Water-Quality Assessment of Part of the 

Upper Mississippi River Basin, Minnesota 

and Wisconsin—Organochlorine Compounds 

in Streambed Sediment and Fish Tissues, 

1995-97

		 

!""#$	%	

!""&
'
Water-Quality Assessment of Part of the 

Upper Mississippi River Basin, Minnesota 

and Wisconsin—Organochlorine Compounds 

in Streambed Sediments and Fish Tissues, 

1995-97

By R.P. McNellis, J.D. Fallon, and K.E. Lee

Water-Resources Investigations Report 00-4213

Contribution from the National Water-Quality Assessment Program
U.S. DEPARTMENT OF THE INTERIOR

Gale A. Norton, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director

Use of brand names in this report is for identification purposes only and does not 

constitute endorsement by the U.S. Geological Survey.

Mound View, Minnesota, 2001

For additional information write to:

U.S. Geological Survey

District Chief

2280 Woodale Drive

Mounds View, MN 55112

Copies of this report can be purchased from:

U.S. Geological Survey

Branch of Information Services

Box 25286, MS 517

Federal Center

Denver, CO 80225

Information regarding the National Water-Quality Assessment (NAWQA) Program is available on the Internet via the World Wide Web. 

You may connect to the NAWQA Home Page using the Universal Resource Locator (URL) at:

URL: http://wwwrvares.er.usgs.gov/nawqa/nawqa_home.html

Information about the Upper Mississippi River Basin Project of the NAWQA Program is available at:

URL: http://mn.water.usgs.gov/umis/index.html

Water-Resources Investigations Report 00-4213
4

Foreword

The mission of the U.S. Geological Survey (USGS) is 

to assess the quantity and quality of the earth resources 

of the Nation and to provide information that will assist 

resource managers and policy makers at Federal, State, 

and local levels in making sound decisions. Assessment 

of water-quality conditions and trends is an important 

part of this overall mission.

One of the greatest challenges faced by waterresources scientists is acquiring reliable information that 

will guide the use and protection of the Nation’s water 

resources. That challenge is being addressed by Federal, 

State, interstate, and local water-resource agencies and 

by many academic institutions. These organizations are 

collecting water-quality data for a host of purposes that 

include: compliance with permits and water-supply 

standards; development of remediation plans for a 

specific contamination problem; operational decisions 

on industrial, wastewater, or water-supply facilities; and 

research on factors that affect water quality. An 

additional need for water-quality information is to 

provide a basis on which regional and national-level 

policy decisions can be based. Wise decisions must be 

based on sound information. As a society we need to 

know whether certain types of water-quality problems 

are isolated or ubiquitous, whether there are significant 

differences in conditions among regions, whether the 

conditions are changing over time, and why these 

conditions change from place to place and over time. 

The information can be used to help determine the 

efficacy of existing water-quality policies and to help 

analysts determine the need for and likely consequences 

of new policies.

To address these needs, the Congress appropriated 

funds in 1986 for the USGS to begin a pilot program in 

seven project areas to develop and refine the National 

Water-Quality Assessment (NAWQA) Program. In 

1991, the USGS began full implementation of the 

program. The NAWQA Program builds upon an 

existing base of water-quality studies of the USGS, as 

well as those of other Federal, State, and local agencies. 

The objectives of the NAWQA Program are to:

• Describe current water-quality conditions for a large 

part of the Nation’s freshwater streams, rivers, and 

aquifers.

• Describe how water quality is changing over time.

• Improve understanding of the primary natural and 

human factors that affect water-quality conditions.

This information will help support the development 

and evaluation of management, regulatory, and 

monitoring decisions by other Federal, State, and local 

agencies to protect, use, and enhance water resources.

The goals of the NAWQA Program are being 

achieved through ongoing and proposed investigations 

of 51 of the Nation’s most important river basins and 

aquifer systems, which are referred to as study units. 

These study units are distributed throughout the Nation 

and cover a diversity of hydrogeologic settings. More 

than two-thirds of the Nation’s freshwater use occurs 

within the 51 study units and more than two-thirds of 

the people served by public water-supply systems live 

within their boundaries.

National synthesis of data analysis, based on 

aggregation of comparable information obtained from 

the study units, is a major component of the program. 

This effort focuses on selected water-quality topics 

using nationally consistent information. Comparative 

studies will explain differences and similarities in 

observed water-quality conditions among study areas 

and will identify changes and trends and their causes. 

The first topics addressed by the national synthesis are 

pesticides, nutrients, volatile organic compounds, and 

aquatic biology. Discussions on these and other waterquality topics will be published in periodic summaries 

of the quality of the Nation’s ground and surface water 

as the information becomes available.

This report is an element of the comprehensive body 

of information developed as part of the NAWQA 

Program. The program depends heavily on the advice, 

cooperation, and information from many Federal, State, 

interstate, Tribal, and local agencies and the public. The 

assistance and suggestions of all are greatly appreciated.

Robert M. Hirsch

Chief Hydrologist
5
6

CONTENTS

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

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

Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Organochlorine compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Streambed sediment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Fish tissue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Comparison between streambed sediment and fish tissues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Comparison to national guidelines and other NAWQA data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

ILLUSTRATIONS

Figure 1. Maps showing location of streambed sediment and fish tissue sampling sites in the Upper Mississippi River Basin

study unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Figures 2-5. Graphs showing:

2. Organochlorine concentrations in streambed sediment and fish tissue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

3. Concentrations of p,p’-DDT and metabolites in streambed sediment, and comparison to national percentile

 concentrations of total DDT based on 1991–94 NAWQA study unit data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

4. Detected concentrations of total polychlorinated biphenyls in fish tissue and streambed sediment, and comparison

 to national percentile concentrations of total DDT based on 1991–94 NAWQA study unit data . . . . . . . . . . . . . . . . . . . . .8

5. Concentrations of p,p’-DDT and metabolites in fish tissues, and comparison to national percentile

 concentrations of total DDT based on 1991–94 NAWQA study unit data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

TABLES

Table 1. Sites at which streambed sediment and fish tissue were sampled in the Upper Mississippi River Basin 

study unit 1995–97. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

 2. Organochlorine compounds analyzed and method reporting limits in streambed sediment and fish tissue samples

collected in the Upper Mississippi River Basin study unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

 3. Fish species obtained in the study unit for analysis of organochlorine compounds in the Upper Mississippi River 

Basin study unit 1995–97 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

CONVERSION FACTORS AND ABBREVIATED WATER QUALITY UNITS

Multiply by to obtain

inch (in.) 2.54 centimeter

square mile (mi2

) 2.590 square kilometer

ounce (oz.) 28.35 gram

Concentrations of constituents in streambed sediment and fish tissues are given in micrograms per kilogram. A microgram is one-millionth of a gram. A gram is one-thousandth of a kilogram.
7
1

Water-Quality Assessment of Part of the 

Upper Mississippi River Basin, Minnesota

and Wisconsin—Organochlorine Compounds

in Streambed Sediments and Fish Tissues, 

1995–97

by R.P. McNellis, J.D. Fallon, and K.E. Lee

ABSTRACT

Streambed sediments and fish tissues were collected in part of the Upper Mississippi River Basin to assess the presence and 

distribution of organochlorine compounds (OCs) including PCBs. A total of 13 OCs were detected among 14 of 27 streambed sediment 

sampling locations. In fish tissues analyzed, 9 OCs were detected among 17 of 24 sites sampled. Eight OCs were detected in both fish 

and streambed sediment samples, they were: cis-chlordane, o,p’-DDD; p,p’-DDD; p,p’-DDE; p,p’-DDT; hexachlorobenzene; transnonachlor; and PCBs. The most frequently detected OCs were: p,p’-DDE; and p,p’-DDD in streambed sediment and p,p’-DDE and 

PCBs in fish tissues. No OCs were detected in streambed sediment at agricultural sites; however, the agricultural sites had 17 detections 

of OCs in fish tissue. Urban streams had concentrations of total DDT and metabolites in streambed sediment that exceed guidelines for 

classification of sites with high probabilities of adverse effects to aquatic organisms. Total DDT was the only OC within an urban land 

use that exceeded guidelines for piscivorous wildlife 

INTRODUCTION

In 1994, the U.S. Geological 

Survey’s (USGS) National Water-Quality 

Assessment (NAWQA) Program began 

studies in part of the Upper Mississippi 

River Basin (UMIS) located in Minnesota 

and Wisconsin (fig.1). Goals of the 

NAWQA Program are to document the 

quality of surface and ground water 

throughout the Nation and to explain 

natural and anthropogenic factors 

affecting water quality and trends over 

time. A specific objective of the UMIS 

NAWQA study was to determine the 

presence and distribution of 

organochlorine compounds in streambed 

sediment and fish tissues among the 

major land use settings of the UMIS study 

unit.

Organochlorine compounds 

(including polychlorinated biphenyls), 

hereinafter referred to as OCs, are 

hydrophobic compounds that are 

persistent in the environment because 

they are resistant to rapid decomposition. 

OCs tend to be sorbed to sediments and 

are transported and deposited with 

sediments. OCs such as p,p’-DDT and

polychlorinated biphenyls (PCBs) were 

widely used pesticides and industrial 

products from the 1940’s into the 1970’s 

when their use was discontinued (Larson 

and others, 1997). Several others, such as 

the insecticide endosulfan I, are still used 

today in agriculture. OCs were frequently 

used as pesticides in agricultural and 

urban areas, but generally had fewer 

applications in forested environments. 

OC use may have been most intense in 

urban areas due to frequent p,p’-DDT 

applications for mosquito control and 

industrial uses of PCBs as high 

temperature lubricants and insulators. 

Atmospheric deposition and 

sediment resuspension continue to 

recirculate OCs to water and biota. OCs 

are a concern because they can 

bioaccumulate in fish tissue and because 

some pose health risks to the 

environment, such as thinning of bald 

eagle egg shells (U.S. Environmental 

Protection Agency, 1992). Several OCs 

are probable carcinogens in humans (U.S. 

Environmental Protection Agency, 1996) 

and exposure to these OCs could occur 

from eating contaminated fish. The 

Minnesota Department of Health (1999) 

has issued fish consumption advisories 

based upon the PCB concentrations in 

fillets and the frequency with which fish 

are included in an individual’s diet. Fish 

and streambed sediment samples in the 

UMIS study unit were analyzed for OCs 

as part of the NAWQA Program. This 

report presents the results of those 

analyses.

The types and concentrations of OCs 

used in the UMIS study unit may relate to 

land use. Therefore, the data analyzed 

were categorized by land use to give a 

general perspective of where OCs may be 

prevalent and thus might have a 

significant effect to the health of humans 

and the environment. The land uses in the 

UMIS consist of an agricultural zone 

across the southwestern one-third of the 

study unit; a forested zone across the 

northeastern one-third of the study unit; 

and a transitional zone in between (fig. 1). 

Urban land use accounts for about 2 

percent of the study unit and is 

concentrated around the Twin Cities 

metropolitan area (TCMA) (Stark and 

others, 1999). 
2

45°

44°

46°

47°

95°

96°

97°

94° 93°

92°

91°

Lake Pepin

St. Croi x

Ri v e r

M i is s si si p e p i R v rM i is

s si si p

e

p i R

v

r

M i is s si si p e p i R v r

Minnesota River

S hi n gl e

Cre e k

MINNESOTA

WISCONSIN

NORTH

DAKOTA

SOUTH

DAKOTA

IOWA

Base from

U.S. Geological

Survey digital data

1:2,000,000, 1972,

1:100,000, 1990, Albers

Equal-Area Conic projection.

Standard parallels: 29°30' and

45°30', central meridian: -93°00'

0 25 50 75 Miles

0 25 50 75 Kilometers

EXPLANATION

Figure 1.--Location of streambed sediment and fish tissue sampling sites in the Upper Mississippi River Basin study unit.

A1

M1

F1

U1

M9

Upper Mississippi River

study unit

MINNESOTA

WISCONSIN

Twin Cities

metropolitan

area (TCMA)

Water

Agriculture

Mixed agriculture

and forest

Boundary of the Twin Cities metropolitan area (TCMA)

Agricultural site

Mixed land use site

Forest site

Urban site

Streambed sediment and fish tissue sampling

site. Letter/number identifier corresponds to site on table1

Mixed land use with streambed

sediment sampling site only - no Forest fish tissue sampling.

Urban

Generalized land use and

land cover modified

from Hitt, 1994

Bloomington

Minneapolis

F1

F7

M1

A3 M2

M3

A1

F2

A2

F6

M6

F3

F4

F5

U5

M9

M7

M8

A6

M5

A5

A4

U2

U1

U3

M4

U4
3

METHODS

Streambed sediment and fish tissues 

were collected once from 27 and 24 sites, 

respectively, during low flow conditions 

(July–November) from 1995 through 

1997 (fig. 1, table 1). Sites were selected 

within the major land uses in the basin 

and along major tributaries to the 

Mississippi River. Sites were selected to 

maximize the probability of OC 

detections within the major land use 

settings of the UMIS (Stark and others, 

1999). At a subset of sites, more than one 

sediment or fish sample was collected to 

assess variability (table 3). Percentages of 

land use (forested and wetland, 

agricultural, urban, water, or other, which 

includes rangeland) were computed for 

basins upstream of each site. Streams 

were classified by the predominant land 

use of each basin. Streams were classified 

as forested if they drained greater than or 

equal to 65 percent forests and wetlands; 

agricultural if they drained greater than 80 

percent agricultural area, urban if they 

were located in the TCMA and drained 

greater than 15 percent urban area, and 

mixed if they fell between these 

categories. Additional characteristics of 

stream sites sampled in this investigation 

are given in Stark and others (1999).

At each site approximately the upper 

1 inch of recently deposited streambed 

sediment was collected from 5 to 10 

depositional areas near both banks and the 

center of the stream using methods 

described by Shelton and Capel (1994). A 

composite was made from these 

subsamples and passed through a 2 μm 

(micrometer) stainless steel sieve to 

obtain a sand or finer grained 

representative sample of depositional 

streambed sediment at each site. 

Streambed sediment composites were 

analyzed for 32 OCs (table 2) by gas 

chromatography with electron-capture 

detection (Foreman and others, 1995) at 

the USGS National Water Quality 

Laboratory in Arvada, Colo. 

Common carp, white sucker, 

shorthead redhorse and golden redhorse 

were collected, depending on availability 

at each site (table 3). These species feed 

on invertebrates and detritus on the 

stream bottom. Bottom feeders were 

chosen because OCs sorb to sediments, 

and because detritivores are likely to be 

exposed to OCs through ingestion of 

contaminated sediment. Five to 10 fish of 

a single species were collected at each site 

with electrofishing equipment. Efforts 

were made to collect similarly aged adult 

fish for each site, but this was not always 

possible. At selected sites 2 species were 

collected, composited, and analyzed 

separately to assess interspecies 

variability (table 3). At site A6 a duplicate 

sample of common carp was collected to 

assess intraspecies variability. Whole fish 

tissues were analyzed at the U.S. 

Geological Survey’s National Water 

Quality Laboratory in Arvada, Colo. At 

the laboratory, fish from each respective 

site were composited into a single sample 

for analysis. Whole fish composites were 

analyzed for 28 OCs (table 2) by dual 

capillary-column gas chromatography 

with electron-capture detection that is 

described in detail by Leiker and others 

(1995). 

Method reporting limits varied 

between streambed sediment and fish 

tissue and among the different OCs (table 

2). Constituents with concentrations 

below the method reporting limit were 

considered to have no detections or 

concentrations of zero. Streambed 

sediment and fish tissue data from sites 

with multiple samples were averaged and 

considered to be one sample.

ORGANOCHLORINE 

COMPOUNDS

Streambed Sediment

Thirteen OCs were detected in 

streambed sediment (four were p,p’-DDT 

and it’s metabolites) at one or more sites 

(fig. 2). Fourteen of 27 sites had one or 

more detections of OCs. The most 

frequently detected OCs were p, p’-DDD, 

p, p’-DDE, and p, p’-DDT. The 

concentrations of all OCs ranged from 0.3 

to 133.3 micrograms per kilogram (μg/

kg) (fig. 2).

The types and concentrations of OCs 

in streambed sediment varied by land use. 

Forest sites had five total detections of 

three compounds, which were p,p’-DDE, 

p,p’-DDD, and endosulfan I (fig. 2). 

Endosulfan I was found in the St. Croix 

and Namakegon Rivers. Endosulfan I is 

an insecticide used to control a variety of 

pests of small fruit and vegetable crops, 

which are commonly grown in the St. 

Croix River Basin.

There were no detections of OCs in 

streambed sediment at any of the 

agricultural land use sites (fig. 2), 

indicating that OCs were used less 

frequently or in lower amounts than in 

urban streams. 

The mixed land use sites had 9 

detections of 4 compounds (fig. 2). In 

order of highest frequency they were: 

p,p’-DDD, p,p’-DDE, PCBs, and 

endosulfan I. The mixed land use sites 

can be characterized generally as large 

river sites that are located within or 

downstream of the TCMA. The two 

detections of PCBs in the mixed land use 

were both in the upstream portions of 

Lake Pepin on the Mississippi River. 

Lake Pepin is a natural river 

impoundment downstream of the TCMA 

that is a depositional area for fine-grained 

sediments. Similar to results reported by 

Fallon and others (1997), most OC 

detections were found within or 

downstream of the TCMA, suggesting 

that the TCMA is a major source of those 

compounds.

Twelve of the 13 OCs were found in 

at least one urban site with the exception 

being endosulfan I. Historically, urban 

areas have had high OC use, mainly p,p’-

DDT for insect control and PCBs for 

industrial applications. All of the urban 

streams had detections of p,p’-DDT and 

the degradation compounds p,p’-DDE and

p,p’-DDD (fig. 3) indicating high or 

frequent p,p’-DDT use in the past. One 

urban stream sampled had detections of 

total PCB concentrations greater than the 

method reporting limit of 50 μg/kg (U2, 

Shingle Creek at Queen Avenue in 

Minneapolis) (fig. 4). 

Fish Tissue

Nine OCs were detected in fish tissue 

(four were p,p’-DDT and it’s metabolite)

(fig. 2). Seventeen of 24 sites had at least 

one OC detection (fig. 5). The most 

frequently detected was p,p’-DDE, which 

was detected at 17 sites. Total PCBs were 

the next most frequently detected OC 

with detections at 13 sites. Concentrations 

of all OCs ranged from 2.6 to 680 μg/kg 

(fig. 2). 

The types and concentrations of OCs 
4

Table 1. Sites at which streambed sediment and fish tissue were sampled in the Upper Mississippi River Basin study u

[Letters in map identifier refer to land use: A, agricultural; F, forest; M, mixed; U, urban. USGS, U.S. Geological Survey; ns, not sampled; mi2, square miles; land use m

Map 

identifier 

(figure 1)

USGS site 

identifier Site name Latitude Longitude

Sampling date 

Sediment Fish Urban 

A1 05270380 Sauk River at Richmond, Minn. 45°26′56" 94°31′30" 7/20/95 7/19/95 0.9 A2 05276005 North Fork Crow River above Paynesville, Minn. 45°22′38" 94°47′00" 7/17/95

9/19/96

9/16/96 0.3 

A3 05280400 Crow River below State Highway 101 at Dayton, Minn. 45°13′20" 93°31′12" 7/24/95 7/18/95 1.4 A4 05320270 Little Cobb River near Beauford, Minn. 43°59′48" 93°54′30" 8/2/95

9/18/96

7/9/97 0.2 

A5 05330000 Minnesota River near Jordan, Minn. 44°41′35" 93°38′30" 7/11/95 7/10/95 0.9 A6 05355090 Cannon River at Lake Byllesby near Cannon Falls, Minn. 44°30′35" 92°57′00" 7/21/95 7/17/95 3.1 F1 05211000 Mississippi River at Grand Rapids, Minn. 47°13′56" 93°31′48" 7/25/95 7/24/95 0.4 F2 05263500 Mississippi River below Little Falls, Minn. 45°56′22" 94°23′20" 7/24/95 7/20/95 0.6 F3 05331833 Namekagon River at Leonards, Wisc. 46°10′18" 91°19′50" 7/19/95 7/25/95 0.7 F4 05331873 Namekagon River above Spring Lake Creek near Hayward, Wisc. 45°59′22" 91°30′33" 9/17/96 10/26/96 1.4 F5 05333500 St. Croix River near Danbury, Wisc. 46°04′28" 92°14′50" 7/19/95 9/27/95 0.3 F6 05336180 Kettle River near Kettle River, Minn. 46°29′03" 92°53′19" 8/1/95 9/27/95 0.0 F7 05339770 St. Croix River near Sunrise, Minn. 45°34′14" 92°52′30" 7/20/95 7/14/95 0.4 M1 05286290 Cedar Creek near Coopers Corner, Minn. 45°23′31" 93°12′44" 9/16/96 10/4/96 0.1 M2 05287000 Rum River at Anoka, Minn. 45°11′54" 93°23′28" 7/21/95 7/21/95 0.7 M3 05288500 Mississippi River near Anoka, Minn. 45°07′36" 93°17′48" 7/13/95 7/18/95 1.1 M4 05288730 Mississippi River at 28th Ave. NE in Minneapolis, Minn. 45°01′12" 93°16′31" 9/27/96 ns 1.7 M5 05331570 Mississippi River at Nininger, Minn. 44°46′22" 92°54′07" 7/12/95 7/11/95 2.5 M6 05341552 St. Croix River at Hudson, Wisc. 44°58′57" 92°46′07" 7/14/95 7/14/95 0.7 M7 442633092130801 Mississippi River in Lake Pepin near Lake City, Minn. 44°26′33" 92°13′08" 7/28/95 ns 2.3 M8 442912092174201 Mississippi River in Lake Pepin near Central Point, Minn. 44°29′12" 92°17′42" 7/28/95 7/13/95 2.3 M9 443334092205201 Mississippi River in Lake Pepin near Frontenac, Minn. 44°33′34" 92°20′52" 7/28/95 ns 2.3 U1 05288695 Shingle Creek at Zane Ave. at Brooklyn Park, Minn. 45°05′31" 93°21′23" 9/27/96 9/19/96 57 U2 05288705 Shingle Creek at Queen Ave. in Minneapolis, Minn. 45°03′00" 93°18′36" 9/26/96 9/17/96 71 U3 05288710 Shingle Creek at 46th Street in Minneapolis, Minn. 45°02′18" 93°17′47" 7/18/95 8/28/95 79 U4 05330902 Nine Mile Creek near James Circle at Bloomington, Minn. 44°48′26" 93°18′05" 7/18/95 7/26/95 87 U5 05345000 Vermillion River near Empire, Minn. 44°40′00" 93°03′17" 7/18/95 7/12/95 16 
5

1 The method reporting limit for this constituent varied among the samples

2 There was no tissue analysis for this constituent at Namakegon River above Spring Lake Creek 

near Hayward, Wisconsin.

Table 2. Organochlorine compounds analyzed and method reporting limits in streambed 

sediment and fish tissue samples collected in the Upper Mississippi River Basin study unit

 [μg/kg, micrograms per kilogram]

Constituent

Method reporting limit

Stream bed 

sediments 

(μg/kg)

Fish tissue 

(μg/kg)

Aldrin 1 5

cis-chlordane 1 1

5 - 11

trans-chlordane 1 15 - 10

Chloroneb 5 Not analyzed 

Dacthal 5 1

5 - 20

o,p’-DDD 1

1 - 3.4 15 - 45

p,p’-DDD 1

1 - 2 15 - 50

o,p’-DDE 1 15 - 10

p,p’-DDE 1 5

o,p’-DDT 12 - 4 15 - 25

p,p’-DDT 2 1

5 - 25

Dieldrin 1

1 - 3.2 15 - 11

Endosulfan I 1 Not analyzed 

Endrin 2 15 - 10

Heptachlor 1 5

Heptachlor epoxide 1 15 - 20

Hexachlorobenzene 2 11 - 50 5

α-hexachlorocyclohexane (α-HCH) 1 15 - 15

β-hexachlorocyclohexane (β-HCH) 2 11 - 1.2 1

5 - 30

δ-hexachlorocyclohexane (δ-HCH) Not analyzed 15 - 18

Isodrin 1 Not analyzed 

Lindane (γ-HCH) 1 15 - 20

o,p’-methoxychlor 1

5 - 39 15 - 10

p,p’-methoxychlor 15 - 5.2 15 - 25

Mirex 1 15 - 10

cis-nonachlor 1 15 - 10

trans-nonachlor 1 1

5 - 10

Oxychlordane 1 15 - 15

PCBs, total 50 50

Pentachloroanisole 1

1 - 50 15 - 25

cis-permethrin 1

5 - 15 Not analyzed 

trans-permethrin 15 - 44 Not analyzed 

Toxaphene 200 1

200 - 2,100

in fish tissue varied by land use. The 

forest sites had fewer detections than the 

other land uses (fig. 2), probably 

attributable to fewer potential sources in 

forested areas. There were three 

detections of p,p’-DDE and one detection 

of PCBs at forested sites. Concentrations 

of OCs also were lower at forested than 

at sites in other land uses. In contrast, 

agricultural sites had the most types of 

OCs (eight) detected in fish tissue (fig. 

2). The most frequent detections at 

agricultural sites was p,p’-DDE. PCBs 

and p,p’-DDE accounted for most of the 

OC detections in fish tissue at the mixed 

land use sites (fig. 2). At urban sites, 

seven OCs were detected in fish tissue. 

Four of the OCs detected at urban sites 

were p,p’-DDT and degradation 

products; the other three were total 

PCBs, cis-chlordane, and transnonachlor. Although DDT and 

degradation products were detected in 

fish tissue samples in all four land uses, 

the concentrations at the urban sites 

generally were greater than those of the 

other land uses (figs. 2 and 5). Urban 

areas may have had longer exposure to 

OCs, which would allow more time for 

bioaccumulation in fish, and urban areas 

may have received larger amounts of 

OCs (particularly p,p’-DDT and PCBs), 

which would allow for more OCs to be 

assimilated by fish.

OC concentrations in fish tissue tend 

to increase in a downstream direction on 

the Mississippi River. PCB 

concentrations in fish tissue were less 

than 50 μg/kg (not detected) at the 

Mississippi River at Grand Rapids and 

typically increased in a downstream 

direction in the Mississippi River to the 

outlet of the study unit at Lake Pepin 

where they were 680 μg/kg. This 

observation is consistent with the 

findings of Lee and Anderson (1998) 

who reported increased concentrations of 

total PCBs below the TCMA between 

1975 and 1995. Lee and Anderson 

(1998) also noted that areas with 

historically high levels of total PCBs in 

streambed sediment tend to have higher 

concentrations of total PCBs in fish 

tissue, which agrees with the findings at 

site M9, Mississippi River in Lake Pepin 

near Central Point, Minn.
6

Table 3. Fish species obtained in the study unit for analysis of organochlorine compounds in the Upper Mississippi River Basin study unit, 

1995–97

 [Map identifier corresponds to site shown in figure 1; na, not available]

Map 

identifier Site name Fish species (common name)

Average total 

length 

(inches)

Average 

weight

(ounces)

A1 Sauk River at Richmond, Minn. Golden redhorse 16.8 34.5

A2 North Fork Crow River above Paynesville, Minn. Common carp 9.7 6.1

A3 Crow River below State Highway 101 at Dayton, Minn. Shorthead redhorse 17.9 38.8

A4 Little Cobb River near Beauford, Minn. Common carp 17.7 45.9

A5 Minnesota River near Jordan, Minn. Common carp 14.6 25.4

A6 Cannon River at Lake Byllesby near Cannon Falls, Minn. Common carp 13.9 22.3

A6 Cannon River at Lake Byllesby near Cannon Falls, Minn. Common carp 13.6 19.6

F1 Mississippi River at Grand Rapids, Minn. White sucker 14.8 20.8

F2 Mississippi River below Little Falls, Minn. Shorthead redhorse 14.5 19.7

F3 Namekagon River at Leonards, Wisc. White sucker 8.5 3.87

F4 Namekagon River above Spring Lake Creek near Hayward, Wisc. White sucker 6.1 1.4

F5 St. Croix River near Danbury, Wisc. Shorthead redhorse 15.5 21.3

F5 St. Croix River near Danbury, Wisc. Golden redhorse 15.1 21.9

F6 Kettle River near Kettle River, Minn. White sucker 5.9 1.31

F7 St. Croix River near Sunrise, Minn. Shorthead redhorse 12.9 13.4

M1 Cedar Creek near Coopers Corner, Minn. White sucker 10.2 6.4

M2 Rum River at Anoka, Minn. Common carp 19.0 54.7

M3 Mississippi River near Anoka, Minn. Common carp 16.9 36.7

M4 Mississippi River at 28th Ave. NE in Minneapolis, Minn. bed sediment only na na

M5 Mississippi River at Nininger, Minn. Common carp 15.7 30.1

M6 St. Croix River at Hudson, Wisc. Common carp 16.5 35.5

M7 Mississippi River in Lake Pepin near Lake City, Minn. bed sediment only na na

M8 Mississippi River in Lake Pepin near Central Point, Minn. Common carp 17.6 44.0

M9 Mississippi River in Lake Pepin near Frontenac, Minn. bed sediment only na na

U1 Shingle Creek at Zane Ave. at Brooklyn Park, Minn. White sucker 11 9.1

U2 Shingle Creek at Queen Ave. in Minneapolis, Minn. White sucker 9 4.6

U2 Shingle Creek at Queen Ave. in Minneapolis, Minn. Common carp 6.7 2.7

U3 Shingle Creek at 46th Street in Minneapolis, Minn. White sucker 7.8 2.8

U4 Nine Mile Creek near James Circle at Bloomington, Minn. White sucker 7.7 3.1

U5 Vermillion River near Empire, Minn. White sucker 8.9 3.8

Comparison Between 

Streambed Sediment and Fish 

Tissues

Eight compounds were found in both 

streambed sediment and fish tissue; they 

were cis-chlordane, o,p’-DDD, p,p’-DDD, 

p,p’-DDE, p,p’-DDT, hexachlorobenzene, 

trans-nonachlor, and PCBs (fig. 2). The 

concentrations of PCBs and total DDT in 

fish tissues were greater than most 

concentrations in streambed sediment. 

However, OCs weren’t necessarily found 

in both streambed sediment and fish tissue 

at the same site. For instance, at 

agricultural sites, there were no OC 

detections in streambed sediment, whereas 

there were 17 detections of OCs in fish 

tissue. This demonstrates that fish tissue is 

an important type of sample when 

determining the distribution and presence 

of OCs. The lack of OCs in streambed 

sediment at agricultural sites may indicate 

that OCs were not used in the same 

manner as in urban areas and(or) that OCs 

(particularly p,p’-DDT metabolites and 

PCBs) don’t persist in streambed sediment 

as in fish tissue. Also, capping, which 

occurs when sediment is deposited on top 

of the existing surface of a streambed, 

may bury contaminants in streambed 

sediment. Capping in agricultural areas 

could occur frequently due to the 

susceptibility of farm fields to erosion. 

Analyzing a streambed core as opposed to 

surficial sediments, may yield OC 

detections from older layers of sediments 

in the agricultural areas.
7

Figure 2.--Organochlorine concentrations in streambed sediment and fish tissue.

CONCENTRATION, IN MICROGRAMS PER KILOGRAM

1,000

100

10

1

2 1 2 99 6 2 5 1 4 1 1 1 3 17 2 13 1 2 3 6 2

0.1

ORGANOCHLORINE COMPOUND

NUMBER OF DETECTIONS BY COMPOUND

STREAMBED SEDIMENT STREAMBED SEDIMENT EXPLANATION

Agricultural site

Mixed land use site

Forest site

Urban site

Sample

cis

trans

o,p'

p.p'

p,p'

p,p'

cis

trans

-chlordane

-chlordane

-DDD

-DDD

-DDE

-DDT

Endosulfan I

Heptachlor epoxide

Hexachlorobenzene

-nonachlor

-nonachlor

Oxychlordane

Total PCBs

cis

o,p'

p.p'

p,p'

p,p'

trans

-chlordane

-DDD

-DDD

-DDE

-DDT

Dieldrin

Hexachlorobenzene

-nonachlor

Total PCBs

FISH TISSUE

Comparison to National 

Guidelines and Other NAWQA 

Data

There are few guidelines for 

streambed sediment to indicate at what 

concentration OCs may cause 

environmental harm. The U.S. 

Environmental Protection Agency 

(USEPA) (1997) developed a procedure 

to estimate the probability of adverse 

effects to aquatic life from contaminated 

sediment at sampling sites based on 

available sediment quality guidelines 

from multiple agencies. Nowell and 

others (1999) summarized the USEPA 

(1997) guidelines to evaluate studies and 

included additional sediment guidelines 

from other sources. Nowell and others 

(1999) guidelines that are applicable to 

data in this study include: total chlordane 

(the sum of cis-chlordane, and transchlordane), 6 μg/kg; total DDT (sum of 

all DDT metabolites), 46.1 μg/kg; p,p’-

DDD, 8.51 μg/kg; p,p’-DDE, 15 μg/kg; 

p,p’-DDT, 7 μg/kg; and total PCBs, 189 

μg/kg. Any site with concentrations 

exceeding these values would be 

categorized as having a high probability 

to affect aquatic life. The only sites with 

concentrations above these guidelines 

were located within the TCMA. Shingle 

Creek at Queen Avenue in Minneapolis 

had total chlordane detections as high as 

26 μg/kg. The total DDT and metabolite 

DDT guidelines were exceeded at various 

urban sites (fig. 3).

Fish consumption guidelines for 

edible portions were exceeded in some 

samples. These guidelines for edible 

portions were compared to concentrations 

in whole fish. The USEPA (1995) has set 
8

a guideline of 10 μg/kg for PCB 

concentrations in edible fish tissue with 

reference to a 70-kg adult eating 6.5 

grams of fish per day for a 70-year life 

span. At least 13 sites exceeded this 

consumption guideline for PCBs in whole

fish (fig. 4)—the guideline is five times 

lower than the method reporting limit 

used for analysis herein, thus some sites 

with concentrations below the method 

reporting limit may have also exceeded 

this consumption guidelines in whole

fish. 

The Minnesota Department of Health 

(MDH) has also issued advisories 

concerning the consumption of fish with 

PCB contamination. The advisories 

issued suggest how often fish are safe to 

eat based on the analysis of the skin-on 

fillet of the fish species in question. 

Concentrations in whole fish were less 

than MDH guidelines for unlimited 

consumption (50 μg/kg) at 11 sites, most 

of which were forest streams. Fish at nine 

sites were in the category of one meal per 

week (50 μg/kg–200 μg/kg), and four 

sites were in the category of one meal per 

month (200 μg/kg–1,000 μg/kg) (Patricia 

McCann, Minnesota Department of 

Health, written commun., 1999).

The New York State Department of 

Environmental Conservation (NYSDEC) 

(Newell and others, 1987) has guidelines 

190 Agricultural sites Mixed land use sites Forest sites Urban sites

Figure 3.--Concentrations of '-DDT and metabolites in streambed sediment, and comparison to national percentile

concentrations of total DDT based on 1991-94 NAWQA study unit data.

p,p

CONCENTRATION, IN

MICROGRAMS PER KILOGRAM 140

160

150

National 90th percentile for total DDT

National 50th percentile for total DDT

170

180

60

50

70

40

SAMPLING SITE (Fig. 1, Table 1)

30

20

10

0

Constituent

p,p'-DDT

p,p'-DDE

p,p'-DDD

o,p'-DDD

EXPLANATION

A1

A2

A3

A4

A5

A6

M1

M2

M3

M4

M5

M6

M7

M8

M9

F1

F2

F3

F4

F5

F6

F7

U1

U2

U3

U4

U5

500

Figure 4.--Detected concentrations of total polychlorinated biphenyls in fish tissue and streambed sediment, and comparison

to national percentile of concentrations based on 1991-94 NAWQA study unit data.

CONCENTRATION, IN

MICROGRAMS PER KILOGRAM

1,000

700

300

National 90th percentile for

streambed sediment

National 90th percentile for

fish tissue

400

900

800

600

100

200

0

Fish tissue

Streambed sediment

EXPLANATION

The national 50th percentiles

for streambed sediment are 0

micrograms per kilogram.

The national 50th percentile for fish

tissue data is 0 micrograms per

kilogram.

No fish tissue data

No fish tissue data

No fish tissue data

SAMPLING SITE (Fig. 1, Table 1)

A1

A2

A3

A4

A5

A6

M1

M2

M3

M4

M5

M6

M7

M8

M9

F1

F2

F3

F4

F5

F6

F7

U1

U2

U3

U4

U5

Agricultural sites Mixed land use sites Forest sites Urban sites
9

for piscivorous wildlife (mink, otters, 

etc.). The total DDT guideline from 

NYSDEC was exceeded only once with a 

total concentration of 248 μg/kg in whole 

fish, (guideline is 200 μg/kg in whole 

fish) at Nine Mile Creek near James 

Circle at Bloomington, Minn. (U4). 

NYSDEC guidelines for total PCB 

concentrations were exceeded at five sites 

(guideline is 110 μg/kg in whole fish) 

with regard to picscivorous wildlife; four 

of these exceedances were at urban or 

mainstem river sites. 

Comparisons were made between the 

UMIS NAWQA data and data from 20 

NAWQA study units that were collected 

during 1991–93 across the nation. Only 

total p,p’-DDT and total PCB 

concentrations for streambed sediment 

and fish tissue data were compared. Three 

urban sites within the TCMA exceeded 

the national 90th percentile for total DDT 

concentrations (fig. 3) in streambed 

sediments. One site exceeded the 90th

percentile for total PCBs in streambed 

sediments (fig. 4). In fish tissues, no sites 

exceeded the 90th percentile fot DDT and 

it’s metabolites; however, 12 sites were 

greater than the 50th percentile for total 

DDT (fig. 5). Total PCB concentrations in 

fish tissue were greater than the 90th 

percentile at one site, and greater than the 

50th percentile at 13 sites (fig. 4).

500

CONCENTRATION, IN

MICROGRAMS PER KILOGRAM 250

350

300

400

450

150

100

200

50

0

National 90th percentile for total DDT

National 50th percentile for total DDT

Agricultural sites Mixed land use sites Forest sites Urban sites

SAMPLING SITE (Fig. 1, Table 1)

Constituent

p,p'-DDT

p,p'-DDE

p,p'-DDD

o,p'-DDD

EXPLANATION

A1

A2

A3

A4

A5

A6

M1

M2

M3

M4

M5

M6

M7

M8

M9

F1

F2

F3

F4

F5

F6

F7

U1

U2

U3

U4

U5

Figure 5.--Concentrations of '-DDT and metabolites in fish tissue, and comparison to national percentile

concentrations of total DDT based on 1991-94 NAWQA study unit data.

p,p

No Data

No Data

No Data

0

SUMMARY

In 1994, the U.S. Geological Survey’s (USGS) National 

Water-Quality Assessment (NAWQA) Program began studies in 

part of the Upper Mississippi River Basin (UMIS) located in 

Minnesota and Wisconsin. Streambed sediments and fish tissues 

were collected in the UMIS to assess the presence and 

distribution of organochlorine compounds (OCs) and PCBs. The 

types and concentrations of OCs used in the UMIS study unit 

may relate to land use. Therefore, the data analyzed were 

categorized by land use to give a general perspective of where 

OCs may be prevalent and thus might have a significant effect to 

the health of humans and the environment. 

A total of 13 OCs were detected among 14 of 27 streambed 

sediment sampling locations. The types and concentrations of 

OCs in streambed sediment varied by land use. Forest sites had 

five total detections of three compounds. There were no 

detections of OCs in streambed sediment at any of the 

agricultural land use sites. The mixed land use sites had 9 

detections of 4 compounds. Twelve of the 13 OCs were found in 

at least one urban site. 

In fish tissues analyzed, 9 OCs were detected among 17 of 

24 sites sampled. The types and concentrations of OCs in fish 

tissue varied by land use. The forest sites had fewer detections 

than the other land uses. In contrast, agricultural sites had the 

most types of OCs (eight) detected in fish tissue. At urban sites, 

seven OCs were detected in fish tissue. OC concentrations in fish 

tissue tend to increase in a downstream direction on the 

Mississippi River. 

 Eight OCs were detected in both fish and streambed 

sediment samples, they were: cis-chlordane, o,p’-DDD, p,p’-

DDD, p,p’-DDE, p,p’-DDT, hexachlorobenzene, transnonachlor, and PCBs. The most frequently detected OCs were 

p,p’-DDE, and p,p’-DDD in streambed sediment and p,p’-DDE 

and PCBs in fish tissues. Although no OCs were detected in 

streambed sediment at agricultural sites, there were 17 detections 

of organochlorines in fish tissue. Urban streams had 

concentrations of total DDT and metabolites in streambed 

sediment that exceed guidelines for classification of sites with 

high probabilities of adverse effects to aquatic organisms. Total 

DDT was the only OC within an urban land use that exceeded 

guidelines for piscivorous wildlife. 
10

REFERENCES

Fallon, J.D., Fong, A.L., and Andrews, 

W.J., 1997, Water-quality assessment of part of the Upper Mississippi River Basin, Minnesota and 

Wisconsin—Pesticides in streams, 

streambed sediment, and groundwater, 1974-94: U.S. Geological 

Survey Water-Resources Investigation Report 97-4141, 53 p.

Foreman, W.T., Connor, B.F., Furlong, 

E.T., Vaught, D.G., and Merten, 

L.M., 1995, Methods of analysis 

by the U.S. Geological Survey 

National Water Quality Laboratory—Determination of organochlorine pesticides and 

polychlorinated biphenyls in bottom sediment by dual capillarycolumn gas chromatography with 

electron-capture detection: U.S. 

Geological Survey Open-File 

Report 95-140, 78 p.

Larson, S.J., Capel, P.D., and Majewski, 

M.S., 1997, Pesticides in surface 

waters—Distributions, trends and 

governing factors: Chelsea, Mich., 

Ann Arbor Press, 373 p.

Lee, K.E., and Anderson, J.P., 1998, 

Water-quality assessment of the 

Upper Mississippi River Basin, 

Minnesota and Wisconsin—Polychlorinated biphenyls in common 

carp and walleye fillets, 1975-95: 

U.S. Geological Survey WaterResources Investigation Report 98-

4126, 27 p.

Leiker, T. J., Madsen, J. E., Deacon, J.R., 

Foreman, W.T., 1995, Methods of 

analysis by the U.S. Geological 

Survey National

Water Quality Laboratory—Determination of chlorinated pesticides 

in aquatic tissue by capillary-column gas chromatography with 

electron-capture detection: U.S. 

Geological Survey Open-File 

Report 94-710, 42 p.

Minnesota Department of Health, 1999, 

Minnesota Fish Consumption 

Advisory: Division of Environmental Health, St. Paul, Minnesota, 96 p.

Newell, A.J., Johnson, D.W., and Allen, 

L.K., 1987, Niagra River Biota 

Contamination Project—Fish flesh 

criteria for piscivorous wildlife: 

New York State Department of 

Environmental Conservation, Division of Fish and Wildlife, Bureau 

of Environmental Protection, 

Technical Report 87-3, 182 p.

Nowell, L.H., Capel, P.D., and Dileanis, 

P.D., 1999, Pesticides in stream 

sediment and aquatic biota—Distribution, trends, and governing 

factors: Boca Raton, Fla., CRC 

Press LLC, 1001 p.

Nowell, L.H. and Resek, E.A., 1994, 

National standards and guidelines 

for pesticides in water, sediment, 

and aquatic organisms—Application to water-quality assessments: 

Rev. Environmental Contaminant 

Toxicology, v. 140 p. 1-164.

Shelton, L.R. and Capel, P.D., 1994 

Guidelines for collecting and processing samples of stream bed sediment for analysis of trace 

elements and organic contaminants 

for the National Water-Quality 

Assessment Program: U.S. Geological Survey Open-File Report 

94-458, 20 p.

Stark, J.R., Fallon, J.D., Fong, A.L., 

Goldstein, R.M., Hanson, P.E., 

Kroening, S.E., and Lee, K.E., 

1999, Water-quality assessment of 

part of the Upper Mississippi River 

Basin, Minnesota and Wisconsin—

Design and implementation of 

water-quality studies, 1995-98: 

U.S. Geological Survey WaterResources Investigation Report 99-

4135, 85 p.

U.S. Environmental Protection Agency, 

1992, National study of chemical 

residues in fish, Volume II: U.S. 

Environmental Protection Agency, 

EPA 823-R-92-008b, variously 

paged.

——1995, Guidance for assessing chemical contaminant data for use in fish 

advisories, Volume I, Fish sampling and analysis, 2d: Office of 

Water, EPA 823-R-95-007, September 1995.

——1996, Drinking water regulations 

and health advisories: U.S. Environmental Protection Agency, 

Office of Water, EPA 822-B-96-

002, October 1996, 11 p.

——1997, National sediment quality survey, Volume I. The incidence and 

severity of sediment contamination 

in surface waters of the United 

States: U.S. Environmental Protection Agency, Office of Science and 

Technology, EPA 823-R-97-006, 

variously paged.