILES

Pre-emergence samples

A B

0

0 100 200

100 300 MILES 200

300 KILOMETERS

Post-emergence samples

C D

0

0 100 200 300 KILOMETERS

100 300 MILES 200

Nicosulfuron concentration,

 in micrograms per liter

Sampling point

EXPLANATION

Not analyzed

Less than 0.01

0.01 to 0.05

0.051 to 0.1

More than 0.1

0

0 100 200 KILOMETERS

100 200 MILES

Figure 16. Spatial distributions of nicosulfuron concentrations in: (A) pre-emergence samples from small stream and

reservoir outflow sites, (B) pre-emergence samples from large river sites, (C) post-emergence samples from small stream

and reservoir outflow sites, and (D) post-emergence samples from large river sites.
46 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Reservoir Outflows

 Results from eight reservoir outflow samples

are given in table 6. A statistical summary of these

results is given in table 8. At least one of the 16 SU,

SA, or IMI herbicides was detected at or above the

MRL in six of eight (75 percent) reservoir outflow

samples. Flumetsulam, imazethapyr, and imazaquin

were each detected in five samples. Nicosulfuron was

detected in four samples. Chlorimuron ethyl was

detected in two samples, and chlorsulfuron was

detected in one sample. Bensulfuron methyl, halosulfuron methyl, imazapyr, metsulfuron methyl, primisulfuron methyl, prosulfuron, sulfometuron methyl,

thifensulfuron methyl, triasulfuron, and triflusulfuron

methyl were not detected at or above the MRL.

The distributions of concentrations of the target

analytes in eight reservoir outflow samples are

summarized in figure 17. In some cases, estimated

concentrations are reported that are below the MRL.

These concentrations are not counted as detections at

or above the MRL in table 8 but are plotted in

figure 17 and used to calculate the percentiles shown

in table 8. The sum of SU, SA, and IMI concentrations

did not exceeded 0.50 μg/L in any of the reservoir

outflow samples.

Ground Water

 Results from 25 ground-water samples are

given in table 9. A statistical summary of these results

is given in table 10. At least one of the 16 SU, SA, or

IMI herbicides was detected at or above the MRL in 5

of 25 (20 percent) ground-water samples. Imazethapyr

was detected in four samples, flumetsulam and imazaquin were each detected in three samples, and nicosulfuron was detected in two samples. Bensulfuron

methyl, chlorimuron ethyl, chlorsulfuron, halosulfuron

methyl, imazapyr, metsulfuron methyl, primisulfuron

methyl, prosulfuron, sulfometuron methyl, thifensulfuron methyl, triasulfuron, and triflusulfuron methyl

were not detected at or above the MRL.

Table 8. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in eight water samples

from the outflow of five midwestern reservoirs (concentrations in micrograms per liter, the 95th percentile is not given as it is

the same as the maximum)

[MRL, method reporting limit; <, less than; E, estimate]

Herbicide Number at or

above MRL

25th

percentile Median 75thpercentile Maximum

bensulfuron methyl 0 <0.010 <0.010 <0.010 <0.010

chlorimuron ethyl 2 <.010 <.010 .026 .080

chlorsulfuron 1 <.010 <.010 <.010 E.023

flumetsulam 5 <.010 .022 .054 .116

halosulfuron methyl 0 <.010 <.010 <.010 <.010

imazapyr 0 <.010 <.010 <.010 <.010

imazaquin 5 <.010 .016 .087 .126

imazethapyr 5 <.010 .032 .076 .158

metsulfuron methyl 0 <.010 <.010 <.010 <.010

nicosulfuron 4 <.010 E.009 .032 .091

primisulfuron methyl 0 <.010 <.010 <.010 <.010

prosulfuron 0 <.010 <.010 <.010 <.010

sulfometuron methyl 0 <.010 <.010 <.010 <.010

thifensulfuron methyl 0 <.010 <.010 <.010 <.010

triasulfuron 0 <.010 <.010 <.010 <.010

triflusulfuron methyl 0 <.010 <.010 <.010 <.010

sum of 16 SUs, SAs, and IMIs 6 .029 .094 .299 .464
OCCURRENCE OF OTHER PESTICIDES 47

Bensulfuron

Chlorimuron

Chlorsulfuron

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Triasulfuron

Triflusulfuron

Sum of analytes

Halosulfuron

Imazapyr

Imazethapyr

Imazaquin

Flumetsulam

0.001 0.010 0.10 1.0 10

CONCENTRATION, IN MILLIGRAMS PER LITER

The distributions of concentrations of the target

analytes in 25 ground-water samples are summarized

in figure 18. In some samples, estimated concentrations are reported that are below the MRL. These

concentrations are not counted as detections at or

above the MRL in table 10, but are plotted in figure 18

and used to calculate the percentiles shown in table 10.

All non-detects are treated as zeros in the calculation

of percentiles. The sum of SU, SA, and IMI concentrations exceeded 0.10 μg/L in only one ground-water

sample.

OCCURRENCE OF OTHER PESTICIDES

Results of analysis for 46 pesticides or pesticide

degradates performed at the NWQL and 13 herbicides

and 10 herbicide degradates performed at the OGRL

are presented below. Although there is some overlap

between these two data sets, the analytical methods

used are not identical and, in particular, the MRL for

the analyses from the OGRL is generally 10 times

higher than the MDLs for analyses from the NWQL.

However, the OGRL analyzes for several herbicide

metabolites that the NWQL does not quantify.

Streams

The results of analysis by the NWQL for

46 pesticides and pesticide degradates in 134 stream

samples are given in tables 11–13. A statistical

summary of these results is given in table 14. At least

1 of the 46 compounds was detected at or above the

MDL in every sample. Some estimated concentrations

are reported that are below the MDL. These concentrations are not counted as detections at or above the

MDL in table 14 but are plotted in figures 19 and 20

and used to calculate the percentiles in table 14.

All non-detects are treated as zeros in the calculation

of percentile values. Acetochlor, atrazine, deethylatrazine, cyanazine, and metolachlor were all detected

in 90 percent (121) or more of the stream samples.

Alachlor, metribuzin, simazine, and trifluralin were

all detected in more than 50 percent (67) of stream

samples. Twelve other pesticides or degradates

were detected in 5 percent (7) or more of stream

samples.

Atrazine had the highest median concentration

(3.77 μg/L) in the NWQL results, followed by metolachlor (1.67 μg/L), acetochlor (0.400 μg/L), and

cyanazine (0.322 μg/L). The distributions of concentrations of the analytes that were detected more than

twice in 134 samples are summarized in figures 19

and 20. The sum of the concentrations of the 46 pesticide and degradates listed in tables 11–14 exceeded

15 μg/L in more than 25 percent of the stream

samples.

The results of analysis by the OGRL for

13 herbicides and 10 herbicide degradates in

141 stream samples and 10 reservoir outflow samples

are given in tables 15 and 16. A statistical summary of

the stream results is given in table 17. One or more of

the 13 herbicides was detected at or above the MRL in

140 (99 percent) of the 141 stream samples. One

or more of the 10 herbicide degradates was detected

in 139 (99 percent) of the samples. Alachlor ESA,

Figure 17. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in eight reservoir outflow samples.
48 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 9. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in water samples collected from 25 midwestern wells

[W1, well sample from round 1; WD, duplicate well sample; <, less than; E, estimate]

Site no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

BensulfuronChlorimuronChlorsulfuronFlumetsulamHalosulfuronImazapyr

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

2 LUS1–14 05/18/98 W1 SU–7 <.010 <.010 <.010 <.010 <.010 <.010

05/18/98 WD SU–10 <.010 <.010 <.010 <.010 <.010 <.010

3 LUS1–26 06/18/98 W1 SU–118 <.010 <.010 <.010 <.010 <.010 <.010

4 LUS2–9 06/15/98 W1 SU–111 <.010 <.010 <.010 <.010 <.010 <.010

5 LUS2–22 06/18/98 W1 SU–121 <.010 <.010 <.010 <.010 <.010 <.010

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.010 <.010 <.010 <.010 <.010 <.010

7 Fort Madison 4 07/22/98 W1 SU–182 <.010 <.010 <.010 <.010 <.010 <.010

8 Shambaugh 3 07/24/98 W1 SU–186 <.010 <.010 <.010 <.010 <.010 E.002

9 Nodaway 4 07/23/98 W1 SU–185 <.010 <.010 <.010 <.010 <.010 <.010

10 Silver City 3 07/31/98 W1 SU–198 <.010 <.010 <.010 <.010 <.010 <.010

07/31/98 WD SU–199 <.010 <.010 <.010 <.010 <.010 <.010

11 Carson (5), 3 07/31/98 W1 SU–200 <.010 <.010 <.010 <.010 <.010 <.010

12 Cumberland 1 07/27/98 W1 SU–188 <.010 <.010 <.010 <.010 <.010 <.010

13 Fontanelle 5 07/23/98 W1 SU–183 <.010 <.010 <.010 <.010 <.010 <.010

14 Menlo 3 07/29/98 W1 SU–193 <.010 <.010 <.010 .016 <.010 <.010

15 Carlisle 5 07/27/98 W1 SU–187 <.010 <.010 <.010 <.010 <.010 E.005

16 Newton 13 06/03/98 W1 SU–71 <.010 <.010 <.010 <.010 <.010 <.010

17 Belle Plaine 4 06/02/98 W1 SU–70 <.010 <.010 <.010 <.010 <.010 <.010

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.010 <.010 <.010 .023 <.010 <.010

08/25/98 WD SU–212 <.010 <.010 <.010 .023 <.010 <.010

19 Vail 1 06/23/98 W1 SU–137 <.010 <.010 <.010 <.010 <.010 <.010

20 Marshalltown 8 06/02/98 W1 SU–72 <.010 <.010 <.010 <.010 <.010 <.010

21 Boone 20 07/28/98 W1 SU–190 <.010 <.010 <.010 .035 <.010 <.010

22 Boxholm 2 07/25/98 W1 SU–189 <.010 <.010 <.010 <.010 <.010 <.010

07/25/98 WD SU–191 <.010 <.010 <.010 <.010 <.010 E.001

23 Holstein 3 06/25/98 W1 SU–139 <.010 <.010 E.009 <.010 <.010 <.010

24 Kingsley 1 06/25/98 W1 SU–138 <.010 <.010 <.010 E.007 <.010 <.010

25 Sheffield 2 07/29/98 W1 SU–192 <.010 <.010 <.010 <.010 <.010 <.010
OCCURRENCE OF OTHER PESTICIDES 49

Site no.

(fig. 5)

Concentration,

in micrograms per liter

ImazaquinImazethapyrMetsulfuronNicosulfuronPrimisulfuronProsulfuronSulfometuronThifensulfuronTriasulfuronTriflusulfuron

Illinois—Continued

1 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010 <0.010

2 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

3 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

4 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

5 .024 E.012 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

Iowa—Continued

6 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

7 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

8 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

9 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

10 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

11 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

12 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

13 <.010 E.002 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

14 E.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

15 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

16 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

17 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

18 <.010 .025 <.010 .016 <.010 <.010 <.010 <.010 <.010 <.010

<.010 .025 <.010 .015 <.010 <.010 <.010 <.010 <.010 <.010

19 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

20 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

21 E.007 .059 <.010 E.010 <.010 <.010 <.010 <.010 <.010 <.010

22 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

<.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

23 .012 .013 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

24 <.010 E.004 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010

25 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010
50 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

atrazine, deethylatrazine, metolachlor, and metolachlor ESA were all detected in 127 (90 percent) or

more of the samples. Acetochlor, acetochlor ESA,

acetochlor OA, deisopropylatrazine, cyanazine,

cyanazine-amide, and metolachlor OA were detected

in 71 (50 percent) or more of stream samples. Eight

other herbicides or degradates were detected in seven

(5 percent) or more of stream samples.

Atrazine had the highest median concentration

(3.27 μg/L) in the OGRL results, followed by metolachlor ESA (1.55 μg/L), metolachlor (1.15 μg/L), and

acetochlor ESA (0.88 μg/L). The median of the sums

of the concentrations of the 13 herbicides (5.96 μg/L)

was smaller than the median of the sums of the

concentrations of the 10 herbicide degradates

(7.53 μg/L). The distributions of concentrations of

the selected analytes in 141 samples from midwestern

streams are summarized in figure 21. The concentrations of several herbicide metabolites such as

acetochlor ESA and alachlor ESA tended to be higher

than the concentrations of the parent compounds.

These findings are consistent with results from several

recent studies which found higher concentrations of

herbicide metabolites relative to the parent herbicides

in streams, tile drains, and ground water (Kolpin and

others, 1998; Kalkhoff and others, 1998; Phillips and

others, 1999).

Reservoir Outflows

The results of analysis by the NWQL for

46 pesticides and pesticide degradates in 10 samples

of reservoir outflow are given in tables 11–13. A statistical summary of these results is given in table 18.

At least one of the 46 compounds was detected at or

above the MDL in every sample. Acetochlor, alachlor,

atrazine, deethylatrazine, cyanazine, metolachlor,

metribuzin, and simazine were all detected at or above

their MDL in nine (90 percent) or more of the reservoir outflow samples. Prometon was the only other

pesticide detected at or above the MDL in more than

five (50 percent) of reservoir outflow samples. Five

other pesticides or degradates were detected at or

above the MDL in two or more samples.

Atrazine had the highest median concentration

(2.01 μg/L) in NWQL results, followed by metolachlor (1.36 μg/L), cyanazine (0.325 μg/L),

acetochlor (0.294 μg/L), deethylatrazine (0.219 μg/L),

Table 10. Statistical summary of sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in 25 water samples

from 25 midwestern wells (concentrations in micrograms per liter)

[MRL, method reporting limit; <, less than; E, estimate]

Herbicide Number at

or above MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

bensulfuron methyl 0 <0.010 <0.010 <0.010 <0.010 <0.010

chlorimuron ethyl 0 <.010 <.010 <.010 <.010 <.010

chlorsulfuron 0 <.010 <.010 <.010 <.010 E.009

flumetsulam 3 <.010 <.010 <.010 .023 .035

halosulfuron methyl 0 <.010 <.010 <.010 <.010 <.010

imazapyr 0 <.010 <.010 <.010 E.002 E.005

imazaquin 2 <.010 <.010 <.010 .012 .024

imazethapyr 4 <.010 <.010 <.010 .025 .059

metsulfuron methyl 0 <.010 <.010 <.010 <.010 <.010

nicosulfuron 2 <.010 <.010 <.010 .010 .016

primisulfuron methyl 0 <.010 <.010 <.010 <.010 <.010

prosulfuron 0 <.010 <.010 <.010 <.010 <.010

sulfometuron methyl 0 <.010 <.010 <.010 <.010 <.010

thifensulfuron methyl 0 <.010 <.010 <.010 <.010 <.010

triasulfuron 0 <.010 <.010 <.010 <.010 <.010

triflusulfuron methyl 0 <.010 <.010 <.010 <.010 <.010

Sum of all 16 analytes 5 <.010 <.010 E.005 .064 .110
OCCURRENCE OF OTHER PESTICIDES 51

Bensulfuron

Chlorimuron

Chlorsulfuron

Metsulfuron

Nicosulfuron

Primisulfuron

Prosulfuron

Sulfometuron

Thifensulfuron

Triasulfuron

Triflusulfuron

Sum of analytes

Halosulfuron

Imazapyr

Imazethapyr

Imazaquin

Flumetsulam

0.001 0.010 0.10 1.0

CONCENTRATION, IN MILLIGRAMS PER LITER

and simazine (0.051 μg/L). The sum of the concentrations of the 46 pesticide and degradates listed in

tables 11–13 exceeded 10 μg/L in 3 of 10 reservoir

outflow samples.

The results of analysis by the OGRL for

13 herbicides and 10 herbicide degradates in

10 reservoir outflow samples are given in tables 15

and 16. A statistical summary of these results is given

in table 19. One or more of the 13 herbicides was

detected at or above the MRL in every sample. One or

more of the 10 herbicide degradates also was detected

at or above the MRL in every sample. Acetochlor,

alachlor ESA, atrazine, deethylatrazine, deisopropylatrazine, hydroxy-atrazine, cyanazine, cyanazineamide, metolachlor, metolachlor ESA, and metolachlor OA were all detected in 9 (90 percent) or more

of the 10 reservoir outflow samples. Acetochlor ESA

and acetochlor OA were detected in 6 (60 percent) or

more of 10 samples. Five other herbicides or degradates were detected in one (10 percent) or more of

reservoir samples.

Atrazine had the highest median concentration

(2.15 μg/L) in OGRL results, followed by metolachlor

ESA (2.11 μg/L), metolachlor OA (1.17 μg/L), metolachlor (1.06), hydroxy-atrazine (0.68 μg/L), and

alachlor ESA (0.63 μg/L). The median of the sum

of the concentrations of the 13 herbicides in the

10 reservoir outflow samples (4.33 μg/L) was smaller

than the median of the sum of the concentrations of the

10 herbicide degradates (7.58 μg/L) (table 19).

Ground Water

The results of analysis by the NWQL for

46 other pesticides and pesticide degradates in

23 ground-water samples are given in tables 20–22.

A statistical summary of these results is given in

table 23. At least 1 of the 46 compounds was detected

at or above the MDL in 15 of the 23 samples.

Atrazine, deethylatrazine, and metolachlor were

detected in 13 (57 percent) or more of the samples.

2,6-Diethylaniline, acetochlor, alachlor, butylate,

cyanazine, metribuzin, prometon, and simazine were

the only other pesticides or degradates that were

detected at a concentration at or above their MDL.

Atrazine had the highest median concentration

(0.039 μg/L) in NWQL results, followed by deethylatrazine (0.029 μg/L), and metolachlor (0.013 μg/L).

The highest concentration for any pesticide or degradate was for metolachlor (0.557 μg/L).

The results of analysis by the OGRL for

13 herbicides and 10 herbicide degradates in

25 ground-water samples are given in tables 24

and 25. A statistical summary of these results is given

in table 26. One or more of the 13 herbicides was

detected at or above the MRL in seven (28 percent)

of the samples. One or more of the 10 herbicide degradates was detected at or above the MRL in 18

(72 percent) of the samples. Metolachlor ESA was

detected most frequently (15 of 25 samples), followed

by alachlor ESA (8 of 25 samples), and deethylatrazine

and metolachlor OA (7 of 25 samples). Atrazine was

the most frequently detected parent herbicide (6 of

25 samples). Acetochlor ESA, acetochlor OA, alachlor

OA, deisopropylatrazine, cyanazine-amide, and metolachlor were all detected in two or more samples.

Metolachlor ESA had the highest median

concentration (0.66 μg/L) in OGRL results and the

highest concentration for any herbicide or degradate

in a ground-water sample (3.77 μg/L).

Figure 18. Sulfonylurea, sulfonamide, and imidazolinone herbicide concentrations in 25 groundwater samples.
52 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water samples from

[S1, pre-emergence stream sample; S2, post-emergence stream sample; RI, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4) Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

2,6-

Diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate

Illinois

1 Vermillion River below Lake

Vermillion Dam, IL

06/10/98 R1 SU–98 <0.0030 0.324 0.009 6.34 <0.0010 <0.0020 <0.0020

07/16/98 R2 SU–177 <.0030 .0330 <.002 1.52 <.0010 <.0020 <.0150

2 Bonpas Creek at Browns, IL 05/23/98 S1 SU–43 <.0030 15.6 .584 E127 <.0010 <.0020 .0061

07/07/98 S2 SU–166 <.0030 .103 .016 1.72 <.0010 <.0020 <.0020

3 Little Wabash River at Carmi, IL 05/23/98 S1 SU–33 <.0030 4.33 4.26 E75.4 <.0010 <.0020 .0208

07/09/98 S2 SU–175 <.0030 .123 .319 7.57 <.0010 <.0020 <.0020

4 S. Branch Kishwaukee River near

Fairdale, IL

05/20/98 S1 SU–29 <.0030 17.7 .525 18.5 <.0010 <.0020 <.0020

07/29/98 S2 SU–195 <.0030 .0140 <.002 .223 <.0010 <.0020 <.0020

5 Iroquois River near Chebanse, IL 06/10/98 S1 SU–99 <.0030 .220 .011 2.22 <.0010 <.0020 <.0020

07/08/98 S2 SU–168 <.0030 .117 .010 2.87 <.0010 <.0020 <.0020

6 Dupage River near Shorewood, IL 06/09/98 S1 SU–100 <.0030 .0328 .005 .085 <.0010 <.0020 <.0020

07/29/98 S2 SU–194 <.0030 <.0020 <.002 .029 <.0010 <.0020 <.0020

7 Illinois River at Marseilles, IL 06/12/98 S1 SU–113 <.0030 .934 .048 3.73 <.0010 <.0020 <.0020

07/09/98 S2 SU–176 <.0030 .197 .017 1.95 <.0010 <.0020 <.0020

8 Spoon River at London Mills, IL 05/20/98 S1 SU–25 <.0030 3.56 .286 E30.0 <.0010 <.0020 <.0020

07/01/98 S2 SU–160 <.0030 .151 .017 3.07 <.0010 <.0020 <.0020

9 Sangamon River near Monticello, IL 05/23/98 S1 SU–35 <.0030 .622 .021 3.30 <.0010 <.0020 .0372

08/05/98 S2 SU–201 <.0030 .0180 <.002 .440 <.0010 <.0020 <.0020

10 Sangamon River at Riverton, IL 05/26/98 S1 SU–44 <.0030 1.99 .180 15.1 <.0010 <.0020 E.0014

07/09/98 S2 SU–174 <.0030 .0901 .025 1.90 <.0010 <.0020 <.0020

11 LaMoine River at Colmar, IL 05/21/98 S1 SU–27 <.0030 11.6 .045 E27.7 <.0010 <.0020 <.0020

06/29/98 S2 SU–142 <.0030 .263 .028 4.25 <.0010 <.0020 <.0020

12 Illinois River at Valley City, IL 06/18/98 S1 SU–120 <.0030 1.16 .063 8.18 <.0010 <.0020 <.0020

08/12/98 S2 SU–207 <.0030 .0199 <.002 .326 <.0010 <.0020 <.0020

13 Mississippi River below Grafton, IL 06/02/98 S1 SU–60 <.0030 .879 .029 3.16 <.0010 <.0020 <.0020

06/15/98 S2 SU–116 <.0030 .901 .069 5.96 <.0010 <.0020 <.0020

14 Kaskaskia River near Cowden, IL 05/20/98 S1 SU–30 <.0030 .478 .027 1.73 <.0010 <.0020 <.0020

07/08/98 S2 SU–169 <.0030 1.01 .045 4.60 <.0010 <.0020 <.0020

15 Shoal Creek near Breese, IL 05/22/98 S1 SU–32 <.0030 11.4 .405 E34.7 <.0010 <.0020 .270

07/08/98 S2 SU–167 <.0030 1.14 .015 7.65 <.0010 <.0020 <.0020

Iowa

16 Turkey River at Spillville, IA 06/02/98 S1 SU–64 <.0030 .298 .018 4.20 <.0010 <.0020 <.0020

06/12/98 S2 SU–109 <.0030 1.45 .284 4.39 <.0010 <.0020 <.0020
OCCURRENCE OF OTHER PESTICIDES 53

70 midwestern streams and 5 midwestern reservoirs

SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Carbaryl Carbofuran

ChlorpyrifosCyanazine Dacthal Deethylatrazine Diazinon Dieldrin Disulfoton EPTC EthalfluralinEthoprophos Fonofos

Illinois—Continued

1 <0.0030 E0.0665 E0.0311 0.557 <0.0020 E0.238 E0.004 E0.003 <0.0170 <0.0020 <0.0040 <0.0030 <0.0030

<.0030 <.0030 <.0200 .188 <.0020 E.287 <.002 <.001 <.0170 <.0200 <.0040 <.0030 <.0030

2 E.0230 <.0030 .0742 1.63 <.0020 E1.10 .005 <.001 <.0170 .0076 <.0040 <.0030 <.0030

E.0100 <.0030 E.0325 .0159 <.0020 E.431 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

3 <.0030 <.0030 .102 1.98 <.0020 E.597 <.002 <.001 <.0170 E.0027 <.0040 <.0030 <.0030

<.0030 <.0030 E.0165 .386 E.0011 E.786 .007 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

4 <.0030 <.0030 <.0040 2.41 <.0020 E.235 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 <.0040 <.0020 E.0653 .021 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

5 E.0138 E.0694 E.0160 .473 <.0020 E.143 <.002 E.002 <.0170 <.0020 <.0040 <.0030 <.0030

E.0089 E.0310 E.0288 .630 <.0020 E.344 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

6 E.106 <.0030 .0054 .0438 <.0020 E.0286 .020 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 <.0040 <.0020 E.0105 .022 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

7 <.0030 E.191 .0323 .827 <.0020 E.184 .029 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0184 <.0030 E.0191 .355 <.0020 E.251 .051 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

8 <.0030 <.0030 .858 E20.0 <.0020 E.377 <.002 .008 <.0170 .0073 <.0040 <.0030 <.0030

E.195 E.0694 .0157 .409 <.0020 E.234 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

9 <.0030 <.0030 <.0500 .316 <.0020 E.245 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.124 <.0030 <.0040 .0652 <.0020 E.114 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

10 E.0096 E.0061 .0370 .643 E.0011 E.329 .005 .007 <.0170 .0075 <.0040 <.0030 <.0030

<.0030 <.0030 .0088 .110 <.0020 E.294 .006 .008 <.0170 <.0020 <.0040 <.0030 <.0030

11 <.0030 <.0030 <.300 9.40 <.0020 E.585 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0259 <.0030 <.0400 1.24 <.0020 E.767 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

12 <.0030 E.0872 <.0600 1.70 <.0020 E.828 <.002 <.001 <.0170 E.0018 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .106 <.0020 E.0806 .071 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

13 <.0030 <.0030 <.0040 .284 <.0020 E.0355 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0244 <.0200 .318 <.0020 E.0824 E.004 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

14 <.0030 <.0030 <.0040 .0290 <.0020 E.0581 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 E.0157 .408 <.0020 E.359 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

15 E.0096 <.0030 .366 2.09 <.0020 E.562 .023 <.001 <.0170 .0061 <.0040 <.0030 <.0030

<.0030 <.0030 E.0201 .326 <.0020 E.640 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Iowa—Continued

16 <.0030 E.0707 <.0400 .957 <.0020 E.290 <.002 <.001 <.0170 E.0020 <.0040 <.0030 <.0030

<.0030 E.653 <.0400 1.56 <.0020 E.461 <.002 <.001 <.0170 E.0030 <.0040 .0454 <.0030
54 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Iowa—Continued

17 Mississippi River at Clinton, IA 05/27/98 S1 SU–55 <0.0030 0.252 0.029 0.400 <0.0010 <0.0020 <0.0020

07/01/98 S2 SU–155 <.0030 .138 .028 .847 <.0010 <.0020 <.0020

18 Wapsipinicon River near Tripoli, IA 05/27/98 S1 SU–54 <.0030 .392 .123 1.47 <.0010 <.0020 <.0020

06/20/98 S2 SU–126 <.0030 .403 .160 8.56 <.0010 <.0020 <.0020

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 <.0030 1.71 .480 11.4 <.0010 <.0020 <.0020

06/12/98 S2 SU–110 <.0030 1.42 .102 11.1 <.0010 <.0020 <.0020

20 Iowa River near Rowan, IA 06/02/98 S1 SU–65 <.0030 .055 .008 .467 <.0010 <.0020 <.0020

06/23/98 S2 SU–129 <.0030 .921 .064 3.97 <.0010 <.0020 <.0020

21 Old Mans Creek near Iowa City, IA 06/10/98 S1 SU–93 <.0030 .849 .296 4.17 <.0010 <.0020 <.0020

06/30/98 S2 SU–147 <.0030 .451 .045 4.04 <.0010 <.0020 <.0020

22 Wolf Creek near Dysart, IA 06/10/98 S1 SU–87 <.0030 .744 .023 6.22 <.0010 <.0020 <.0020

06/22/98 S2 SU–128 <.0030 1.00 .066 4.50 <.0010 <.0020 <.0020

23 Iowa River at Wapello, IA 05/27/98 S1 SU–53 Sample not analyzed (ruined in laboratory)

06/19/98 S2 SU–127 <.0030 .417 .050 5.16 <.0010 <.0020 <.0020

24 N. Skunk River near Sigourney, IA 05/21/98 S1 SU–21 <.0030 15.6 .012 E23.4 <.0010 <.0020 <.0020

06/10/98 S2 SU–95 <.0030 .511 .138 8.00 <.0010 <.0020 <.0020

25 Skunk River at Augusta, IA 05/26/98 S1 SU–45 <.0030 10.6 .120 E48.1 <.0010 <.0020 .0045

06/18/98 S2 SU–122 <.0030 .983 .079 9.84 <.0010 <.0020 <.0020

26 Des Moines River at Fort Dodge, IA 05/16/98 S1 SU–8 <.0030 16.1 .027 .732 <.0010 <.0020 <.0020

06/12/98 S2 SU–108 <.0030 .117 <.002 .480 <.0010 <.0020 <.0020

27 Raccoon River at Van Meter, IA 05/17/98 S1 SU–9 <.0030 1.16 .020 2.38 <.0010 <.0020 <.0020

06/10/98 S2 SU–89 <.0030 .416 .014 3.08 <.0010 <.0020 <.0020

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 <.0030 .543 .012 1.78 <.0010 <.0020 <.0020

06/18/98 S2 SU–123 <.0030 .313 .007 1.23 <.0010 <.0020 <.0020

29 Maple River at Mapleton, IA 05/29/98 S1 SU–59 <.0030 3.03 .026 10.0 <.0010 <.0020 <.0020

06/09/98 S2 SU–90 <.0030 .194 <.002 4.11 <.0010 <.0020 <.0020

30 Boyer River at Logan, IA 05/22/98 S1 SU–31 <.0030 3.26 .458 16.0 <.0010 <.0020 <.0020

06/09/98 S2 SU–96 <.0030 .714 .017 5.54 <.0010 <.0020 <.0020

31 Chariton River below Rathbun

Lake Dam, IA

06/04/98 R1 SU–69 <.0030 .164 .005 1.05 <.0010 <.0020 <.0020

06/29/98 R2 SU–148 <.0030 .308 .006 1.91 <.0010 <.0020 <.0020

Indiana

33 Whitewater River near Alpine, IN 05/26/98 S1 SU–47 E.0016 2.80 1.79 24.2 <.0010 <.0020 .0238

07/08/98 S2 SU–162 <.0030 .118 .048 1.62 <.0010 <.0020 <.0020

Table 11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water samples from

[S1, pre-emergence stream sample; S2, post-emergence stream sample; RI, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4) Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

2,6-

Diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate
OCCURRENCE OF OTHER PESTICIDES 55

Iowa—Continued

17 <0.0030 <0.0030 0.0047 0.0707 <0.0020 E0.0276 <0.002 <0.001 <0.0170 E0.0037 <0.0040 <0.0030 <0.0030

<.0030 E.0248 <.0040 .110 <.0020 E.130 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

18 <.0030 E.0575 <.0080 .180 <.0020 E.162 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.302 .0222 .653 <.0020 E.600 <.002 <.001 <.0170 E.0019 <.0040 <.0030 <.0030

19 <.0030 E1.03 <.0040 .430 <.0020 E.415 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0085 E1.01 E.0194 .681 E.0014 E.754 <.002 <.001 <.0170 <.0020 <.0040 <.0030 E.0022

20 <.0030 E.0119 <.0040 .0109 <.0020 E.0568 <.002 <.001 <.0170 E.0023 <.0040 <.0030 <.0030

<.0030 E.0894 <.0040 .0988 <.0020 E.283 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

21 <.0030 E.0320 <.0040 .916 <.0020 E.291 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0392 .0176 .721 <.0020 E.571 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

22 <.0030 E.0865 <.0040 .570 <.0020 E.359 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0494 <.0040 .874 <.0020 E.415 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

23 Sample not analyzed

<.0030 E.0937 E.0261 .788 E.0014 E.514 <.002 E.004 <.0170 <.0020 <.0040 <.0030 <.0030

24 <.0030 <.0030 E.0864 2.51 <.0020 E.297 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0200 E.112 <.0040 2.06 <.0020 E.477 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

25 <.0030 E.0258 <.300 14.0 <.0020 E.539 .005 .006 <.0170 <.0020 <.0040 <.0030 E.0022

<.0030 E.122 E.0594 1.51 <.0020 E.631 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

26 <.0030 <.0030 .0356 .154 <.0020 E.0339 <.002 <.001 <.0170 .0230 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0353 <.0020 E.0479 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

27 <.0030 E.0063 <.0040 .442 <.0020 E.0480 <.002 <.001 <.0170 .0759 <.0040 <.0030 <.0030

<.0030 E.0601 <.0040 .333 <.0020 E.156 <.002 <.001 <.0170 .0045 <.0040 <.0030 <.0030

28 <.0030 <.0030 <.0040 .0416 <.0020 E.0686 .005 <.001 <.0170 .0041 <.0040 <.0030 <.0030

<.0030 E.0500 <.0040 .0319 <.0020 E.147 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

29 <.0030 <.0030 <.0800 2.24 <.0020 E.228 <.002 <.001 <.0170 E.0032 <.0040 <.0030 .0063

<.0030 <.0200 <.0040 .310 <.0020 E.135 <.002 <.001 <.0170 .0047 <.0040 <.0030 <.0030

30 <.0030 <.0030 <.0040 8.07 <.0020 E.308 <.002 <.001 <.0170 .0308 <.0040 <.0030 <.0030

<.0030 E.222 .0341 1.01 <.0020 E.180 .035 <.001 <.0170 .0107 <.0040 <.0030 <.0030

31 <.0030 <.0030 <.0040 .328 <.0020 E.101 <.002 <.001 <.0170 E.0019 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .321 <.0020 E.179 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Indiana—Continued

33 <.0030 E.0387 <.190 6.75 E.0012 E.364 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .415 <.0020 E.216 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

70 midwestern streams and 5 midwestern reservoirs—Continued

SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Carbaryl Carbofuran

ChlorpyrifosCyanazine Dacthal Deethylatrazine Diazinon Dieldrin Disulfoton EPTC EthalfluralinEthoprophos Fonofos
56 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana—Continued

34 Blue River at Fredericksburg, IN 05/27/98 S1 SU–50 <0.0030 0.481 0.049 7.22 <0.0010 <0.0020 <0.0020

07/08/98 S2 SU–163 <.0030 .0474 .016 1.09 <.0010 <.0020 <.0020

35 Mississinewa River below

Mississinewa Lake Dam, IN

06/09/98 R1 SU–83 <.0030 .545 .019 5.70 <.0010 <.0020 <.0020

07/09/98 R2 SU–164 <.0030 .821 .099 6.90 <.0010 <.0020 <.0020

36 Eel River near Logansport, IN 05/21/98 S1 SU–18 Sample not analyzed (broken bottle)

06/30/98 S2 SU–152 <.0030 .245 1.12 3.14 <.0010 <.0020 <.0020

37 Wildcat Creek near Jerome, IN 05/21/98 S1 SU–19 <.0030 1.76 .054 12.3 <.0010 <.0020 <.0020

06/30/98 S2 SU–151 <.0030 E.312 .306 6.27 <.0010 <.0020 <.0020

38 Wildcat Creek near Lafayette, IN 05/20/98 S1 SU–22 <.0030 1.09 .029 4.56 <.0010 <.0020 <.0020

07/01/98 S2 SU–150 <.0030 E.198 .038 2.87 <.0010 <.0020 <.0020

39 White River near Nora, IN 05/28/98 S1 SU–51 <.0030 1.56 .039 10.2 <.0010 <.0020 <.0020

07/01/98 S2 SU–149 <.0030 E.445 .104 5.06 <.0010 <.0020 <.0020

40 Sugar Creek near Edinburgh, IN 05/26/98 S1 SU–46 <.0030 4.16 .148 E28.7 <.0010 <.0020 <.0020

07/20/98 S2 SU–178 <.0030 .127 .047 .715 <.0010 <.0020 <.0020

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 <.0030 4.44 .913 E27.9 <.0010 <.0020 <.0020

07/06/98 S2 SU–161 <.0030 .166 .194 1.89 <.0010 <.0020 <.0020

42 Wabash River at New Harmony, IN 05/27/98 S1 SU–57 Sample not analyzed (ruined in laboratory)

06/23/98 S2 SU–136 <.0030 1.04 .176 10.4 <.0010 <.0020 <.0020

Minnesota

43 Cottonwood River near

New Ulm, MN

05/26/98 S1 SU–49 <.0030 .0937 .008 .145 <.0010 <.0020 <.0020

07/21/98 S2 SU–180 <.0030 .0605 .017 .176 <.0010 <.0020 <.0020

44 Little Cobb River near Beauford, MN 05/18/98 S1 SU–12 <.0030 2.08 .154 .102 <.0010 <.0020 <.0020

08/17/98 S2 SU–208 <.0030 <.0020 <.002 .062 <.0010 <.0020 <.0020

45 Minnesota River near Jordan, MN 05/19/98 S1 SU–13 <.0030 1.32 .086 .122 <.0010 <.0020 <.0020

06/26/98 S2 SU–135 <.0030 .320 .112 1.09 <.0010 <.0020 <.0020

46 Mississippi River at Hastings, MN 05/20/98 S1 SU–14 <.0030 .411 .063 .175 <.0010 <.0020 <.0020

05/20/98 S2 SU–206 <.0030 <.0020 <.002 .088 <.0010 <.0020 <.0020

47 Des Moines River at Jackson, MN 05/26/98 S1 SU–48 <.0030 .530 .012 .536 <.0010 <.0020 <.0020

08/24/98 S2 SU–210 <.0030 .0494 <.002 .159 <.0010 <.0020 <.0020

48 Rock River at Luverne, MN 06/24/98 S1 SU–130 <.0030 .0455 <.002 .103 <.0010 <.0020 <.0020

06/25/98 S2 SU–131 <.0030 .0757 <.002 .147 <.0010 <.0020 <.0020

Kansas

49 Black Vermillion River at

Frankfort, KS

05/05/98 S1 SU–1 <.0030 .0197 .038 .381 <.0010 <.0020 <.0020

06/09/98 S2 SU–107 <.0030 .0278 1.17 8.71 <.0010 <.0020 <.0020

Table 11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water samples from

[S1, pre-emergence stream sample; S2, post-emergence stream sample; RI, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4) Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

2,6-

Diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate
OCCURRENCE OF OTHER PESTICIDES 57

Indiana—Continued

34 <0.0030 <0.0030 <0.0100 0.232 <0.0020 E0.325 <0.002 <0.001 <0.0170 <0.0020 <0.0040 <0.0030 <0.0030

E.0107 <.0030 <.0040 .0384 <.0020 E.277 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

35 <.0030 <.0030 <.0040 2.00 <.0020 E.200 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0282 E.232 <.100 2.90 <.0020 E.729 .012 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

36 Sample not analyzed

<.0030 <.0030 <.0040 .288 <.0020 E.398 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

37 <.0030 <.0030 <.0040 14.0 <.0020 E.332 <.002 <.008 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.150 .0136 .879 <.0020 E.608 <.002 E.015 <.0170 <.0020 <.0040 <.0030 <.0030

38 <.0030 <.0030 E.0323 .304 <.0020 E.155 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0060 E.0153 .0065 .376 <.0020 E.419 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

39 <.0030 E.0246 E.0447 1.13 <.0020 E.304 .007 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0488 <.0040 .578 <.0020 E.652 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

40 E.0060 E.0696 E.0720 2.18 <.0020 E.381 .009 E.003 <.0170 <.0020 <.0040 <.0030 <.0030

E.0381 <.0030 .0408 <.0500 <.0020 E.140 .022 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

41 <.0030 E.0309 E.0903 2.59 <.0020 E.597 E.004 <.001 <.0170 <.0020 <.0040 <.0030 E.0015

E.0074 <.0030 <.0100 .130 <.0020 E.296 .006 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

42 Sample not analyzed

<.0030 E.157 <.0040 1.78 <.0020 E.875 .012 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Minnesota—Continued

43 <.0030 E.0656 <.0040 .0493 <.0020 E.0166 <.002 <.001 <.0170 .0047 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0290 <.0020 E.0342 .018 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

44 <.0030 <.0030 <.0040 .0132 <.0020 E.0354 <.002 <.001 <.0170 <.0600 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 <.0040 <.0020 E.0106 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

45 <.0030 <.0030 <.0040 .0277 <.0020 E.0208 <.002 <.001 <.0170 .0160 <.0040 <.0030 <.0030

<.0030 E.0174 <.0040 .0864 <.0020 E.111 E.002 <.001 <.0170 E.0033 <.0040 <.0030 <.0030

46 <.0030 <.0030 <.0040 .0638 <.0020 E.0185 <.002 <.001 <.0170 .0232 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0176 <.0020 E.0258 .005 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

47 <.0030 <.0030 <.0040 .0206 <.0020 E.0287 <.002 <.001 <.0170 .0066 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 <.0040 <.0020 E.0636 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

48 <.0030 <.0030 <.0040 <.0040 <.0020 E.0425 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0260 <.0040 <.0040 <.0020 E.0444 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Kansas—Continued

49 <.0030 <.0030 <.0040 .0060 <.0020 E.0167 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.645 <.0040 E.0176 <.0020 E.405 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

70 midwestern streams and 5 midwestern reservoirs—Continued

SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Carbaryl Carbofuran

ChlorpyrifosCyanazine Dacthal Deethylatrazine Diazinon Dieldrin Disulfoton EPTC EthalfluralinEthoprophos Fonofos
58 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Kansas—Continued

50 Big Blue River below Tuttle

Creek Lake Dam, KS

06/03/98 R1 SU–74 <0.0030 0.194 0.388 1.85 <0.0010 <0.0020 <0.0020

07/29/98 R2 SU–197 <.0030 .279 .815 1.09 <.0010 <.0020 <.0020

51 Delaware River near Muscotah, KS 05/05/98 S1 SU–2 <.0030 .0340 .007 .377 <.0010 <.0020 <.0020

06/10/98 S2 SU–105 <.0030 .0992 .557 4.12 <.0010 <.0020 <.0020

Kentucky

52 Ohio River at Cannelton Dam, KY 06/04/98 S1 SU–75 <.0030 .186 .055 1.49 <.0010 <.0020 <.0020

07/07/98 S2 SU–173 <.0030 .0506 .014 .696 <.0010 <.0020 <.0020

 Missouri

53 Nodaway River near Graham, MO 06/18/98 S1 SU–119 Sample not analyzed (ruined in laboratory)

08/19/98 S2 SU–209 <.0030 .0047 .005 .254 <.0010 <.0020 <.0020

Nebraska

54 North Dry Creek near Kearney, NE 05/22/98 S1 SU–28 <.0030 5.29 .151 7.95 <.0010 <.0020 <.0020

06/08/98 S2 SU–76 <.0030 .223 .069 8.78 <.0010 <.0020 <.0020

55 Maple Creek near Nickerson, NE 05/21/98 S1 SU–37 <.0030 E25.1 10.9 E30.0 <.0010 <.0020 <.0020

06/08/98 S2 SU–79 <.0030 2.26 .106 12.6 <.0010 <.0020 <.0020

56 Salt Creek at Roca, NE 05/15/98 S1 SU–6 <.0030 .398 17.2 E224 <.0010 <.0020 <.0020

06/10/98 S2 SU–94 <.0030 .930 1.84 E37.3 <.0010 <.0020 <.0020

57 Wahoo Creek at Ithaca, NE 05/15/98 S1 SU–5 <.0030 1.58 3.80 E38.1 <.0010 <.0020 <.0020

06/08/98 S2 SU–78 <.0030 .490 .380 7.73 <.0010 <.0020 <.0020

58 Platte River at Louisville, NE 05/22/98 S1 SU–39 <.0030 3.08 2.70 E25.1 <.0010 <.0020 <.0020

06/09/98 S2 SU–77 <.0030 .729 .839 8.80 <.0010 <.0020 <.0020

59 Big Nemaha River at Falls City, NE 05/26/98 S1 SU–41 <.0030 .396 .251 4.43 <.0010 <.0020 <.0020

06/08/98 S2 SU–80 <.0030 1.42 .908 E37.6 <.0010 <.0020 <.0020

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 <.0030 3.89 8.58 E46.5 <.0010 <.0020 <.0020

06/10/98 S2 SU–82 <.0030 1.04 .722 9.54 <.0010 <.0020 <.0020

61 Big Blue River at Barneston, NE 05/15/98 S1 SU–4 <.0030 1.15 2.94 7.06 <.0010 <.0020 <.0020

06/09/98 S2 SU–104 E.0035 .781 8.19 E24.4 <.0010 <.0020 <.0020

62 Little Blue River near Fairbury, NE 05/12/98 S1 SU–3 Sample not analyzed (broken bottle)

06/08/98 S2 SU–81 Sample not analyzed (mislabled bottle)

Ohio

63 Clear Creek near Rockbridge, OH 06/10/98 S1 SU–86 <.0030 .0321 .017 .290 <.0010 <.0020 <.0020

06/30/98 S2 SU–145 <.0030 .210 .017 1.60 <.0010 <.0020 <.0020

64 Scioto River near Prospect, OH 06/02/98 S1 SU–63 <.0030 .896 .025 4.94 <.0010 E.0039 <.0020

06/29/98 S2 SU–141 <.0030 .172 .029 4.01 <.0010 <.0020 <.0020

65 Olentangy River at Claridon, OH 06/09/98 S1 SU–85 <.0030 .0437 .009 .897 <.0010 <.0020 <.0020

06/29/98 S2 SU–157 <.0030 .401 .055 4.32 <.0010 <.0020 <.0020

Table 11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water samples from

[S1, pre-emergence stream sample; S2, post-emergence stream sample; RI, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4) Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

2,6-

Diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate
OCCURRENCE OF OTHER PESTICIDES 59

Kansas—Continued

50 <0.0030 <0.0030 <0.0040 0.150 <0.0020 E0.0785 <0.002 <0.001 <0.0170 <0.0020 <0.0040 <0.0030 <0.0030

<.0030 <.0030 <.0040 .0331 <.0020 E.349 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

51 <.0030 <.0030 <.0040 .0291 <.0020 E.0243 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0520 <.0020 E.170 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Kentucky—Continued

52 E.0202 <.0030 .0122 .280 <.0020 E.0525 .008 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 .0050 .0735 <.0020 E.0705 .007 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Missouri—Continued

53 Sample not analyzed

<.0030 <.0030 <.0040 .0387 <.0020 E.0557 .008 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Nebraska—Continued

54 <.0030 <.0030 .0089 .127 <.0020 E.578 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0185 <.0030 <.0040 .0685 <.0020 E.692 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

55 <.0030 <.0030 <.0040 3.57 <.0020 E.465 <.002 <.001 <.0170 <.0020 <.0040 <.0030 .0629

<.0030 E.0156 <.0040 3.67 <.0020 E.441 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

56 <.0030 <.0030 <.0040 .246 <.0020 E.989 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0587 <.0040 1.80 <.0020 E1.26 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

57 <.0030 <.0030 <.0040 4.42 <.0020 E.318 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0588 E.149 <.0040 1.41 E.0015 E.252 .011 <.001 <.0170 .0148 <.0040 <.0030 <.0030

58 <.0030 E.0111 <.0040 4.67 <.0020 E.610 <.002 <.001 <.0170 E.0036 <.0040 <.0030 <.0030

<.0030 E.0713 <.0200 1.49 <.0020 E.327 .007 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

59 <.0030 <.0030 <.0040 .592 <.0020 E.102 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0220 <.0040 9.52 <.0020 E.568 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

60 <.0030 <.0030 <.0040 .992 <.0020 E.820 .011 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0200 .0143 .0628 <.0020 E.501 .033 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

61 <.0030 <.0030 .0405 .0337 <.0020 E.101 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 E.0412 <.0400 .427 <.0020 E.734 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

62 Sample not analyzed

Sample not analyzed

Ohio—Continued

63 <.0030 <.0030 <.0040 .0247 <.0020 E.0329 .025 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0087 <.0030 .0072 .149 <.0020 E.284 .004 .006 <.0170 <.0020 <.0040 <.0030 <.0030

64 E.117 <.0030 <.0600 1.31 <.0020 E.286 .028 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0304 <.0030 E.0177 .390 E.0011 E.644 .008 .007 <.0170 <.0020 <.0040 <.0030 <.0030

65 <.0030 <.0030 <.0040 .0363 <.0020 E.0773 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0334 <.0030 E.0141 .402 E.0011 E.570 .011 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

70 midwestern streams and 5 midwestern reservoirs—Continued

SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Carbaryl Carbofuran

ChlorpyrifosCyanazine Dacthal Deethylatrazine Diazinon Dieldrin Disulfoton EPTC EthalfluralinEthoprophos Fonofos
60 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Ohio—Continued

66 Olentangy River below

Delaware, Lake Dam, OH

06/09/98 R1 SU–84 <0.0030 0.257 0.009 2.11 <0.0010 <0.0020 <0.0020

06/29/98 R2 SU–153 <.0030 .478 .046 5.16 <.0010 <.0020 <.0020

67 Big Darby Creek at Darbyville, OH 06/03/98 S1 SU–62 <.0030 .688 .122 9.18 <.0010 <.0020 <.0020

06/29/98 S2 SU–140 <.0030 .178 .022 2.55 <.0010 <.0020 <.0020

68 Scioto River at Higby, OH 06/04/98 S1 SU–73 <.0030 1.08 .069 6.97 <.0010 <.0020 <.0020

07/08/98 S2 SU–165 <.0030 .290 .024 3.80 <.0010 <.0020 <.0020

69 L. Miami River near Oldtown, OH 06/10/98 S1 SU–92 <.0030 .0539 .015 .445 <.0010 <.0020 <.0020

06/30/98 S2 SU–144 <.0030 .0278 .007 .510 <.0010 <.0020 <.0020

70 Mad River at Eagle City, OH 06/10/98 S1 SU–91 <.0030 <.0020 <.002 .048 <.0010 <.0020 <.0020

06/30/98 S2 SU–146 <.0030 .0289 .008 .536 <.0010 <.0020 <.0020

71 Tiffin River at Stryker, OH 06/01/98 S1 SU–66 <.0030 .262 .150 1.63 <.0010 <.0020 <.0020

07/07/98 S2 SU–172 <.0030 .0365 .010 .581 <.0010 <.0020 <.0020

72 Auglaize River at Fort Jennings, OH 06/17/98 S1 SU–117 <.0030 1.45 .188 9.96 <.0010 <.0020 <.0020

07/08/98 S2 SU–171 <.0030 .297 .030 2.21 <.0010 <.0020 <.0020

Wisconsin

73 Root River at Racine, WI 06/01/98 S1 SU–61 <.0030 .193 .040 .351 <.0010 <.0020 <.0020

08/03/98 S2 SU–204 <.0030 <.0020 <.002 .106 <.0010 <.0020 <.0020

74 St. Croix River at St. Croix Falls, WI 06/03/98 S1 SU–68 <.0030 .0259 .011 .104 <.0010 <.0020 <.0020

08/05/98 S2 SU–205 <.0030 <.0020 <.002 .013 <.0010 <.0020 <.0020

75 Wisconsin River at Muscoda, WI 06/16/98 S1 SU–133 <.0030 .0479 .027 .264 <.0010 <.0020 <.0020

08/07/98 S2 SU–202 <.0030 E.0084 .009 .134 <.0010 <.0020 <.0020

76 Rock River at Afton, WI 06/17/98 S1 SU–134 <.0030 .127 .010 .346 <.0010 <.0020 <.0020

07/21/98 S2 SU–179 <.0030 .0106 <.002 .526 <.0010 <.0020 <.0020

Table 11. Pesticide and pesticide degradate (2,6-diethylaniline through fonofos) concentrations in water samples from

[S1, pre-emergence stream sample; S2, post-emergence stream sample; RI, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4) Site name

Date of

collection

(month/

day/year)

Sample

type

Concentration,

in micrograms per liter

Sample

no.

2,6-

Diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate
OCCURRENCE OF OTHER PESTICIDES 61

Ohio—Continued

66 <0.0030 <0.0030 <0.0040 0.0678 <0.0020 E0.113 <0.002 <0.001 <0.0170 <0.0020 <0.0040 <0.0030 <0.0030

E.0085 <.0030 <.0040 .624 <.0020 E.712 <.002 <.001 <.0170 E.0027 <.0040 <.0030 <.0030

67 E.0043 <.0030 <.0700 1.93 <.0020 E.415 .005 E.002 <.0170 <.0020 <.0040 <.0030 <.0030

E.119 <.0030 .0159 .224 E.0011 E.260 .030 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

68 <.0030 <.0030 <.0040 1.79 <.0020 E.269 .016 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0120 <.0030 .0247 .623 <.0020 E.450 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

69 <.0030 <.0030 <.0040 .0536 <.0020 E.0673 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0067 <.0030 .0045 .0620 <.0020 E.0796 E.004 E.001 <.0170 <.0020 <.0040 <.0030 <.0030

70 <.0030 <.0030 E.0035 <.0040 <.0020 E.0089 .008 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

E.0490 <.0030 E.0037 .0298 <.0020 E.108 .005 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

71 E.0108 <.0030 <.0300 .407 <.0020 E.107 .008 <.001 <.0170 E.0019 <.0040 <.0030 E.0033

<.0030 <.0030 <.0040 .167 <.0020 E.0820 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

72 <.0030 <.0030 <.0040 1.87 <.0020 E.870 E.004 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 .0192 .385 <.0020 E.395 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

Wisconsin—Continued

73 E.0655 E.0122 <.0080 .167 E.0018 E.109 .016 <.001 <.0170 .0083 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0213 <.0020 E.0152 .010 <.001 <.0170 .0200 <.0040 <.0030 <.0030

74 <.0030 <.0030 <.0040 .0071 <.0020 E.0172 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 <.0040 <.0020 E.0081 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

75 <.0030 <.0030 <.0040 .0671 <.0020 E.0381 .006 <.001 <.0170 .0047 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .0166 <.0020 E.0364 <.002 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

76 <.0030 <.0030 <.0040 .144 <.0020 E.0624 <.002 <.001 <.0170 .0092 <.0040 <.0030 <.0030

<.0030 <.0030 <.0040 .349 <.0020 E.101 .011 <.001 <.0170 <.0020 <.0040 <.0030 <.0030

70 midwestern streams and 5 midwestern reservoirs—Continued

SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Carbaryl Carbofuran

ChlorpyrifosCyanazine Dacthal Deethylatrazine Diazinon Dieldrin Disulfoton EPTC EthalfluralinEthoprophos Fonofos
62 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 70 midwestern

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide

Illinois

1 Vermillion River below Lake

Vermillion Dam, IL

06/10/98 R1 SU–98 <0.004 <0.0020 <0.005 1.33 0.014 <0.0040 <0.0030

07/16/98 R2 SU–177 <.004 <.0020 <.005 .619 .009 <.0040 <.0030

2 Bonpas Creek at Browns, IL 05/23/98 S1 SU–43 <.004 .0246 <.005 23.8 .198 .0182 <.0030

07/07/98 S2 SU–166 <.004 <.0020 <.005 1.32 <.015 <.0040 <.0030

3 Little Wabash River at Carmi, IL 05/23/98 S1 SU–33 <.004 .0336 .009 15.0 .344 .0486 <.0030

07/09/98 S2 SU–175 <.004 .0253 <.005 2.86 1.76 <.0040 <.0030

4 S. Branch Kishwaukee River near

Fairdale, IL

05/20/98 S1 SU–29 <.004 <.0020 <.005 13.0 .007 <.0040 <.0030

07/29/98 S2 SU–195 <.004 <.0020 <.005 .070 <.004 <.0040 <.0030

5 Iroquois River near Chebanse, IL 06/10/98 S1 SU–99 <.004 <.0020 <.005 1.06 .015 <.0040 <.0030

07/08/98 S2 SU–168 <.004 <.0020 <.005 1.32 .014 <.0040 <.0030

6 Dupage River near Shorewood, IL 06/09/98 S1 SU–100 .004 <.0020 .009 .029 <.004 <.0040 <.0030

07/29/98 S2 SU–194 <.004 <.0020 <.005 .006 <.004 <.0040 <.0030

7 Illinois River at Marseilles, IL 06/12/98 S1 SU–113 <.004 <.0020 <.005 1.31 .103 <.0040 <.0030

07/09/98 S2 SU–176 <.004 <.0020 <.005 .796 .016 <.0040 <.0030

8 Spoon River at London Mills, IL 05/20/98 S1 SU–25 <.004 <.0020 <.005 6.81 .274 <.0040 <.0030

07/01/98 S2 SU–160 <.004 <.0020 <.005 .907 .018 <.0040 <.0030

9 Sangamon River near Monticello, IL 05/23/98 S1 SU–35 <.004 <.0020 <.005 2.57 <.004 <.0040 <.0030

08/05/98 S2 SU–201 <.004 <.0020 <.005 .147 <.004 <.0040 <.0030

10 Sangamon River at Riverton, IL 05/26/98 S1 SU–44 .005 <.0020 <.005 2.61 .089 <.0040 <.0030

07/09/98 S2 SU–174 <.004 <.0020 <.005 .553 <.004 <.0040 <.0030

11 LaMoine River at Colmar, IL 05/21/98 S1 SU–27 <.004 <.0020 <.005 1.81 <.600 <.0040 <.0030

06/29/98 S2 SU–142 <.004 <.0020 <.005 .775 .046 <.0040 <.0030

12 Illinois River at Valley City, IL 06/18/98 S1 SU–120 <.004 <.0020 .009 2.13 .061 <.0040 <.0030

08/12/98 S2 SU–207 <.004 <.0020 <.005 .112 <.004 <.0040 <.0030

13 Mississippi River below Grafton, IL 06/02/98 S1 SU–60 <.004 <.0020 <.005 1.36 <.004 <.0040 <.0030

06/15/98 S2 SU–116 <.004 <.0020 <.005 1.75 .021 <.0040 <.0030

14 Kaskaskia River near Cowden, IL 05/20/98 S1 SU–30 <.004 <.0020 <.005 .622 <.004 <.0040 <.0030

07/08/98 S2 SU–169 <.004 <.0020 .007 1.82 .010 <.0040 <.0030

15 Shoal Creek near Breese, IL 05/22/98 S1 SU–32 <.012 <.0020 <.005 7.30 .190 .0289 <.0030

07/08/98 S2 SU–167 <.004 .129 <.005 1.98 .162 <.0040 <.0030

Iowa

16 Turkey River at Spillville, IA 06/02/98 S1 SU–64 <.004 <.0020 E.004 .139 .018 <.0040 <.0030

06/12/98 S2 SU–109 <.004 <.0020 <.005 .184 .075 <.0040 <.0030

17 Mississippi River at Clinton, IA 05/27/98 S1 SU–55 <.004 <.0020 <.005 .161 <.004 <.0040 <.0030

07/01/98 S2 SU–155 <.004 <.0020 <.005 .368 <.004 <.0040 <.0030
OCCURRENCE OF OTHER PESTICIDES 63

streams and 5 midwestern reservoirs

[SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Parathion Parathionmethyl

PebulatePendimethalin Phorate PrometonPropachlor Propanil PropargitePropyzamideSimazineTebuthiuron Terbacil

Illinois—Continued

1 <0.004 <0.0060 <0.0040 0.0140 <0.0020 0.0388 <0.0070 <0.0040 <0.0130 <0.0030 0.0255 <0.0100 <0.0070

<.004 <.0060 <.0040 .0194 <.0020 .0250 <.0070 <.0040 <.0130 <.0030 .0141 <.0100 <.0070

2 <.004 <.0060 <.0040 .0724 <.0020 .0213 <.0070 <.0040 <.0130 <.0030 E1.10 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0080 <.0070 <.0040 <.0130 <.0030 .0821 <.0100 <.0070

3 <.004 <.0060 <.0040 <.0040 <.0020 .0378 <.0070 <.0040 <.0130 <.0030 7.91 E.0097 <.0070

<.004 <.0060 <.0040 .0169 <.0020 .0388 <.0070 <.0040 <.0130 <.0030 .370 .0100 <.0070

4 <.004 <.0060 <.0040 .176 <.0020 .0283 <.0070 <.0040 <.0130 <.0030 .0538 .0757 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

5 <.004 <.0060 <.0040 .0106 <.0020 .0320 <.0070 <.0040 <.0130 <.0030 .0111 <.0100 <.0070

<.004 <.0060 <.0040 .0172 <.0020 E.0102 <.0070 <.0040 <.0130 <.0030 .0159 .0113 <.0070

6 <.004 <.0060 <.0040 .0097 <.0020 E.0160 <.0070 <.0040 <.0130 <.0030 .0088 .0104 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 E.0083 <.0070

7 <.004 <.0060 <.0040 .0398 <.0020 .0400 <.0070 <.0040 <.0130 <.0030 .0293 .0156 <.0070

<.004 <.0060 <.0040 .0145 <.0020 .0419 <.0070 <.0040 <.0130 <.0030 .0266 .0171 E.0123

8 <.004 <.0060 <.0040 .320 <.0020 E.0051 E.0060 <.0040 <.0130 <.0030 .184 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0169 <.0070 <.0040 <.0130 <.0030 .0223 <.0100 <.0070

9 <.004 <.0060 <.0040 .103 <.0020 E.0107 <.0070 <.0040 <.0130 <.0030 .0212 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0277 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

10 <.004 <.0060 <.0040 .0487 <.0020 .0719 <.0070 <.0040 <.0130 <.0030 .0670 .0231 <.0070

<.004 <.0060 <.0040 .0178 <.0020 .0420 <.0070 <.0040 <.0130 <.0030 .0224 .0135 <.0070

11 <.004 <.0060 <.0040 .230 <.0020 E.0086 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 .0418 <.0020 E.0074 <.0070 <.0040 <.0130 <.0030 .0205 <.0100 <.0070

12 <.004 <.0060 <.0040 .0370 <.0020 .0283 <.0070 <.0040 <.0130 <.0030 .0631 .0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0357 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

13 <.004 <.0060 <.0040 <.0040 <.0020 E.0159 <.0070 <.0040 <.0130 <.0030 .0261 <.0100 <.0070

<.004 <.0060 <.0040 .0227 <.0020 E.0105 <.0070 <.0040 <.0130 <.0030 .0364 <.0100 <.0070

14 <.004 <.0060 <.0040 <.0040 <.0020 E.0117 <.0070 <.0040 <.0130 <.0030 .169 E.0048 <.0070

<.004 <.0060 <.0040 .0147 <.0020 .0228 <.0070 <.0040 <.0130 <.0030 .0754 .0117 <.0070

15 <.004 <.0060 <.0040 <.0040 <.0020 E.0114 <.0070 <.0040 <.0130 <.0030 .218 E.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0099 .125 <.0040 <.0130 <.0030 .0550 .0290 <.0070

Iowa—Continued

16 <.004 <.0060 <.0040 .0084 <.0020 E.0043 <.0070 <.0040 <.0130 <.0030 .0176 <.0100 <.0070

<.004 <.0060 <.0040 .0111 <.0020 E.0067 <.0070 <.0040 <.0130 <.0030 .0202 <.0100 <.0070

17 <.004 <.0060 <.0040 <.0040 <.0020 E.0049 <.0070 <.0040 <.0130 <.0030 .0126 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0162 E.0051 <.0070
64 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Iowa—Continued

18 Wapsipinicon River near Tripoli, IA 05/27/98 S1 SU–54 <0.004 <0.0020 <0.005 0.938 0.021 <0.0040 <0.0030

06/20/98 S2 SU–126 <.004 <.0020 <.005 2.46 .029 <.0040 <.0030

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 <.004 <.0020 <.005 2.18 .015 <.0040 <.0030

06/12/98 S2 SU–110 <.004 <.0020 <.005 3.86 .037 <.0040 <.0030

20 Iowa River near Rowan, IA 06/02/98 S1 SU–65 <.004 <.0020 <.005 .230 <.004 <.0040 <.0030

06/23/98 S2 SU–129 <.004 <.0020 <.005 2.31 .026 <.0040 <.0030

21 Old Mans Creek near Iowa City, IA 06/10/98 S1 SU–93 <.004 <.0020 <.005 1.73 .014 <.0040 <.0030

06/30/98 S2 SU–147 <.004 <.0020 <.005 1.67 .022 <.0040 <.0030

22 Wolf Creek near Dysart, IA 06/10/98 S1 SU–87 <.004 <.0020 <.005 1.99 .154 <.0040 <.0030

06/22/98 S2 SU–128 <.004 <.0020 <.005 3.11 .059 <.0040 <.0030

23 Iowa River at Wapello, IA 05/27/98 S1 SU–53 Sample not analyzed (ruined in laboratory)

06/19/98 S2 SU–127 <.004 <.0020 <.005 1.96 .030 <.0040 <.0030

24 N. Skunk River near Sigourney, IA 05/21/98 S1 SU–21 <.004 <.0020 <.005 2.73 .284 <.0040 <.0030

06/10/98 S2 SU–95 <.004 <.0020 <.005 3.26 .216 <.0040 <.0030

25 Skunk River at Augusta, IA 05/26/98 S1 SU–45 .005 <.0020 <.005 9.61 .071 <.0040 <.0030

06/18/98 S2 SU–122 <.004 <.0020 <.005 3.46 .035 <.0040 <.0030

26 Des Moines River at Fort Dodge, IA 05/16/98 S1 SU–8 <.004 <.0020 <.005 5.60 .033 <.0040 <.0030

06/12/98 S2 SU–108 <.004 <.0020 <.005 .281 .016 <.0040 <.0030

27 Raccoon River at Van Meter, IA 05/17/98 S1 SU–9 .008 <.0020 <.005 3.12 .012 <.0040 <.0030

06/10/98 S2 SU–89 <.004 <.0020 <.005 1.34 .056 <.0040 <.0030

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 <.004 <.0020 <.005 .562 <.004 <.0040 <.0030

06/18/98 S2 SU–123 <.004 <.0020 <.005 .399 <.004 <.0040 <.0030

29 Maple River at Mapleton, IA 05/29/98 S1 SU–59 .005 <.0020 <.005 6.73 .225 <.0040 <.0030

06/09/98 S2 SU–90 <.004 <.0020 <.005 2.13 .035 <.0040 <.0030

30 Boyer River at Logan, IA 05/22/98 S1 SU–31 <.004 <.0020 <.005 10.3 .071 <.0040 <.0030

06/09/98 S2 SU–96 <.004 <.0020 <.005 2.38 .079 <.0040 <.0030

31 Chariton River below Rathbun

Lake Dam, IA

06/04/98 R1 SU–69 <.004 <.0020 <.005 .196 <.004 <.0040 <.0030

06/29/98 R2 SU–148 <.004 <.0020 <.005 .461 .007 <.0040 <.0030

Indiana

33 Whitewater River near Alpine, IN 05/26/98 S1 SU–47 <.004 <.0020 <.005 2.48 .268 <.0040 <.0030

07/08/98 S2 SU–162 <.004 <.0020 <.005 .868 .030 <.0040 <.0030

34 Blue River at Fredericksburg, IN 05/27/98 S1 SU–50 <.004 <.0020 <.005 1.38 <.004 <.0040 <.0030

07/08/98 S2 SU–163 <.004 <.0020 <.005 .187 <.004 <.0040 <.0030

Table 12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 70 midwestern

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide
OCCURRENCE OF OTHER PESTICIDES 65

Iowa—Continued

18 <0.004 <0.0060 <0.0040 0.0103 <0.0020 E0.0052 <0.0070 <0.0040 <0.0130 <0.0030 0.0179 <0.0100 <0.0070

<.004 <.0060 <.0040 .0385 <.0020 .0219 <.0070 <.0040 <.0130 <.0030 .0324 E.0100 <.0070

19 <.004 <.0060 <.0040 .0611 <.0020 E.0064 <.0070 <.0040 <.0130 <.0030 .0341 E.0038 <.0070

<.004 <.0060 <.0040 .0585 <.0020 E.0103 <.0070 <.0040 <.0130 <.0030 .0342 .0122 <.0070

20 <.004 <.0060 <.0040 <.0040 <.0020 E.0066 <.0070 <.0040 <.0130 <.0030 E.0042 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0126 <.0070 <.0040 <.0130 <.0030 .0158 <.0100 <.0070

21 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0136 <.0100 <.0070

<.004 <.0060 <.0040 .0058 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0210 <.0100 <.0070

22 <.004 <.0060 <.0040 .0262 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0284 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0442 <.0070 <.0040 <.0130 <.0030 .0285 <.0100 <.0070

23 Sample not analyzed

<.004 <.0060 <.0040 .0153 <.0020 E.0117 <.0070 <.0040 <.0130 <.0030 .0282 <.0100 <.0070

24 <.004 <.0060 <.0040 <.0200 <.0020 <.0180 E.0033 <.0040 <.0130 <.0030 .0785 .0127 <.0070

<.004 <.0060 <.0040 .0200 <.0020 E.0114 <.0070 <.0040 <.0130 <.0030 .0321 E.0054 <.0070

25 <.004 <.0060 <.0040 .0452 <.0020 .0181 .0211 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 .0211 <.0020 E.0096 <.0070 <.0040 <.0130 <.0030 .0283 <.0100 <.0070

26 <.004 <.0060 <.0040 .148 <.0020 E.0114 .175 <.0040 <.0130 <.0030 <.0050 E.0029 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0102 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

27 <.004 <.0060 <.0040 .0309 <.0020 .0873 E.0038 <.0040 <.0130 <.0030 .0098 E.0021 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0296 <.0070 <.0040 <.0130 <.0030 .0137 <.0100 <.0070

28 <.004 <.0060 <.0040 <.0040 <.0020 .0224 <.0070 <.0040 <.0130 <.0030 .0171 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0308 <.0070 <.0040 <.0130 <.0030 .0092 <.0100 <.0070

29 <.004 <.0060 <.0040 .176 <.0020 E.0053 .0139 <.0040 <.0130 <.0030 .0331 <.0100 <.0070

<.004 <.0060 <.0040 <.0400 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0139 <.0100 <.0070

30 <.004 <.0060 <.0040 .187 <.0020 .0375 <.0070 <.0040 <.0130 <.0030 .0808 .0247 <.0070

<.004 <.0060 <.0040 .0637 <.0020 .0268 E.0021 <.0040 <.0130 <.0030 .0259 .0129 <.0070

31 <.004 <.0060 <.0040 <.0040 <.0020 E.0067 <.0070 <.0040 <.0130 <.0030 .0426 E.0080 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0585 E.0089 <.0070

Indiana—Continued

33 <.004 <.0060 <.0040 .0226 <.0020 .0195 <.0070 <.0040 <.0130 <.0030 .971 E.0071 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0155 <.0070 <.0040 <.0130 <.0030 .138 <.0100 <.0070

34 <.004 <.0060 <.0040 <.0040 <.0020 E.0133 <.0070 <.0040 <.0130 <.0030 2.39 E.0061 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0725 <.0070 <.0040 <.0130 <.0030 .370 <.0100 <.0070

streams and 5 midwestern reservoirs—Continued

[SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Parathion Parathionmethyl

PebulatePendimethalin Phorate PrometonPropachlor Propanil PropargitePropyzamideSimazineTebuthiuron Terbacil
66 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana—Continued

35 Mississinewa River below

Mississinewa Lake Dam, IN

06/09/98 R1 SU–83 <0.004 <0.0020 <0.005 1.38 0.225 <0.0040 <0.0030

07/09/98 R2 SU–164 <.004 <.0020 <.005 3.08 .188 <.0040 <.0030

36 Eel River near Logansport, IN 05/21/98 S1 SU–18 Sample not analyzed (broken bottle)

06/30/98 S2 SU–152 <.004 <.0020 <.005 .727 .012 <.0040 <.0030

37 Wildcat Creek near Jerome, IN 05/21/98 S1 SU–19 <.004 <.0020 <.005 1.67 .204 <.0040 <.0030

06/30/98 S2 SU–151 <.004 <.0020 <.005 2.80 .104 <.0040 <.0030

38 Wildcat Creek near Lafayette, IN 05/20/98 S1 SU–22 <.004 <.0020 <.005 2.97 .067 <.0040 <.0030

07/01/98 S2 SU–150 <.004 <.0020 <.005 1.74 .025 <.0040 <.0030

39 White River near Nora, IN 05/28/98 S1 SU–51 <.004 <.0020 <.005 3.84 .099 <.0040 <.0030

07/01/98 S2 SU–149 <.004 <.0020 <.005 2.62 .056 <.0040 <.0030

40 Sugar Creek near Edinburgh, IN 05/26/98 S1 SU–46 E.003 <.0020 <.005 6.56 .237 <.0040 <.0030

07/20/98 S2 SU–178 <.004 <.0020 <.005 4.53 .332 <.0040 <.0030

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 <.004 <.0020 <.005 7.34 .148 <.0040 <.0030

07/06/98 S2 SU–161 <.004 .0277 <.005 .959 .035 <.0040 <.0030

42 Wabash River at New Harmony, IN 05/27/98 S1 SU–57 Sample not analyzed (ruined in laboratory)

06/23/98 S2 SU–136 <.004 <.0020 <.005 5.10 .096 <.0040 <.0030

Minnesota

43 Cottonwood River near

 New Ulm, MN

05/26/98 S1 SU–49 <.004 <.0020 <.005 .075 <.004 <.0040 <.0030

07/21/98 S2 SU–180 <.004 <.0020 <.005 .359 <.004 <.0040 <.0030

44 Little Cobb River near Beauford, MN 05/18/98 S1 SU–12 <.004 <.0020 <.005 .575 <.004 <.0040 <.0030

08/17/98 S2 SU–208 <.004 <.0020 <.005 .026 <.004 <.0040 <.0030

45 Minnesota River near Jordan, MN 05/19/98 S1 SU–13 <.004 <.0020 <.005 .403 <.004 <.0040 <.0030

06/26/98 S2 SU–135 <.004 <.0020 <.005 .548 .014 <.0040 <.0030

46 Mississippi River at Hastings, MN 05/20/98 S1 SU–14 <.004 <.0020 <.005 .199 <.004 <.0040 <.0030

05/20/98 S2 SU–206 <.004 <.0020 <.005 .018 <.004 <.0040 <.0030

47 Des Moines River at Jackson, MN 05/26/98 S1 SU–48 <.004 <.0020 <.005 .104 <.004 <.0040 <.0030

08/24/98 S2 SU–210 <.004 <.0020 <.005 .189 <.004 <.0040 <.0030

48 Rock River at Luverne, MN 06/24/98 S1 SU–130 <.004 <.0020 <.005 .062 <.004 <.0040 <.0030

06/25/98 S2 SU–131 <.004 <.0020 <.005 .408 <.004 <.0040 <.0030

Kansas

49 Black Vermillion River at

Frankfort, KS

05/05/98 S1 SU–1 <.004 <.0020 <.005 .137 <.004 <.0040 <.0030

06/09/98 S2 SU–107 <.004 <.0020 <.005 10.1 .116 <.0040 <.0030

50 Big Blue River below Tuttle

Creek Lake Dam, KS

06/03/98 R1 SU–74 <.004 <.0020 <.005 .830 .026 <.0040 <.0030

07/29/98 R2 SU–197 <.004 <.0020 <.005 3.17 .026 <.0040 <.0030

51 Delaware River near Muscotah, KS 05/05/98 S1 SU–2 <.004 <.0020 <.005 .191 <.004 <.0040 <.0030

06/10/98 S2 SU–105 <.004 <.0020 <.005 2.07 .030 <.0040 <.0030

Table 12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 70 midwestern

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide
OCCURRENCE OF OTHER PESTICIDES 67

Indiana—Continued

35 <0.004 <0.0060 <0.0040 <0.0040 <0.0020 0.0324 <0.0070 <0.0040 <0.0130 <0.0030 0.493 0.0146 <0.0070

<.004 <.0060 <.0040 .0229 <.0020 .0292 <.0070 <.0040 <.0130 <.0030 .358 <.0200 <.0070

36 Sample not analyzed

<.004 <.0060 <.0040 <.0040 <.0020 .0143 <.0070 <.0040 <.0130 <.0030 .126 .0045 <.0070

37 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0888 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0144 <.0070 <.0040 <.0130 <.0030 .0840 <.0100 <.0070

38 <.004 <.0060 <.0040 <.0150 <.0020 .0275 <.0070 <.0040 <.0130 <.0030 .0291 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0222 <.0070 <.0040 <.0200 <.0030 .0675 E.0088 <.0070

39 <.004 <.0060 <.0040 <.0100 <.0020 .0302 E.0034 <.0040 <.0130 <.0030 .536 E.0061 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0491 <.0070 <.0040 <.0130 <.0030 .196 E.0085 <.0070

40 <.004 <.0060 <.0040 .0129 <.0020 .0261 <.0070 <.0040 <.0130 <.0030 .509 E.0090 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .218 <.0070 <.0040 <.0130 <.0030 .0325 <.0100 <.0070

41 <.004 <.0060 <.0040 <.0200 <.0020 .0297 <.0070 <.0040 <.0130 <.0030 1.17 E.0076 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0203 <.0070 <.0040 <.0130 <.0030 .0610 <.0100 <.0070

42 Sample not analyzed

<.004 <.0060 <.0040 .0223 <.0020 .0351 <.0070 <.0040 <.0130 <.0030 .395 .0119 <.0070

Minnesota—Continued

43 <.004 <.0060 <.0040 <.0040 <.0020 E.0055 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0522 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

44 <.004 <.0060 <.0400 <.0040 <.0020 <.0180 .173 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0867 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

45 <.004 <.0060 <.0040 <.0040 <.0020 E.0077 .0163 <.0040 <.0130 <.0030 .0083 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0145 <.0070 <.0040 <.0130 <.0030 E.0042 <.0100 <.0070

46 <.004 <.0060 <.0040 <.0040 <.0020 E.0101 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0154 <.0070 <.0040 <.0130 <.0030 .0070 <.0100 <.0070

47 <.004 <.0060 <.0040 <.0040 <.0020 .0365 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0960 <.0030 <.0050 <.0100 <.0070

48 <.004 <.0060 <.0040 <.0040 <.0020 E.0108 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 .0393 <.0020 E.0115 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

Kansas—Continued

49 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 .0228 <.0040 <.0130 <.0030 .0225 <.0100 <.0070

50 <.004 <.0060 <.0040 <.0040 <.0020 E.0094 .0170 <.0040 <.0130 <.0030 .0161 E.0061 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0140 .0104 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

51 <.004 <.0060 <.0040 <.0040 <.0020 E.0050 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .346 <.0070 <.0040 <.0130 <.0030 .0568 <.0100 <.0070

streams and 5 midwestern reservoirs—Continued

[SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Parathion Parathionmethyl

PebulatePendimethalin Phorate PrometonPropachlor Propanil PropargitePropyzamideSimazineTebuthiuron Terbacil
68 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Kentucky

52 Ohio River at Cannelton Dam, KY 06/04/98 S1 SU–75 <0.004 <0.0020 <0.005 0.365 0.016 <0.0040 <0.0030

07/07/98 S2 SU–173 <.004 <.0020 <.005 .373 <.004 <.0040 <.0030

 Missouri

53 Nodaway River near Graham, MO 06/18/98 S1 SU–119 Sample not analyzed (ruined in laboratory)

08/19/98 S2 SU–209 <.004 <.0020 <.005 .049 <.043 <.0040 <.0030

Nebraska

54 North Dry Creek near Kearney, NE 05/22/98 S1 SU–28 E.002 <.0020 <.005 3.23 <.004 <.0040 <.0030

06/08/98 S2 SU–76 <.004 <.0020 <.005 1.10 <.004 <.0040 <.0030

55 Maple Creek near Nickerson, NE 05/21/98 S1 SU–37 <.004 <.0020 <.005 17.9 .200 <.0040 <.0030

06/08/98 S2 SU–79 <.004 <.0020 <.005 7.16 .243 <.0040 <.0030

56 Salt Creek at Roca, NE 05/15/98 S1 SU–6 <.004 <.0020 <.005 E143 .329 <.0040 <.0030

06/10/98 S2 SU–94 .005 <.0020 .008 14.7 .646 <.0040 <.0030

57 Wahoo Creek at Ithaca, NE 05/15/98 S1 SU–5 <.004 <.0020 <.005 17.3 .020 <.0040 <.0030

06/08/98 S2 SU–78 <.004 <.0020 <.005 1.24 .033 <.0040 <.0030

58 Platte River at Louisville, NE 05/22/98 S1 SU–39 <.004 <.0020 <.005 6.26 .310 <.0040 <.0030

06/09/98 S2 SU–77 <.004 <.0020 <.005 2.97 .143 <.0040 <.0030

59 Big Nemaha River at Falls City, NE 05/26/98 S1 SU–41 <.004 <.0020 <.005 2.32 .017 <.0040 <.0030

06/08/98 S2 SU–80 <.004 <.0020 <.005 3.21 .011 <.0040 <.0030

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 <.004 <.0020 <.005 17.7 .358 <.0040 <.0030

06/10/98 S2 SU–82 <.004 <.0020 <.005 3.44 .143 <.0040 <.0030

61 Big Blue River at Barneston, NE 05/15/98 S1 SU–4 .0042 <.0020 <.005 4.05 .256 <.0040 <.0030

06/09/98 S2 SU–104 <.004 <.0020 <.005 10.2 .242 <.0040 <.0030

62 Little Blue River near Fairbury, NE 05/12/98 S1 SU–3 Sample not analyzed (broken bottle)

06/08/98 S2 SU–81 Sample not analyzed (mislabled bottle)

Ohio

63 Clear Creek near Rockbridge, OH 06/10/98 S1 SU–86 .042 <.0020 <.005 .291 <.004 <.0040 <.0030

06/30/98 S2 SU–145 <.004 .0852 <.005 1.34 .099 <.0040 <.0030

64 Scioto River near Prospect, OH 06/02/98 S1 SU–63 .009 <.0020 <.005 3.71 .223 <.0040 <.0030

06/29/98 S2 SU–141 <.004 <.0020 <.005 5.75 .105 <.0040 <.0030

65 Olentangy River at Claridon, OH 06/09/98 S1 SU–85 <.004 <.0020 <.005 .831 <.004 <.0040 <.0030

06/29/98 S2 SU–157 <.004 <.0020 <.005 5.45 .065 <.0040 <.0030

66 Olentangy River below

Delaware, Lake Dam, OH

06/09/98 R1 SU–84 <.004 <.0020 <.005 1.65 .048 <.0040 <.0030

06/29/98 R2 SU–153 <.004 <.0020 <.005 4.36 .087 <.0040 <.0030

67 Big Darby Creek at Darbyville, OH 06/03/98 S1 SU–62 <.004 <.0020 <.005 3.04 .078 <.0040 <.0030

06/29/98 S2 SU–140 .005 <.0020 <.005 2.89 .018 <.0040 <.0030

Table 12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 70 midwestern

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide
OCCURRENCE OF OTHER PESTICIDES 69

Kentucky—Continued

52 <0.004 <0.0060 <0.0040 <0.0040 <0.0020 E0.0160 <0.0070 <0.0040 <0.0130 <0.0030 0.151 E0.0097 <0.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0110 <.0070 <.0040 <.0130 <.0030 .112 <.0100 <.0070

Missouri—Continued

53 Sample not analyzed

<.004 <.0060 <.0040 <.0040 <.0020 E.0051 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

Nebraska—Continued

54 <.004 <.0060 <.0040 <.0040 <.0020 .166 .0772 <.0040 <.0130 <.0030 .0505 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .159 .0185 <.0040 <.0130 <.0030 .0235 <.0100 <.0070

55 <.004 <.0060 <.0040 .0667 <.0020 .0520 <.0070 <.0040 <.0130 <.0030 .0510 <.0100 <.0070

<.004 <.0060 <.0040 .0636 <.0020 E.0106 E.0022 <.0040 <.0130 <.0030 .0412 <.0100 <.0070

56 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 .161 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0188 .0642 <.0040 <.0130 <.0030 .188 <.0100 <.0070

57 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 .334 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 .0780 <.0020 .0284 <.0070 <.0040 <.0130 <.0030 .0208 <.0100 <.0070

58 <.004 <.0060 <.0040 .0359 <.0020 .0522 .0402 <.0040 <.0130 <.0030 .221 <.0100 <.0070

<.004 <.0060 <.0040 .0347 <.0020 .0613 .0149 <.0040 <.0130 <.0030 .0289 E.0038 <.0070

59 <.004 <.0060 <.0040 <.0040 <.0020 .340 .0135 <.0040 <.0130 <.0030 .0768 <.0100 <.0070

<.004 <.0060 <.0040 .0287 <.0020 E.0076 .557 <.0040 <.0130 <.0030 .0734 E.0042 <.0070

60 <.004 <.0060 <.0040 <.0040 <.0020 .132 .192 <.0040 <.0130 <.0030 .0489 <.0100 <.0070

<.004 <.0060 <.0040 .0885 <.0020 .0531 .0218 <.0040 <.0130 <.0030 .0367 <.0100 <.0070

61 <.004 .016 <.0040 .0104 <.0020 .0389 .0134 <.0040 <.0130 <.0030 <.0050 E.0035 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0148 .607 <.0040 <.0130 <.0030 .0428 E.0050 <.0070

62 Sample not analyzed

Sample not analyzed

Ohio—Continued

63 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0723 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0217 <.0070 <.0040 <.0130 <.0030 .455 <.0100 <.0070

64 <.004 <.0060 <.0040 .0170 <.0020 .0516 <.0070 <.0040 <.0130 <.0030 2.07 <.0100 <.0070

<.004 <.0060 <.0040 .0279 <.0020 .0368 <.0070 <.0040 <.0130 <.0030 .784 E.0090 <.0070

65 <.004 <.0060 <.0040 <.0040 <.0020 E.0098 <.0070 <.0040 <.0130 <.0030 .0390 <.0100 <.0070

<.004 <.0060 <.0040 .0206 <.0020 E.0172 <.0070 <.0040 <.0130 <.0030 .391 <.0100 <.0070

66 <.004 <.0060 <.0040 <.0040 <.0020 .0232 <.0070 <.0040 <.0130 <.0030 .352 <.0100 <.0070

<.004 <.0060 <.0040 .0121 <.0020 .0286 <.0070 <.0040 <.0130 <.0030 1.03 E.0080 <.0070

67 <.004 <.0060 <.0040 <.0040 <.0020 E.0091 <.0070 <.0040 <.0130 <.0030 .979 <.0100 <.0070

<.004 <.0060 <.0040 .0163 <.0020 .0224 <.0070 <.0040 <.0130 <.0030 .846 <.0100 <.0070

streams and 5 midwestern reservoirs—Continued

[SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Parathion Parathionmethyl

PebulatePendimethalin Phorate PrometonPropachlor Propanil PropargitePropyzamideSimazineTebuthiuron Terbacil
70 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Ohio—Continued

68 Scioto River at Higby, OH 06/04/98 S1 SU–73 <0.004 <0.0020 <0.005 2.30 0.107 <0.0040 <0.0030

07/08/98 S2 SU–165 <.004 <.0020 <.005 2.31 .043 <.0040 <.0030

69 L. Miami River near Oldtown, OH 06/10/98 S1 SU–92 <.004 <.0020 <.005 .177 .007 <.0040 <.0030

06/30/98 S2 SU–144 <.004 <.0020 <.005 .301 .010 <.0040 <.0030

70 Mad River at Eagle City, OH 06/10/98 S1 SU–91 <.004 <.0020 <.005 .030 <.004 <.0040 <.0030

06/30/98 S2 SU–146 <.004 <.0020 .008 .875 .020 <.0040 <.0030

71 Tiffin River at Stryker, OH 06/01/98 S1 SU–66 <.004 .0470 <.005 .481 .101 <.0040 <.0030

07/07/98 S2 SU–172 <.004 <.0020 <.005 .127 .012 <.0040 <.0030

72 Auglaize River at Fort Jennings, OH 06/17/98 S1 SU–117 <.004 <.0020 <.005 6.58 .413 <.0040 <.0030

07/08/98 S2 SU–171 <.004 <.0020 <.005 2.26 .096 <.0040 <.0030

Wisconsin

73 Root River at Racine, WI 06/01/98 S1 SU–61 <.004 <.0020 <.005 .181 <.004 <.0040 <.0030

08/03/98 S2 SU–204 <.004 <.0020 <.005 .017 <.004 <.0040 <.0030

74 St. Croix River at St. Croix Falls, WI 06/03/98 S1 SU–68 <.004 <.0020 <.005 .016 <.004 <.0040 <.0030

08/05/98 S2 SU–205 <.004 <.0020 <.005 <.002 <.004 <.0040 <.0030

75 Wisconsin River at Muscoda, WI 06/16/98 S1 SU–133 <.004 <.0020 <.005 .171 <.004 <.0040 <.0030

08/07/98 S2 SU–202 <.004 <.0020 <.005 .032 <.004 <.0040 <.0030

76 Rock River at Afton, WI 06/17/98 S1 SU–134 <.004 <.0020 <.005 .073 <.004 <.0040 <.0030

07/21/98 S2 SU–179 <.004 <.0020 <.005 .048 <.004 <.0040 <.0030

Table 12. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 70 midwestern

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide
OCCURRENCE OF OTHER PESTICIDES 71

Ohio—Continued

68 <0.004 <0.0060 <0.0040 <0.0040 <0.0020 0.0375 <0.0070 <0.0040 <0.0130 <0.0030 0.499 E0.0057 <0.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0215 <.0070 <.0040 <.0130 <.0030 .442 E.0095 <.0070

69 <.004 <.0060 <.0040 <.0040 <.0020 E.0048 <.0070 <.0040 <.0130 <.0030 .330 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0078 <.0070 <.0040 <.0130 <.0030 .147 <.0100 <.0070

70 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0062 <.0070 <.0040 <.0130 <.0030 .0632 <.0100 <.0070

71 <.004 <.0060 <.0040 <.0040 <.0020 E.0100 <.0070 <.0040 <.0130 <.0030 .197 E.0068 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0178 <.0070 <.0040 <.0130 <.0030 .0544 .0132 <.0070

72 <.004 <.0060 <.0040 <.0040 <.0020 .0392 <.0070 <.0040 <.0130 <.0030 .682 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0334 <.0070 <.0040 <.0130 <.0030 .144 <.0100 <.0070

Wisconsin—Continued

73 <.004 <.0060 <.0040 .0118 <.0020 .0198 <.0070 <.0040 <.0130 <.0030 .0095 .0138 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 .0314 <.0070 <.0040 <.0130 <.0030 <.0050 .0188 <.0070

74 <.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.0100 <.0070

75 <.004 <.0060 <.0040 <.0040 <.0020 E.0061 <.0070 <.0040 <.0130 <.0030 .0154 <.0100 <.0070

<.004 <.0060 <.0040 <.0040 <.0020 E.0082 <.0070 <.0040 <.0130 <.0030 .0104 <.0100 <.0070

76 <.004 <.0060 <.0040 <.0040 <.0020 E.0110 <.0070 <.0040 <.0130 <.0030 .0263 E.0061 E.0136

<.004 <.0060 <.0040 <.0040 <.0020 .0294 <.0070 <.0040 <.0130 <.0030 .0229 <.0100 <.0070

streams and 5 midwestern reservoirs—Continued

[SD, stream duplicate sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than; E, estimate]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

Parathion Parathionmethyl

PebulatePendimethalin Phorate PrometonPropachlor Propanil PropargitePropyzamideSimazineTebuthiuron Terbacil
72 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE

Illinois

1 Vermillion River below Lake

Vermillion Dam, IL

06/10/98 R1 SU–98 <0.0130 <0.0020 <0.0010 0.0062 <0.0020 <0.0050 <0.0060

07/16/98 R2 SU–177 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 .0062

2 Bonpas Creek at Browns, IL 05/23/98 S1 SU–43 <.0130 <.0020 <.0010 .0053 <.0020 <.0050 <.0060

07/07/98 S2 SU–166 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

3 Little Wabash River at Carmi, IL 05/23/98 S1 SU–33 <.0130 .0322 <.0010 .0104 <.0020 <.0050 <.0060

07/09/98 S2 SU–175 <.0130 <.0020 <.0010 .0070 <.0020 <.0050 <.0060

4 S. Branch Kishwaukee River near

Fairdale, IL

05/20/98 S1 SU–29 .0478 <.0020 <.0010 .0054 <.0020 <.0050 <.0060

07/29/98 S2 SU–195 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

5 Iroquois River near Chebanse, IL 06/10/98 S1 SU–99 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/08/98 S2 SU–168 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

6 Dupage River near Shorewood, IL 06/09/98 S1 SU–100 <.0130 <.0020 <.0010 .0057 <.0020 <.0050 <.0060

07/29/98 S2 SU–194 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

7 Illinois River at Marseilles, IL 06/12/98 S1 SU–113 <.0130 <.0020 <.0010 .0069 <.0020 <.0050 <.0060

07/09/98 S2 SU–176 <.0130 <.0020 <.0010 .0062 <.0020 <.0050 <.0060

8 Spoon River at London Mills, IL 05/20/98 S1 SU–25 .0276 <.0020 <.0010 .0328 <.0020 <.0050 <.0060

07/01/98 S2 SU–160 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

9 Sangamon River near Monticello, IL 05/23/98 S1 SU–35 .0296 <.0020 <.0010 .0157 <.0020 <.0050 <.0060

08/05/98 S2 SU–201 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

10 Sangamon River at Riverton, IL 05/26/98 S1 SU–44 <.0130 <.0020 <.0010 .0182 <.0020 <.0050 <.0060

07/09/98 S2 SU–174 <.0130 <.0020 <.0010 .0064 <.0020 <.0050 <.0060

11 LaMoine River at Colmar, IL 05/21/98 S1 SU–27 <.0130 <.0020 <.0010 .0076 <.0020 <.0050 <.0060

06/29/98 S2 SU–142 <.0130 <.0020 <.0010 .0041 <.0020 <.0050 <.0060

12 Illinois River at Valley City, IL 06/18/98 S1 SU–120 <.0130 <.0020 <.0010 E.0028 <.0020 <.0050 <.0060

08/12/98 S2 SU–207 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

13 Mississippi River below Grafton, IL 06/02/98 S1 SU–60 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/15/98 S2 SU–116 <.0130 <.0020 <.0010 E.0020 <.0020 <.0050 <.0060
OCCURRENCE OF OTHER PESTICIDES 73

Illinois—Continued

14 Kaskaskia River near Cowden, IL 05/20/98 S1 SU–30 <0.0130 <0.0020 <0.0010 <0.0020 <0.0020 <0.0050 <0.0060

07/08/98 S2 SU–169 <.0130 <.0020 <.0010 .0064 <.0020 <.0050 <.0060

15 Shoal Creek near Breese, IL 05/22/98 S1 SU–32 <.0130 .0130 <.0010 .0367 <.0020 <.0050 <.0060

07/08/98 S2 SU–167 <.0130 <.0020 <.0010 .0342 <.0020 <.0050 <.0060

Iowa

16 Turkey River at Spillville, IA 06/02/98 S1 SU–64 <.0130 <.0020 <.0010 .0045 <.0020 <.0050 <.0060

06/12/98 S2 SU–109 <.0130 <.0020 <.0010 .0054 <.0020 <.0050 <.0060

17 Mississippi River at Clinton, IA 05/27/98 S1 SU–55 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/01/98 S2 SU–155 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

18 Wapsipinicon River near Tripoli, IA 05/27/98 S1 SU–54 <.0130 <.0020 <.0010 .0048 <.0020 <.0050 <.0060

06/20/98 S2 SU–126 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/12/98 S2 SU–110 <.0130 <.0020 <.0010 .0081 <.0020 <.0050 <.0060

20 Iowa River near Rowan, IA 06/02/98 S1 SU–65 <.0130 <.0020 <.0010 .0055 <.0020 <.0050 <.0060

06/23/98 S2 SU–129 <.0130 <.0020 <.0010 .0119 <.0020 <.0050 <.0060

21 Old Mans Creek near Iowa City, IA 06/10/98 S1 SU–93 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/30/98 S2 SU–147 <.0130 <.0020 <.0010 E.0024 <.0020 <.0050 <.0060

22 Wolf Creek near Dysart, IA 06/10/98 S1 SU–87 <.0130 <.0020 <.0010 .0041 <.0020 <.0050 <.0060

06/22/98 S2 SU–128 <.0130 <.0020 <.0010 .0150 <.0020 <.0050 <.0060

23 Iowa River at Wapello, IA 05/27/98 S1 SU–53 Sample not analyzed (ruined in laboratory)

06/19/98 S2 SU–127 <.0130 <.0020 <.0010 .0067 <.0020 <.0050 <.0060

24 N. Skunk River near Sigourney, IA 05/21/98 S1 SU–21 <.0130 <.0020 <.0010 .0045 <.0020 <.0050 <.0060

06/10/98 S2 SU–95 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

25 Skunk River at Augusta, IA 05/26/98 S1 SU–45 <.0130 <.0020 <.0010 .0062 <.0020 <.0050 <.0060

06/18/98 S2 SU–122 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE
74 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Iowa—Continued

26 Des Moines River at Fort Dodge, IA 05/16/98 S1 SU–8 <0.0130 <0.0020 <0.0010 0.268 <0.0020 <0.0050 <0.0060

06/12/98 S2 SU–108 <.0130 <.0020 <.0010 .0047 <.0020 <.0050 E.0028

27 Raccoon River at Van Meter, IA 05/17/98 S1 SU–9 <.0130 <.0020 <.0010 .0856 <.0020 <.0050 <.0060

06/10/98 S2 SU–89 <.0130 <.0020 <.0010 .0297 <.0020 <.0050 <.0060

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 <.0130 <.0020 <.0010 E.0031 <.0020 <.0050 <.0060

06/18/98 S2 SU–123 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

29 Maple River at Mapleton, IA 05/29/98 S1 SU–59 <.0130 <.0020 <.0010 .0514 <.0020 <.0050 <.0060

06/09/98 S2 SU–90 <.0130 <.0020 <.0010 .0119 <.0020 <.0050 <.0060

30 Boyer River at Logan, IA 05/22/98 S1 SU–31 <.0130 <.0020 <.0010 .0491 <.0020 <.0050 <.0060

06/09/98 S2 SU–96 <.0130 <.0020 <.0010 .0302 <.0020 <.0050 <.0060

31 Chariton River below Rathbun

Lake Dam, IA

06/04/98 R1 SU–69 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/29/98 R2 SU–148 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Indiana

33 Whitewater River near Alpine, IN 05/26/98 S1 SU–47 <.0130 <.0020 <.0010 .0059 <.0020 <.0050 <.0060

07/08/98 S2 SU–162 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

34 Blue River at Fredericksburg, IN 05/27/98 S1 SU–50 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/08/98 S2 SU–163 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

35 Mississinewa River below

Mississinewa Lake Dam, IN

06/09/98 R1 SU–83 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/09/98 R2 SU–164 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

36 Eel River near Logansport, IN 05/21/98 S1 SU–18 Sample not analyzed (broken bottle)

06/30/98 S2 SU–152 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

37 Wildcat Creek near Jerome, IN 05/21/98 S1 SU–19 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/30/98 S2 SU–151 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

38 Wildcat Creek near Lafayette, IN 05/20/98 S1 SU–22 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/01/98 S2 SU–150 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE
OCCURRENCE OF OTHER PESTICIDES 75

Indiana—Continued

39 White River near Nora, IN 05/28/98 S1 SU–51 <0.0130 <0.0020 <0.0010 <0.0020 <0.0020 <0.0050 <0.0060

07/01/98 S2 SU–149 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

40 Sugar Creek near Edinburgh, IN 05/26/98 S1 SU–46 <.0130 <.0020 <.0010 .0047 <.0020 <.0050 <.0060

07/20/98 S2 SU–178 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/06/98 S2 SU–161 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

42 Wabash River at New Harmony, IN 05/27/98 S1 SU–57 Sample not analyzed (ruined in laboratory)

06/23/98 S2 SU–136 <.0130 <.0020 <.0010 .0070 <.0020 <.0050 <.0060

Minnesota

43 Cottonwood River near

New Ulm, MN

05/26/98 S1 SU–49 <.0130 <.0020 <.0010 .0050 <.0020 <.0050 <.0060

07/21/98 S2 SU–180 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

44 Little Cobb River near Beauford, MN 05/18/98 S1 SU–12 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

08/17/98 S2 SU–208 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

45 Minnesota River near Jordan, MN 05/19/98 S1 SU–13 <.0130 <.0020 <.0010 .0051 <.0020 <.0050 <.0060

06/26/98 S2 SU–135 <.0130 <.0020 <.0010 .0062 <.0020 <.0050 <.0060

46 Mississippi River at Hastings, MN 05/20/98 S1 SU–14 <.0130 <.0020 <.0010 E.0036 <.0020 <.0050 <.0060

05/20/98 S2 SU–206 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

47 Des Moines River at Jackson, MN 05/26/98 S1 SU–48 <.0130 <.0020 <.0010 .0050 <.0020 <.0050 <.0060

08/24/98 S2 SU–210 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

48 Rock River at Luverne, MN 06/24/98 S1 SU–130 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/25/98 S2 SU–131 <.0130 <.0020 <.0010 .0080 <.0020 <.0050 <.0060

Kansas

49 Black Vermillion River at

Frankfort, KS

05/05/98 S1 SU–1 <.0130 <.0020 <.0010 E.0033 <.0020 <.0050 <.0060

06/09/98 S2 SU–107 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

50 Big Blue River below Tuttle

Creek Lake Dam, KS

06/03/98 R1 SU–73 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/29/98 R2 SU–197 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

51 Delaware River near Muscotah, KS 05/05/98 S1 SU–2 <.0130 <.0020 <.0010 E.0031 <.0020 <.0050 <.0060

06/10/98 S2 SU–105 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE
76 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Kentucky

52 Ohio River at Cannelton Dam, KY 06/04/98 S1 SU–75 <0.0130 <0.0020 <0.0010 <0.0020 <0.0020 <0.0050 <0.0060

07/07/98 S2 SU–173 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 E.0019

 Missouri

53 Nodaway River near Graham, MO 06/18/98 S1 SU–119 Sample not analyzed (ruined in laboratory)

08/19/98 S2 SU–209 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Nebraska

54 North Dry Creek near Kearney, NE 05/22/98 S1 SU–28 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/08/98 S2 SU–76 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

55 Maple Creek near Nickerson, NE 05/21/98 S1 SU–37 <.0130 <.0020 <.0010 .0188 <.0020 <.0050 <.0060

06/08/98 S2 SU–79 <.0130 <.0020 <.0010 .0234 <.0020 <.0050 <.0060

56 Salt Creek at Roca, NE 05/15/98 S1 SU–6 <.0130 <.0020 <.0010 E.0034 <.0020 <.0050 <.0060

06/10/98 S2 SU–94 <.0130 <.0020 <.0010 .0078 <.0020 <.0050 <.0060

57 Wahoo Creek at Ithaca, NE 05/15/98 S1 SU–5 <.0130 <.0020 <.0010 E.0026 <.0020 <.0050 <.0060

06/08/98 S2 SU–78 <.0130 <.0020 <.0010 .0360 <.0020 <.0050 <.0060

58 Platte River at Louisville, NE 05/22/98 S1 SU–39 <.0130 <.0020 <.0010 .0338 <.0020 <.0050 <.0060

06/09/98 S2 SU–77 <.0130 <.0020 <.0010 .0300 <.0020 <.0050 <.0060

59 Big Nemaha River at Falls City, NE 05/26/98 S1 SU–41 <.0130 <.0020 <.0010 .0052 <.0020 <.0050 <.0060

06/08/98 S2 SU–80 <.0130 <.0020 <.0010 .0088 <.0020 <.0050 <.0060

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 <.0130 <.0020 <.0010 .0041 <.0020 <.0050 <.0060

06/10/98 S2 SU–82 <.0130 <.0020 <.0010 .0057 <.0020 <.0050 <.0060

61 Big Blue River at Barneston, NE 05/15/98 S1 SU–4 <.0130 <.0020 <.0010 .0339 <.0020 <.0050 <.0060

06/09/98 S2 SU–104 <.0130 <.0020 <.0010 .0081 <.0020 <.0050 <.0060

62 Little Blue River near Fairbury, NE 05/12/98 S1 SU–3 Sample not analyzed (bottle broken)

06/08/98 S2 SU–81 Sample not analyzed (bottle mislabeled)

Ohio

63 Clear Creek near Rockbridge, OH 06/10/98 S1 SU–86 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/30/98 S2 SU–145 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE
OCCURRENCE OF OTHER PESTICIDES 77

Ohio—Continued

64 Scioto River near Prospect, OH 06/02/98 S1 SU–63 <0.0130 <0.0020 <0.0010 0.0047 <0.0020 <0.0050 E0.0020

06/29/98 S2 SU–141 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

65 Olentangy River at Claridon, OH 06/09/98 S1 SU–85 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/29/98 S2 SU–157 <.0130 <.0020 <.0010 .0061 <.0020 <.0050 <.0060

66 Olentangy River below

Delaware, Lake Dam, OH

06/09/98 R1 SU–84 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/29/98 R2 SU–153 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

67 Big Darby Creek at Darbyville, OH 06/03/98 S1 SU–62 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/29/98 S2 SU–140 <.0130 <.0020 <.0010 .0061 <.0020 <.0050 <.0060

68 Scioto River at Higby, OH 06/04/98 S1 SU–73 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/08/98 S2 SU–165 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

69 L. Miami River near Oldtown, OH 06/10/98 S1 SU–92 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/30/98 S2 SU–144 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

70 Mad River at Eagle City, OH 06/10/98 S1 SU–91 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

06/30/98 S2 SU–146 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

71 Tiffin River at Stryker, OH 06/01/98 S1 SU–66 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/07/98 S2 SU–172 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

72 Auglaize River at Fort Jennings, OH 06/17/98 S1 SU–117 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/08/98 S2 SU–171 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Wisconsin

73 Root River at Racine, WI 06/01/98 S1 SU–61 <.0130 <.0020 <.0010 .0047 <.0020 <.0050 <.0060

08/03/98 S2 SU–204 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

74 St. Croix River at St. Croix Falls, WI 06/03/98 S1 SU–68 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

08/05/98 S2 SU–205 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

75 Wisconsin River at Muscoda, WI 06/16/98 S1 SU–133 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

08/07/98 S2 SU–202 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

76 Rock River at Afton, WI 06/17/98 S1 SU–134 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

07/21/98 S2 SU–179 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Table 13. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 70 midwestern

streams and 5 midwestern reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate

stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE
78 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 14. Statistical summary of 46 pesticide and pesticide degradate concentrations in 134 water samples from

71 Midwestern streams (concentrations in micrograms per liter)

[<, less than; E, estimate]

Herbicide

Method

detection limit

(MDL)

Number at or

above MDL

25th

percentile Median 75thpercentile

95th

percentile Maximum

2,6-diethylaniline 0.003 1 <0.003 <0.003 <0.003 <0.003 0.004

acetochlor .002 128 .099 .400 1.14 11.40 25.1

alachlor .002 119 .014 .040 .16 2.94 17.2

atrazine .001 134 .536 3.77 8.78 37.6 224

azinphos-methyl .001 0 <.001 <.001 <.001 <.001 <.001

benfluralin .002 1 <.002 <.002 <.002 <.002 .004

butylate .002 6 <.002 <.002 <.002 E.001 .270

carbaryl .003 32 <.003 <.003 <.003 .059 .195

carbofuran .003 47 <.003 <.003 .031 .191 1.03

chlorpyrifos .004 44 <.004 <.004 .014 .072 .858

cyanazine .004 125 .049 .322 1.01 6.75 20.0

dacthal .002 0 <.002 <.002 <.002 .001 .002

deethylatrazine .002 134 .067 .256 .446 .820 1.26

diazinon .002 48 <.002 <.002 .006 .028 .071

dieldrin .001 12 <.001 <.001 <.001 .006 .015

disulfoton .017 0 <.017 <.017 <.017 <.017 <.017

EPTC .002 28 <.002 <.002 <.002 .015 .076

ethalfluralin .004 0 <.004 <.004 <.004 <.004 <.004

ethoprophos .003 1 <.003 <.003 <.003 <.003 .045

fonofos .003 3 <.003 <.003 <.003 <.003 .063

lindane .004 10 <.004 <.004 <.004 .005 .042

linuron .002 7 <.002 <.002 <.002 .025 .129

malathion .005 6 <.005 <.005 <.005 E.004 .009

metolachlor .002 133 .301 1.67 3.21 14.7 143

metribuzin .004 88 <.004 .020 .099 .329 1.76

molinate .004 3 <.004 <.004 <.004 <.004 .049

napropamide .003 0 <.003 <.003 <.003 <.003 <.003

parathion .004 0 <.004 <.004 <.004 <.004 <.004

parathion methyl .006 1 <.006 <.006 <.006 <.006 .016

pebulate .004 0 <.004 <.004 <.004 <.004 <.004

pendimethalin .004 51 <.004 <.004 .020 .103 .320

phorate .002 0 <.002 <.002 <.002 <.002 <.002

prometon .018 59 E.007 E.015 .031 .087 .346

propachlor .007 20 <.007 <.007 <.007 .161 .607

propanil .004 0 <.004 <.004 <.004 <.004 <.004

propargite .013 0 <.013 <.013 <.013 <.013 <.013

propyzamide .003 0 <.003 <.003 <.003 <.003 <.003

simazine .005 105 .009 .029 .086 .971 7.91

tebuthiuron .010 21 <.010 <.010 E.006 .016 .076

terbacil .007 2 <.007 <.007 <.007 <.007 .014

terbufos .013 3 <.013 <.013 <.013 <.013 .048

thiobencarb .002 2 <.002 <.002 <.002 <.002 .032

tri-allate .001 0 <.001 <.001 <.001 <.001 <.001

trifluralin .002 68 <.002 .002 .006 .034 .268

alpha-HCH .002 0 <.002 <.002 <.002 <.002 <.002

cis-Permethrin .005 0 <.005 <.005 <.005 <.005 <.005

p,p'-DDE .006 0 <.006 <.006 <.006 <.006 .003

Sum of 46 pesticides

and degradates

.001 134 1.34 7.04 16.0 65.6 385
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 79

1%

96%

89%

100%

1%

4%

24%

35%

33%

93%

100%

36%

9%

21%

1%

2%

2,6-diethylaniline

Acetochlor

Alachlor

Atrazine

Benfluralin

Butylate

Carbaryl

Carbofuran

Chlorpyrifos

Cyanazine

Deethylatrazine

Diazinon

Dieldrin

ETPC

Ethoprophos

Fonofos

0.001 0.1 10.0 1,000

CONCENTRATION, IN MICROGRAMS PER LITER

7%

5%

4%

99%

66%

2%

38%

44%

15%

78%

16%

1%

2%

1%

51%

100%

Lindane

Linuron

Malathion

Metolachlor

Metribuzin

Molinate

Pendimethalin

Prometon

Propachlor

Simazine

Tebuthiuron

Terbacil

Terbufos

Thiobencarb

Trifluralin

Sum of analytes

0.001 0.1 10.0

CONCENTRATION, IN MICROGRAMS PER LITER

1,000

OCCURRENCE OF NUTRIENTS AND

PHYSICAL PROPERTIES

Streams

The results of analyses of 7 nutrients, and

measurements of 3 physical properties for 141 stream

samples are given in table 27. The discharges on the

day of sample collection are given in table 4. A statistical summary of these results is given in table 28.

Nitrate was detected at or above the MRL in 136

(98 percent) of 139 samples. Nitrate concentrations

were the highest of the nutrients with a median

concentration of 4.34 milligrams per liter (mg/L) and

more than 10 percent of the samples exceeding the

EPA Maximum Contaminant Level (MCL) of 10 mg/L

(U.S. Environmental Protection Agency, 1996b).

Nitrite was detected at or above the MRL in 132

(96 percent) of 138 samples. However, nitrite

concentrations were very low, with a median

concentration of only 0.056 mg/L. Ammonia plus

organic N was detected in 136 (99 percent) of

137 samples. Organic N concentrations were generally

higher than ammonia concentrations. The median

organic N concentration was 0.468 mg/L. Ammonia

as N was detected at or above the MRL in 123

(89 percent) of 138 samples, with a median concentration of 0.063 mg/L. Dissolved phosphorus and orthophosphate were detected at or above the MRL in

97 percent and 96 percent of samples, respectively.

They occurred at similar concentrations; the median

dissolved phosphorus concentration was 0.107 mg/L,

and the median orthophosphate concentration was

0.084 mg/L. Stream samples tended to be slightly

basic; the median pH of the samples was 7.8. Specific

conductances were moderate with a median of

500 microsiemens per centimeter at 25 degrees

Celsius (μS/cm). Daily mean discharge on the date

of sample collection ranged from 3 to 267,000 cubic

feet per second (ft3/s); the median discharge was

1,070 ft3/s.

Figure 20. Pesticide and pesticide degradate

(lindane to trifluralin) concentrations and percent

detections at or above the method detection limit in

134 stream samples.

Figure 19. Pesticide and pesticide degradate

(2,6-diethylaniline to fonofos) concentrations and

percent detections at or above the method detection

limit in 134 stream samples.
80 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine

Illinois

1 Vermillion River below Lake

Vermillion Dam, IL

06/10/98 R1 SU–98 0.36 <0.05 <0.05 4.94 0.49

06/10/98 LD SU–98 .37 <.05 <.05 5.22 .55

07/16/98 R2 SU–177 <.05 <.05 <.05 1.37 .15

07/16/98 LD SU–177 <.05 <.05 <.05 1.15 .13

2 Bonpas Creek at Browns, IL 05/23/98 S1 SU–43 8.39 .39 <.05 73.34 1.31

07/07/98 S2 SU–166 .08 <.05 <.05 1.53 <.05

3 Little Wabash River at Carmi, IL 05/23/98 S1 SU–33 3.77 3.80 <.05 51.32 1.95

07/09/98 S2 SU–175 .08 .30 <.05 6.50 .42

4 S. Branch Kishwaukee River near

Fairdale, IL

05/20/98 S1 SU–29 12.50 .37 <.05 13.92 3.01

07/29/98 S2 SU–195 <.05 <.05 <.05 .22 <.05

5 Iroquois River near Chebanse, IL 06/10/98 S1 SU–99 .22 <.05 <.05 1.90 .44

07/08/98 S2 SU–168 .09 <.05 <.05 2.71 .54

6 Dupage River near Shorewood, IL 06/09/98 S1 SU–100 .06 <.05 <.05 .09 .45

07/29/98 S2 SU–194 <.05 <.05 <.05 .05 <.05

7 Illinois River at Marseilles, IL 06/12/98 S1 SU–113 .98 .05 <.05 4.62 .85

07/09/98 S2 SU–176 .13 <.05 <.05 1.40 .23

8 Spoon River at London Mills, IL 05/20/98 S1 SU–25 4.09 .20 <.05 35.23 67.16

07/01/98 S2 SU–160 .14 <.05 <.05 2.67 .26

9 Sangamon River near Monticello, IL 05/23/98 S1 SU–35 .54 <.05 <.05 4.07 .22

05/23/98 LD SU–35 .57 <.05 <.05 4.16 .23

08/05/98 S2 SU–201 <.05 <.05 <.05 .43 <.05

10 Sangamon River at Riverton, IL 05/26/98 S1 SU–44 1.46 .13 <.05 8.03 .51

07/09/98 S2 SU–174 .07 <.05 <.05 1.49 .07

07/09/98 LD SU–174 .06 <.05 <.05 1.27 .06

07/09/98 LD SU–174 .07 <.05 <.05 1.35 <.05

11 LaMoine River at Colmar, IL 05/21/98 S1 SU–27 9.80 .05 <.05 23.30 10.54

06/29/98 S2 SU–142 .36 <.05 <.05 4.32 1.40

06/29/98 LD SU–142 .35 <.05 <.05 4.22 1.34

12 Illinois River at Valley City, IL 06/18/98 S1 SU–120 .98 .06 <.05 7.08 1.46

08/12/98 S2 SU–207 <.05 <.05 <.05 .30 .09

13 Mississippi River below Grafton, IL 06/02/98 S1 SU–60 .79 <.05 <.05 3.25 .88

06/15/98 S2 SU–116 .71 .06 <.05 5.03 .82

06/15/98 LD SU–116 .44 <.05 <.05 3.77 .58

06/15/98 LD SU–116 .61 .05 <.05 4.03 .63

14 Kaskaskia River near Cowden, IL 05/20/98 S1 SU–30 .33 <.05 <.05 1.76 .10

05/20/98 LD SU–30 .36 <.05 <.05 1.73 .08

07/08/98 S2 SU–169 .77 <.05 <.05 4.66 .21
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 81

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn

Illinois—Continued

1 0.97 <0.05 <0.05 <0.05 <0.05 0.06 <0.05 <0.05

1.03 <.05 <.05 <.05 <.05 .05 <.05 <.05

.48 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.41 <.05 <.05 <.05 <.05 <.05 <.05 <.05

2 14.09 .17 <.05 <.05 <.05 .68 14.15 <.05

.93 <.05 <.05 <.05 <.05 <.05 .08 <.05

3 14.44 .34 <.05 <.05 <.05 .43 5.38 <.05

1.70 1.34 <.05 <.05 <.05 .07 .22 <.05

4 9.58 <.05 <.05 <.05 <.05 .12 <.05 <.05

.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

5 .75 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.91 <.05 <.05 <.05 <.05 <.05 <.05 <.05

6 .19 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

7 1.16 .17 <.05 <.05 <.05 .05 <.05 <.05

.50 <.05 <.05 <.05 <.05 <.05 <.05 <.05

8 4.30 .35 <.05 <.05 <.05 .32 .14 <.05

.68 <.05 <.05 <.05 <.05 <.05 <.05 <.05

9 2.60 <.05 <.05 <.05 <.05 .05 <.05 <.05

2.69 <.05 <.05 <.05 <.05 .05 <.05 <.05

.11 <.05 <.05 <.05 <.05 <.05 <.05 <.05

10 1.69 .09 <.05 <.05 <.05 .08 .06 <.05

.33 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.28 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.40 <.05 <.05 <.05 <.05 <.05 <.05 <.05

11 1.35 .60 <.05 <.05 <.05 .16 .07 <.05

.78 .07 <.05 <.05 <.05 .06 <.05 <.05

.78 .06 <.05 <.05 <.05 .06 <.05 <.05

12 1.63 .06 <.05 <.05 <.05 .08 .06 <.05

.09 <.05 .06 <.05 <.05 <.05 <.05 <.05

13 1.12 <.05 <.05 <.05 <.05 <.05 <.05 <.05

1.24 <.05 <.05 <.05 <.05 .06 .06 <.05

.84 <.05 <.05 <.05 <.05 .06 .06 <.05

.96 <.05 <.05 <.05 <.05 <.05 <.05 <.05

14 .41 <.05 <.05 <.05 <.05 <.05 .11 <.05

.43 <.05 <.05 <.05 <.05 <.05 .13 <.05

1.19 <.05 <.05 <.05 <.05 .06 .07 <.05
82 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Illinois—Continued

15 Shoal Creek near Breese, IL 05/22/98 S1 SU–32 9.52 0.21 <0.05 25.68 1.96

07/08/98 S2 SU–167 1.10 <.05 <.05 9.95 .21

Iowa

16 Turkey River at Spillville, IA 06/02/98 S1 SU–64 .24 <.05 <.05 3.37 .66

06/12/98 S2 SU–109 1.29 .25 <.05 3.53 1.66

17 Mississippi River at Clinton, IA 05/27/98 S1 SU–55 .25 <.05 <.05 .31 .11

07/01/98 S2 SU–155 .10 <.05 <.05 .62 .11

18 Wapsipinicon River near Tripoli, IA 05/27/98 S1 SU–54 .33 .08 <.05 1.12 .12

06/20/98 S2 SU–126 .36 .12 <.05 7.29 .45

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 1.48 .32 <.05 8.39 .25

06/12/98 S2 SU–110 1.16 .08 <.05 7.91 .55

20 Iowa River near Rowan, IA 06/02/98 S1 SU–65 .05 <.05 <.05 .39 <.05

06/23/98 S2 SU–129 .63 <.05 <.05 3.27 .07

21 Old Mans Creek near Iowa City, IA 06/10/98 S1 SU–93 .57 .21 <.05 3.15 .78

06/22/98 S2 SU–147 .28 <.05 <.05 3.05 .40

22 Wolf Creek near Dysart, IA 06/10/98 S1 SU–87 .64 <.05 <.05 6.02 .69

06/22/98 S2 SU–128 .68 <.05 <.05 4.34 .54

23 Iowa River at Wapello, IA 05/27/98 S1 SU–53 .43 .05 <.05 1.86 .50

06/19/98 S2 SU–127 .38 <.05 <.05 3.91 .75

24 N. Skunk River near Sigourney, IA 05/21/98 S1 SU–21 14.50 <.05 <.05 23.64 2.25

06/10/98 S2 SU–95 .35 .10 <.05 8.26 2.09

25 Skunk River at Augusta, IA 05/26/98 S1 SU–45 7.58 .10 <.05 19.51 9.21

06/18/98 S2 SU–122 .90 .06 <.05 7.55 1.55

26 Des Moines River at Fort Dodge, IA 05/16/98 S1 SU–8 12.17 <.05 <.05 .53 .13

06/12/98 S2 SU–108 .11 <.05 <.05 .44 <.05

27 Raccoon River at Van Meter, IA 05/17/98 S1 SU–9 .94 <.05 <.05 2.73 .30

06/10/98 S2 SU–89 .32 <.05 <.05 3.20 .28

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 .39 <.05 <.05 1.60 <.05

06/18/98 S2 SU–123 .23 <.05 <.05 1.19 <.05

29 Maple River at Mapleton, IA 05/29/98 S1 SU–59 2.36 <.05 <.05 8.24 1.78

06/09/98 S2 SU–90 .19 <.05 <.05 4.31 .25

30 Boyer River at Logan, IA 05/22/98 S1 SU–31 3.93 .41 <.05 14.76 12.82

06/09/98 S2 SU–96 .64 <.05 <.05 5.23 .99

31 Chariton River below Rathbun

Lake Dam, IA

06/04/98 R1 SU–69 .13 <.05 <.05 1.05 .15

06/29/98 R2 SU–148 .23 <.05 <.05 1.64 .24

32 Nishnabotna River at Hamburg, IA 06/17/98 S2 SU–124 .40 .05 <.05 5.06 .57

Table 15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 83

Illinois—Continued

15 7.55 0.17 <0.05 <0.05 <0.05 <0.05 0.22 <0.05

1.65 .20 <.05 <.05 .09 .11 .06 <.05

Iowa—Continued

16 .10 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.14 .09 <.05 <.05 <.05 <.05 <.05 <.05

17 .12 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.20 <.05 <.05 <.05 <.05 <.05 <.05 <.05

18 .54 <.05 <.05 <.05 <.05 .06 <.05 <.05

2.03 <.05 <.05 <.05 <.05 .07 <.05 <.05

19 1.82 <.05 <.05 <.05 <.05 .08 <.05 <.05

2.16 .18 <.05 <.05 <.05 .09 <.05 <.05

20 .15 <.05 <.05 <.05 <.05 <.05 <.05 <.05

1.61 <.05 <.05 <.05 <.05 <.05 <.05 <.05

21 1.20 <.05 <.05 <.05 <.05 .05 <.05 <.05

.98 <.05 <.05 <.05 <.05 <.05 <.05 <.05

22 1.84 .15 <.05 <.05 <.05 .06 <.05 <.05

2.03 .05 <.05 <.05 <.05 .05 <.05 <.05

23 .65 <.05 <.05 <.05 <.05 <.05 <.05 <.05

1.42 <.05 <.05 <.05 <.05 .05 <.05 <.05

24 2.37 .33 <.05 <.05 <.05 .15 .06 <.05

2.44 .18 <.05 <.05 <.05 .11 <.05 <.05

25 6.46 .09 <.05 <.05 <.05 .27 .06 <.05

2.86 <.05 <.05 <.05 <.05 .09 <.05 <.05

26 5.10 .05 <.05 <.05 .28 <.05 <.05 <.05

.22 <.05 <.05 <.05 <.05 <.05 <.05 <.05

27 2.91 <.05 .06 <.05 <.05 <.05 <.05 <.05

1.15 <.05 <.05 <.05 <.05 <.05 <.05 <.05

28 .36 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.37 <.05 <.05 <.05 <.05 <.05 <.05 <.05

29 4.50 .23 <.05 <.05 <.05 .08 <.05 <.05

2.25 .05 <.05 <.05 <.05 .06 <.05 <.05

30 10.45 .10 <.05 <.05 <.05 .16 .08 <.05

1.95 .11 <.05 <.05 <.05 .07 <.05 <.05

31 .15 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.34 <.05 <.05 <.05 <.05 <.05 <.05 <.05

32 1.16 .10 <.05 <.05 <.05 .06 <.05 <.05

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn
84 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana

33 Whitewater River near Alpine, IN 05/26/98 S1 SU–47 1.70 1.05 <0.05 11.26 3.93

07/08/98 S2 SU–162 .13 .06 <.05 1.50 .30

34 Blue River at Fredericksburg, IN 05/27/98 S1 SU–50 .40 <.05 <.05 5.89 .19

07/08/98 S2 SU–163 .05 <.05 <.05 .71 .05

35 Mississinewa River below

Mississinewa Lake Dam, IN

06/09/98 R1 SU–83 .45 <.05 <.05 4.27 1.99

07/09/98 R2 SU–164 .74 .08 <.05 5.63 2.36

36 Eel River near Logansport, IN 05/21/98 S1 SU–18 2.77 .06 <.05 7.23 .49

06/30/98 S2 SU–152 .22 .86 <.05 2.77 .26

37 Wildcat Creek near Jerome, IN 05/21/98 S1 SU–19 1.31 <.05 <.05 11.95 22.31

06/30/98 S2 SU–151 .21 .22 <.05 5.21 .77

38 Wildcat Creek near Lafayette, IN 05/20/98 S1 SU–22 .78 <.05 <.05 4.14 .18

07/01/98 S2 SU–150 .14 <.05 <.05 2.26 .24

39 White River near Nora, IN 05/28/98 S1 SU–51 1.39 <.05 <.05 9.46 1.40

07/01/98 S2 SU–149 .37 .09 <.05 4.75 .53

07/01/98 LD SU–149 .38 .09 –.05 4.86 .58

40 Sugar Creek near Edinburgh, IN 05/26/98 S1 SU–46 3.40 .12 <.05 14.66 1.97

07/20/98 S2 SU–178 .07 <.05 <.05 .67 <.05

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 4.40 .73 <.05 21.77 3.12

07/06/98 S2 SU–161 .15 .16 <.05 1.65 .13

42 Wabash River at New Harmony, IN 05/27/98 S1 SU–57 1.98 .14 <.05 9.13 1.22

05/27/98 SD SU–58 1.37 <.05 <.05 6.69 .76

06/23/98 S2 SU–136 .98 .17 <.05 8.36 1.98

Minnesota

43 Cottonwood River near New Ulm, MN 05/26/98 S1 SU–49 .09 <.05 <.05 .16 .11

07/21/98 S2 SU–180 <.05 <.05 <.05 .16 <.05

07/21/98 SD SU–181 <.05 <.05 <.05 .16 <.05

44 Little Cobb River near Beauford, MN 05/18/98 S1 SU–12 2.11 .13 <.05 .10 <.05

08/17/98 S2 SU–208 <.05 <.05 <.05 .07 <.05

45 Minnesota River near Jordan, MN 05/19/98 S1 SU–13 1.19 .07 <.05 .10 <.05

06/26/98 S2 SU–135 .24 .09 <.05 .90 .10

46 Mississippi River at Hastings, MN 05/20/98 S1 SU–14 .32 .05 <.05 .16 <.05

05/20/98 SD SU–15 .38 .06 <.05 .15 .09

05/20/98 LD SU–15 .41 .06 <.05 .17 .10

05/20/98 S2 SU–206 <.05 <.05 <.05 .08 <.05

47 Des Moines River at Jackson, MN 05/26/98 S1 SU–48 .39 <.05 <.05 .38 <.05

08/24/98 S2 SU–210 <.05 <.05 <.05 .15 <.05

Table 15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 85

Indiana—Continued

33 1.38 0.23 <0.05 <0.05 <0.05 0.09 0.54 <0.05

.71 .05 <.05 <.05 <.05 <.05 .13 <.05

34 1.05 <.05 <.05 <.05 <.05 .06 1.68 <.05

.12 <.05 .09 <.05 <.05 <.05 .13 <.05

35 1.15 .22 <.05 <.05 <.05 .05 .31 <.05

2.48 .20 <.05 <.05 <.05 .07 .19 <.05

36 2.48 .35 <.05 <.05 .05 .06 .10 <.05

.52 <.05 <.05 <.05 <.05 <.05 .09 <.05

37 1.02 .20 <.05 <.05 <.05 .09 .07 <.05

2.09 .09 <.05 <.05 .21 .06 .06 <.05

38 2.07 .06 <.05 <.05 <.05 <.05 <.05 <.05

1.19 <.05 <.05 <.05 <.05 <.05 .05 <.05

39 3.78 .07 <.05 <.05 <.05 .05 .22 <.05

2.28 .06 .05 <.05 <.05 .05 .15 <.05

2.35 .06 .06 <.05 <.05 .06 .15 <.05

40 4.00 .33 <.05 <.05 <.05 .15 .37 <.05

4.07 .32 .16 <.05 <.05 <.05 <.05 <.05

41 4.65 .16 <.05 <.05 <.05 .18 .82 <.05

.74 <.05 <.05 <.05 <.05 <.05 .06 <.05

42 1.87 .07 <.05 <.05 <.05 .09 .38 <.05

1.21 .06 <.05 <.05 <.05 .07 .28 <.05

4.22 .10 <.05 <.05 <.05 .10 .26 <.05

Minnesota—Continued

43 .07 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.20 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.20 <.05 <.05 <.05 <.05 <.05 <.05 <.05

44 .55 <.05 <.05 <.05 .14 <.05 <.05 <.05

<.05 <.05 .09 <.05 <.05 <.05 <.05 <.05

45 .36 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.41 <.05 <.05 <.05 <.05 <.05 <.05 <.05

46 .14 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.17 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.19 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

47 .07 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.13 <.05 <.05 <.05 <.05 <.05 <.05 <.05

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn
86 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Minnesota—Continued

48 Rock River at Luverne, MN 06/24/98 S1 SU–130 <0.05 <0.05 <0.05 0.10 <0.05

06/25/98 S2 SU–131 .05 <.05 <.05 .13 <.05

06/25/98 LD SU–131 .05 <.05 <.05 .14 <.05

Kansas

49 Black Vermillion River at

Frankfort, KS

05/05/98 S1 SU–1 <.05 .05 <.05 .36 <.05

06/09/98 S2 SU–107 <.05 1.09 <.05 9.59 <.05

50 Big Blue River below Tuttle

Creek Lake Dam, KS

06/03/98 R1 SU–74 .16 .35 <.05 1.99 .10

07/29/98 R2 SU–197 .27 .65 <.05 .93 <.05

07/29/98 LD SU–197 .30 .72 <.05 1.05 <.05

51 Delaware River near Muscotah, KS 05/05/98 S1 SU–2 <.05 <.05 <.05 .22 <.05

06/10/98 S2 SU–105 .09 .41 <.05 3.94 <.05

Kentucky

52 Ohio River at Cannelton Dam, KY 06/04/98 S1 SU–75 .14 <.05 <.05 1.19 .16

07/07/98 S2 SU–173 .06 <.05 <.05 .58 .09

 Missouri

53 Nodaway River near Graham, MO 06/18/98 S1 SU–119 .12 <.05 <.05 3.35 .59

08/19/98 S2 SU–209 <.05 <.05 <.05 .27 <.05

Nebraska

54 North Dry Creek near Kearney, NE 05/22/98 S1 SU–28 5.57 .14 <.05 15.80 .20

05/22/98 LD SU–28 5.44 .13 <.05 15.80 .20

06/08/98 S2 SU–76 .18 .05 <.05 7.89 <.05

55 Maple Creek near Nickerson, NE 05/21/98 S1 SU–37 21.32 8.77 .06 27.09 6.66

06/08/98 S2 SU–79 2.05 .05 <.05 9.30 4.00

56 Salt Creek at Roca, NE 05/15/98 S1 SU–6 .18 18.27 <.05 172.18 .14

06/10/98 S2 SU–94 .81 1.61 <.05 34.79 2.48

57 Wahoo Creek at Ithaca, NE 05/15/98 S1 SU–5 1.83 4.94 <.05 34.06 5.00

06/08/98 S2 SU–78 .33 .22 <.05 4.49 .91

58 Platte River at Louisville, NE 05/22/98 S1 SU–39 2.81 2.18 <.05 20.46 8.00

06/09/98 S2 SU–77 .65 .74 <.05 6.22 1.31

59 Big Nemaha River at Falls City, NE 05/26/98 S1 SU–41 .36 .20 <.05 3.77 .44

06/08/98 S2 SU–80 1.25 .85 <.05 22.33 9.66

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 2.15 4.17 <.05 28.43 .55

06/10/98 S2 SU–82 .83 .57 <.05 10.63 .08

06/01/98 LD SU–82 .85 .57 <.05 11.64 .09

61 Big Blue River at Barneston, NE 05/15/98 S1 SU–4 1.02 2.84 <.05 8.08 <.05

06/09/98 S2 SU–104 .57 7.90 <.05 25.03 .33

62 Little Blue River near Fairbury, NE 05/12/98 S1 SU–3 .05 .13 <.05 .22 <.05

06/08/98 S2 SU–81 <.05 <.05 <.05 .98 <.05

Table 15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 87

Minnesota—Continued

48 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

.24 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.25 <.05 <.05 <.05 <.05 <.05 <.05 <.05

Kansas—Continued

49 .11 <.05 <.05 <.05 <.05 <.05 <.05 <.05

8.80 .17 <.05 <.05 <.05 .10 <.05 <.05

50 .74 <.05 <.05 <.05 <.05 <.05 <.05 <.05

2.39 <.05 <.05 <.05 <.05 <.05 <.05 <.05

2.73 <.05 <.05 <.05 <.05 <.05 <.05 <.05

51 .09 <.05 <.05 <.05 <.05 <.05 <.05 <.05

1.48 <.05 <.05 <.05 <.05 <.05 <.05 <.05

Kentucky—Continued

52 .23 <.05 <.05 <.05 <.05 <.05 .11 <.05

.30 <.05 <.05 <.05 <.05 <.05 .09 <.05

Missouri—Continued

53 .93 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

Nebraska—Continued

54 3.00 <.05 .14 <.05 .08 .15 .05 <.05

2.75 <.05 .13 <.05 .07 .14 .05 <.05

.82 <.05 .12 <.05 <.05 .09 <.05 <.05

55 15.26 .22 <.05 <.05 <.05 .16 .06 <.05

4.60 .50 <.05 <.05 <.05 <.05 <.05 <.05

56 124.3 .19 <.05 <.05 .06 .60 <.05 <.05

12.31 .84 <.05 <.05 <.05 .29 <.05 <.05

57 16.03 <.05 <.05 <.05 .31 .36 .08 <.05

.80 <.05 <.05 <.05 <.05 .05 <.05 <.05

58 6.76 .37 <.05 <.05 <.05 .14 .17 <.05

2.66 .14 .05 <.05 <.05 .07 <.05 <.05

59 1.49 <.05 .25 <.05 <.05 <.05 .06 <.05

3.06 <.05 <.05 <.05 .41 <.05 .05 <.05

60 11.81 .31 <.05 <.05 .11 .19 .07 <.05

3.89 .13 <.05 <.05 <.05 .11 <.05 <.05

4.29 .15 <.05 <.05 <.05 .12 <.05 <.05

61 3.84 .37 <.05 <.05 <.05 .07 <.05 <.05

9.51 .23 <.05 <.05 .42 .25 <.05 <.05

62 .13 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.14 <.05 <.05 <.05 <.05 <.05 <.05 <.05

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn
88 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Ohio

63 Clear Creek near Rockbridge, OH 06/10/98 S1 SU–86 <0.05 <0.05 <0.05 0.21 <0.05

06/30/98 S2 SU–145 .19 <.05 <.05 1.52 .14

64 Scioto River near Prospect, OH 06/02/98 S1 SU–63 .83 <.05 <.05 4.40 1.17

06/29/98 S2 SU–141 .20 <.05 <.05 3.76 .43

06/29/98 LD SU–141 .19 –.05 –.05 3.82 .40

65 Olentangy River at Claridon, OH 06/09/98 S1 SU–85 <.05 <.05 <.05 .88 <.05

06/29/98 S2 SU–157 .18 <.05 <.05 4.00 .16

06/29/98 SB SU–156 <.05 <.05 <.05 <.05 <.05

66 Olentangy River below Delaware,

Lake Dam, OH

06/09/98 R1 SU–84 .20 <.05 <.05 2.30 .10

06/29/98 R2 SU–153 .53 <.05 <.05 5.33 .60

07/01/98 RD SU–154 .41 <.05 <.05 4.20 .43

67 Big Darby Creek at Darbyville, OH 06/03/98 S1 SU–62 .66 .10 <.05 8.07 1.65

06/03/98 LD SU–62 .70 .11 <.05 8.53 1.64

06/29/98 S2 SU–140 .14 <.05 <.05 2.37 .16

68 Scioto River at Higby, OH 06/04/98 S1 SU–73 .90 .05 <.05 5.98 1.58

07/08/98 S2 SU–165 .22 <.05 <.05 3.30 .45

69 L. Miami River near Oldtown, OH 06/10/98 S1 SU–92 <.05 <.05 <.05 .24 <.05

06/30/98 S2 SU–144 <.05 <.05 <.05 .43 .10

70 Mad River at Eagle City, OH 06/10/98 S1 SU–91 <.05 <.05 <.05 .06 <.05

06/30/98 S2 SU–146 <.05 <.05 <.05 .45 <.05

71 Tiffin River at Stryker, OH 06/01/98 S1 SU–66 .24 .13 <.05 1.51 .31

06/01/98 SD SU–67 .24 .13 <.05 1.39 .31

07/07/98 S2 SU–172 <.05 <.05 <.05 .61 .16

07/07/98 LD SU–172 <.05 <.05 <.05 .60 .16

72 Auglaize River at Fort Jennings, OH 06/17/98 S1 SU–117 1.28 .14 <.05 7.82 1.84

07/08/98 S2 SU–171 .19 <.05 <.05 2.07 .38

Wisconsin

73 Root River at Racine, WI 06/01/98 S1 SU–61 .14 <.05 <.05 .24 .12

08/03/98 S2 SU–204 <.05 <.05 <.05 .12 <.05

74 St. Croix River at St. Croix Falls, WI 06/03/98 S1 SU–68 <.05 <.05 <.05 .09 <.05

08/05/98 S2 SU–205 <.05 <.05 <.05 <.05 <.05

08/05/98 LD SU–205 <.05 <.05 <.05 <.05 <.05

75 Wisconsin River at Muscoda, WI 06/16/98 S1 SU–133 .05 <.05 <.05 .28 .08

08/07/98 S2 SU–202 <.05 <.05 <.05 .12 <.05

76 Rock River at Afton, WI 06/17/98 S1 SU–134 .11 <.05 <.05 .37 .14

06/17/98 LD SU–134 .12 <.05 <.05 .38 .15

07/21/98 S2 SU–179 <.05 <.05 <.05 .47 .25

07/21/98 LD SU–179 <.05 <.05 <.05 .49 .21

Table 15. Concentrations of 13 herbicides in water samples from 71 midwestern streams and 5 midwestern reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample;

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 89

Ohio—Continued

63 0.16 <0.05 <0.05 <0.05 <0.05 <0.05 0.05 <0.05

1.09 .12 <.05 <.05 <.05 <.05 .29 <.05

64 2.81 .24 <.05 <.05 <.05 <.05 1.17 <.05

4.15 .13 <.05 <.05 <.05 .05 .57 <.05

4.07 .13 <.05 <.05 <.05 .05 .58 <.05

65 .67 <.05 <.05 <.05 <.05 <.05 <.05 <.05

3.75 <.05 <.05 <.05 <.05 <.05 .17 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

66 1.52 .05 <.05 <.05 <.05 <.05 .24 <.05

4.06 .10 <.05 <.05 <.05 .06 .67 <.05

3.26 .08 <.05 <.05 <.05 .05 .53 <.05

67 2.24 .07 <.05 <.05 <.05 .07 .74 <.05

2.24 .09 <.05 <.05 <.05 .08 .77 <.05

2.32 <.05 <.05 <.05 <.05 <.05 .61 <.05

68 1.97 .09 <.05 <.05 <.05 .06 .30 <.05

1.67 <.05 <.05 <.05 <.05 <.05 .21 <.05

69 .10 <.05 <.05 <.05 <.05 <.05 .20 <.05

.23 <.05 <.05 <.05 <.05 <.05 .11 <.05

70 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.71 <.05 <.05 <.05 <.05 <.05 .05 <.05

71 .41 .09 <.05 <.05 <.05 <.05 .16 <.05

.40 .08 <.05 <.05 <.05 <.05 .15 <.05

.10 <.05 <.05 <.05 <.05 <.05 .06 <.05

.10 <.05 <.05 <.05 <.05 <.05 .06 <.05

72 4.67 .49 <.05 <.05 <.05 .08 .54 <.05

1.50 .08 <.05 <.05 <.05 <.05 .13 <.05

Wisconsin—Continued

73 .11 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

74 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

75 .15 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

76 .07 <.05 <.05 <.05 <.05 <.05 <.05 <.05

.07 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

SD, duplicate stream sample; RD, duplicate reservoir sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn
90 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA

Illinois

1 Vermillion River below

Lake Vermillion Dam,

IL

06/10/98 R1 SU–98 1.29 0.62 0.59 <0.20 0.99 0.43 0.44 0.49 4.18 1.15

06/10/98 LD SU–98 1.23 .59 .57 <.20 1.06 .43 .42 .45 4.08 1.09

07/16/98 R2 SU–177 .45 <.20 .66 <.20 .59 .50 .55 .60 3.30 1.31

07/16/98 LD SU–177 .60 <.20 <.20 .69 <.20 .47 .51 .74 3.50 1.39

2 Bonpas Creek at

Browns, IL

05/23/98 S1 SU–43 1.53 2.25 .50 <.20 <.05 2.67 2.34 .58 1.17 1.12

07/07/98 S2 SU–166 1.16 .92 .91 <.20 <.05 .77 .42 <.20 2.63 1.86

3 Little Wabash River at

Carmi, IL

05/23/98 S1 SU–33 .78 .65 .61 .51 .32 1.36 1.10 .88 .94 .86

07/09/98 S2 SU–175 .88 .86 1.38 <.20 .48 1.17 .79 1.30 2.84 2.81

4 S. Branch Kishwaukee

Rivernear Fairdale, IL

05/20/98 S1 SU–29 2.76 1.10 1.18 <.20 .19 .64 .39 1.26 4.97 2.12

07/29/98 S2 SU–195 1.45 .39 2.97 <.20 .05 .17 .09 <.20 5.63 .81

5 Iroquois River near

Chebanse, IL

06/10/98 S1 SU–99 .90 .55 1.60 <.20 .76 .24 .30 .30 4.56 1.38

07/08/98 S2 SU–168 1.17 .89 1.02 <.20 1.02 .62 .57 .45 2.86 1.48

6 Dupage River near

Shorewood, IL

06/09/98 S1 SU–100 <.20 <.20 <.20 <.20 .05 .10 .09 <.20 <.20 <.20

07/29/98 S2 SU–194 1.36 <.20 1.17 <.20 <.05 .06 <.05 <.20 .44 .36

7 Illinois River at

Marseilles, IL

06/12/98 S1 SU–113 1.70 1.61 1.03 .61 1.05 .51 .37 .74 1.84 1.47

07/09/98 S2 SU–176 1.60 1.52 1.01 <.20 .72 .37 .35 <.20 2.08 1.08

8 Spoon River at London

Mills, IL

05/20/98 S1 SU–25 1.52 1.36 .32 .27 3.98 1.18 1.07 1.72 1.93 .58

07/01/98 S2 SU–160 .86 .51 .35 <.20 .47 .44 1.07 1.72 1.93 .58

9 Sangamon River near

Monticello, IL

05/23/98 S1 SU–35 1.63 .91 .72 <.20 .55 .41 .31 <.20 4.00 1.83

05/23/98 LD SU–35 1.63 .98 .71 <.20 .51 .39 .29 <.20 4.06 1.81

08/05/98 S2 SU–201 1.56 <.20 .58 <.20 .15 .16 .13 .67 3.88 .71

10 Sangamon River at

Riverton, IL

05/26/98 S1 SU–44 1.20 .95 .46 <.20 .66 .83 .51 <.20 1.60 1.01

07/09/98 S2 SU–174 <.20 <.20 <.20 <.20 .22 .46 .29 <.20 <.20 <.20

07/09/98 LD SU–174 <.20 <.20 <.20 <.20 .18 .51 .33 <.20 <.20 <.20

07/09/98 LD SU–174 <.20 <.20 <.20 <.20 .20 .46 .29 <.20 <.20 <.20

11 LaMoine River at

Colmar, IL

05/21/98 S1 SU–27 .75 .55 .20 <.20 1.08 1.02 .67 .57 .75 .29

06/29/98 S2 SU–142 1.60 1.48 .61 <.20 2.40 1.34 1.38 .67 1.21 .95

06/29/98 LD SU–142 1.98 1.85 .56 <.20 2.38 1.26 1.36 .46 1.41 .98

12 Illinois River at Valley

City, IL

06/18/98 S1 SU–120 2.25 2.16 .74 <.20 1.74 .98 .63 .66 1.91 1.38

08/12/98 S2 SU–207 .47 .30 .96 <.20 .12 .14 .10 <.20 1.46 .57
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 91

Illinois—Continued

13 Mississippi River below

Grafton, IL

06/02/98 S1 SU–60 0.82 0.71 0.64 <0.20 0.69 0.32 0.19 <0.20 2.02 0.73

06/15/98 S2 SU–116 1.85 1.26 1.02 <.20 .95 .64 .39 <.20 2.58 1.03

14 Kaskaskia River near

Cowden, IL

05/20/98 S1 SU–30 1.05 .34 .36 <.20 <.05 .14 .09 .45 2.45 .79

05/20/98 LD SU–30 1.01 .34 .35 <.20 <.05 .15 .09 .39 2.39 .84

07/08/98 S2 SU–169 1.67 1.52 .63 <.20 .21 .66 .35 .52 2.45 1.15

15 Shoal Creek near

Breese, IL

05/22/98 S1 SU–32 .77 .75 .41 .33 .46 1.08 .81 1.44 .87 .66

07/08/98 S2 SU–167 1.48 .80 .83 <.20 .44 1.41 .93 .58 2.59 .95

Iowa

16 Turkey River at

Spillville, IA

06/02/98 S1 SU–64 1.17 .40 2.14 <.20 .50 .49 .32 <.20 2.06 1.08

06/12/98 S2 SU–109 5.01 4.27 3.02 .96 1.84 .95 .52 .43 1.64 <.20

17 Mississippi River at

Clinton, IA

05/27/98 S1 SU–55 .31 <.20 .42 <.20 <.05 .08 .05 <.20 .73 .29

07/01/98 S2 SU–155 .65 .43 .66 <.20 .11 .17 .10 .25 .86 .31

18 Wapsipinicon River near

Tripoli, IA

05/27/98 S1 SU–54 2.77 1.07 3.15 <.20 .11 .31 .12 <.20 12.44 2.52

06/20/98 S2 SU–126 2.22 1.27 1.91 .39 .73 .93 .50 <.20 4.22 2.04

19 Wapsipinicon River at

Independence, IA

05/29/98 S1 SU–56 1.72 .85 1.41 <.20 .16 .77 .44 <.20 4.43 1.03

06/12/98 S2 SU–110 3.02 2.39 1.33 <.20 .59 1.20 .56 1.26 3.71 1.49

20 Iowa River near

Rowan, IA

06/02/98 S1 SU–65 .76 <.20 1.58 <.20 <.05 .08 .05 <.20 7.04 1.10

06/23/98 S2 SU–129 1.49 1.34 .88 <.20 .08 .52 .23 <.20 3.19 1.39

21 Old Mans Creek near

Iowa City, IA

06/10/98 S1 SU–93 <.20 <.20 <.20 <.20 1.12 .53 .38 <.20 <.20 <.20

06/30/98 S2 SU–147 2.54 1.76 1.02 <.20 .17 .68 .47 1.16 3.51 1.83

22 Wolf Creek near

Dysart, IA

06/10/98 S1 SU–87 1.89 1.58 1.21 <.20 .60 .62 .40 .64 6.29 1.91

06/22/98 S2 SU–128 1.34 1.05 .63 <.20 .71 .76 .52 <.20 2.42 1.06

23 Iowa River at

Wapello, IA

05/27/98 S1 SU–53 .88 .43 1.05 <.20 .29 .23 .14 <.20 3.95 .85

06/19/98 S2 SU–127 1.67 1.33 .98 <.20 1.05 .80 .46 <.20 2.72 1.16

24 N. Skunk River near

Sigourney, IA

05/21/98 S1 SU–21 1.49 .95 .52 <.20 .44 .77 .49 .72 2.94 1.03

06/10/98 S2 SU–95 1.41 1.25 .91 <.20 2.31 .85 .53 <.20 3.94 1.64

25 Skunk River at

Augusta, IA

05/26/98 S1 SU–45 2.69 3.99 .87 <.20 4.51 1.39 .70 .96 2.88 1.61

06/18/98 S2 SU–122 2.92 2.35 1.00 <.20 2.11 1.18 .64 .88 4.58 2.07

26 Des Moines River at

Fort Dodge, IA

05/16/98 S1 SU–8 1.77 <.20 .52 <.20 <.05 .09 .08 <.20 2.08 1.32

06/12/98 S2 SU–108 1.46 .65 .58 <.20 .06 .09 .09 <.20 4.41 .86

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA
92 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Iowa—Continued

27 Raccoon River at

Van Meter, IA

05/17/98 S1 SU–9 <0.20 <0.20 0.49 <0.20 0.16 0.13 0.10 <0.20 2.30 1.18

06/10/98 S2 SU–89 1.50 1.21 .60 <.20 <.05 <.05 <.05 .84 3.44 1.31

28 Little Sioux River at

Correctionville, IA

05/27/98 S1 SU–42 .68 .53 .32 <.20 <.05 .10 .08 <.20 1.67 .53

06/18/98 S2 SU–123 1.19 1.18 .33 <.20 .06 .20 .11 <.20 1.47 .51

29 Maple River at

Mapleton, IA

05/29/98 S1 SU–59 .45 .51 .24 <.20 .74 .41 .34 1.48 .85 .67

06/09/98 S2 SU–90 .34 <.20 .30 <.20 .37 .24 .19 .74 1.43 .39

30 Boyer River at

Logan, IA

05/22/98 S1 SU–31 2.13 2.58 .70 <.20 4.97 1.03 .76 2.68 1.67 1.86

06/09/98 S2 SU–96 .68 .82 .20 <.20 .79 .41 .37 <.20 .76 .53

31 Chariton River below

Rathbun Lake Dam, IA

06/04/98 R1 SU–69 <.20 <.20 .26 <.20 .35 .21 .13 .78 .81 .38

06/29/98 R2 SU–148 .33 .25 .22 <.20 .50 .23 .13 .56 .76 .51

32 Nishnabotna River at

Hamburg, IA

06/17/98 S2 SU–124 .95 .99 .26 <.20 .73 .73 .45 .93 1.04 .74

Indiana

33 Whitewater River near

Alpine, IN

05/26/98 S1 SU–47 1.15 .76 .50 .55 .99 .76 .48 .57 .69 .47

07/08/98 S2 SU–162 .48 .35 .58 .40 .43 .47 .39 .21 .99 .50

34 Blue River at

Fredericksburg, IN

05/27/98 S1 SU–50 .49 .28 .24 <.20 .36 .51 .32 <.20 1.01 .26

07/08/98 S2 SU–163 <.20 <.20 <.20 <.20 .13 .35 .27 <.20 .59 <.20

35 Mississinewa River below

Mississinewa Lake

Dam, IN

06/09/98 R1 SU–83 .61 .50 .51 <.20 .88 .81 .33 .67 2.05 .82

07/09/98 R2 SU–164 1.60 1.58 .70 <.20 2.09 1.39 1.00 .50 2.16 1.50

36 Eel River near

Logansport, IN

05/21/98 S1 SU–18 <.20 <.20 .53 <.20 .11 .52 .42 1.21 1.26 1.27

06/30/98 S2 SU–152 2.21 2.06 1.23 .61 .56 .62 .38 .74 1.36 .96

37 Wildcat Creek near

Jerome, IN

05/21/98 S1 SU–19 .99 .65 .53 <.20 1.45 .71 .59 .98 4.80 1.04

06/30/98 S2 SU–151 1.94 1.14 1.16 .44 1.42 .85 .65 1.01 6.36 2.40

38 Wildcat Creek near

Lafayette, IN

05/20/98 S1 SU–22 .85 .46 .44 <.20 .15 .34 .21 .55 3.10 .91

07/01/98 S2 SU–150 1.64 1.04 .72 <.20 .41 .57 .38 .82 3.67 1.75

39 White River near

Nora, IN

05/28/98 S1 SU–51 .97 .80 .62 .22 .43 .53 .38 <.20 3.11 1.26

07/01/98 S2 SU–149 1.47 1.16 .76 .20 .78 .94 .64 .67 3.45 2.01

07/01/98 LD SU–149 1.51 1.23 .76 .22 .96 .93 .64 .55 3.67 2.05

40 Sugar Creek near

Edinburgh, IN

05/26/98 S1 SU–46 1.65 1.63 .63 <.20 .88 1.05 .52 <.20 2.57 1.28

07/20/98 S2 SU–178 .64 .43 .39 <.20 <.05 .30 .14 <.20 1.46 1.03

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 93

Indiana—Continued

41 E. Fork White River near

Bedford, IN

05/28/98 S1 SU–52 1.68 1.89 0.67 0.40 0.90 1.42 .76 1.23 1.50 1.00

07/06/98 S2 SU–161 .88 .60 .51 <.20 .22 .58 .33 .27 1.17 .82

42 Wabash River at New

Harmony, IN

05/27/98 S1 SU–57 .78 .80 .35 <.20 .75 .62 .42 <.20 .86 .65

05/27/98 SD SU–58 .60 .70 .29 <.20 .56 .54 .38 <.20 .80 .52

06/23/98 S2 SU–136 2.31 1.97 1.38 .26 2.22 1.51 .95 <.20 3.25 2.04

Minnesota

43 Cottonwood River near

New Ulm, MN

05/26/98 S1 SU–49 .40 <.20 .48 <.20 .20 .05 .20 <.20 1.30 .36

07/21/98 S2 SU–180 .65 .28 .79 <.20 <.05 <.05 .05 <.20 1.58 .46

07/21/98 SD SU–181 .63 <.20 .78 <.20 <.05 <.05 <.05 <.20 1.43 .43

44 Little Cobb River near

Beauford, MN

05/18/98 S1 SU–12 1.94 <.20 .99 <.20 <.05 .07 <.05 <.20 3.54 .99

08/17/98 S2 SU–208 1.96 .59 1.99 .24 <.05 <.05 <.05 <.20 4.69 .76

45 Minnesota River near

Jordan, MN

05/19/98 S1 SU–13 .95 .65 .70 <.20 <.05 <.05 <.05 <.20 1.78 .62

06/26/98 S2 SU–135 1.76 1.29 1.45 .43 .17 .19 .96 <.20 2.65 .83

46 Mississippi River at

Hastings, MN

05/20/98 S1 SU–14 <.20 <.20 .45 <.20 <.05 <.05 <.05 <.20 .99 .34

05/20/98 SD SU–15 <.20 <.20 .46 <.20 <.05 <.05 <.05 <.20 1.02 .32

05/20/98 LD SU–15 <.20 <.20 .48 <.20 <.05 <.05 <.05 <.20 1.04 .35

05/20/98 S2 SU–206 <.20 <.20 .62 <.20 <.05 <.05 <.05 <.20 .53 <.20

47 Des Moines River at

Jackson, MN

05/26/98 S1 SU–48 .71 .66 .37 <.20 <.05 .06 .05 <.20 2.00 .49

08/24/98 S2 SU–210 1.54 1.22 .93 <.20 <.05 .12 .07 <.20 4.97 1.24

48 Rock River at

Luverne, MN

06/24/98 S1 SU–130 <.20 <.20 <.20 <.20 <.05 .06 .05 <.20 1.67 <.20

06/25/98 S2 SU–131 <.20 .50 <.20 <.20 <.05 .08 .05 <.20 1.29 <.20

06/25/98 LD SU–131 <.20 .44 <.20 <.20 <.05 .09 .05 <.20 1.29 <.20

Kansas

49 Black Vermillion River

at Frankfort, KS

05/05/98 S1 SU–1 <.20 <.20 .22 <.20 <.05 .05 <.05 <.20 .35 .21

06/09/98 S2 SU–107 <.20 <.20 1.17 1.40 <.05 1.56 .42 1.58 1.22 1.34

50 Big Blue River below

Tuttle Creek Lake

Dam, KS

06/03/98 R1 SU–74 <.20 <.20 .36 <.20 <.05 .15 .08 1.07 .52 .33

07/29/98 R2 SU–197 .56 .79 1.34 1.95 .06 .73 .43 2.73 .96 1.35

07/29/98 LD SU–197 .56 .81 1.42 2.11 .07 .78 .46 3.16 1.03 1.39

51 Delaware River near

Muscotah, KS

05/05/98 S1 SU–2 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 .38 <.20

06/10/98 S2 SU–105 .36 <.20 .37 <.20 <.05 .32 .15 .48 .83 .61

Kentucky

52 Ohio River at Cannelton

Dam, KY

06/04/98 S1 SU–75 <.20 <.20 <.20 <.20 .08 .10 .06 <.20 <.20 <.20

07/07/98 S2 SU–173 <.20 <.20 .25 <.20 .10 .14 .11 <.20 <.20 .38

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA
94 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

 Missouri

53 Nodaway River near

Graham, MO

06/18/98 S1 SU–119 0.95 0.63 0.38 <0.20 0.93 0.79 0.46 0.88 1.55 0.75

08/19/98 S2 SU–209 <.20 <.20 .26 <.20 <.05 .12 .09 <.20 .91 <.20

Nebraska

54 North Dry Creek near

Kearney, NE

05/22/98 S1 SU–28 .65 .59 .28 <.20 <.05 1.62 .77 1.12 .51 .34

05/22/98 LD SU–28 .64 .58 .26 <.20 <.05 1.46 .68 1.17 .52 .30

06/08/98 S2 SU–76 1.28 1.51 .53 <.20 <.05 1.67 .73 .79 .56 .56

55 Maple Creek near

Nickerson, NE

05/21/98 S1 SU–37 1.16 1.66 .38 .50 .93 1.29 .70 2.02 .50 .40

06/08/98 S2 SU–79 1.69 2.62 .47 <.20 <.05 1.10 .80 1.73 .59 .67

56 Salt Creek at

Roca, NE

05/15/98 S1 SU–6 <.20 <.20 .59 <.20 <.05 1.74 .97 3.13 1.51 1.01

06/10/98 S2 SU–94 1.29 2.21 2.81 1.03 1.37 3.66 2.17 4.31 5.17 6.37

57 Wahoo Creek at

Ithaca, NE

05/15/98 S1 SU–5 <.20 <.20 .55 .66 .77 .98 .58 4.47 .55 .76

06/08/98 S2 SU–78 .36 .47 .41 .41 .48 .55 .39 <.20 .34 .41

58 Platte River at

Louisville, NE

05/22/98 S1 SU–39 1.19 1.64 .83 1.06 3.03 1.68 1.04 2.75 .92 1.13

06/09/98 S2 SU–77 1.05 1.48 .72 .61 .78 1.51 .57 2.40 .92 1.10

59 Big Nemaha River at

Falls City, NE

05/26/98 S1 SU–41 <.20 <.20 .30 <.20 .18 .24 .14 <.20 .52 .42

06/08/98 S2 SU–80 .46 .69 .42 .42 <.05 <.05 <.05 1.59 .58 .43

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 S1 SU–36 <.20 <.20 .58 <.20 .17 1.45 .86 2.59 .59 .42

06/10/98 S2 SU–82 .69 1.06 .69 .67 <.05 2.16 .64 4.43 .58 .72

06/01/98 LD SU–82 .70 1.06 .67 .66 <.05 2.28 .65 4.20 .55 .77

61 Big Blue River at

Barneston, NE

05/15/98 S1 SU–4 <.20 <.20 .26 <.20 <.05 .31 .15 1.13 .38 .21

06/09/98 S2 SU–104 .61 1.23 2.74 4.30 <.05 <.05 <.05 2.23 1.58 1.82

62 Little Blue River near

Fairbury, NE

05/12/98 S1 SU–3 <.20 <.20 <.20 <.20 <.05 .07 <.05 <.20 <.20 <.20

06/08/98 S2 SU–81 <.20 <.20 .52 .69 <.05 .19 .10 <.20 .40 .34

Ohio

63 Clear Creek near

Rockbridge, OH

06/10/98 S1 SU–86 .50 <.20 <.20 <.20 <.05 .05 <.05 <.20 .91 .28

06/30/98 S2 SU–145 4.17 3.87 .81 <.20 .47 .51 .36 .52 3.66 2.28

64 Scioto River near

Prospect, OH

06/02/98 S1 SU–63 2.35 .49 4.52 <.20 .66 .53 .45 <.20 2.44 3.18

06/29/98 S2 SU–141 1.54 1.08 2.13 .21 .76 1.08 .88 .84 5.08 3.30

06/29/98 LD SU–141 1.50 1.02 2.06 .33 .67 1.09 .88 .72 4.94 3.19

65 Olentangy River at

Claridon, OH

06/09/98 S1 SU–85 <.20 <.20 .60 <.20 <.05 .14 .09 .31 1.92 .58

06/29/98 S2 SU–157 1.92 2.00 1.22 <.20 .22 .71 .54 .78 2.87 2.12

06/29/98 SB SU–156 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA
OCCURRENCE OF NUTRIENTS AND PHYSICAL PROPERTIES 95

Ohio—Continued

66 Olentangy River below

Delaware Lake

Dam, OH

06/09/98 R1 SU–84 0.58 <0.20 0.75 <0.20 0.05 0.55 0.19 0.68 3.20 1.19

06/29/98 R2 SU–153 2.91 3.22 1.28 <.20 .80 1.29 .98 1.32 5.31 4.83

07/01/98 RD SU–154 2.44 2.87 1.11 .25 .65 1.01 .76 1.14 4.71 4.25

67 Big Darby Creek at

Darbyville, OH

06/03/98 S1 SU–62 1.78 1.01 .64 <.20 .81 .79 .52 <.20 3.04 1.37

06/03/98 LD SU–62 1.66 1.07 .66 <.20 .67 .83 .58 <.20 2.99 1.23

06/29/98 S2 SU–140 .36 .45 .34 <.20 .13 .46 .41 .49 .75 .68

68 Scioto River at

Higby, OH

06/04/98 S1 SU–73 .57 .49 .41 <.20 .67 .41 .33 .45 1.55 .59

07/08/98 S2 SU–165 1.09 1.05 .99 <.20 .49 .64 .48 .51 2.52 1.61

69 L. Miami River near

Oldtown, OH

06/10/98 S1 SU–92 .24 <.20 .31 <.20 <.05 .07 .08 <.20 1.13 .28

06/30/98 S2 SU–144 .78 .33 .51 <.20 .21 .16 .14 <.20 1.73 .58

70 Mad River at Eagle

City, OH

06/10/98 S1 SU–91 <.20 <.20 .31 <.20 <.05 <.05 <.05 <.20 .63 <.20

06/30/98 S2 SU–146 .44 .22 .44 <.20 <.05 .16 .09 <.20 1.25 .50

71 Tiffin River at

Stryker, OH

06/01/98 S1 SU–66 <.20 <.20 .62 <.20 .08 .20 .17 <.20 1.07 .47

06/01/98 SD SU–67 <.20 <.20 .60 <.20 .08 .17 .15 <.20 1.21 .53

07/07/98 S2 SU–172 .32 <.20 .54 <.20 .16 .15 .12 <.20 .66 .33

07/07/98 LD SU–172 .30 <.20 .62 <.20 .17 .15 .11 <.20 .66 .24

72 Auglaize River at Fort

Jennings, OH

06/17/98 S1 SU–117 4.03 4.17 2.15 <.20 1.53 1.68 1.05 .89 6.23 3.83

07/08/98 S2 SU–171 1.91 1.86 2.01 <.20 .57 .65 .51 .68 5.03 3.45

Wisconsin

73 Root River at

Racine, WI

06/01/98 S1 SU–61 <.20 <.20 <.20 .38 .22 .18 .16 <.20 .69 .30

08/03/98 S2 SU–204 <.20 <.20 .37 <.20 <.05 .05 <.05 <.20 1.35 <.20

74 St. Croix River at

St. Croix Falls, WI

06/03/98 S1 SU–68 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

08/05/98 S2 SU–205 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

08/05/98 LD SU–205 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

75 Wisconsin River at

Muscoda, WI

06/16/98 S1 SU–133 <.20 <.20 .29 <.20 <.05 .07 <.05 <.20 <.20 <.20

08/07/98 S2 SU–202 .26 <.20 .56 <.20 <.05 .07 <.05 <.20 .56 .21

76 Rock River at

Afton, WI

06/17/98 S1 SU–134 .60 <.20 .85 <.20 .09 .13 .09 <.20 .93 .41

06/17/98 LD SU–134 .58 <.20 .82 <.20 .10 .14 .09 <.20 .86 .38

07/21/98 S2 SU–179 .84 .71 1.23 .22 .12 .18 .07 <.20 .78 .44

07/21/98 LD SU–179 .76 .74 1.20 .25 .12 .19 .10 <.20 .76 .42

Table 16. Concentrations of 10 herbicide degradates in water samples from 71 midwestern streams and 5 midwestern

reservoirs—Continued

[S1, pre-emergence stream sample; S2, post-emergence stream sample; R1, first reservoir outflow sample; R2, second reservoir outflow sample; SD, duplicate stream sample; RD, duplicate reservoir sample; LD, laboratory duplicate sample; SB, blank stream sample; SS, spiked stream sample; <, less than]

Site no.

(figs. 3, 4)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

Deisopropylatrazine

HydroxyatrazineMetolachlor

ESA

Metolachlor

OA
96 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Reservoir Outflows

The results of analyses of 7 nutrients and

measurements of 3 physical properties for 10 reservoir

outflow samples are given in table 27. The discharges

on the day of sample collection are given in table 4.

A statistical summary of these results is given in

table 29. Nitrate was detected at or above the MRL

in all 10 samples. Nitrate concentrations were the

highest of the nutrients with a median concentration of

1.83 mg/L, and one sample exceeded the EPA MCL of

10 mg/L. Nitrite was detected at or above the MRL in

9 of 10 samples. Nitrite concentrations were very low,

with a median concentration of only 0.040 mg/L.

Ammonia was detected in 7 of 10 samples, and

ammonia plus organic N was detected in 9 of

10 samples. Organic N concentrations were generally

higher, with a median concentrations of 0.389 mg/L

compared to 0.061 mg/L for ammonia. Dissolved

phosphorus and orthophosphate were each detected

at or above the MRL in 8 of 10 samples. They

occurred at similar concentrations; the median

dissolved phosphorus concentration was 0.063 mg/L,

and the median orthophosphate concentration was

0.059 mg/L. Reservoir outflow samples tended

to be slightly basic, although less so than the stream

samples. The median pH of the reservoir outflow

samples was 7.4. Specific conductances (median value

of 409 μS/cm) were lower in reservoir outflows than in

streams. Daily mean discharge on the date of sample

collection ranged from 34 to 3,610 ft3/s; the median

discharge was 653 ft3

/s.

Table 17. Statistical summary of 23 herbicide and herbicide degradate concentrations in 141 water samples from

71 midwestern streams (concentrations in micrograms per liter)

[<, less than]

Herbicide

Method

reporting limit

(MRL)

Number at or

above MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

acetochlor 0.05 115 0.08 0.32 0.98 7.58 21.3

acetochlor ESA .20 109 .32 .88 1.60 2.69 5.01

acetochlor OA .20 96 <.20 .60 1.21 2.35 4.27

alachlor .05 62 <.05 <.05 .13 2.18 18.3

alachlor ESA .20 127 .36 .58 .99 2.14 4.52

alachlor OA .20 30 <.20 <.20 <.20 .66 4.30

ametryn .05 1 <.05 <.05 <.05 <.05 .06

atrazine .05 140 .47 3.27 7.91 27.1 172

deethylatrazine .05 131 .14 .49 .85 1.68 3.66

deisopropylatrazine .05 125 .09 .36 .54 .97 2.34

hydroxy-atrazine .20 67 <.20 <.20 .79 2.40 4.47

cyanazine .05 104 <.05 .25 .88 6.66 67.2

cyanazine-amide .05 99 <.05 .21 .73 2.22 4.99

metolachlor .05 132 .20 1.15 2.48 10.5 124

metolachlor ESA .20 131 .76 1.55 2.87 5.08 12.4

metolachlor OA .20 123 .39 .76 1.28 2.40 6.37

metribuzin .05 56 <.05 <.05 .10 .35 1.34

prometon .05 11 <.05 <.05 <.05 .06 .35

prometryn .05 0 <.05 <.05 <.05 <.05 <.05

propachlor .05 11 <.05 <.05 <.05 .09 .42

propazine .05 61 <.05 <.05 .07 .25 .68

simazine .05 58 <.05 <.05 .08 .57 14.2

terbutryn .05 0 <.05 <.05 <.05 <.05 <.05

Sum of 13 herbicides .05 140 1.12 5.96 13.4 47.8 316

Sum of 10 degradates .05 139 3.47 7.53 10.93 17.7 30.4
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 97

82%

77%

68%

44%

90%

21%

99%

93%

89%

48%

74%

70%

94%

93%

87%

40%

8%

8%

43%

41%

99%

99%

Acetochlor

Acetochlor ESA

Acetochlor OA

Alachlor

Alachlor ESA

Alachlor OA

Atrazine

Deethylatrazine

Deisopropylatrazine

Hydroxy-atrazine

Cyanazine

Cyanazine-amide

Metolachlor

Metolachlor ESA

Metolachlor OA

Metribuzin

Prometon

Propachlor

Propazine

Simazine

Sum of herbicides

Sum of degradates

0.01 0.1 1.0 10.0 100.0 1,000

CONCENTRATION, IN MICROGRAMS PER LITER

Ground Water

The results of analyses of 7 nutrients and

measurements of 3 physical properties for 25 groundwater samples are given in table 30. A statistical

summary of these results is given in table 31. Nitrate

plus nitrite was detected at or above the MRL in 18

(72 percent) of 25 samples. Nitrate concentrations

were the highest of the nutrients with a median

concentration of 1.33 mg/L and three samples

exceeded the EPA MCL of 10 mg/L. Nitrite was

detected at or above the MRL in only 7 (33 percent)

of 21 samples, and concentrations were very low.

Ammonia was detected at or above the MRL in 18

(72 percent) of 25 samples, and ammonia plus organic

N was detected in 13 (52 percent) of 25 samples.

Unlike in streams and reservoir outflow, ammonia

concentrations were generally higher than organic N

concentrations in ground-water samples (table 31).

Dissolved phosphorus was detected at or above the

MRL in 14 (67 percent) of 21 samples and orthophosphate was detected in 22 (88 percent) of 25 samples.

Orthophosphate tended to occur at a higher concentrations with the median value of 0.077 mg/L for orthophosphate compared to 0.036 mg/L for dissolved

phosphorus. Ground-water samples tended to be

slightly basic; the median pH of the samples was 7.19.

Specific conductances were higher than for streams or

reservoir outflows, with a median value of 675 μS/cm.

HERBICIDES IN PRE-EMERGENCE

AND POST-EMERGENCE STREAM

AND RESERVOIR OUTFLOW SAMPLES

Because they are more frequently applied after

crops have emerged, the frequency of detections and

concentrations of SU, SA, and IMI herbicides was

expected to be greater in post-emergence stream

runoff and reservoir outflow samples than in preemergence samples. The opposite was expected for

herbicides such as acetochlor, atrazine, and metolachlor that are more often applied prior to crop emergence, and would be expected to occur at higher

concentrations in the pre-emergence sample. A

summary of discharge and herbicide concentration

in pre- and post-emergence stream runoff and reservoir outflow samples is given for flumetsulam,

imazethapyr, nicosulfuron, acetochlor, atrazine, and

metolachlor in table 32. Flumetsulam, imazethapyr,

and nicosulfuron were all more frequently detected

in post-emergence samples than in pre-emergence

samples. There is little difference in detection frequencies for acetochlor, atrazine, and metolachlor between

pre- and post-emergence samples (table 32).

Paired difference tests were used to determine

if the observed differences between pre- and postemergence herbicide concentrations are statistically

significant. Because the distributions of herbicide

concentrations are positively skewed, the nonparametric Wilcoxon signed-rank test was used

(Helsel and Hirsch, 1992). The following hypothesis

was tested.

Figure 21. Herbicide and herbicide degradate concentrations and percent detections at or above the method

reporting limit in 141 midwestern stream samples.
98 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 18. Statistical summary of 46 pesticide and pesticide degradate concentrations in 10 water samples from five

Midwestern reservoir outflows (concentrations in micrograms per liter, the 95th percentile is not given as it is the same

as the maximum)

[<, less than; E, estimated]

Herbicide

Method

reporting limit

(MRL)

Number at or

above MRL

25th

percentile Median 75thpercentile Maximum

2,6-diethylaniline 0.003 0 <0.003 <0.003 <0.003 <0.003

acetochlor .002 10 .194 .294 .478 .821

alachlor .002 9 .006 .014 .099 .815

atrazine .001 10 1.52 2.01 5.70 6.90

azinphos-methyl .001 0 <.001 <.001 <.001 <.001

benfluralin .002 0 <.002 <.002 <.002 <.002

butylate .002 0 <.002 <.002 <.002 <.002

carbaryl .003 2 <.003 <.003 <.003 .028

carbofuran .003 2 <.003 <.003 <.003 .232

chlorpyrifos .004 1 <.004 <.004 <.004 .031

cyanazine .004 10 .150 .325 .624 2.90

dacthal .002 0 <.002 <.002 <.002 <.002

deethylatrazine .002 10 .133 .219 .349 .729

diazinon .002 2 <.002 <.002 <.002 .012

dieldrin .001 1 <.001 <.001 <.001 .003

disulfoton .017 0 <.017 <.017 <.017 <.017

EPTC .002 1 <.002 <.002 <.002 .0027

ethalfluralin .004 0 <.004 <.004 <.004 <.004

ethoprophos .003 0 <.003 <.003 <.003 <.003

fonofos .003 0 <.003 <.003 <.003 <.003

lindane .004 0 <.004 <.004 <.004 <.004

linuron .002 0 <.002 <.002 <.002 <.002

malathion .005 0 <.005 <.005 <.005 <.005

metolachlor .002 10 .619 1.36 3.08 4.36

metribuzin .004 9 .009 .026 .087 .225

molinate .004 0 <.004 <.004 <.004 <.004

napropamide .003 0 <.003 <.003 <.003 <.003

parathion .004 0 <.004 <.004 <.004 <.004

parathion methyl .006 0 <.006 <.006 <.006 <.006

pebulate .004 0 <.004 <.004 <.004 <.004

pendimethalin .004 4 <.004 <.004 .014 .023

phorate .002 0 <.002 <.002 <.002 <.002

prometon .018 6 E.0094 .024 .029 .039

propachlor .007 2 <.007 <.007 <.007 .017

propanil .004 0 <.004 <.004 <.004 <.004

propargite .013 0 <.013 <.013 <.013 <.013

propyzamide .003 0 <.003 <.003 <.003 <.003

simazine .005 9 .016 .051 .358 1.03

tebuthiuron .010 1 <.005 E.0031 .008 .015

terbacil .007 0 <.007 <.007 <.007 <.007

terbufos .013 0 <.013 <.013 <.013 <.013

thiobencarb .002 0 <.002 <.002 <.002 <.002

tri-allate .001 0 <.001 <.001 <.001 <.001

trifluralin .002 1 <.002 <.002 <.002 .0062

alpha-HCH .002 0 <.002 <.002 <.002 <.002

cis-permethrin .005 0 <.005 <.005 <.005 <.005

p,p'-DDE .006 1 <.006 <.006 <.006 .0062

Sum of 46 pesticides and

degradates

.001 10 3.08 4.98 10.4 14.7
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 99

Null Hypothesis. Concentrations/streamflows in

pre-emergence samples are not significantly different

from values in post-emergence samples (median of

differences = 0).

Alternate Hypothesis. Concentrations/

streamflows in pre-emergence samples are significantly different from values in post-emergence

samples (median of differences not equal to 0).

Differences were calculated as the postemergence value minus pre-emergence value, so a

significant test result with a positive signed rank would

mean that the post-emergence values are larger than

the pre-emergence values, while a negative signed

rank would mean the opposite. The expected relations

are observed for flumetsulam, imazethapyr, and nicosulfuron. Concentrations of these herbicides are all

significantly larger in the post-emergence samples

than in pre-emergence samples (table 33). The median

of the paired differences is largest for nicosulfuron

(0.031 μg/L). The expected relations also are observed

for acetochlor, atrazine, and metolachlor. Concentration of these herbicides are all significantly larger in

the pre-emergence samples than in post-emergence

samples (table 33). The median of the paired differences is largest for atrazine (–0.66 μg/L). Some of the

differences in concentration could be a result of differences in streamflow. Results of the paired-difference

test on streamflow indicate that post-emergence

streamflows were larger than pre-emergence flows, but

that the difference is not statistically significant at the

p = 0.05 level.

Table 19. Statistical summary of 13 herbicide and 10 herbicide degradate concentrations in 10 water samples from five

midwestern reservoir outflows (concentration in micrograms per liter, the 95th percentile is not given as it is the same as

the maximum)

[<, less than]

Herbicide

Method

reporting limit

(MRL)

Number at or

above MRL

25th

percentile Median 75thpercentile Maximum

acetochlor 0.05 9 0.16 0.25 0.45 0.74

acetochlor ESA .20 8 .33 .57 1.29 2.91

acetochlor OA .20 6 <.20 .38 .79 3.22

alachlor .05 3 <.05 <.05 .08 .65

alachlor ESA .20 10 .36 .63 .75 1.34

alachlor OA .20 1 <.20 <.20 <.20 1.95

ametryn .05 0 <.05 <.05 <.05 <.05

atrazine .05 10 1.37 2.15 4.94 5.63

deethylatrazine .05 10 .23 .53 .81 1.39

deisopropylatrazine .05 10 .13 .38 .55 1.00

hydroxy-atrazine .20 10 .56 .68 1.07 2.73

cyanazine .05 9 .10 .20 .60 2.36

cyanazine-amide .05 9 .06 .55 .88 2.09

metolachlor .05 10 .48 1.06 2.39 4.06

metolachlor ESA .20 10 .81 2.11 3.30 5.31

metolachlor OA .20 10 .51 1.17 1.35 4.83

metribuzin .05 4 <.05 <.05 .10 .22

prometon .05 0 <.05 <.05 <.05 <.05

prometryn .05 0 <.05 <.05 <.05 <.05

propachlor .05 0 <.05 <.05 <.05 <.05

propazine .05 4 <.05 <.05 .06 .07

simazine .05 4 <.05 <.05 .24 .67

terbutryn .05 0 <.05 <.05 <.05 <.05

Sum of 13 herbicides .05 10 2.45 4.33 8.44 11.8

Sum of 10 degradates .05 10 3.49 7.58 10.9 21.94
100 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 20. Pesticide and pesticide degradate (2,6 diethylaniline through fonofos) concentrations in water samples

 [W1, well sample from round 1; WD, duplicate well sample; <, less than; E, estimate]

Site no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

2,6-

diethylaniline

AcetochlorAlachlorAtrazine

Azinphosmethyl

BenfluralinButylate

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.0030 <0.0020 <0.0020 <0.0010 <0.0010 <0.0020 <0.0020

2 LUS1–14 05/18/98 W1 SU–7 Sample not analyzed (broken bottle)

3 LUS1–26 06/18/98 W1 SU–118 <.0030 <.0020 <.0020 E.0034 <.0010 <.0020 <.0020

4 LUS2–9 06/15/98 W1 SU–111 <.0030 <.0020 <.0020 .010 <.0010 <.0020 <.0020

5 LUS2–22 06/18/98 W1 SU–121 <.0030 <.0020 <.0020 .032 <.0010 <.0020 <.0020

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

7 Fort Madison 4 07/22/98 W1 SU–182 .0894 <.0020 <.0020 <.0010 <.0010 <.0020 .0042

8 Shambaugh 3 07/24/98 W1 SU–186 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

9 Nodaway 4 07/23/98 W1 SU–185 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

10 Silver City 3 07/31/98 W1 SU–198 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

11 Carson (5), 3 07/31/98 W1 SU–200 <.0030 <.0020 <.0020 .014 <.0010 <.0020 <.0020

12 Cumberland 1 07/27/98 W1 SU–188 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

13 Fontanelle 5 07/23/98 W1 SU–183 <.0030 <.0020 <.0020 .036 <.0010 <.0020 <.0020

14 Menlo 3 07/29/98 W1 SU–193 <.0030 <.0020 <.0020 .091 <.0010 <.0020 <.0020

15 Carlisle 5 07/27/98 W1 SU–187 <.0030 <.0020 <.0020 .015 <.0010 <.0020 <.0020

16 Newton 13 06/03/98 W1 SU–71 <.0030 <.0020 <.0020 .039 <.0010 <.0020 <.0020

17 Belle Plaine 4 06/02/98 W1 SU–70 Sample not analyzed (broken bottle)

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.0030 <.0020 <.0020 .410 <.0010 <.0020 <.0020

19 Vail 1 06/23/98 W1 SU–137 <.0030 <.0020 <.0020 .004 <.0010 <.0020 <.0020

20 Marshalltown 8 06/02/98 W1 SU–72 .0045 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

21 Boone 20 07/28/98 W1 SU–190 <.0030 E.0039 <.0020 .179 <.0010 <.0020 <.0020

22 Boxholm 2 07/25/98 W1 SU–189 <.0030 <.0020 <.0020 <.0010 <.0010 <.0020 <.0020

23 Holstein 3 06/25/98 W1 SU–139 <.0030 <.0020 .016 .123 <.0010 <.0020 <.0020

24 Kingsley 1 06/25/98 W1 SU–138 <.0030 <.0020 <.0020 .011 <.0010 <.0020 <.0020

25 Sheffield 2 07/29/98 W1 SU–192 <.0030 <.0020 <.0020 .221 <.0010 <.0020 <.0020
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 101

collected in 1998 from 23 midwestern wells

Site no.

(fig. 5)

Concentration,

in micrograms per liter

CarbarylCarbofuranChlorpyrifosCyanazineDacthalDeethylatrazineDiazinonDieldrinDisulfoton EPTC EthalfluralinEthoprophosFonofos

Illinois—Continued

1 <0.0030 <0.0030 <0.0040 <0.0040 <0.0020 <0.0020 <0.002 <0.0010 <0.0170 <0.0020 <0.0040 <0.0030 <0.0030

2 Sample not analyzed

3 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

4 <.0030 <.0030 <.0040 <.0040 <.0020 E.0243 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

5 <.0030 <.0030 <.0040 <.0040 <.0020 E.0283 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

Iowa—Continued

6 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

7 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

8 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

9 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

10 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

11 <.0030 <.0030 <.0040 <.0040 <.0020 E.0094 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

12 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

13 <.0030 <.0030 <.0040 <.0040 <.0020 E.0071 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

14 <.0030 <.0030 <.0040 <.0040 <.0020 E.0740 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

15 <.0030 <.0030 <.0040 <.0040 <.0020 E.0068 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

16 <.0030 <.0030 <.0040 <.0040 <.0020 .0808 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

17 Sample not analyzed

18 <.0030 <.0030 <.0040 <.0040 <.0020 E.103 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

19 <.0030 <.0030 <.0040 <.0040 <.0020 E.0065 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

20 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

21 <.0030 <.0030 <.0040 <.0040 <.0020 E.0287 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

22 <.0030 <.0030 <.0040 <.0040 <.0020 <.0020 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

23 <.0030 <.0030 <.0040 .0074 <.0020 E.0423 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

24 <.0030 <.0030 <.0040 <.0040 <.0020 .0188 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030

25 <.0030 <.0030 <.0040 <.0040 <.0020 E.237 <.0020 <.0010 <.0170 <.0020 <.0040 <.0030 <.0030
102 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 21. Pesticide and pesticide degradate (lindane through terbacil) concentrations in water samples from 23 midwestern wells

[W1, well sample from round 1; WD, duplicate well sample; <, less than; E, estimate]

Site no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

LindaneLinuronMalathionMetolachlorMetribuzinMolinateNapropamide

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.0040 <0.0020 <0.0050 <0.0020 <0.0040 <0.0040 <0.0030

2 LUS1–14 05/18/98 W1 SU–7 Sample not analyzed (broken bottle)

3 LUS1–26 06/18/98 W1 SU–118 <.0040 <.0020 <.0050 E.0024 <.0040 <.0040 <.0030

4 LUS2–9 06/15/98 W1 SU–111 <.0040 <.0020 <.0050 .005 <.0040 <.0040 <.0030

5 LUS2–22 06/18/98 W1 SU–121 <.0040 <.0020 <.0050 .364 <.0040 <.0040 <.0030

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

7 Fort Madison 4 07/22/98 W1 SU–182 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

8 Shambaugh 3 07/24/98 W1 SU–186 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

9 Nodaway 4 07/23/98 W1 SU–185 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

10 Silver City 3 07/31/98 W1 SU–198 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

11 Carson (5), 3 07/31/98 W1 SU–200 <.0040 <.0020 <.0050 .007 <.0040 <.0040 <.0030

12 Cumberland 1 07/27/98 W1 SU–188 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

13 Fontanelle 5 07/23/98 W1 SU–183 <.0040 <.0020 <.0050 .013 <.0040 <.0040 <.0030

14 Menlo 3 07/29/98 W1 SU–193 <.0040 <.0020 <.0050 .002 <.0040 <.0040 <.0030

15 Carlisle 5 07/27/98 W1 SU–187 <.0040 <.0020 <.0050 .006 <.0040 <.0040 <.0030

16 Newton 13 06/03/98 W1 SU–71 <.0040 <.0020 <.0050 .035 <.0040 <.0040 <.0030

17 Belle Plaine 4 06/02/98 W1 SU–70 Sample not analyzed (broken bottle)

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.0040 <.0020 <.0050 .100 <.0040 <.0040 <.0030

19 Vail 1 06/23/98 W1 SU–137 <.0040 <.0020 <.0050 E.002 <.0040 <.0040 <.0030

20 Marshalltown 8 06/02/98 W1 SU–72 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

21 Boone 20 07/28/98 W1 SU–190 <.0040 <.0020 <.0050 .190 <.0040 <.0040 <.0030

22 Boxholm 2 07/25/98 W1 SU–189 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030

23 Holstein 3 06/25/98 W1 SU–139 <.0040 <.0020 <.0050 .557 <.0040 <.0040 <.0030

24 Kingsley 1 06/25/98 W1 SU–138 <.0040 <.0020 <.0050 .003 .006 <.0040 <.0030

25 Sheffield 2 07/29/98 W1 SU–192 <.0040 <.0020 <.0050 <.0020 <.0040 <.0040 <.0030
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 103

Site no.

(fig. 5)

Concentration,

in micrograms per liter

Parathion

Parathionmethyl

Pebulate

Pendimethalin

PhoratePrometonPropachlorPropanilPropargitePropyzamideSimazineTebuthiuronTerbacil

Illinois—Continued

1 <0.0040 <0.0060 <0.0040 <0.0040 <0.0020 <0.0180 <0.0070 <0.0040 <0.0130 <0.0030 <0.0050 <0.010 <0.0070

2 Sample not analyzed

3 <.0040 <.0060 <.0040 <.0040 <.0020 <.0108 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

4 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

5 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

Iowa—Continued

6 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

7 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

8 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

9 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

10 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

11 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

12 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

13 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

14 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

15 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

16 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

17 Sample not analyzed

18 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 .0051 <.010 <.0070

19 <.0040 <.0060 <.0040 <.0040 <.0020 .0414 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

20 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

21 <.0040 <.0060 <.0040 <.0040 <.0020 E.0079 <.0070 <.0040 <.0130 <.0030 E.0032 <.010 <.0070

22 <.0040 <.0060 <.0040 <.0040 <.0020 <.0180 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

23 <.0040 <.0060 <.0040 <.0040 <.0020 E.0112 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

24 <.0040 <.0060 <.0040 <.0040 <.0020 .0222 <.0070 <.0040 <.0130 <.0030 <.0050 <.010 <.0070

25 <.0040 <.0060 <.0040 <.0040 <.0020 .146 <.0070 <.0040 <.0130 <.0030 E.0031 <.010 <.0070
104 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 22. Pesticide and pesticide degradate (terbufos through p,p'-DDE) concentrations in water samples from 23 midwestern

wells

[W1, well sample from round 1; WD, duplicate well sample; <, less than]

Site no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

TerbufosThiobencarbTriallateTrifluralinalphaHCH

cispermethrin

p,p' -

DDE

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.0130 <0.0020 <0.0010 <0.0020 <0.0020 <0.0050 <0.0060

2 LUS1–14 05/18/98 W1 SU–7 Sample not analyzed (broken bottle)

3 LUS1–26 06/18/98 W1 SU–118 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

4 LUS2–9 06/15/98 W1 SU–111 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

5 LUS2–22 06/18/98 W1 SU–121 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

7 Fort Madison 4 07/22/98 W1 SU–182 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

8 Shambaugh 3 07/24/98 W1 SU–186 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

9 Nodaway 4 07/23/98 W1 SU–185 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

10 Silver City 3 07/31/98 W1 SU–198 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

11 Carson (5), 3 07/31/98 W1 SU–200 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

12 Cumberland 1 07/27/98 W1 SU–188 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

13 Fontanelle 5 07/23/98 W1 SU–183 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

14 Menlo 3 07/29/98 W1 SU–193 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

15 Carlisle 5 07/27/98 W1 SU–187 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

16 Newton 13 06/03/98 W1 SU–71 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

17 Belle Plaine 4 06/02/98 W1 SU–70 Sample not analyzed (broken bottle)

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

19 Vail 1 06/23/98 W1 SU–137 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

20 Marshalltown 8 06/02/98 W1 SU–72 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

21 Boone 20 07/28/98 W1 SU–190 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

22 Boxholm 2 07/25/98 W1 SU–189 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

23 Holstein 3 06/25/98 W1 SU–139 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

24 Kingsley 1 06/25/98 W1 SU–138 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060

25 Sheffield 2 07/29/98 W1 SU–192 <.0130 <.0020 <.0010 <.0020 <.0020 <.0050 <.0060
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 105

Table 23. Statistical summary of 46 pesticide and pesticide degradate concentrations in 23 water samples from

23 midwestern wells (concentrations in micrograms per liter)

[<, less than; E, estimate]

Herbicide Method

reporting limit

Number

above MRL

25th

 percentile Median 75thpercentile

95th

percentile Maximum

2,6-diethylaniline 0.003 2 <0.003 <0.003 <0.003 0.0045 0.089

acetochlor .002 1 <.002 <.002 <.002 <.002 E.004

alachlor .002 1 <.002 <.002 <.002 <.002 .016

atrazine .001 14 <.001 .010 .039 .221 .410

azinphos-methyl .001 0 <.001 <.001 <.001 <.001 <.001

benfluralin .002 0 <.002 <.002 <.002 <.002 <.002

butylate .002 1 <.002 <.002 <.002 <.002 .004

carbaryl .003 0 <.003 <.003 <.003 <.003 <.003

carbofuran .003 0 <.003 <.003 <.003 <.003 <.003

chlorpyrifos .004 0 <.004 <.004 <.004 <.004 <.004

cyanazine .004 1 <.004 <.004 <.004 <.004 .0074

dacthal .002 0 <.002 <.002 <.002 <.002 <.002

deethylatrazine .002 13 <.002 .0068 .029 .103 E.237

diazinon .002 0 <.002 <.002 <.002 <.002 <.002

dieldrin .001 0 <.001 <.001 <.001 <.001 <.001

disulfoton .017 0 <.017 <.017 <.017 <.017 <.017

EPTC .002 0 <.002 <.002 <.002 <.002 <.002

ethalfluralin .004 0 <.004 <.004 <.004 <.004 <.004

ethoprophos .003 0 <.003 <.003 <.003 <.003 <.003

fonofos .003 0 <.003 <.003 <.003 <.003 <.003

lindane .004 0 <.004 <.004 <.004 <.004 <.004

linuron .002 0 <.002 <.002 <.002 <.002 <.002

malathion .005 0 <.005 <.005 <.005 <.005 <.005

metolachlor .002 13 <.002 .002 .013 .364 .557

metribuzin .004 1 <.004 <.004 <.004 <.004 .006

molinate .004 0 <.004 <.004 <.004 <.004 <.004

napropamide .003 0 <.003 <.003 <.003 <.003 <.003

parathion .004 0 <.004 <.004 <.004 <.004 <.004

parathion methyl .006 0 <.006 <.006 <.006 <.006 <.006

pebulate .004 0 <.004 <.004 <.004 <.004 <.004

pendimethalin .004 0 <.004 <.004 <.004 <.004 <.004

phorate .002 0 <.002 <.002 <.002 <.002 <.002

prometon .018 3 <.018 <.018 <.018 .041 .146

propachlor .007 0 <.007 <.007 <.007 <.007 <.007

propanil .004 0 <.004 <.004 <.004 <.004 <.004

propargite .013 0 <.013 <.013 <.013 <.013 <.013

propyzamide .003 0 <.003 <.003 <.003 <.003 <.003

simazine .005 1 <.005 <.005 <.005 E.0032 .0051

tebuthiuron .010 0 <.010 <.010 <.010 <.010 <.010

terbacil .007 0 <.007 <.007 <.007 <.007 <.007

terbufos .013 0 <.013 <.013 <.013 <.013 <.013

thiobencarb .002 0 <.002 <.002 <.002 <.002 <.002

tri-allate .001 0 <.001 <.001 <.001 <.001 <.001

trifluralin .002 0 <.002 <.002 <.002 <.002 <.002

alpha-HCH .002 0 <.002 <.002 <.002 <.002 <.002

cis-permethrin .005 0 <.005 <.005 <.005 <.005 <.005

p,p'-DDE .006 0 <.006 <.006 <.006 <.006 <.006

Sum of 46 pesticides and

degradates

.001 15 <.001 .021 .093 .515 .715
106 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 24. Concentrations of 13 herbicides in water samples from 25 midwestern wells

[W1, well sample from round 1; WD, duplicate well sample; LD, laboratory duplicate sample; <, less than]

Site no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

AcetochlorAlachlorAmetrynAtrazineCyanazine

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.05 <0.05 <0.05 <0.05 <0.05

2 LUS1–14 05/18/98 W1 SU–7 <.05 <.05 <.05 <.05 <.05

05/18/98 WD SU–10 <.05 <.05 <.05 <.05 <.05

05/18/98 LD SU–10 <.05 <.05 <.05 <.05 <.05

3 LUS1–26 06/18/98 W1 SU–118 <.05 <.05 <.05 <.05 <.05

06/18/98 LD SU–118 <.05 <.05 <.05 <.05 <.05

4 LUS2–9 06/15/98 W1 SU–111 <.05 <.05 <.05 <.05 <.05

5 LUS2–22 06/18/98 W1 SU–121 <.05 <.05 <.05 <.05 <.05

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.05 <.05 <.05 <.05 <.05

7 Fort Madison 4 07/22/98 W1 SU–182 <.05 <.05 <.05 <.05 <.05

8 Shambaugh 3 07/24/98 W1 SU–186 <.05 <.05 <.05 <.05 <.05

07/24/98 LD SU–186 <.05 <.05 <.05 <.05 <.05

9 Nodaway 4 07/23/98 W1 SU–185 <.05 <.05 <.05 <.05 <.05

10 Silver City 3 07/31/98 W1 SU–198 <.05 <.05 <.05 <.05 <.05

11 Carson (5), 3 07/31/98 W1 SU–200 <.05 <.05 <.05 <.05 <.05

12 Cumberland 1 07/27/98 W1 SU–188 <.05 <.05 <.05 <.05 <.05

07/27/98 LD SU–188 <.05 <.05 <.05 <.05 <.05

13 Fontanelle 5 07/23/98 W1 SU–183 <.05 <.05 <.05 <.05 <.05

14 Menlo 3 07/29/98 W1 SU–193 <.05 <.05 <.05 .08 <.05

07/29/98 LD SU–193 <.05 <.05 <.05 .08 <.05

15 Carlisle 5 07/27/98 W1 SU–187 <.05 <.05 <.05 <.05 <.05

16 Newton 13 06/03/98 W1 SU–71 <.05 <.05 <.05 <.05 <.05

17 Belle Plaine 4 06/02/98 W1 SU–70 <.05 <.05 <.05 .20 <.05

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.05 <.05 <.05 .40 <.05

19 Vail 1 06/23/98 W1 SU–137 <.05 <.05 <.05 <.05 <.05

20 Marshalltown 8 06/02/98 W1 SU–72 <.05 <.05 <.05 <.05 <.05

06/02/98 LD SU–72 <.05 <.05 <.05 <.05 <.05

21 Boone 20 07/28/98 W1 SU–190 <.05 <.05 <.05 .18 <.05

22 Boxholm 2 07/25/98 W1 SU–189 <.05 <.05 <.05 <.05 <.05

23 Holstein 3 06/25/98 W1 SU–139 <.05 <.05 <.05 .09 <.05

24 Kingsley 1 06/25/98 W1 SU–138 <.05 <.05 <.05 <.05 <.05

25 Sheffield 2 07/29/98 W1 SU–192 <.05 <.05 <.05 .22 <.05
HERBICIDES IN PRE-EMERGENCE AND POST-EMERGENCE STREAM AND RESERVOIR OUTFLOW SAMPLES 107

Site no.

(fig. 5)

Concentration,

in micrograms per liter

MetolachlorMetribuzinPrometonPrometrynPropachlorPropazineSimazineTerbutryn

Illinois—Continued

1 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05

2 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

3 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

4 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

5 .41 <.05 <.05 <.05 <.05 <.05 <.05 <.05

Iowa—Continued

6 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

7 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

8 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

9 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

10 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

11 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

12 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

13 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

14 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

15 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

16 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

17 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

18 .07 <.05 <.05 <.05 <.05 <.05 <.05 <.05

19 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

20 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

<.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

21 .16 <.05 <.05 <.05 <.05 <.05 <.05 <.05

22 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

23 .43 <.05 <.05 <.05 <.05 <.05 <.05 <.05

24 <.05 <.05 <.05 <.05 <.05 <.05 <.05 <.05

25 <.05 <.05 .16 <.05 <.05 <.05 <.05 <.05
108 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 25. Concentrations of 10 herbicide degradates in water samples from 25 midwestern wells

[W1, well sample from round 1; WD, duplicate well sample, LD, laboratory duplicate sample; <, less than]

Site

no.

Site

name

Date of

collection

(month/

day/year)

Sample

type

Sample

no.

Concentration,

in micrograms per liter

Acetochlor

ESA

Acetochlor

OA

Alachlor

ESA

Alachlor

OA

CyanazineamideDeethylatrazine

DeisopropylatrazineHydroxyatrazine

Metolachlor

ESA

Metolachlor

OA

Illinois

1 LUS1–4 05/19/98 W1 SU–11 <0.20 <0.20 <0.20 <0.20 <0.05 <0.05 <0.05 <0.20 <0.20 <0.20

2 LUS1–14 05/18/98 W1 SU–7 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

05/18/98 WD SU–10 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

05/18/98 LD SU–10 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

3 LUS1–26 06/18/98 W1 SU–118 3.47 1.43 .44 <.20 <.05 <.05 <.05 <.20 3.05 1.13

06/18/98 LD SU–118 3.08 1.23 .35 <.20 <.05 <.05 <.05 <.20 2.78 .99

4 LUS2–9 06/15/98 W1 SU–111 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 1.37 <.20

5 LUS2–22 06/18/98 W1 SU–121 <.20 <.20 <.20 <.20 <.05 .05 <.05 <.20 <.20 <.20

Iowa

6 Blockton 1 07/23/98 W1 SU–184 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

7 Fort Madison 4 07/22/98 W1 SU–182 <.20 <.20 1.93 .72 <.05 <.05 <.05 <.20 1.17 .45

8 Shambaugh 3 07/24/98 W1 SU–186 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

07/24/98 LD SU–186 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

9 Nodaway 4 07/23/98 W1 SU–185 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

10 Silver City 3 07/31/98 W1 SU–198 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 .37 <.20

11 Carson (5), 3 07/31/98 W1 SU–200 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 .60 <.20

12 Cumberland 1 07/27/98 W1 SU–188 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

07/27/98 LD SU–188 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

13 Fontanelle 5 07/23/98 W1 SU–183 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 1.62 .53

14 Menlo 3 07/29/98 W1 SU–193 <.20 <.20 2.25 <.20 .14 .15 .39 <.20 .75 <.20

07/29/98 LD SU–193 <.20 <.20 2.54 <.20 .13 .14 .37 <.20 .84 <.20

15 Carlisle 5 07/27/98 W1 SU–187 <.20 <.20 2.99 <.20 <.05 <.05 <.05 <.20 .75 <.20

16 Newton 13 06/03/98 W1 SU–71 <.20 <.20 <.20 <.20 <.05 .08 .05 <.20 1.05 <.20

17 Belle Plaine 4 06/02/98 W1 SU–70 <.20 <.20 3.26 1.23 <.05 <.05 <.05 <.20 1.84 1.29

18 Cedar Rapids S6 08/25/98 W1 SU–211 <.20 <.20 <.20 <.20 <.05 .14 .06 <.20 <.20 <.20

19 Vail 1 06/23/98 W1 SU–137 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 <.20 <.20

20 Marshalltown 8 06/02/98 W1 SU–72 <.20 <.20 1.07 <.20 <.05 <.05 <.05 <.20 1.87 .70

06/02/98 LD SU–72 <.20 <.20 1.09 <.20 <.05 <.05 <.05 <.20 1.82 .78

21 Boone 20 07/28/98 W1 SU–190 1.54 .39 .64 <.20 <.05 .05 <.05 <.20 3.77 .87

22 Boxholm 2 07/25/98 W1 SU–189 <.20 <.20 .72 2.00 <.05 <.05 <.05 <.20 <.20 <.20

23 Holstein 3 06/25/98 W1 SU–139 <.20 <.20 <.20 <.20 .06 .06 <.05 <.20 1.06 .61

24 Kingsley 1 06/25/98 W1 SU–138 <.20 <.20 <.20 <.20 <.05 <.05 <.05 <.20 .66 <.20

25 Sheffield 2 07/29/98 W1 SU–192 <.20 <.20 <.20 <.20 <.05 .39 .85 <.20 1.16 <.20
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 109

SULFONYLUREA, SULFONAMIDE, AND

IMIDAZOLINONE HERBICIDES RELATIVE

TO ATRAZINE AND METOLACHLOR

Because they have similar chemical properties, much lower application rates, and a shorter

history of use, SU, SA, and IMI herbicides were

expected to occur at fraction (1/100th or less) of

the concentrations of other herbicides such as atrazine (Battaglin and others, 1998a). In figures 22

and 23, the concentrations in streams and reservoir

outflows of imazethapyr, flumetsulam, and nicosulfuron, the three most frequently detected SU,

SA, or IMI herbicides, are plotted in relation to

the concentrations of atrazine and metolachlor, the

two most frequently detected other herbicides in

results from the NWQL. On figures 22 and 23, the

circles are pre-emergence samples and the triangles

are post-emergence samples. The lines crossing

these plots show the 1:10, 1:100, and 1:1,000 ratios

of concentration. The data plotted in figure 22

indicate that in about one-half of the samples,

imazethapyr, flumetsulam, and nicosulfuron occur

at 1/100th or less the concentration of atrazine. The

ratios of metolachlor concentration to imazethapyr,

flumetsulam, and nicosulfuron concentrations

(fig. 23) are, in general, smaller than the ratios of

these compounds to atrazine.

Table 26. Statistical summary of 13 herbicide and 10 herbicide degradate concentrations in 25 water samples from

25 midwestern wells (concentrations in micrograms per liter)

[<, less than]

Herbicide

Method

reporting limit

(MRL)

Number at or

above MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

acetochlor 0.05 0 <0.05 <0.05 <0.05 <0.05 <0.05

acetochlor ESA .20 2 <.20 <.20 <.20 1.54 3.47

acetochlor OA .20 2 <.20 <.20 <.20 .39 1.43

alachlor .05 0 <.05 <.05 <.05 <.05 <.05

alachlor ESA .20 8 <.20 <.20 .64 2.99 3.26

alachlor OA .20 3 <.20 <.20 <.20 1.23 2.00

ametryn .05 0 <.05 <.05 <.05 <.05 <.05

atrazine .05 6 <.05 <.05 <.05 .22 .40

deethylatrazine .05 7 <.05 <.05 .05 .15 .39

deisopropylatrazine .05 4 <.05 <.05 <.05 .39 .85

hydroxy-atrazine .20 0 <.20 <.20 <.20 <.20 <.20

cyanazine .05 0 <.05 <.05 <.05 <.05 <.05

cyanazine-amide .05 2 <.05 <.05 <.05 .06 .14

metolachlor .05 4 <.05 <.05 <.05 .41 .43

metolachlor ESA .20 15 <.20 .66 1.17 3.05 3.77

metolachlor OA .20 7 <.20 <.20 .45 1.13 1.29

metribuzin .05 0 <.05 <.05 <.05 <.05 <.05

prometon .05 1 <.05 <.05 <.05 <.05 .16

prometryn .05 0 <.05 <.05 <.05 <.05 <.05

propachlor .05 0 <.05 <.05 <.05 <.05 <.05

propazine .05 0 <.05 <.05 <.05 <.05 <.05

simazine .05 0 <.05 <.05 <.05 <.05 <.05

terbutryn .05 0 <.05 <.05 <.05 <.05 <.05

Sum of 13 herbicides .05 7 <.05 <.05 .08 .47 .52

Sum of 10 degradates .05 18 <.05 1.18 3.64 7.62 9.52
110 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and outflow from

5 midwestern reservoirs

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; --, not analyzed; <, less than]

Site no.

(figs. 3,

4)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon

Illinois

1 Vermillion River below

Lake Vermillion

Dam, IL

06/10/98 SU–98 19.5 602 7.4 <0.02 0.042 0.389 11.06 0.084 0.079 --

07/16/98 SU–177 25.5 422 7.8 .076 .06 .465 6.26 .063 .062 --

2 Bonpas Creek at

Browns, IL

05/23/98 SU–43 20.5 178 6.4 .552 .081 1.392 2.05 .234 .024 --

07/07/98 SU–166 24.2 120 6.82 .028 .038 .533 1.36 .089 .084 --

3 Little Wabash River

at Carmi, IL

05/23/98 SU–33 20.0 177 6.4 .664 .069 1.285 1.06 .291 .269 --

07/09/98 SU–175 27.2 340 7.06 .088 .081 .734 1.66 .055 .051 --

4 S. Branch Kishwaukee

River near Fairdale, IL

05/20/98 SU–29 17.8 514 8.05 .509 .107 1.553 10.80 .151 .076 --

07/29/98 SU–195 23.4 835 8.0 <.02 .022 .338 4.34 .253 .211 --

5 Iroquois River near

Chebanse, IL

06/10/98 SU–99 17.8 645 7.5 <.02 .038 .509 9.91 .057 .044 --

07/08/98 SU–168 23.0 366 7.8 .054 .035 .545 6.49 .127 .125 --

6 Dupage River near

Shorewood, IL

06/09/98 SU–100 16.3 1,085 -- <.02 .029 .537 6.10 .957 .993 --

07/29/98 SU–194 26.0 1,045 8.52 <.02 <.01 .464 .82 1.097 <.01 --

7 Illinois River at

Marseilles, IL

06/12/98 SU–113 21.2 580 7.63 .15 .095 .601 5.16 .293 .309 --

07/09/98 SU–176 27.4 521 7.7 .041 .043 .55 5.34 .269 .242 --

8 Spoon River at

London Mills, IL

05/20/98 SU–25 18.9 541 7.64 .035 .08 .575 8.16 .086 .037 --

07/01/98 SU–160 22.5 578 7.89 .048 .05 .489 9.31 .099 .074 --

9 Sangamon River near

Monticello, IL

05/23/98 SU–35 16.3 436 7.54 .123 .051 .562 9.21 .097 .096 4.1

08/05/98 SU–201 23.0 486 7.8 .047 .013 .309 2.52 .081 .074 2.9

10 Sangamon River at

Riverton, IL

05/26/98 SU–44 21.0 484 7.58 .052 .122 .554 8.08 .151 .025 --

07/09/98 SU–174 25.7 479 7.56 .197 .055 .471 6.21 .180 .167 --

11 LaMoine River at

Colmar, IL

05/21/98 SU–27 20.0 376 7.58 .21 .102 .869 5.46 .099 .105 4.7

06/29/98 SU–142 24.3 251 7.44 .088 .063 .687 4.14 .132 .116 6.4

12 Illinois River at

Valley City, IL

06/18/98 SU–120 22.8 491 7.53 <.02 .088 .505 6.76 .157 .148 4.3

08/12/98 SU–207 28.4 630 7.66 .089 .056 .351 2.89 .313 .316 4.5

13 Mississippi River below

Grafton, IL

06/02/98 SU–60 23.3 522 7.92 .053 .197 .389 4.85 .118 .117 4.8

06/15/98 SU–116 21.8 495 8.13 .029 .098 .475 5.47 .167 .14 4.3

14 Kaskaskia River near

Cowden, IL

05/20/98 SU–30 17.5 505 7.9 .082 .123 .393 8.44 .034 .036 17.5

07/08/98 SU–169 23.2 418 7.65 .061 .101 .542 6.09 .071 .075 23.2

15 Shoal Creek near

Breese, IL

05/22/98 SU–32 20.0 301 7.1 .767 .137 1.547 2.28 .582 .601 --

07/08/98 SU–167 25.2 233 7.08 .295 .068 1.096 1.92 .392 .351 --

Iowa

16 Turkey River at

Spillville, IA

06/02/98 SU–64 25.5 515 7.8 .110 .068 .360 10.21 .031 .048 --

06/12/98 SU–109 15.8 482 7.43 .163 .067 .830 13.06 .164 .157 --
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 111

Iowa—Continued

17 Mississippi River at

Clinton, IA

05/27/98 SU–55 20.5 461 7.6 0.033 0.063 0.593 1.17 0.026 0.065 6.5

07/01/98 SU–155 25.7 440 7.4 <.02 .146 .468 2.80 .132 .141 5.0

18 Wapsipinicon River

near Tripoli, IA

05/27/98 SU–54 17.9 457 7.63 .081 .105 .593 14.46 .03 .014 2.7

06/20/98 SU–126 18.7 275 7.29 <.02 .072 .559 8.12 .092 .075 5.5

19 Wapsipinicon River at

Independence, IA

05/29/98 SU–56 20.5 406 7.5 .120 .087 .602 11.30 .093 .065 --

06/12/98 SU–110 19.0 272 7.26 .135 .05 .606 6.98 .167 .164 --

20 Iowa River near

Rowan, IA

06/02/98 SU–65 15.1 683 8.09 .063 .077 .536 11.80 .071 .069 3.7

06/23/98 SU–129 21.1 412 7.47 .022 .141 .867 9.71 .206 .169 5.4

21 Old Mans Creek near

Iowa City, IA

06/10/98 SU–93 14.6 494 7.6 .102 .09 .475 11.99 .146 .120 3.4

06/30/98 SU–147 19.7 363 7.2 .048 .10 .719 7.78 .102 .030 6.1

22 Wolf Creek near

Dysart, IA

06/10/98 SU–87 15.6 458 7.67 .073 .048 .429 14.10 .146 .131 3.0

06/22/98 SU–128 21.1 284 7.43 .038 .048 .426 7.34 .193 .186 3.8

23 Iowa River at

Wapello, IA

05/27/98 SU–53 20.2 500 8.42 .061 .047 .294 8.05 .049 .012 3.2

06/19/98 SU–127 19.8 489 7.66 .087 .062 .518 9.74 .152 .137 3.4

24 N. Skunk River near

Sigourney, IA

05/21/98 SU–21 19.0 391 7.3 .092 .096 .651 7.74 .107 .057 --

06/10/98 SU–95 15.2 405 7.74 .109 .076 .662 8.98 .078 .096 --

25 Skunk River at

Augusta, IA

05/26/98 SU–45 17.0 327 7.26 .15 .113 .840 7.91 .134 .044 18.

06/18/98 SU–122 20.4 385 7.55 .047 .071 .508 8.34 .136 .146 4.8

26 Des Moines River at

Fort Dodge, IA

05/16/98 SU–8 17.0 437 7.7 -- -- -- 8.52 -- -- --

06/12/98 SU–108 18.5 711 8.2 <.02 .025 .401 13.85 .085 .056 --

27 Raccoon River at

Van Meter, IA

05/17/98 SU–9 20.5 598 7.7 .112 .08 .542 11.95 .109 .106 --

06/10/98 SU–89 16.0 522 8.1 .062 .04 .405 11.15 .113 .067 --

28 Little Sioux River at

Correctionville, IA

05/27/98 SU–42 18.5 642 8.1 .053 .048 .362 8.45 .075 .059 --

06/18/98 SU–123 22.0 678 8.0 .028 .043 .434 12.25 .100 .101 --

29 Maple River at

Mapleton, IA

05/29/98 SU–59 21.5 514 7.7 .444 .109 1.078 8.80 .141 .152 --

06/09/98 SU–90 14.0 574 8.2 .164 .042 .723 8.10 .154 .151 --

30 Boyer River at Logan, IA 05/22/98 SU–31 15.5 471 7.6 .425 .097 .923 4.92 .186 .523 --

06/09/98 SU–96 14.0 384 7.7 .183 .041 .555 3.95 .128 .111 --

31 Chariton River below

Rathbun Lake

Dam, IA

06/04/98 SU–69 18.0 240 7.0 .073 .025 .451 .63 .015 .023 --

06/29/98 SU–148 20.8 234 7.28 .029 <.01 .377 .80 .021 .016 --

32 Nishnabotna River above

Hamburg, IA

06/04/98 SU–124 19.5 172 7.3 .07 .033 <.10 2.69 .056 .066 --

Table 27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and outflow from

5 midwestern reservoirs—Continued

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; --, not analyzed; <, less than]

Site no.

(figs. 3,

4)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon
112 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Indiana

33 Whitewater River near

Alpine, IN

05/26/98 SU–47 16.2 592 8.11 0.055 0.060 0.463 5.89 0.030 0.029 --

07/08/98 SU–162 23.5 428 7.94 .039 .024 .300 2.74 .058 .051 --

34 Blue River at

Fredericksburg, IN

05/27/98 SU–50 17.4 342 7.73 <.02 .023 .182 3.35 .073 .045 --

07/08/98 SU–163 21.6 289 7.45 .04 .024 .472 1.97 .115 .118 --

35 Mississinewa River

below Mississinewa

Lake Dam, IN

06/09/98 SU–83 18.7 444 8.10 .049 .013 <.10 .07 <.01 <.01 --

07/09/98 SU–164 23.3 340 7.38 .104 .197 .630 4.49 .141 .106 --

36 Eel River near

Logansport, IN

05/21/98 SU–18 20.8 550 7.91 Sample not analyzed --

06/30/98 SU–152 24.1 968 8.34 <.02 .045 .489 4.24 .050 .050 --

37 Wildcat Creek near

Jerome, IN

05/21/98 SU–19 17.9 524 7.79 .273 .119 -- 11.88 -- .057 --

06/30/98 SU–151 21.5 474 7.60 .029 .075 .579 10.05 .049 .027 --

38 Wildcat Creek near

Lafayette, IN

05/20/98 SU–22 21.4 651 8.28 .050 .035 .438 7.76 .172 .015 --

07/01/98 SU–150 22.5 509 8.03 .036 .031 .498 6.40 .128 .132 --

39 White River near

Nora, IN

05/28/98 SU–51 20.7 624. 8.04 .022 .055 .333 5.50 .076 .117 --

07/01/98 SU–149 24.7 607 7.97 <.02 .032 .517 5.32 .121 .118 --

40 Sugar Creek near

Edinburgh, IN

05/26/98 SU–46 17.6 521 7.95 .046 .075 .595 7.55 .072 .030 --

07/20/98 SU–178 23.2 242 7.57 .125 .040 .617 1.22 .118 .102 --

41 E. Fork White River

near Bedford, IN

05/28/98 SU–52 21.4 373 7.66 .027 .084 .572 4.03 .083 .085 --

07/06/98 SU–161 25.3 371 7.67 .072 .046 .425 2.57 .053 .057 --

42 Wabash River at New

Harmony, IN

05/27/98 SU–57 20.5 370 7.60 .087 .114 .429 3.55 .076 .066 4.2

06/23/98 SU–136 26.0 332 7.60 .021 .089 .474 4.47 .106 .119 4.4

Minnesota

43 Cottonwood River near

New Ulm, MN

05/26/98 SU–49 21.3 1,086 8.25 .058 .036 .533 9.43 <.01 <.01 --

07/21/98 SU–180 24.9 752 8.12 .024 .034 .438 3.68 .046 .04 --

44 Little Cobb River near

Beauford, MN

05/18/98 SU–12 19.5 655 7.94 .068 .127 .893 16.19 .103 .103 6.6

08/17/98 SU–208 25.8 549 7.97 .037 <.01 .886 <.05 .092 .084 8.5

45 Minnesota River near

Jordan, MN

05/19/98 SU–13 21.0 824 8.14 .046 .042 .537 9.64 .051 .040 5.3

06/26/98 SU–135 23.5 746 8.07 .024 .044 .771 10.47 .125 .129 5.4

46 Mississippi River at

Hastings, MN

05/20/98 SU–14 21.2 632 8.05 .128 .065 .983 3.33 .075 .065 7.2

05/20/98 SU–206 24.9 570 8.08 .066 .041 .641 1.03 .127 .127 8.0

47 Des Moines River at

Jackson, MN

05/26/98 SU–48 17.6 728 8.63 .053 .042 .561 3.47 <.01 <.01 --

08/24/98 SU–210 26.3 636 8.59 .085 .013 .733 <.05 .046 .042 --

48 Rock River at

Luverne, MN

06/24/98 SU–130 24.2 697 8.23 .037 .041 .359 2.98 .023 .027 --

06/25/98 SU–131 21.1 530 8.03 .236 .055 .732 2.78 .227 .137 --

Table 27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and outflow from

5 midwestern reservoirs—Continued

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; --, not analyzed; <, less than]

Site no.

(figs. 3,

4)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 113

Kansas

49 Black Vermillion River

at Frankfort, KS

05/05/98 SU–1 17.6 652 7.87 0.041 0.024 0.359 0.88 0.064 0.072 --

06/09/98 SU–107 17.3 504 7.84 .171 .092 .727 3.21 .147 .089 --

50 Big Blue River below

Tuttle Creek Lake

Dam, KS

06/03/98 SU–73 22.6 515 8.26 <.02 .037 .422 1.52 .140 .163 --

07/29/98 SU–197 27.6 395 8.26 <.02 .015 .341 .92 .084 .088 --

51 Delaware River near

Muscotah, KS

05/05/98 SU–2 22.2 579 8.32 .022 .019 .308 .80 .051 .042 --

06/10/98 SU–105 21.8 571 8.17 .045 .072 .431 1.93 .141 .086 --

Kentucky

52 Ohio River at Cannelton

Dam, KY

06/04/98 SU–75 23.4 335 7.3 .049 .058 .221 1.30 .053 .044 2.6

07/07/98 SU–173 24.4 231 7.0 .041 <.01 .248 1.07 .026 .023 4.0

Missouri

53 Nodaway River near

Graham, MO

06/18/98 SU–119 20.5 240 7.7 Sample not analyzed

08/19/98 SU–209 30.5 309 9.2 .063 <.01 .269 <.05 .022 .031 --

Nebraska

54 North Dry Creek near

Kearney, NE

05/22/98 SU–28 16.5 1,040 8.0 .763 .220 2.042 5.37 .627 .567 9.1

06/08/98 SU–76 15.5 1,040 7.9 .231 .223 .910 7.57 .539 .503 6.1

55 Maple Creek near

Nickerson, NE

05/21/98 SU–37 21.0 657 7.93 .402 .403 1.347 5.52 .261 .24 --

06/08/98 SU–79 14.0 405 7.74 .609 .144 1.630 4.46 .178 .15 --

56 Salt Creek at

Roca, NE

05/15/98 SU–6 19.0 452 7.75 .770 .083 1.963 4.98 .168 .141 --

06/10/98 SU–94 18.5 383 7.69 .251 .075 .848 4.87 .136 .108 --

57 Wahoo Creek at

Ithaca, NE

05/15/98 SU–5 19.0 420 7.10 .624 .078 1.326 3.19 .125 .056 --

06/08/98 SU–78 15.0 534 7.78 .303 .079 .646 3.48 .170 .153 --

58 Platte River at

Louisville, NE

05/22/98 SU–39 19.0 464 7.44 .555 .075 1.101 2.05 .042 .060 6.1

06/09/98 SU–77 15.5 440 7.92 .200 .061 .665 2.61 .129 .144 4.9

59 Big Nemaha River at

Falls City, NE

05/26/98 SU–41 21.0 620 -- <.02 .029 .302 2.05 .224 .224 --

06/08/98 SU–80 17.0 555 7.88 .491 .121 1.201 4.89 .204 .159 --

60 W. Fork Big Blue River,

Dorchester, NE

05/23/98 SU–36 19.0 417 7.22 .292 .172 1.008 4.20 .556 .541 --

06/10/98 SU–82 17.5 460 7.56 .164 .083 .619 3.88 .37 .37 --

61 Big Blue River at

Barneston, NE

05/15/98 SU–4 22.0 592 8.26 .056 .029 .387 .64 .161 .145 --

06/09/98 SU–104 18.5 543 7.90 .168 .078 .741 4.41 .369 .370 --

62 Little Blue River near

Fairbury, NE

05/12/98 SU–3 21.5 464 8.32 .042 <.01 .247 .63 .192 .190 --

06/08/98 SU–81 16.0 438 7.64 .151 .041 .428 1.60 .241 .254 --

Ohio

63 Clear Creek near

Rockbridge, OH

06/10/98 SU–86 18.6 395 8.3 .038 .019 .182 1.35 .057 .026 --

06/30/98 SU–145 21.1 420 7.8 <.02 .036 .446 5.30 .044 .040 --

Table 27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and outflow from

5 midwestern reservoirs—Continued

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; --, not analyzed; <, less than]

Site no.

(figs. 3,

4)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon
114 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Ohio—Continued

64 Scioto River near

Prospect, OH

06/02/98 SU–63 21.6 797 7.7 0.682 0.192 1.309 4.82 0.392 0.374 --

06/29/98 SU–141 23.0 392 7.2 .197 .107 1.043 7.87 .273 .166 --

65 Olentangy River at

Claridon, OH

06/09/98 SU–85 15.9 730 7.7 .062 .026 .373 1.23 .017 .046 --

06/29/98 SU–157 21.0 187 7.4 .101 .070 .791 3.76 .081 .068 --

66 Olentangy River below

Delaware, Lake

Dam, OH

06/09/98 SU–84 19.8 442 7.4 .307 .120 .727 2.30 <.01 <.01 --

06/29/98 SU–153 23.8 266 7.1 .219 .102 .873 4.89 .062 .055 --

67 Big Darby Creek at

Darbyville, OH

06/03/98 SU–62 20.4 750 8.2 .124 .067 .446 8.44 .122 .130 --

06/29/98 SU–140 21.8 106 7.4 .106 .027 .526 1.37 .161 .091 --

68 Scioto River at

Higby, OH

06/04/98 SU–73 20.8 574 8.3 .037 .038 .341 3.19 .069 .060 --

07/08/98 SU–165 24.0 490 8.0 .065 .029 .420 4.14 .068 .076 --

69 L. Miami River near

Oldtown, OH

06/10/98 SU–92 15.5 685 8.0 .028 .016 .168 4.36 <.01 .018 --

06/30/98 SU–144 20.8 679 8.3 <.02 .016 .211 4.77 .035 .037 --

70 Mad River at Eagle

City, OH

06/10/98 SU–91 14.4 727 8.1 .063 .038 .147 4.147 .041 .023 --

06/30/98 SU–146 17.9 664 8.0 <.02 .022 .267 4.098 .025 .018 --

71 Tiffin River at

Stryker, OH

06/01/98 SU–66 21.0 623 8.0 .135 .069 .573 1.89 .049 .048 --

07/07/98 SU–172 22.5 631 7.9 .064 .024 .418 1.12 .064 .067 -

72 Auglaize River at

Fort Jennings, OH

06/17/98 SU–117 20.0 597 7.9 .053 .093 .786 10.43 .111 .120 --

07/08/98 SU–171 23.0 534 7.8 .063 .021 .686 6.00 .126 .129 --

73 Root River at Racine, WI 06/01/98 SU–61 19.0 747 7.8 .096 .075 .814 2.27 .051 .015 --

08/03/98 SU–204 23.5 753 8.0 .121 .013 .647 .11 .124 .117 --

Wisconsin

74 St. Croix River at

St. Croix Falls, WI

06/03/98 SU–68 17.6 171 7.7 .060 .022 .336 .12 .034 .018 5.8

08/05/98 SU–205 22.5 191 7.9 .060 <.01 .439 .09 <.01 <.01 --

75 Wisconsin River at

Muscoda, WI

06/16/98 SU–133 20.5 237 8.4 .051 .010 .371 .18 .037 <.01 --

08/07/98 SU–202 21.5 298 7.6 .055 .015 .594 .56 .030 .051 --

76 Rock River at Afton, WI 06/17/98 SU–134 22.0 639 8.4 .047 .014 .706 .87 .062 .043 --

07/21/98 SU–179 27.0 549 8.6 .028 .025 .840 .69 .032 .035 --

Table 27. Concentrations of nutrients and field data for water samples from 71 midwestern streams and outflow from

5 midwestern reservoirs—Continued

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; --, not analyzed; <, less than]

Site no.

(figs. 3,

4)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 115

Table 29. Statistical summary of nutrient, field, and discharge data in water samples from five midwestern reservoir outflows

(the 95th percentile is not given as it is the same as the maximum)

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; N, nitrogen; P, phosphorus, C, carbon;

ft3/s, cubic feet per second; ND, no data; <, less than]

Parameter

Method

reporting

limit

(MRL)

Number of

samples

analyzed

Number at

or above

MRL

25th

percentile Median 75thpercentile Maximum

Water temperature (°C) 0.10 10 10 19.5 21.7 23.8 27.6

Specific conductance (μS/cm) 1.0 10 10 266 409 444 602

pH (standard units) .10 10 10 7.28 7.40 8.10 8.26

Ammonia as N (mg/L) .02 10 7 <.02 .061 .104 .307

Ammonia plus organic N (mg/L) .10 10 9 .377 .437 .630 .873

Organic N (mg/L)1 .10 10 9 .348 .389 .422 .654

Nitrite as N (mg/L) .01 10 9 .015 .040 .102 .197

Nitrite plus nitrate as N (mg/L) .05 10 10 .80 1.91 4.89 11.1

Nitrate as N (mg/L)2 .05 10 10 .80 1.83 4.79 11.0

Dissolved phosphorus as P (mg/L) .006 10 8 .015 .063 .084 .141

Orthophosphate as P (mg/L) .01 10 8 .016 .059 .088 .163

Dissolved organic carbon as C (mg/L) .33 0 ND ND ND ND ND

Daily mean discharge (ft3/s) .01 10 10 162 653 1,540 3,610

1

Calculated as ammonia plus organic N concentration minus ammonia concentration with non-detects set equal to zero.

2

Calculated as nitrite plus nitrate concentration minus nitrite concentration with non-detects set equal to zero.

Table 28. Statistical summary of nutrient, field, and discharge data in water samples from 71 midwestern streams

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; N, nitrogen; P, phosphorus, C, carbon;

ft3

/s, cubic feet per second]

Parameter

Method

reporting

limit

(MRL)

Number of

samples

analyzed

Number at

or above

MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

Water temperature (°C) 0.10 141 141 17.9 20.8 22.8 26.0 30.5

Specific conductance (μS/cm) 1.0 141 141 391 500 624 824 1,086

pH (standard units) .10 139 139 7.58 7.80 8.04 8.4 9.2

Ammonia as N (mg/L) .02 138 123 .038 .063 .135 .609 .770

Ammonia plus organic N (mg/L) .10 137 136 .425 .542 .732 1.35 2.04

Organic N (mg/L)1 .10 137 136 .336 .468 .575 .846 1.28

Nitrite as N (mg/L) .01 138 132 .032 .056 .084 .146 .403

Nitrite plus nitrate as N (mg/L) .05 139 136 2.05 4.47 8.08 12.0 16.2

Nitrate as N (mg/L)2 .05 139 136 .198 4.34 7.96 11.87 16.1

Dissolved phosphorus as P (mg/L) .006 137 133 .056 .107 .161 .392 1.10

Orthophosphate as P (mg/L) .01 138 133 .044 .084 .141 .374 .993

Dissolved organic carbon as C (mg/L) .33 37 37 4.0 4.8 6.1 9.1 18.0

Daily mean discharge (ft3/s) .01 141 141 268 1,070 5,030 56,600 267,000

1Calculated as ammonia plus organic N concentration minus ammonia concentration with non-detects set equal to zero.

2Calculated as nitrite plus nitrate concentration minus nitrite concentration with non-detects and missing values set equal to zero.
116 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 30. Concentrations of nutrients and field data for water samples from 25 midwestern wells

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; ND, no data; <, less than]

Site

no.

(fig. 5)

Site

name

Date of

collection

(month/

day/year)

Sample

no.

Water

temperature

(°C)

Specific

conductance

(μS/cm)

pH

(standard

units)

Concentration,

in milligrams per liter

Ammonia

as

nitrogen

Nitrite

as

nitrogen

Ammonia

and

organic

nitrogen

Nitrite

plus

nitrate

as

nitrogen

Phosphorus

(dissolved)

Orthophosphate

as

phosphorus

Dissolved

organic

carbon

Illinois

1 LUS1–4 05/19/98 SU–11 31.5 675 7.1 0.582 0.017 0.709 0.06 0.013 0.031 1.2

2 LUS1–14 05/18/98 SU–7 19.5 660 7.33 1.39 <.01 1.349 <.05 .024 .077 1.7

3 LUS1–26 06/18/98 SU–118 30.0 647 7.34 .056 .047 <.1 17.38 <.01 .015 .7

4 LUS2–9 06/15/98 SU–111 19.5 561 7.2 .032 <.01 <.1 7.77 .017 <.01 .6

5 LUS2–22 06/18/98 SU–121 21.8 786 7.05 .062 <.01 <.1 26.02 <.01 .018 .7

Iowa

6 Blockton 1 07/23/98 SU–184 13.5 1,770 7.87 2.7 ND 3.5 <.1 ND .400 ND

7 Fort Madison 4 07/22/98 SU–182 21.4 511 6.94 5.05 <.01 5.90 .05 .239 .317 ND

8 Shambaugh 3 07/24/98 SU–186 11.0 473 6.53 <.1 ND .2 <.1 ND .300 ND

9 Nodaway 4 07/23/98 SU–185 11.5 577 6.91 <.1 ND .2 1.10 ND <.1 ND

10 Silver City 3 07/31/98 SU–198 11.5 982 7.37 .261 <.01 .281 <.05 <.01 .015 ND

11 Carson (5), 3 07/31/98 SU–200 11.0 742 7.19 .060 <.01 <.1 1.33 <.01 .011 ND

12 Cumberland 1 07/27/98 SU–188 13.5 350 7.03 <.02 <.01 <.1 .08 <.01 .012 ND

13 Fontanelle 5 07/23/98 SU–183 11.5 675 7.05 .600 ND .8 <.1 ND .500 ND

14 Menlo 3 07/29/98 SU–193 10.5 490 7.34 .02 <.01 <.1 5.49 .164 .175 ND

15 Carlisle 5 07/27/98 SU–187 12.0 600 7.36 <.02 <.01 <.1 .78 <.01 .015 ND

16 Newton 13 06/03/98 SU–71 10.4 692 7.06 <.02 .017 <.1 7.90 .103 .109 ND

17 Belle Plaine 4 06/02/98 SU–70 11.2 624 11.1 .340 1.081 .494 5.15 .036 .340 ND

18 Cedar Rapids S6 08/25/98 SU–211 17.1 514 7.14 .212 .047 .291 3.09 .049 .062 ND

19 Vail 1 06/23/98 SU–137 12.5 899 7.0 .020 <.01 <.1 6.45 .112 .121 ND

20 Marshalltown 8 06/02/98 SU–72 10.7 737 7.28 1.323 <.01 1.507 <.05 .047 .077 ND

21 Boone 20 07/28/98 SU–190 11.5 761 7.33 <.02 .031 .16 5.30 .078 .100 ND

22 Boxholm 2 07/25/98 SU–189 11.0 1,067 7.35 1.621 <.01 1.672 <.05 .151 .025 ND

23 Holstein 3 06/25/98 SU–139 10.5 735 7.07 .025 .012 <.1 7.20 .074 .082 ND

24 Kingsley 1 06/25/98 SU–138 10.0 884 7.02 .024 <.01 <.1 9.44 .128 .135 ND

25 Sheffield 2 07/29/98 SU–192 12.0 583 7.44 <.02 <.01 <.1 11.56 <.01 <.023 ND
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 117

Table 31. Statistical summary of nutrient and field data in water samples from 25 midwestern wells

[°C, degrees Celsius; μS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter; N, nitrogen; P, phosphorus, C, carbon; ft3/s,

cubic feet per second; <, less than]

Parameter

Method

reporting limit

(MRL)

Number of

samples

analyzed

Number at

or above

MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

Water temperature (°C) 0.10 25 25 11.0 11.5 17.1 30.0 31.5

Specific conductance (μS/cm) 1.0 25 25 577 675 761 1,067 1,770

pH (standard units) .10 25 25 7.05 7.19 7.34 7.87 11.1

Ammonia as N (mg/L) .02 25 18 <.02 .056 .582 2.70 5.05

Ammonia plus organic N (mg/L) .10 25 13 <.10 .160 .709 3.50 5.90

Organic N (mg/L)1 .10 25 13 <.10 <.10 0.16 .80 .85

Nitrite as N (mg/L) .01 21 7 <.01 <.01 .017 .047 1.08

Nitrite plus nitrate as N (mg/L) .05 25 18 <.05 1.33 7.20 17.4 26.0

Nitrate as N (mg/L)2 .05 25 18 .05 1.33 7.19 17.3 26.0

Dissolved phosphorus as P (mg/L) .006 21 14 <.006 .036 .103 .164 .239

Orthophosphate as P (mg/L) .01 25 22 .015 .077 .135 .40 .50

Dissolved organic carbon as C (mg/L) .33 5 5 .7 .7 1.2 1.7 1.7

1Calculated as ammonia plus organic N concentration minus ammonia concentration with non-detects set equal to zero.

2Calculated as nitrite plus nitrate concentration minus nitrite concentration with non-detects and missing values set equal to zero.

Table 32. Statistical summary of selected herbicide concentrations and discharge in pre-emergence and post-emergence

water samples from midwestern streams and reservoir outflows (concentration in μg/L)

[<, less than]

Herbicide Number of

samples

Number

above MRL

25th

percentile Median 75thpercentile

95th

percentile Maximum

flumetsulam pre-emergence 72 37 <0.010 0.011 0.049 0.127 0.358

flumetsulam post-emergence 69 55 .013 .032 .062 .169 .220

imazethapyr pre-emergence 72 44 <.010 .019 .056 .134 .689

imazethapyr post-emergence 69 53 .014 .045 .097 .236 .407

nicosulfuron pre-emergence 72 19 <.010 <.010 .010 .065 .266

nicosulfuron post-emergence 69 55 .012 .028 .059 .132 .161

acetochlor pre-emergence 70 69 .22 .80 2.80 15.6 25.1

acetochlor post-emergence 74 69 .05 .20 .49 1.42 2.26

atrazine pre-emergence 70 70 .54 .32 15.1 48.1 224

atrazine post-emergence 74 74 .70 2.97 5.96 12.6 37.6

metolachlor pre-emergence 70 70 .29 1.70 4.05 17.7 143

metolachlor post-emergence 74 73 .37 1.33 2.89 7.16 14.7

Discharge,

in cubic feet per second

pre-emergence 75 75 210 883 4,220 56,600 172,000

post-emergence 76 76 360 1,235 4,795 101,000 267,000
118 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

Table 33. Median of differences between post-emergence and pre-emergence concentrations of selected herbicides and

Wilcoxon signed-rank test results (differences in micrograms per liter)

[<, less than]

Herbicide Number

of pairs

Median of paired

differences between

post- and pre-emergence

concentrations

Wilcoxon signed-rank test results

Rank p value Accept alternate

hypothesis?

flumetsulam 65 0.016 442 <0.001 yes

imazethapyr 65 .017 334 .005 yes

nicosulfuron 65 .023 598 <.001 yes

acetochlor 70 –.42 –870 <.001 yes

atrazine 70 –.66 –573 .001 yes

metolachlor 70 –.14 –360 .032 yes

Discharge,

in cubic feet per second

discharge 75 82 341 .07 no

1,000

100

10

1.0

0.1

0.01

0.001 0.01 0.10 1.0 10

IMAZETHAPYR CONCENTRATION,

IN MICROGRAMS PER LITER

ATRAZINE CONCENTRATION, IN MICROGRAMS PER LITER

Pre-emergence

Post-emergence

A

0.001 0.01 0.10 1.0 10

FLUMETSULAM CONCENTRATION,

IN MICROGRAMS PER LITER

B

1:1,000

1:100

1:10

1:1,000

1:100

1:10

0.001 0.01 0.10 1.0 10

NICOSULFURON CONCENTRATION,

IN MICROGRAMS PER LITER

C

1:1,000

1:100

1:10

EXPLANATION

Figure 22. Concentrations of atrazine in samples collected from midwestern streams and reservoir outflows in relation to:

(A) imazethapyr, (B) flumetsulam, and (C) nicosulfuron.
SULFONYLUREA, SULFONAMIDE, AND IMIDAZOLINONE HERBICIDES RELATIVE TO ATRAZINE AND METOLACHLOR 119

Metolachlor

to atrazine

10/1 1/10 1/1,000 1/100,000

Pre-emergence

Post-emergence

Nicosulfuron to

metolachlor

Nicosulfuron

to atrazine

Flumetsulam to

metolachlor

Flumetsulam

to atrazine

Imazethapyr to

metolachlor

Imazethapyr

to atrazine

CONCENTRATION RATIOS

EXPLANATION

SU, SA, and IMI herbicide concentrations

were expected to be smaller relative to atrazine and

metolachlor concentrations in the pre-emergence

samples than the post-emergence samples because

the majority of atrazine and metolachlor is applied

before crops emerge, and the majority of the SU,

SA, and IMI herbicides are applied after crops

emerge. In 68 pre-emergence stream and reservoir

outflow samples, the median imazethapyr, flumetsulam, and nicosulfuron to atrazine concentration

ratios were 1:157, 1:173, and 1:315, respectively. In

68 post-emergence stream and reservoir outflow

samples, the median imazethapyr, flumetsulam, and

nicosulfuron to atrazine concentration ratios were

1:50, 1:75, and 1:68, respectively. In all cases, the

medians of the ratios of these three compounds to

metolachlor concentrations were less than the

medians of ratios to atrazine concentration. This

was expected as the median atrazine to metolachlor

ratios was 2.6:1 for pre-emergence samples and

2.4:1 for post-emergence samples. The distributions

of imazethapyr, flumetsulam, and nicosulfuron to

atrazine and metolachlor ratios from pre- and postemergence stream and reservoir outflow samples

are shown in figure 24.

Figure 24. Ratios of imazethapyr, flumetsulam, and

nicosulfuron concentrations to atrazine and metolachlor concentrations in pre- and post-emergence

stream and reservoir outflow samples.

1,000

100

10

1.0

0.1

0.01

0.001 0.01 0.10 1.0 10

IMAZETHAPYR CONCENTRATION,

IN MICROGRAMS PER LITER

METOLACHLOR CONCENTRATION, IN MICROGRAMS PER LITER

Pre-emergence

Post-emergence

A

0.001 0.01 0.10 1.0 10

FLUMETSULAM CONCENTRATION,

IN MICROGRAMS PER LITER

1:1,000

1:100

1:10

1:1,000

1:100

1:10

0.001 0.01 0.10 1.0 10

NICOSULFURON CONCENTRATION,

IN MICROGRAMS PER LITER

B C

1:1,000

1:100

1:10

EXPLANATION

Figure 23. Concentrations of metolachlor in samples collected from midwestern streams and reservoir outflows in

relation to: (A) imazethapyr, (B) flumetsulam, and (C) nicosulfuron.
120 Concentration of Selected Sulfonylurea, Sulfonamide, and Imidazolinone Herbicides, Other Pesticides, and

Nutrients in 71 Streams, 5 Reservoir Outflows, and 25 Wells in the Midwestern United States, 1998

CONCLUSIONS

Sulfonylurea (SU), sulfonamide (SA), and

imidazolinone (IMI) herbicides were detected in

samples of both surface water and ground water from

across the Midwestern United States. The frequency

of detection and concentrations of SU, SA, and IMI

herbicides were generally larger in streams and reservoir outflows than in ground-water samples. At least

1 of the 16 SUs, SAs or IMIs was detected at or above

the method reporting limit (MRL) of 0.01 μg/L in 111

of 133 stream samples, 6 of 8 reservoir samples, and 5

of 25 ground-water samples. In stream and reservoir

samples, the frequency of detection and concentrations

of SU, SA, and IMI herbicides were larger in postemergence samples than in pre-emergence samples.

SU, SA, and IMI herbicides were detected less

frequently and at substantially lower concentrations

than other herbicides like atrazine and metolachlor

that are applied in greater total amounts.

The observed ranges and maximum concentrations of SU, SA, and IMI herbicides in samples

collected from midwestern streams during postapplication runoff events in 1998 were very close to

what was expected. The majority of SU, SA, and IMI

detections were at concentrations less than 0.1 μg/L.

These concentrations are not likely to be toxic to nontarget aquatic plants or humans, but they do add to the

overall burden of pesticides carried by midwestern

streams. The maximum concentrations of SU, SA, and

IMI herbicide in samples collected from midwestern

ground water in 1998 were slightly higher than

expected.

Several other pesticides, particularly triazine

and chloroacetanilide herbicides, occurred more

frequently and at higher concentrations than did the

SU, SA, and IMI herbicides. In streams and reservoir

outflows, the SU, SA, and IMI herbicides generally

occurred 1/50th or less of the concentrations of atrazine and metolachlor. The ratios of imazethapyr,

flumetsulam, and nicosulfuron concentrations to atrazine and metolachlor concentrations were larger in

pre-emergence samples (when atrazine and metolachlor concentrations tended to be higher) than in

post-emergence samples.

 The results and interpretations presented here

are limited by the quantity of samples that have been

analyzed for SU, SA, and IMI herbicides. The data

that are available are lacking, mostly due to the low

frequency of sample collection and resulting limited

temporal distribution of results. More frequent

sampling at selected sites is required to determine if

herbicides are present at other times of the year and to

determine annual mean concentrations and fluxes of

SU, SA, and IMI herbicides in midwestern streams.

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USGS/WRIR 00–4225

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