U.S. Department of the Interior

U.S. Geological Survey

Prepared in cooperation with

U.S. Environmental Protection Agency

Concentrations and Loads of Cadmium, Zinc

and Lead in the Main Stem Coeur d’Alene Riv

Idaho—March, June, September, and Octobe

1999

Open-File Report 01–34

This report has not been reviewed for conformity with U.S. Geological Survey editorial standards. 
Concentrations and Loads of Cadmium, Zinc

and Lead in the Main Stem Coeur d’Alene Riv

Idaho—March, June, September, and October 

1999

By Paul F. Woods

Open-File Report 01–34

Prepared in cooperation with

U.S. Environmental Protection Agency

Boise, Idaho

2001
U.S. DEPARTMENT OF THE INTERIOR

GALE A. NORTON, Secretary

U.S. GEOLOGICAL SURVEY

Charles G. Groat, Director 

Any use of firm, trade, and brand names in this report is for

identification purposes only and does not constitute 

endorsement by the U.S. Government.

Additional information can be obtained from:

District Chief

U.S. Geological Survey

230 Collins Road

Boise, ID 83702-4520

http://idaho.usgs.gov

This report is available online in PDF for

http://idaho.usgs.gov/public/reports.html

and can be viewed using Adobe Acrobat 

Reader. The URL is:
iii

CONTENTS

Abstract ............................................................................................................................................................

Introduction ......................................................................................................................................................

Description of study area..................................................................................................................................

Approach ..........................................................................................................................................................

Sampling design.........................................................................................................................................

Locations of data-collection stations .........................................................................................................

Collection of discharge data ......................................................................................................................

Collection and analysis of water-quality data............................................................................................

Calculation of loads ...................................................................................................................................

Spatial and temporal patterns in trace elements ...............................................................................................

Cadmium concentrations and loads...........................................................................................................

Zinc concentrations and loads ...................................................................................................................

Lead concentrations and loads...................................................................................................................

Exchange of trace elements between river and flood plain..............................................................................

References cited ...............................................................................................................................................

FIGURES

1. Map showing locations of seven water-quality stations monitored for trace-element transport 

during March, June, September, and October 1999, main stem Coeur d’Alene River, Idaho............

2–14. Graphs showing:

2. Variation in river or lake stage between October 1998 and October 1999 at four U.S. 

Geological Survey stations in the Coeur d’Alene River Basin, Idaho .......................................

3. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999 ........................

4. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999 ...........................

5. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, September 21–22, 1999 .........

6. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, October 19–20, 1999..............

7. Instantaneous values for discharges and concentrations and loads of zinc at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999 ........................

8. Instantaneous values for discharges and concentrations and loads of zinc at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999 ...........................

9. Instantaneous values for discharges and concentrations and loads of zinc at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, September 21–22, 1999..........

10. Instantaneous values for discharges and concentrations and loads of zinc at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, October 19–20, 1999..............

11. Instantaneous values for discharges and concentrations and loads of lead at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999 ........................

12. Instantaneous values for discharges and concentrations and loads of lead at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999 ...........................

13. Instantaneous values for discharges and concentrations and loads of lead at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, September 21–22, 1999..........
iv

14. Instantaneous values for discharges and concentrations and loads of lead at seven water-quali

stations on the main stem Coeur d’Alene River, Idaho, October 19–20, 1999..........................

TABLES

1. Identification numbers and names of seven U.S. Geological Survey water-quality stations 

monitored during March, June, September, and October 1999 on the main stem Coeur d’Alene 

River, Idaho .........................................................................................................................................

2. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on March 9, 1999,

at six water-quality stations on the Coeur d’Alene River and one lake station near the mouth of

the Coeur d’Alene River, Idaho...........................................................................................................

3. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on June 8, 1999,

at six water-quality stations on the Coeur d’Alene River and one lake station near the mouth of

the Coeur d’Alene River, Idaho...........................................................................................................

4. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on September 21–22

1999, at six water-quality stations on the Coeur d’Alene River and one lake station near the mouth

of the Coeur d’Alene River, Idaho ......................................................................................................

5. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on October 19–20, 

1999, at six water-quality stations on the Coeur d’Alene River and one lake station near the mouth 

of the Coeur d’Alene River, Idaho ......................................................................................................

CONVERSION FACTORS AND OTHER ABBREVIATED UNITS

Multiply By To obtain

cubic foot per second (ft3/s) 0.02832 cubic meter per second

cubic yard (yd3) 0.7645 cubic meter

foot (ft) 0.3048 meter

foot per second (ft/s) 0.3048 meter per second

mile (mi) 1.609 kilometer

pound (lb) 0.4536 kilogram

pound per day (lb/d) 0.4536 kilogram per day

square mile (mi2) 2.590 square kilometer

Other abbreviated units:

L . . . . . . . . . . liter

μg/L. . . . . . . . microgram per liter

μm . . . . . . . . . micrometer

mg/L . . . . . . . milligram per liter

mm . . . . . . . . millimeter
1

Abstract

The Remedial Investigation/Feasibility Study 

conducted by the U.S. Environmental Protection 

Agency within the Spokane River Basin of northern Idaho and eastern Washington included extensive data-collection activities in numerous studies 

to determine the nature and extent of trace-element 

contamination within the basin. The objective of 

this particular study was to improve our understanding of the effects of different river discharges 

and lake levels of Coeur d’Alene Lake on the 

transport of cadmium, zinc, and lead within the 

main stem Coeur d’Alene River. In particular, 

water-quality data and loads during a broad range 

of hydrologic conditions were examined to determine if the river channel, flood plain, and associated ground water along the main stem Coeur 

d’Alene River acted as sources or sinks of trace 

elements. Water-quality samples were collected 

at six riverine stations and one lake station along 

a 35-mile reach during March, June, September, 

and October of 1999. Samples were analyzed for 

whole-water recoverable, filtered (0.45 micrometer), and dissolved (0.01 micrometer) concentrations of cadmium, zinc, and lead.

Concentrations and loads of cadmium and 

zinc measured during the four sampling trips were 

predominately in the filtered and dissolved fraction, rather than particulate. The smallest concentrations were measured during the June sampling 

trip when flows were high and snowmelt runoff 

diluted riverine concentrations. Conversely, the 

largest concentrations were measured during the 

latter two sampling trips when flows were low because a larger proportion of the river’s discharge 

was contributed by ground-water inflow. Du

each sampling trip, cadmium and zinc conc

tions generally decreased in a downstream d

tion, even as discharge increased in a down

direction.

Spatial and temporal trends exhibited b

concentrations and loads during the four sam

trips were different from those of cadmium 

zinc because of the propensity for lead to ad

sediment particles. Whole-water recoverabl

concentrations and loads during the four sam

trips were predominantly in the particulate 

tion, with filtered and dissolved concentratio

loads composing a much smaller proportion 

recoverable fraction compared to cadmium 

zinc. Filtered lead concentrations generally 

creased at a faster rate in the downstream di

than dissolved lead concentrations; thus, co

lead either was being formed by complexat

reactions or being added by sediment erosio

the downstream direction.

INTRODUCTION

Mining and ore-processing activities condu

since the late 1880s in the South Fork Coeur d’

River Basin have produced extensive deposits o

element-contaminated sediments throughout th

Fork Coeur d’Alene River valley and its tributa

the channel and flood plain of the main stem Co

d’Alene River, and the lakebed of Coeur d’Alen

Snowmelt runoff and occasional floods continu

transport and redistribute trace-element-contam

sediments throughout the 6,680-mi2 Spokane R

Basin of northern Idaho and eastern Washington 

back of report). 

Concentrations and Loads of Cadmium, Zinc

and Lead in the Main Stem Coeur d’Alene Riv

Idaho—March, June, September, and October 

1999

By Paul F. Woods
2

The U.S. Environmental Protection Agency (EPA) 

has recently (1998) initiated a Remedial Investigation/Feasibility Study (RI/FS) of the Spokane River 

Basin under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act 

(CERCLA) of 1980, which requires EPA to evaluate 

contaminant release, fate, and transport. The Remedial 

Investigation (RI) phase involves data collection to 

characterize site conditions, development of conceptual 

models, determination of the nature and extent of traceelement contamination, and risk assessment for human 

health and the environment. The RI phase is followed 

by the Feasibility Study (FS) phase where remedial 

action alternatives are developed and evaluated. In 

March of 1998, the U.S. Geological Survey (USGS) 

was requested by EPA to collect data characterizing 

hydrology and water quality in support of the RI/FS of 

the Spokane River Basin. The study described in this 

report was conducted by the USGS as Task 7 (Evaluation of suspended and bedload sediment transport 

within the Coeur d’Alene River Basin and affected 

areas—Subtask A) and an amendment to Task 2 (Additional geochemical analytes and fourth sampling trip 

for segment 3 stations) of Interagency Agreements 

DW14957278–01–0 and DW14957278–01–2 with 

EPA.

The objective of the study was to determine 

whether the river channel, bank sediments, adjacent 

flood-plain sediments, and associated ground water 

along the main stem Coeur d’Alene River acted as 

sources or sinks of trace elements between the USGS 

gaging station near Cataldo (station 12413500) and the 

river’s mouth at Coeur d’Alene Lake. Water-quality 

samples were collected for analysis of cadmium, zinc, 

and lead at six riverine stations and one lake station 

(fig. 1) during March, June, September, and October 

of 1999. 

DESCRIPTION OF STUDY AREA

The study area was situated within the flood plain 

of the main stem Coeur d’Alene River. The flood plain 

is a broad, flat river valley bounded by steep hillslopes; 

the width of the flood plain ranges from 0.2 to 3 mi. 

The river-mile distance between the upstream boundary of the study area and the river’s mouth at Coeur 

d’Alene Lake is about 35 mi. The upstream boundary 

receives drainage from about 1,230 mi2

; at the river’s 

mouth, the drainage area is about 1,480 mi2. Th

mary source of inflow to the study area is from 

North and South Forks of the Coeur d’Alene Ri

During the 1999 water year, mean daily dischar

for the North Fork and South Fork were 2,240 a

687 ft3

/s, respectively (Woods, 2001). Numerou

tributary streams enter the main stem Coeur d’A

River; none provide substantial inflow volumes. 

lateral lakes and associated wetlands lie within 

flood plain; most have surface-water connection

the Coeur d’Alene River. 

The main stem Coeur d’Alene River is free 

ing in its upper reach to about station S2 (fig. 1

Downstream from S2, the river’s gradient is low

0.019 percent (Bender, 1991). The low gradient

combination with the lake-surface elevation of 

d’Alene Lake, creates backwater conditions thro

much of the study reach. The lake-surface eleva

Coeur d’Alene Lake is controlled by Post Falls 

situated on the Spokane River near Post Falls (fi

The annual variation in lake-surface elevation a

affects river stage in much of the study reach. Th

river’s banks are alternately inundated and dew

during the year by variations in lake-surface ele

The flood plain and river channel of the ma

Coeur d’Alene River are mostly covered with tr

element-contaminated alluvial sediments of var

thickness, which were derived from the mixing 

ings and mining-related wastes with uncontami

materials (Bookstrom and others, 1999). The ac

riverbed of the main stem Coeur d’Alene River 

been estimated to contain about 176,000,000 yd

mining-waste-contaminated alluvium (A.A. Bo

strom, U.S. Geological Survey, written commun

2000).

The transport of mining-waste contaminan

through the study reach was evident from annua

of whole-water recoverable (WWR) cadmium, 

and zinc reported by Woods (2001) for the follo

three USGS gaging stations within the study re

Coeur d’Alene River near Cataldo (station 1241

Coeur d’Alene River at Rose Lake (station 124

and Coeur d’Alene River near Harrison (station 

12413860). Large downstream increases in WW

loads were measured for the three trace elemen

tween the Cataldo and Harrison stations. At the C

station, annual loads of WWR cadmium, lead, a

were as follows: cadmium, 9,860 lb; lead, 200,0

and zinc, 1,300,000 lb. The loads of lead and zi

increased to 246,000 lb and 1,500,000 lb, respe
3

at the Rose Lake gaging station; the cadmium load 

had decreased to 8,790 lb. At the downstream gaging 

station near Harrison, the loads had increased to 

10,400 lb, 590,000 lb, and 1,570,000 lb for cadmium, 

lead, and zinc, respectively. 

The majority of the load of WWR cadmium 

and zinc was composed of the fraction that passes a 

filter with a pore size of 0.45 μm; however, only about 

10 percent of the load of WWR lead was transported 

in the filtered fraction (Woods, 2001). Therefore, the 

majority of the WWR lead load was transported in 

association with suspended sediment. On the basis of a 

study reported by Clark and Woods (2001), the majority of suspended sediment in transport within the main 

stem Coeur d’Alene River was as fine-grained particles 

(<63 μm diameter) at discharges less than 15,000 ft3

/s. 

The particle size of sediment carried as bedload at the 

Rose Lake gaging station was dominated by finegrained sediments less than 1 mm in diameter; an 

absence of bedload transport was measured at the 

Harrison gaging station (Clark and Woods, 2001).

APPROACH

Sampling Design

Four sampling trips were designed to evaluate 

trace-element transport in the main stem Coeur 

d’Alene River over a broad range of hydrologic conditions during 1999. Two sampling trips occurred during 

low lake stages; one on the recession of a winter discharge event (March 9) and the other during base-flow 

discharge near the end of the autumn reduction in lake 

stage (October 19–20). The other two sampling trips 

occurred during high lake stages; one on the recession 

of the annual snowmelt peak (June 8) and the other at 

the initiation of lake-stage reduction following several 

months of high stage (September 21–22). Dates of the 

four sampling trips are plotted on a graph showing the 

relation of lake stage to stream stage at three USGS 

gaging stations that bracketed the river reach sampled 

in this study (fig. 2, back of report). 

Locations of Data-Collection Stations

Listed in table 1 (back of report) are USGS station 

numbers and names for the seven stations sampled in 

this study. The locations of the stations are illust

figure 1 in relation to the number preceding the 

station number listed in table 1. 

Collection of Discharge Data

Discharge data for the six riverine stations 

obtained in two ways. Discharge measurements 

made at USGS gaging stations near Cataldo (st

12413500), at Rose Lake (station 12413810), a

Harrison (station 12413860). The Cataldo gagin

tion was contiguous with station 17; the Rose L

Harrison gaging stations were within 0.6 mi of 

S3 and S6, respectively. Estimated discharges a

intervening stations (S2, S4, and S5) were inter

from the measured discharges, as shown in table 

charge measurements were made from bridges 

cableways using standardized USGS methods f

lection of streamflow data, computation of disc

and quality assurance procedures which are des

in six USGS Techniques of Water-Resources In

tions reports (Buchanan and Somers, 1968, 196

Riggs, 1968; Carter and Davidian, 1968; Kenne

1983, 1984). 

Collection and Analysis of Water-Qu

Data

Depth-integrated water-quality samples we

lected from the estimated centroid of flow by pu

with a high-volume peristaltic pump. The pump

ple was composited in a churn sample splitter f

which subsamples were withdrawn for laborato

yses. Samples destined for WWR analyses were 

drawn initially; filtered samples were then with

via a peristaltic pump and through a nonmetalli

tion apparatus having a filter pore size of 0.45 μ

man capsule filters). This pore size is the traditi

size used to define “dissolved,” but recent data i

that colloidal material may pass through. There

additional 2-L sample of filtered water was obta

for later processing for analysis of colloidal-bou

trace elements. The “dissolved” sample, as defi

this study, was obtained by filtering the 2-L filte

(0.45 μm) sample through a tangential micro/ul

tration system (Millipore Minitan II) equipped 

ter plates having a filter pore size of 0.01 μm. A
4

element samples were preserved with 2 mL of Ultrex 

nitric acid. Water-quality sample preparation, collection, and field processing were conducted using 

“clean” protocols that ensure noncontamination at the 

parts-per-billion level, as described in Horowitz and 

others (1994). Samples were shipped in plastic coolers 

to the USGS National Water-Quality Laboratory in 

Denver, Colorado, using chain-of-custody procedures 

and documentation.

Water-quality samples were analyzed for WWR, 

filtered (0.45 μm), and dissolved (0.01 μm) concentrations of cadmium, zinc, and lead, as well as hardness. 

All analyses were performed at the USGS National 

Water-Quality Laboratory using low-level detection 

limit methods described by Fishman and Friedman 

(1989) and quality assurance/quality control procedures described by Pritt and Raese (1995). The waterquality data collected during this study are presented in 

tables 2–5 (back of report). 

Calculation of Loads

Trace-element concentration data were combined 

with discharge data to compute instantaneous loads of 

cadmium, zinc, and lead at each riverine station for the 

four sampling trips (tables 2–5). Instantaneous loads, in 

pounds per day, were computed by multiplying the following four variables: instantaneous discharge, in cubic 

feet per second; constituent concentration, in milligrams per liter; a conversion factor of 0.0027 to convert 

flow and concentration units; and a conversion factor of 

2,000 to convert tons to pounds.

SPATIAL AND TEMPORAL PATTERNS IN 

TRACE ELEMENTS

Cadmium Concentrations and Loads

The March 9, 1999, sampling trip was during midlevel lake stage for Coeur d’Alene Lake and near the 

end of a recession of a rain-on-snow runoff event in the 

Coeur d’Alene River (fig. 2). Discharge increased 

downstream along the main stem Coeur d’Alene River 

from 2,280 ft3/s at station 17 to 3,600 ft3/s at station S6 

(fig. 3, back of report). Mean cross-sectional velocities 

at stations S3 and S6 were slow, 0.5 ft/s and 0.7 ft/s, 

respectively. At the six river stations, concentrations 

of WWR, filtered (0.45 μm), and dissolved (0.0

cadmium, in μg/L, ranged from 1.6 to 1.9, from 

2.0, and from 0.40 to 1.5, respectively. Concent

of WWR and filtered cadmium were nearly equ

declined about 0.3 μg/L between station 17 and 

lake station (fig. 3). Dissolved cadmium represe

about 20 percent of WWR cadmium at station 1

(fig. 3). At station S3, the percent contribution o

solved cadmium had increased to about 75 perc

from station S5 to station S7, the percentage ha

creased to about 90. The downstream increase i

percentage of WWR cadmium composed by the 

solved fraction indicates that cadmium was des

from colloidal material, resulting in an increase

solved concentration and a smaller difference b

the 0.45- and 0.01-μm fractions. The load of the 

filtered, and dissolved cadmium increased in th

stream direction, primarily in response to down

increases in discharge (fig. 3). Because WWR a

tered cadmium concentrations declined slightly 

tween stations 17 and S5, loads of these fractio

not increase as rapidly as those for dissolved cad

whose concentrations increased through this rea

The next sampling trip on June 8, 1999, w

the end of the recession of the annual snowmelt 

In contrast to the March sampling trip, lake stag

near its annual maximum (fig. 2). Discharge ran

from 5,130 ft3/s at station 17 to 7,640 ft3/s at sta

(fig. 4, back of report). Mean cross-sectional ve

at stations S3 and S6 were 1 ft/s and 1.3 ft/s, re

tively—about twice as fast as those measured d

the March 9 sampling trip. Concentrations of W

filtered, and dissolved cadmium, in μg/L, range

0.74 to 0.84, from 0.66 to 0.79, and from 0.56 t

respectively. Concentrations of WWR and filter

mium differed by less than 0.1 μg/L and decrea

generally similar pattern between station 17 and 

lake station, S7 (fig. 4). At stations 17, S2, and 

solved cadmium represented about 90 percent o

cadmium; by station S5, the percentage had dec

about 75 (fig. 4). As with WWR and filtered cad

dissolved cadmium concentrations tended to de

a downstream direction, but at a more rapid rate 

WWR or filtered concentrations, indicating that 

dal material was more prevalent in the lower re

the river. Loads of WWR and filtered cadmium 

ally increased in the downstream direction in re

to increased discharge, whereas the decrease in 

solved cadmium load between stations S3 and S
5

attributable to the decrease in dissolved concentration 

in that river reach (fig. 4).

The third sampling trip on September 21–22, 

1999, was at the end of about 3 months of sustained 

high lake stage and 3 months of low-discharge conditions, which were representative of the summer/fall 

recession (fig. 2). Although discharge increased over 

the entire study reach by about 90 ft3

/s, discharge 

decreased between stations 17 and S3 by about 60 ft3

/s 

(fig. 5, back of report). Mean cross-sectional velocities 

at stations S3 and S6 were slow, 0.06 ft/s and 0.09 ft/s, 

respectively. The loss in discharge in the upper portion 

of the river indicates movement of surface water into 

ground water within the adjacent flood plain, presumably through bank-storage effects associated with high 

lake stage. Concentrations of WWR, filtered, and dissolved cadmium, in μg/L, ranged from 1.1 to 2.9, from 

0.96 to 3.0, and from 0.92 to 3.0, respectively. Essentially all of the cadmium in the river was carried in the 

dissolved fraction. Concentrations declined in a downstream direction by about 2 μg/L (fig. 5). This level of 

concentration decrease was greater than that measured 

in the March and June sampling trips. The decrease in 

dissolved cadmium load between stations 17 and S3 

(fig. 5) is attributable to the decrease in both concentration and discharge, which presumably results from the 

movement of surface water into ground water. In contrast, the increase in discharge downstream from station S3, concurrent with decreasing dissolved cadmium 

concentrations, indicates an inflow of dilute ground 

water from bank-storage releases and the alluvial aquifer. 

The final sampling trip of October 19–20, 1999, 

also was during the low-discharge conditions of the 

summer/fall recession; however, the stage of Coeur 

d’Alene Lake had been reduced by about 4 ft compared 

to June’s maximum stage (fig. 2). The spatial trends 

and magnitudes of discharge (fig. 6, back of report) 

were similar to those observed during the September 

sampling trip. Mean cross-sectional velocities at stations S3 and S6 were slow, 0.06 ft/s and 0.09 ft/s, 

respectively. Concentrations of WWR, filtered, and dissolved cadmium, in μg/L, ranged from 1.7 to 2.9, from 

1.8 to 2.8, and from 1.7 to 2.8, respectively. Also similar to September, cadmium concentrations declined 

downstream from station 17 (fig. 6). Unlike September, 

an increase in cadmium concentration, nearly all in the 

dissolved fraction, was measured at station S6. This 

increase may indicate the release of bank storage and a 

corresponding inflow of dissolved cadmium from the 

riverbanks and adjacent flood plain in response 

removal of the hydraulic head generated by the 

a high lake stage. Outflow from Blue Lake, a la

lake upstream from station S5, was discounted 

source of dissolved cadmium because samples 

tion S5 did not indicate increased cadmium con

tions.

Cadmium concentrations and loads measu

ing the four sampling trips were predominantly 

filtered and dissolved fraction. The smallest con

tions were measured on June 8 because snowm

off diluted riverine concentrations. Conversely, 

highest cadmium concentrations were measured 

the latter two sampling trips because a larger pr

tion of the river’s discharge was contributed by 

water inflow. The downstream pattern during ea

pling trip was for cadmium concentrations to de

even as discharge increased in a downstream di

The first two sampling trips were conducted at 

charges much higher than those during the last 

trips; thus, cadmium concentrations were domin

surface-water inflow. In contrast, ground water 

more influence on cadmium concentrations dur

last two low-flow sampling trips. In the reach th

surface water to the adjacent ground water duri

tember and October (station 17 to station S3), ca

concentrations also declined slightly. This patte

gests that dissolved and filtered cadmium migra

the ground-water system. Downstream from the 

reach, cadmium concentrations continued to de

as discharge increased. The increases in dischar

ing base-flow conditions indicate an influx of g

water into the river; the concurrent decreases in 

mium concentrations indicate dilution by that g

water inflow. 

Zinc Concentrations and Loads

The spatial and temporal patterns exhibited 

WWR, filtered, and dissolved zinc during the fo

pling trips (figs. 7–10, back of report) were sim

those described in the preceding section for WW

tered, and dissolved cadmium (figs. 3–6). The m

difference between the two trace elements was th

concentrations were substantially higher than ca

concentrations. Concentrations of WWR, filtere

dissolved zinc, in μg/L, for the four sampling tr
6

ranged from 110 to 540, from 110 to 550, and from 

65 to 530, respectively. 

As with cadmium, zinc concentrations and loads 

were dominated by the filtered and dissolved fractions. 

During each sampling trip, zinc concentrations 

decreased in a downstream direction as discharge 

increased, with the exception of dissolved zinc in 

March, which increased between stations 17 and S5. 

The interaction of surface and ground water affected 

zinc concentrations in a manner analogous to that of 

cadmium concentrations.

Lead Concentrations and Loads

The spatial and temporal trends exhibited by 

WWR, filtered, and dissolved lead during the four sampling trips (figs. 11–14, back of report) were different 

from those of cadmium (figs. 3–6) and zinc (figs. 7–

10). Much of the difference is attributable to the propensity for lead to adsorb to sediment particles, whereas cadmium and zinc are much more soluble in water. 

Coeur d’Alene Lake was at a mid-level lake stage 

and the Coeur d’Alene River was near the end of a 

recession of a rain-on-snow runoff event during the 

March 9 sampling trip (fig. 2). Concentrations of 

WWR, filtered, and dissolved lead, in μg/L, ranged 

from 5.3 to 17, from 1.3 to 3.0, and from <1 to 0.40, 

respectively. The increase in discharge through the 

main stem Coeur d’Alene River occurred in concert 

with increased concentrations and loads of WWR 

lead down the river, except between stations S3 and 

S4 (fig. 11). Concentrations of WWR lead decreased 

3.5 μg/L between stations S3 and S4, possibly due to 

deposition of sediment-associated lead. Concentrations 

of filtered and dissolved lead increased slightly between stations 17 and S7 (fig. 11). Filtered lead concentrations represented between 14 and 25 percent of 

WWR lead concentrations among the stations. Dissolved lead represented only 2 percent of WWR lead at 

station S6; percentages at the other stations could not 

be computed because dissolved lead was reported as 

less than 1.0 μg/L. 

The June 8 sampling trip occurred near the end of 

the recession of the annual snowmelt peak; lake stage 

was near its annual maximum (fig. 2). Discharge 

through the entire study reach ranged from 5,130 ft3

/s 

at station 17 to 7,640 ft3/s at station S6 (fig. 12); these 

were the largest discharges measured during the four 

sampling trips. Mean cross-sectional velocities 

tions S3 and S6 were 1 ft/s and 1.3 ft/s, respecti

these were the largest measured over the four sa

trips. Suspended sediment concentrations were 

largest measured over the four sampling trips. T

range in suspended sediment concentration on J

was 44 to 56 mg/L; the maximum concentration 

sured on the other three sampling trips was 2.3 

(tables 2–5). Concentrations of WWR, filtered, 

solved lead, in μg/L, ranged from 13 to 20, from 

4.0, and from <1 to 0.36, respectively. Concentr

of WWR lead decreased slightly (2.6 μg/L) betw

stations 17 and S4 and then increased by more t

7 μg/L to 20 μg/L at station S7 (fig. 12). Filtere

concentrations increased 2.8 μg/L in the downs

direction but represented only 10 to 21 percent 

WWR lead concentrations, which was substant

less than the filtered proportion of WWR cadmi

zinc. Dissolved lead represented 1.9 percent of 

lead at station S6; percentages at the other statio

could not be computed because dissolved lead w

reported as less than 1.0 μg/L. Lead loads for th

fractions generally followed the same pattern as 

for concentrations.

Three months of sustained high lake stage 

3 months of low-discharge conditions preceded 

September 21–22 sampling trip (fig. 2). Althoug

charge increased through the entire study reach 

about 90 ft3

/s, discharge decreased in the upper 

(stations 17 to S3) by about 60 ft3

/s (fig. 13). Co

trations of WWR, filtered, and dissolved lead, i

ranged from 5.7 to 21, from 2.1 to 4.9, and from 

0.56, respectively. Despite low-discharge condi

concentrations of WWR lead increased almost f

between stations 17 and S5 (fig. 13), whereas fi

and dissolved concentrations changed only abo

fold. This increase in the particulate fraction of 

concentrations indicates resuspension of sedime

associated lead. Concentrations of filtered lead 

sented between 22 and 37 percent of WWR lea

centrations among the stations. Dissolved lead r

sented between 1.2 and 3.5 percent of WWR le

stations S5 and 17, respectively; percentages at 

other stations either were within that range or co

be computed because dissolved lead was report

less than 1.0 μg/L.

The final sampling trip of October 19–20, 

also occurred during the low-discharge conditio

the summer/fall recession; however, the stage o

d’Alene Lake had been reduced by about 4 ft (fi
7

Concentrations of WWR, filtered, and dissolved lead, 

in μg/L, ranged from 4.6 to 22, from 1.0 to 6.5, and 

from <1 to 1.1, respectively. As was observed in the 

previous sampling trip, WWR lead concentrations increased between stations 17 and S3 even though discharge declined between those stations (fig. 14). Concentrations of filtered and dissolved lead also increased 

slightly in a downstream direction until they declined 

downstream from station S5 (fig. 14). Filtered lead concentrations represented between 20 and 32 percent of 

WWR lead concentrations. Dissolved lead concentrations at six of the seven stations represented between 

3.1 and 12.9 percent of WWR lead concentrations. Lead 

concentrations and loads in October were very similar 

in magnitude and spatial pattern to those measured in 

September, thereby indicating that the 4-ft lowering of 

lake stage had minimal effect on the sources and transport of lead during base-flow conditions.

During the four sampling trips, WWR lead 

concentrations and loads were predominantly in the 

particulate (>0.45 μm) fraction. The spatial variations 

in WWR lead were largely attributable to its propensity 

to be associated with sediment particles and being 

subjected to the physical processes of erosion and 

deposition. 

Filtered and dissolved lead concentrations during 

the four sampling trips were much lower than WWR 

lead concentrations. The downstream pattern generally 

was for filtered lead concentrations to increase at a 

faster rate than dissolved lead concentrations; thus, it is 

hypothesized that colloidal lead was being formed or 

supplied by instream sources in the downstream direction. Colloidal lead was presumably being produced by 

several processes, one of which was ground-water 

inflow of dissolved lead and subsequent complexation 

with iron and manganese. A second source of colloidal 

lead was erosion of very fine riverbed and riverbank 

sediments. A third process was desorption; lead associated with sediment particles was released and entered 

the dissolved fraction and was then complexed with 

iron and manganese to form colloidal lead. This third 

process was evident when increases in filtered lead paralleled decreases in WWR lead, indicative of desorption (June 8, stations 17 to S4). The interplay of these 

three processes complicated the interpretation of the 

spatial and temporal behavior of filtered and dissolved 

lead throughout the main stem Coeur d’Alene River. 

For example, a portion of the dissolved lead input to 

the river via ground water might shift to the filtered 

fraction via complexation with iron and manganese, 

and then settle to the riverbed in areas of slow v

during low-discharge conditions. Lead deposite

river channel may then later be eroded from the 

bed sediments by increased riverine turbulence 

transported downstream. During transport, the l

might desorb from its colloidal complex and ree

dissolved fraction. 

EXCHANGE OF TRACE ELEMENTS 

BETWEEN RIVER AND FLOOD PLAIN

The objective of this study was to determin

whether sediments in the river’s channel and ba

adjacent flood-plain sediments along the main s

Coeur d’Alene River act as sources or sinks for 

elements. Four sampling trips were designed to 

the objective by measuring spatial and tempora

terns in trace-element concentrations and loads 

several combinations of lake levels and riverine 

charges. The basic premise was that as lake leve

associated hydraulic heads were reduced, groun

and (or) bank-storage water would be more read

charged into the river. This discharge to the rive

postulated to be retarded or reversed when lake 

were at their summer high and inundated much 

riverbank. The low lake-level scenario was addr

by sampling trips conducted on March 9 and O

19–20. The sampling trip of September 21–22 

addressed the sustained high lake-level scenario

second sampling trip, on June 8, occurred durin

flow on the recession of the annual snowmelt pe

thereby reflected a transient situation in which l

els were briefly higher than the normal summer 

The initial sampling trip on March 9 occur

ing mid-level lake stage and near the end of a re

of a rain-on-snow runoff event. During the prev

3 months, the lake’s level had increased and dec

several times in response to rain-on-snow runof

(fig. 2); therefore, the riverbanks had alternating 

sodes of inundation and dewatering. The relativ

large downstream increases in dissolved cadmiu

zinc concentrations between stations 17 and S4 

cate these two trace elements may have moved 

river from the adjacent ground-water system (w

includes bank storage). Ground water and bank-

water moving through flood-plain sediments en

in soluble trace elements conceivably could pic

cadmium and zinc, thereby transporting them to 
8

river when the hydraulic gradient favored discharge to 

the river. However, part of the increase in dissolved 

concentrations of cadmium and zinc may have been 

due to desorption from colloidal complexes because filtered concentrations tended to decrease in the downstream direction in conjunction with increased discharge while dissolved concentrations tended to increase. Dissolved and filtered lead concentrations continued to increase slightly in the downstream direction 

below station S4, suggesting either the ground-water 

system as a potential source of dissolved lead or additional desorption from the colloidal to the dissolved 

phase. The limited spatial variability for filtered and 

dissolved lead, however, does not permit a definitive 

answer to the question of whether the river receives 

dissolved lead from the adjacent ground-water system 

or desorption from colloidal material. Increases in discharge generally paralleled increases in WWR lead 

concentration and load, more so than for filtered and 

dissolved lead, which was indicative of the predominance of particulate lead, presumably caused by the 

erosion of sediment-associated lead from the river 

channel and riverbanks.

The June 8 sampling trip was during the final 

recession of the annual snowmelt peak, when lake 

stage was about 1 ft above its normal summer level 

(fig. 2). Compared to the March 9 sampling trip, 

WWR, filtered, and dissolved concentrations of cadmium and zinc on June 8 had been reduced by about 

50 percent because of dilution by the large volume of 

snowmelt runoff that preceded this sampling trip. More 

notably, the spatial pattern for dissolved cadmium and 

zinc essentially reversed between the March and June 

sampling trips, changing from a downstream increase 

in March to a downstream decrease in June. The downstream decrease in dissolved cadmium and zinc was 

maintained for the next two sampling trips in September and October. The high discharge generated by 

snowmelt runoff had a noticeable effect on the partitioning of WWR concentrations of cadmium and zinc 

among the particulate, filtered, and dissolved fractions, 

as evidenced by decreased percentages of dissolved 

and filtered concentrations composing the WWR concentrations. It is speculated that the shift in partitioning 

occurred because colloidal-bound cadmium and zinc 

had solubilized, thereby causing increased dissolved 

concentrations during high flow from stations 17 to S3. 

Downstream from S3, colloidal cadmium and zinc 

apparently reformed as dissolved concentrations 

decreased. Spatial patterns for WWR lead concentrations in June indicated possible deposition of pa

late lead between stations 17 and S4 and erosion 

ticulate lead between stations S4 and S6. 

The third sampling trip on September 21–22

was at the end of about 3 months of high lake st

at low-discharge conditions representative of th

mer/fall recession (fig. 2). Because of the high l

stage, cadmium and zinc were likely transporte

river water into the adjacent ground-water syste

bank storage between stations 17 and S3, a losi

reach. Between stations S3 and S6, streamflow 

increased, probably due to ground-water inflow

though WWR cadmium and zinc concentration

creased in a downstream direction, spatial chan

the partitioning among particulate and soluble p

were not evident because essentially all cadmiu

zinc concentrations were in the filtered and diss

fractions throughout the entire study reach. Filt

and WWR lead concentrations increased throug

losing reach, indicating a possible source of col

and particulate lead in this reach that is not asso

with ground-water inflow. This pattern of concen

increase suggests that lead-enriched sediments 

ing a colloidal fraction were entrained into the r

flow. Dissolved lead concentrations were very l

showed little spatial variation. Downstream from 

tion S3, WWR lead concentrations continued to 

crease as filtered concentrations stabilized, indi

additional sediment inputs. Decreases in WWR 

tered lead concentrations downstream from stat

may indicate deposition of both particulate and 

dal lead.

The final sampling trip of October 19–20, 

also was during the low-discharge conditions of 

summer/fall recession; however, the stage of Co

d’Alene Lake had been reduced by about 4 ft (fi

With the reduction of the river’s hydraulic head

potential for release of bank-storage water and d

of trace elements from the adjacent ground-wat

tem was more likely than in the previous three s

pling trips. However, except for the reach betwe

tions S5 and S6, spatial variations in cadmium a

concentrations were similar to those described f

September sampling trip. The increase in concen

of cadmium and zinc, nearly all in the dissolved 

tion, coupled with the increase in discharge, res

the only notable load increase for cadmium and 

between stations S5 and S6. This increase, attri

almost entirely to the dissolved fraction, indicat

ground-water source of dissolved cadmium and 
9

from the riverbanks and adjacent flood plain in response to reduction of the hydraulic head generated by 

the lowering of lake stage. Concentrations of filtered 

and dissolved lead were slightly higher during this 

sampling trip compared to those during higher lake 

stages, possibly indicative of ground water adding lead 

to the river. Some unquantified portion of the added 

dissolved load presumably was attributable to groundwater discharge into the river; however, desorption or 

erosion of colloidal-bound lead also probably contributed to the concentration increases. 

REFERENCES CITED

Bender, S., 1991, Investigation of the chemical composition and distribution of mining wastes in Killarney Lake, Coeur d’Alene area, northern Idaho: 

Moscow, University of Idaho, M.S. thesis.

Bookstrom, A.A., Box, S.E., Jackson, B.L., Brandt, 

T.R., Derkey, P.D., and Munts, S.R., 1999, 

Digital map of surficial geology, wetlands, and 

deepwater habitats, Coeur d’Alene River valley, 

Idaho: U.S. Geological Survey Open-File 

Report 99–548.

Buchanan, T.J., and Somers, W.P., 1968, Stage measurements at gaging stations: U.S. Geological 

Survey Techniques of Water-Resources Investigations, book 3, chap. A7, 28 p.

——— 1969, Discharge measurements at gaging stations: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, 

chap. A8, 65 p.

Carter, R.W., and Davidian, J., 1968, General procedure for gaging streams: U.S. Geological Survey 

Techniques of Water-Resources Investigations, 

book 3, chap. A6, 13 p.

Clark, G.M., and Woods, P.F., 2001, Transport o

pended and bedload sediment at eight stat

the Coeur d’Alene River Basin, Idaho: U.

logical Survey Open-File Report 00–472, 

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

ods for determination of inorganic substan

water and fluvial sediments: U.S. Geologi

vey Techniques of Water-Resources Inves

tions, book 5, chap. A1, 545 p.

Horowitz, A.J., Demas, C.R., Fitzgerald, K.K., 

T.L., and Rickert, D.A., 1994, U.S. Geolo

Survey protocol for the collection and pro

of surface-water samples for the subseque

determination of inorganic constituents in 

water: U.S. Geological Survey Open-File 

94–539, 57 p.

Kennedy, E.J., 1983, Computation of continuou

records of streamflow: U.S. Geological Su

Techniques of Water-Resources Investigat

book 3, chap. A13, 53 p.

——— 1984, Discharge ratings at gaging statio

U.S. Geological Survey Techniques of Wa

Resources Investigations, book 3, chap. A

59 p.

Pritt, J.W., and Raese, J.W., eds., 1995, Quality 

ance/quality control manual, National Wa

Quality Laboratory: U.S. Geological Surv

Open-File Report 95–443, 35 p. 

Riggs, H.C., 1968, Some statistical tools in hyd

U.S. Geological Survey Techniques of Wa

Resources Investigations, book 4, chap. A

Woods, P.F., 2001, Concentrations and loads of 

mium, lead, zinc, and nutrients measured 

the 1999 water year within the Spokane R

Basin, Idaho and Washington: U.S. Geolo

Survey Open-File Report 00–441, 32 p.

FIGURES 1–14

$ $

$

$

$

$

St. Joe River Coeur d'Alene Indian Reservation

Coeur d'Alene Lake

Kootenai County

Benewah County

Spokane River

Shoshone County

St. Maries River

17 S2 S3

S4

S5 S6 S7

City of Coeur d'Alene

Cave Lake Anderson Lake

Kilarney Lake

Black Lake

Blue Lake

Swan Lake

Rose Lake

Medicine Lake

Thompson Lake Bull Run Lake

Porter's Lake

#

#

#

Cataldo

Harrison

South Fork Coeur d'Alene River

Coeur d'Alene River

North Fork Coeur d'Alene River

$

116 22' 30"

o

45'

o 47

22' 30"

7 00'11

o

0

4

0

47 o

$ 

Figure 1. Locations of seven water-quality stations monitored for trace-element transport during and October 1999, main stem Coeur d'Alene River, Idaho.

Post Falls Dam

Latour Creek

13
Stage of Coeur d'Alene River at Rose Lake

Station number 12413810

0

2

4

6

8

10

12

Oct-98

Nov-98

Dec-98

Jan-99

Feb-99

Mar-99

Apr-99

May-99

Jun-99

Jul-99

Aug-99Sep-99

Oct-99

Relative stage, in feet

Sample 

collected

Stage at Coeur d'Alene Lake

Station number 12415500

0

2

4

6

8

10

12

Oct-98

Nov-98

Dec-98

Jan-99

Feb-99

Mar-99

Apr-99

May-99

Jun-99

Jul-99

Aug-99

Sep-99

Oct-99

Sample 

collected

Stage of Coeur d'Alene River near Harrison

Station number 12413860

0

2

4

6

8

10

12

Oct-98

Nov-98

Dec-98

Jan-99

Feb-99

Mar-99

Apr-99

May-99

Jun-99

Jul-99

Aug-99

Sep-99

Oct-99

Relative stage, in feet

Sample 

collected

Stage of Coeur d'Alene River near Cataldo

Station number 12413500

0

2

4

6

8

10

12

Oct-98

Nov-98

Dec-98

Jan-99

Feb-99

Mar-99

Apr-99

May-99

Jun-99

Jul-99

Aug-99

Sep-99

Oct-99

Relative stage, in feet

Sample 

collected

Figure 2. Variation in river or lake stage between October 1998 and October 1999

at four U.S. Geological Survey stations in the Coeur d’Alene River Basin, Idaho Relative stage, in feet

14
2200

2400

2600

2800

3000

3200

3400

3600

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 3. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999.

CADMIUM LOAD

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

CADMIUM CONCENTRATION

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

15
5000

5500

6000

6500

7000

7500

8000

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 4. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999.

CADMIUM LOAD

20.0

22.0

24.0

26.0

28.0

30.0

32.0

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

CADMIUM CONCENTRATION

0.00

0.10

0.20

0.30

0.40

0.50

0.60

0.70

0.80

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

16
300

320

340

360

380

400

420

440

460

480

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 5. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, September 21-22, 1999.

CADMIUM LOAD

3.00

3.50

4.00

4.50

5.00

5.50

6.00

6.50

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

CADMIUM CONCENTRATION

0.50

1.00

1.50

2.00

2.50

3.00

3.50

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

17
250

300

350

400

450

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 6. Instantaneous values for discharges and concentrations and loads of cadmium at seven waterquality stations on the main stem Coeur d’Alene River, Idaho, October 19-20, 1999.

CADMIUM LOAD

3.00

3.50

4.00

4.50

5.00

5.50

6.00

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

CADMIUM CONCENTRATION

1.50

2.00

2.50

3.00

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

18
2200

2400

2600

2800

3000

3200

3400

3600

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 7. Instantaneous values for discharges and concentrations and loads of zinc at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999.

ZINC LOAD

0

1000

2000

3000

4000

5000

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

ZINC CONCENTRATION

0

50

100

150

200

250

300

350

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

19
5000

5500

6000

6500

7000

7500

8000

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 8. Instantaneous values for discharges and concentrations and loads of zinc at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999.

ZINC LOAD

3000

3500

4000

4500

5000

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

ZINC CONCENTRATION

80

90

100

110

120

130

140

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

20
300

320

340

360

380

400

420

440

460

480

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 9. Instantaneous values for discharges and concentrations and loads of zinc at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, September 21-22, 1999.

ZINC LOAD

600

700

800

900

1000

1100

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

ZINC CONCENTRATION

150

200

250

300

350

400

450

500

550

600

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

21
250

300

350

400

450

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 10. Instantaneous values for discharges and concentrations and loads of zinc at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, October 19-20, 1999.

ZINC LOAD

600

650

700

750

800

850

900

950

1000

1050

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

ZINC CONCENTRATION

300

350

400

450

500

550

600

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

22
2200

2400

2600

2800

3000

3200

3400

3600

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 11. Instantaneous values for discharges and concentrations and loads of lead at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, March 9, 1999.

LEAD LOAD

0

50

100

150

200

250

300

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

LEAD CONCENTRATION

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

23
5000

5500

6000

6500

7000

7500

8000

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 12. Instantaneous values for discharges and concentrations and loads of lead at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, June 8, 1999.

LEAD LOAD

0

100

200

300

400

500

600

700

800

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

LEAD CONCENTRATION

0.0

5.0

10.0

15.0

20.0

25.0

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

24
300

320

340

360

380

400

420

440

460

480

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 13. Instantaneous values for discharges and concentrations and loads of lead at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, September 21-22, 1999.

LEAD LOAD

0.0

10.0

20.0

30.0

40.0

50.0

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

LEAD CONCENTRATION

0.0

5.0

10.0

15.0

20.0

25.0

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

25
250

300

350

400

450

S7S6S5S4S3S2

17

CUBIC FEET PER SECOND

INSTANTANEOUS DISCHARGE

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Figure 14. Instantaneous values for discharges and concentrations and loads of lead at seven water-quality 

stations on the main stem Coeur d’Alene River, Idaho, October 19-20, 1999.

LEAD LOAD

0.0

10.0

20.0

30.0

40.0

50.0

S7S6S5S4S3S2

17

POUNDS PER DAY

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

LEAD CONCENTRATION

0.0

5.0

10.0

15.0

20.0

25.0

S7S6S5S4S3S2

17

MICROGRAMS PER LITER

Whole Water Recoverable Filtered (0.45 um) Dissolved (0.01 um)

Relative location of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

Relative locaton of seven water-quality stations on Coeur d’Alene River and Coeur d’Alene Lake

26
TABLES 1–5
Blank page 8
Upstream

measured 

station

Downstream

measured 

station

17 12413500 CDR near Cataldo, ID M na na 

S2 12413755

CDR below

Latour Creek near 

Cataldo, ID

I 17 S3 

S3 12413815

CDR below

Rose Creek near 

Rose Lake, ID

M na na 

S4 12413825

CDR above

Killarney Lake outlet 

near Rose Lake, ID

I S3 S6 

S5 12413858

CDR below

Blue Lake near 

Harrison, ID

I S3 S6 

S6 12413862

CDR at

Harrison bridge near 

Harrison, ID

M na na 

S71 472721116480100

Coeur d’Alene Lake

between Harrison 

and Harlow Point 

near Harrison, ID

na na na 

Table 1. Identification numbers and names of seven U.S. Geological Survey water-quality stations moJune, September, and October 1999 on the main stem Coeur d’Alene River, Idaho

[USGS, U.S. Geological Survey; na, not applicable; CDR, Coeur d’Alene River; ID, Idaho]

1 Lake station

Station

number on 

figure 1

USGS

station

number

USGS

station

name

Measured (M)

or

Interpolated (I)

 Source of discharge data

Interpolated disc

29
WWR2 F3 D4 WW

17 CDR near Cataldo 3/9/99 2,280 1.9 1.9 2.0 0.40 23 

S2 CDR below Latour Creek 3/9/99 2,430 ns ns ns ns ns S3 CDR below Rose Creek 3/9/99 2,670 1.0 1.7 1.7 1.3 25 S4 CDR above Killarney Lake Outlet 3/9/99 2,910 1.0 1.7 1.8 1.4 27 S5 CDR below Blue Lake 3/9/99 3,160 1.9 1.6 1.6 1.5 27 S6 CDR at Harrison Bridge 3/9/99 3,600 0.6 1.6 1.6 1.4 31 S7 CDA Lake at mouth of CDR 3/9/99 na ns 1.6 1.6 1.5 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 3/9/99 2,280 1.9 280 290 65 340

S2 CDR below Latour Creek 3/9/99 2,430 ns ns ns ns ns S3 CDR below Rose Creek 3/9/99 2,670 1.0 250 270 190 360S4 CDR above Killarney Lake Outlet 3/9/99 2,910 1.0 260 300 230 410S5 CDR below Blue Lake 3/9/99 3,160 1.9 240 260 240 410S6 CDR at Harrison Bridge 3/9/99 3,600 0.6 260 260 230 510S7 CDA Lake at mouth of CDR 3/9/99 na ns 240 240 220 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 3/9/99 2,280 1.9 5.3 1.3 <1 65 

S2 CDR below Latour Creek 3/9/99 2,430 ns ns ns ns ns S3 CDR below Rose Creek 3/9/99 2,670 1.0 11 1.6 <1 16S4 CDR above Killarney Lake Outlet 3/9/99 2,910 1.0 7.6 1.5 0.20 12S5 CDR below Blue Lake 3/9/99 3,160 1.9 15 2.2 <1 26S6 CDR at Harrison Bridge 3/9/99 3,600 0.6 15 2.6 0.30 29S7 CDA Lake at mouth of CDR 3/9/99 na ns 17 3 0.40 na 

Table 2. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on March 9, 1999, at six wastations on the Coeur d’Alene River and one lake station near the mouth of the Coeur d’Alene River, Idaho

[CDR, Coeur d’Alene River; CDA, Coeur d’Alene; Inst. Q, instantaneous discharge; ft 3/s, cubic feet per second; USGS, U.S. Geological Su

ug/L, micrograms per liter; WWR, whole-water recoverable; F, filtered; D, dissolved; mg/L, milligrams per liter; <, less than; ns, not sampna, not applicable]

Station number

on figure 1 USGS station name Sample date

Inst.

Q1

(ft3/s)

Suspended-sediment 

concentration (mg/L)

Cadmium concentration (μg/L) Cad

1 Discharge measured at stations 17, S3, and S6. Discharge estimated by interpolation at stations S2, S4, and S5.2 Weak-acid digestion performed on water, suspended-sediment mixture at U.S. Geological Survey’s National Water-Qual3 Filtrate passing a 0.45-micrometer capsule filter.4 Filtrate passing a 0.01-micrometer tangential flow filter.

Zinc concentration (μg/L) Z

Lead concentration (μg/L) L

30
WWR2 F3 D4 WW

17 CDR near Cataldo 6/8/99 5,130 56 0.84 0.79 0.74 23 

S2 CDR below Latour Creek 6/8/99 5,480 52 0.83 0.77 0.74 25 S3 CDR below Rose Creek 6/8/99 6,050 51 0.82 0.79 0.75 27 S4 CDR above Killarney Lake Outlet 6/8/99 6,460 51 0.84 0.76 <1 29 S5 CDR below Blue Lake 6/8/99 6,890 44 0.75 0.71 0.56 28 S6 CDR at Harrison Bridge 6/8/99 7,640 52 0.74 0.67 0.57 30 S7 CDA Lake at mouth of CDR 6/8/99 na ns 0.74 0.66 <1 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 6/8/99 5,130 56 130 130 110 360

S2 CDR below Latour Creek 6/8/99 5,480 52 120 120 110 360S3 CDR below Rose Creek 6/8/99 6,050 51 120 120 110 390S4 CDR above Killarney Lake Outlet 6/8/99 6,460 51 120 120 110 420S5 CDR below Blue Lake 6/8/99 6,890 44 110 110 93 410S6 CDR at Harrison Bridge 6/8/99 7,640 52 120 110 96 500S7 CDA Lake at mouth of CDR 6/8/99 na ns 110 110 100 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 6/8/99 5,130 56 16 1.8 <1 44

S2 CDR below Latour Creek 6/8/99 5,480 52 14 1.5 <1 41S3 CDR below Rose Creek 6/8/99 6,050 51 13 2.4 0.08 42S4 CDR above Killarney Lake Outlet 6/8/99 6,460 51 13 2.7 <1 45S5 CDR below Blue Lake 6/8/99 6,890 44 17 3.3 <1 63S6 CDR at Harrison Bridge 6/8/99 7,640 52 18 3.8 0.36 74S7 CDA Lake at mouth of CDR 6/8/99 na ns 20 4.0 0.22 na 

Table 3. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on June 8, 1999, at six watestations on the Coeur d’Alene River and one lake station near the mouth of the Coeur d’Alene River, Idaho

[CDR, Coeur d’Alene River; CDA, Coeur d’Alene; Inst. Q, instantaneous discharge; ft 3/s, cubic feet per second; USGS, U.S. Geological Su

ug/L, micrograms per liter; WWR, whole-water recoverable; F, filtered; D, dissolved; mg/L, milligrams per liter; <, less than; ns, not sampna, not applicable]

Station number

on figure 1 USGS station name Sample date

Inst.

Q1

(ft3/s)

Suspended-sediment 

concentration (mg/L)

Cadmium concentration (μg/L) Cad

1 Discharge measured at stations 17, S3, and S6. Discharge estimated by interpolation at stations S2, S4, and S5.2 Weak-acid digestion performed on water, suspended-sediment mixture at U.S. Geological Survey’s National Water-Qual3 Filtrate passing a 0.45-micrometer capsule filter.4 Filtrate passing a 0.01-micrometer tangential flow filter.

Zinc concentration (μg/L) Z

Lead concentration (μg/L) L

31
WWR2 F3 D4 WW

17 CDR near Cataldo 9/22/99 373 ns 2.9 3.0 3.0 5.

S2 CDR below Latour Creek 9/22/99 350 0.8 2.8 2.8 2.8 5.S3 CDR below Rose Creek 9/22/99 316 ns 2.6 2.6 2.6 4.S4 CDR above Killarney Lake Outlet 9/22/99 355 1.5 2.5 2.4 2.3 4.S5 CDR below Blue Lake 9/22/99 395 ns 1.8 1.6 1.6 3.S6 CDR at Harrison Bridge 9/21/99 465 1.8 1.8 1.5 1.5 4.S7 CDA Lake at mouth of CDR 9/21/99 na ns 1.1 0.96 0.92 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 9/22/99 373 ns 540 530 530 110

S2 CDR below Latour Creek 9/22/99 350 0.8 500 530 520 94S3 CDR below Rose Creek 9/22/99 316 ns 450 470 480 77S4 CDR above Killarney Lake Outlet 9/22/99 355 1.5 440 440 440 84S5 CDR below Blue Lake 9/22/99 395 ns 300 290 290 64S6 CDR at Harrison Bridge 9/21/99 465 1.8 300 280 280 75S7 CDA Lake at mouth of CDR 9/21/99 na ns 200 180 170 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 9/22/99 373 ns 5.7 2.1 0.20 11 

S2 CDR below Latour Creek 9/22/99 350 0.8 6.5 2.1 <1 12 S3 CDR below Rose Creek 9/22/99 316 ns 14 4.3 0.48 24 S4 CDR above Killarney Lake Outlet 9/22/99 355 1.5 15 4.9 0.43 29 S5 CDR below Blue Lake 9/22/99 395 ns 21 4.5 0.25 45 S6 CDR at Harrison Bridge 9/21/99 465 1.8 18 4.0 0.56 45 S7 CDA Lake at mouth of CDR 9/21/99 na ns 13 2.7 <1 na 

Table 4. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on September 21-22, 1999, stations on the Coeur d’Alene River and one lake station near the mouth of the Coeur d’Alene River, Idaho

[CDR, Coeur d’Alene River; CDA, Coeur d’Alene; Inst. Q, instantaneous discharge; ft 3/s, cubic feet per second; USGS, U.S. Geological Su

ug/L, micrograms per liter; WWR, whole-water recoverable; F, filtered; D, dissolved; mg/L, milligrams per liter; <, less than; ns, not sampna, not applicable]

Station number

on figure 1 USGS station name Sample date

Inst.

Q1

(ft3/s)

Suspended-sediment 

concentration (mg/L)

Cadmium concentration (μg/L) Cad

1 Discharge measured at stations 17, S3, and S6. Discharge estimated by interpolation at stations S2, S4, and S5.2 Weak-acid digestion performed on water, suspended-sediment mixture at U.S. Geological Survey’s National Water-Qual3 Filtrate passing a 0.45-micrometer capsule filter.4 Filtrate passing a 0.01-micrometer tangential flow filter.

Zinc concentration (μg/L) Z

Lead concentration (μg/L) L

32
WWR2 F3 D4 WW

17 CDR near Cataldo 10/20/99 359 ns 2.9 2.8 2.8 5.

S2 CDR below Latour Creek 10/20/99 324 0.5 2.9 2.8 2.5 5.S3 CDR below Rose Creek 10/20/99 266 ns 2.7 2.5 2.5 3.S4 CDR above Killarney Lake Outlet 10/20/99 310 1.5 2.4 2.3 2.2 4.S5 CDR below Blue Lake 10/20/99 355 ns 2.0 1.9 1.8 3.S6 CDR at Harrison Bridge 10/19/99 435 2.3 2.2 2.1 2.1 5.S7 CDA Lake at mouth of CDR 10/19/99 na ns 1.7 1.8 1.7 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 10/20/99 359 ns 500 540 520 97

S2 CDR below Latour Creek 10/20/99 324 0.5 510 550 470 89S3 CDR below Rose Creek 10/20/99 266 ns 470 500 480 68S4 CDR above Killarney Lake Outlet 10/20/99 310 1.5 430 470 430 72S5 CDR below Blue Lake 10/20/99 355 ns 340 370 340 65S6 CDR at Harrison Bridge 10/19/99 435 2.3 400 430 400 94S7 CDA Lake at mouth of CDR 10/19/99 na ns 320 340 330 na 

WWR2 F3 D4 WW

17 CDR near Cataldo 10/20/99 359 ns 4.9 1.0 <1 9.

S2 CDR below Latour Creek 10/20/99 324 0.5 4.6 1.4 0.6 8.S3 CDR below Rose Creek 10/20/99 266 ns 15 3.4 0.8 22 S4 CDR above Killarney Lake Outlet 10/20/99 310 1.5 15 4.4 0.6 25 S5 CDR below Blue Lake 10/20/99 355 ns 22 6.5 1.1 42 S6 CDR at Harrison Bridge 10/19/99 435 2.3 19 6.0 0.6 45 S7 CDA Lake at mouth of CDR 10/19/99 na ns 16 5.0 0.5 na 

Table 5. Concentrations and instantaneous loads of cadmium, zinc, and lead measured on October 19-20, 1999, at stations on the Coeur d’Alene River and one lake station near the mouth of the Coeur d’Alene River, Idaho

[CDR, Coeur d’Alene River; CDA, Coeur d’Alene; Inst. Q, instantaneous discharge; ft 3/s, cubic feet per second; USGS, U.S. Geological Su

ug/L, micrograms per liter; WWR, whole-water recoverable; F, filtered; D, dissolved; mg/L, milligrams per liter; <, less than; ns, not sampna, not applicable]

Station number

on figure 1 USGS station name Sample date

Inst.

Q1

(ft3/s)

Suspended-sediment 

concentration (mg/L)

Cadmium concentration (μg/L) Cad

1 Discharge measured at stations 17, S3, and S6. Discharge estimated by interpolation at stations S2, S4, and S5.2 Weak-acid digestion performed on water, suspended-sediment mixture at U.S. Geological Survey’s National Water-Qual3 Filtrate passing a 0.45-micrometer capsule filter.4 Filtrate passing a 0.01-micrometer tangential flow filter.

Zinc concentration (μg/L) Z

Lead concentration (μg/L) L

33
Woods, P.F. / Concentrations and Loads of Cadmium, Zinc, and Lead, Main Stem Coeur d’Alene River Basin, Idaho, 199