WATER-QUALITY, BED-SEDIMENT, AND BIOLOGICAL 

DATA (OCTOBER 1992 THROUGH SEPTEMBER 1993) 

AND STATISTICAL SUMMARIES OF WATER-QUALITY 

DATA (MARCH 1985 THROUGH SEPTEMBER 1993) 

FOR STREAMS IN THE UPPER CLARK FORK BASIN, 

MONTANA

By John H. Lambing, Michelle I. Hornberger, Ellen V. Axtmann, and Daryll A. Pope

U.S. GEOLOGICAL SURVEY 

Open-File Report 94-375

Prepared in cooperation with the

U.S. ENVIRONMENTAL PROTECTION AGENCY

Helena, Montana 

August 1994
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Gordon P. Eaton, Director

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

District Chief

U.S. Geological Survey

428 Federal Building

301 South Park Avenue

Drawer 10076

Helena, MT 59626-0076

U.S. Geological Survey 

Earth Science Information Center 

Open-File Reports Section 

Box25286, MS 517 

Denver Federal Center 

Denver, CO 80225
CONTENTS

Page

Abstract..................................................................................................^ 1

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

Sampling locations and types of data.................................................................................................................................... 2

Water-quality data................................................^ 3

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

Results...........................................^ 5

Quality assurance....................................................................................................................................................... 5

Bed-sediment data................................................................................................................................................................. 8

Methods.................................................................................................^ 8

Results. ........................................................................................................ 9

Quality assurance..........................................................................................................................................^ 9

Biological data....................................................................................................................................................................... 10

Methods.........................................^ 10

Results........................................................................................................................................................................ 11

Quality assurance................................................................................................^^ 11

Statistical summaries of water-quality data........................................................................................................................... 11

Selected references...........................................................................................................................................................^ 11

Data.........................................^ 14

ILLUSTRATION

Figure 1. Map showing location of study area................................................................................................................. 2

TABLES

Table 1. Type and period of data collection at sampling stations in the upper Clark Fork basin, Montana................... 3

2. Properties and constituents analyzed in samples of water, bed sediment, and biota from the upper

Clark Fork basin, Montana......................................................................................................................... 4

3. Data-quality objectives for analyses of water-quality samples collected in the upper

Clark Fork basin, Montana......................................................................................................................... 7

4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 ......... 15

5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, March

through September 1993............................................................................................................................. 36

6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana,

April through September 1993.................................................................................................................... 38

7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October

1992 through September 1993.................................................................................................................... 40

8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner,

Montana, October 1992 through September 1993...................................................................................... 44

9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October

1992 through September 1993.................................................................................................................... 48

10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October

1992 through September 1993.................................................................................................................... 52

11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana.......................... 56

12. Precision of chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana....... 58

CONTENTS iii
TABLES-Contlnued

Page

Table 13. Precision of chemical analyses of laboratory replicates for water samples, upper Clark Fork basin,

Montana..................................................................................................................................^ 59

14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks....................... 60

15. Recovery efficiency for trace-element analyses of laboratory-spiked stream samples, upper Clark

Fork basin, Montana................................................................................................................................... 61

16. Chemical analyses of field blanks for water samples...................................................................................... 62

17. Trace-element analyses of fine bed sediment, upper Clark Fork basin, Montana, August 1993..................... 63

18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1993................... 64

19. Recovery efficiency for trace-element analyses of standard reference materials for bed sediment................ 65

20. Trace-element analyses of procedural blanks for bed sediment...................................................................... 66

21. Trace-element analyses of aquatic insects, upper Clark Fork basin, Montana, August 1993.......................... 67

22. Recovery efficiency for trace-element analyses of standard reference material for biota............................... 68

23. Trace-element analyses of procedural blanks for biota.................................................................................... 69

24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 through

September 1993.......................................................................................................................................... 70

CONVERSION FACTORS AND ABBREVIATED WATER-QUALITY UNITS

Multiply________________________________By___________________To obtain

cubic foot per second (ftVs) 0.028317 cubic meter per second

foot (ft) 0.3048 meter (m)

gallon (gal) 3.785 liter (L)

inch (in.) 25.4 millimeter (nun)

inch (in.) 25,400 micrometer (Urn)

mile (mi) 1.609 kilometer

ounce (oz) 28.35 gram (g)

part per million 1 microgram per gram (Jlg/g)

square mile (mi2) 2.59 square kilometer 

ton per day (ton/d)_________________________907.2_____________________kilogram per day

Temperature in degrees Celsius (°C) can be converted to degrees Fahrenheit (°F) by the following equation:

°F = 9/5(°C) + 32 

Abbreviated water-quality units used in this report:

|4.g/g micrograms per gram

)4.g/L micrograms per liter

|lg/mL micrograms per milliliter

jLlS/cm microsiemens per centimeter at 25 °C

mg/L milligrams per liter

Water-year definition:

A water year is the 12-month period October 1 through September 30. It is designated by the calendar year in which it ends.

iv Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
WATER-QUALITY, BED-SEDIMENT, AND 

BIOLOGICAL DATA (OCTOBER 1992 THROUGH 

SEPTEMBER 1993) AND STATISTICAL SUMMARIES 

OF WATER-QUALITY DATA (MARCH 1985 THROUGH 

SEPTEMBER 1993) FOR STREAMS IN THE UPPER 

CLARK FORK BASIN, MONTANA

By John H. Lambing, Michelle I. Hornberger, Ellen V. Axtmann, and Daryll A. Pope

Abstract

Water, bed sediment, and biota were sampled in streams from Butte to below Missoula as 

part of a program to characterize aquatic resources 

in the upper Clark Fork basin of western Montana. 

Water-quality data were obtained periodically at 

16 stations during October 1992 through September 1993 (water year 1993); daily suspendedsediment data were obtained at six of these stations. Bed-sediment and biological data were 

obtained at 11 stations in August 1993. Sampling 

stations were located on the Clark Fork and major 

tributaries. The primary constituents analyzed 

were trace elements associated with mine tailings 

from historic mining and smelting activities.

Water-quality data include concentrations of 

major ions, trace elements, and suspended sediment in samples collected periodically during 

water year 1993. Daily values of streamflow, suspended-sediment concentration, and suspendedsediment discharge are given for six stations. Bedsediment data include trace-element concentrations in the fine and bulk fractions. Biological data 

include trace-element concentrations in wholebody tissue of aquatic benthic insects. Qualityassurance data are reported for analytical results of 

water, bed sediment, and biota. A statistical summary of water-quality data is provided for the 

period of record at each station since 1985.

INTRODUCTION

The Clark Fork originates near Warm Springs in 

western Montana at the confluence of Silver Bow and 

Warm Springs Creeks (fig. 1). Along the 148-mi reach

of stream from Silver Bow Creek in Butte to the Clark 

Fork at Milltown Reservoir, six major tributaries enter: 

Blacktail Creek, Warm Springs Creek, Little Blackfoot 

River, Flint Creek, Rock Creek, and Blackfoot River. 

Principal surface-water uses in the upper 6,000-mi2 

Clark Fork basin above Missoula include irrigation, 

stock watering, light industry, hydroelectric power generation, and habitat for trout fisheries. Current land 

uses primarily include cattle production, logging, mining, and recreation. Large-scale mining and smelting 

had been prevalent land uses in the upper basin for 

more than one hundred years, but are now largely discontinued.

Deposits of copper, gold, silver, and lead ores 

were extensively mined, milled, and smelted in the 

drainages of Silver Bow and Warm Springs Creeks 

from about 1860 to 1980. Moderate- and small-scale 

mining also occurred in the basins of most of the major 

tributaries to the upper Clark Fork. Tailings derived 

from mineral processing commonly contain large 

quantities of trace elements such as cadmium, copper, 

lead, and zinc that can accumulate to potentially toxic 

levels in aquatic organisms. Since mining began in the 

basin, tailings have been eroded and transported downstream and redeposited in stream channels, on flood 

plains, and in Warm Springs Ponds and Milltown Reservoir. The river continues to erode, transport, and 

redeposit tailings-laden sediment along the river corridor, especially during high flows.

Concern about the potential toxicity of tailings to 

aquatic biota and human health has resulted in a comprehensive effort by State, Federal, and private entities 

to characterize the aquatic resources in the upper Clark 

Fork basin to guide and monitor remedial cleanup 

activities. Establishment of a long-term data base was 

considered necessary to statistically detect trends over 

time in order to evaluate the effectiveness of remediaAbstract
47C

Base from U.S. Geological Survey State 

base map, 1=1,000,000, 

1966

EXPLANATION

12324200 STATION AND NUMBER 

Streamflow gaging 

A Continuous record 

A Periodic measurement 

Water quality, bed sediment, biota 

<V Periodic water quality 

^.Daily suspended sediment 

VOnce- annual bed sediment 

"V Once-annual biota

46C

Figure 1 . Location of study area.

tion. Water-quality data have been collected by the 

U.S. Geological Survey (USGS) at selected sites in the 

upper Clark Fork basin since 1985 (Lambing, 

1987,1988,1989,1990, and 1991). Trace-element data 

have been collected annually since 1986 for bed sediment and biota (aquatic benthic insects) at selected 

sites as part of research studies on bed-sediment contamination and bioaccumulation of metals conducted 

by the USGS (Axtmann and Luoma, 1991; Cain and 

others, 1992). In March 1993, an expanded sampling 

program for water, bed sediment, and biota was implemented in cooperation with the U.S. Environmental 

Protection Agency.

The purpose of this report is to present waterquality data for 16 stations and trace-element data for 

bed sediment and biota at 11 stations in the upper Clark 

Fork basin collected from October 1992 through September 1993 (water year 1993). Quality-assurance data

are presented for water quality, bed sediment, and 

biota. Statistical summaries also are provided for 

water-quality data collected since 1985.

SAMPLING LOCATIONS AND TYPES OF 

DATA

Sampling stations in the upper Clark Fork basin 

are located on both the Clark Fork mainstem and major 

tributaries from Butte to below Missoula (fig. 1). 

Mainstem sites were selected to divide the upper Clark 

Fork into reaches of relatively uniform length, with 

each reach encompassing either a major tributary or 

depositional environment (Warm Springs Ponds and 

Milltown Reservoir). Tributaries were sampled to 

describe water-quality characteristics and to provide 

reference comparisons to the mainstem for bed sediment and biota from major hydrologic sources in the

Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
upper basin. Water-quality data were obtained periodically at 16 stations; daily suspended-sediment data 

were obtained at six of these stations; bed-sediment and 

biological data were obtained once-annually at 11 stations (table 1).

A list of properties and constituents analyzed in 

samples of water, bed sediment, and biota is given in 

table 2. Results of analyses for water, bed sediment, 

and biota for water year 1993 are listed in tables 4 

through 23 at the back of the report. Statistical summaries of water-quality data collected since 1985 are 

given in table 24 at the back of the report.

Quality assurance of data was maintained 

through the use of documented procedures designed to 

provide environmentally representative data. Acceptable performance of the procedures was verified with 

quality-control samples that were collected systematically to provide a measure of the accuracy, precision,

and bias of the environmental data and to identify problems associated with sampling, processing, or analysis.

WATER-QUALITY DATA

Water-quality data consist of measurements of 

physical properties and concentrations of chemical and 

physical constituents analyzed in stream samples. 

Samples were collected 6 to 10 times per year at a 

schedule designed to adequately describe seasonal and 

hydrologic variability.

Methods

Cross-sectional water samples were collected 

from multiple verticals across the stream using depthintegration methods described by Guy and Norman 

(1970), USGS (1977), and Knapton (1985). These

Table 1. Type and period of data collection at sampling stations in the upper Clark Fork basin, Montana

[Abbreviation: P, present. Symbol: , no data]

Station 

number 

(fig. 1)

12323230

12323250

12323600

12323750

12323770

12323800

12324200

12324590

12324680

12331500

12331800

12334510

12334550

12340000

12340500

12353000

Station name

Blacktail Creek at Harrison Avenue,

at Butte

Silver Bow Creek below Blacktail

Creek, at Butte

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Warm Springs Creek at Warm

Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

Little Blackfoot River near Garrison

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Rock Creek near Clinton

Clark Fork at Turah Bridge, near

Bonner

Blackfoot River near Bonner

Clark Fork above Missoula

Clark Fork below Missoula4

Continuousrecord 

streamflow

10/83-P

07/88-P

03/72-09/79,

04/93-P

10/83-P

07/88-P

10/78-P

10/72-P

10/77-P

08/90-P

04/93-P

10/72-P

05/86-P

10/39-P

03/29-P

10/29-P

Periodic 

water 

quality1

03/93-P

03/93-P

03/93-P

03/93-P

03/93-P

07/88-P

03/85-P

03/85-P

03/93-P

03/85-P

03/93-P

03/85-P

03/85-P

03/85-P

10/89-P

10/78-P

Daily 

suspended 

sediment

03/93-P

04/93-P

-

03/85-09/86,

04/87-P

-

~

~

03/85-P

07/86-04/87,

06/88-P

07/86-04/87,

06/88-P

-

Fine 

bed 

sediment2

07/92-P

08/93

08/87-P

08/86-P

07/92-P

08/86-P

08/86-P

08/87-P

08/86-P

08/86-P

08/86-P

Bulk 

bed 

sediment2

08/93

08/93

08/93

08/93

08/93

08/93

08/93

08/93

08/93

08/93

08/93

Biota2

-3

08/93

08/87-P

08/86-P

07/92-P

08/86-P

08/86-P

08/87-P

08/86-P

08/86-P

..

08/86-P

1Onsite measurements of physical properties and laboratory analyses of major ions, trace elements, and suspended sediment. Prior to 

March 1993, laboratory analyses included only trace elements and suspended sediment, with the exception of Clark Fork below 

Missoula.

laboratory analyses of trace elements.

3Site sampled, but insufficient number of insects obtainable for analysis.

4Bed sediment and biota sampled about 30 miles downstream from water-quality station to conform to previous sampling location.

WATER-QUALITY DATA
Table 2. Properties and constituents analyzed in samples of water, bed sediment, 

and biota from the upper Clark Fork basin, Montana

Water

Property

Streamflow 

Specific conductance 

pH 

Temperature

Constituent1

Hardness 

Calcium 

Magnesium 

Sodium 

Potassium

Alkalinity 

Sulfate

Chloride

Fluoride

Silica

Dissolved solids

Arsenic

Cadmium

Copper 

Iron

Lead

Manganese 

Zinc

Suspended 

sediment

Bed 

sediment

Constituent

Cadmium 

Chromium 

Copper 

Iron 

Lead

Manganese 

Nickel

Silver

Zinc

Biota

Constituent

Cadmium 

Chromium 

Copper 

Iron 

Lead

Manganese 

Nickel

Zinc

1 Prior to March 1993, water-quality constituents included only trace elements and 

suspended sediment.

methods provide a vertically and laterally dischargeweighted sample that is representative of the entire 

flow through the cross section of a stream. Sampling 

equipment consisted of standard USGS depthintegrating suspended-sediment samplers (DH-48TM 

and D-74TM) which are equipped with nylon nozzles 

and coated with a non-metallic epoxy paint.

Onsite measurements of water temperature, specific conductance, and pH were made during collection 

of periodic water-quality samples. Onsite sample processing, including filtration and acidification, was performed according to Ward and Hair (1990), USGS 

(1977), Knapton (1985), and internal agency memoranda (A.J. Horowitz, U.S. Geological Survey, written 

commun., 1993). Instantaneous streamflow at the time 

of water sampling was determined at all stations, either 

by direct measurement or from stage-discharge rating 

tables (Rantz and others, 1982).

Water samples were analyzed for the major ions 

and trace elements listed in table 2 by the USGS 

National Water Quality Laboratory (NWQL) in Denver, Colo. Trace elements were analyzed for both dissolved and total-recoverable concentrations. Analytical 

methods are described by Fishman and Friedman 

(1989) and Fishman (1993).

Cross-sectional water samples also were collected for analysis of suspended sediment whenever 

periodic water-quality samples were collected. These 

samples were analyzed for suspended-sediment concentration and particle-size distribution (percent less 

than 0.062 mm diameter) by the USGS sediment laboratory in Helena, Mont., according to methods 

described by Guy (1969) and Lambing and Dodge 

(1993).

At the six daily suspended-sediment stations 

listed in table 1, suspended-sediment samples were collected 2 to 7 times per week. These samples were collected by local contracted observers using depth 

integration at a single vertical near mid-stream and 

were analyzed for suspended-sediment concentration. 

Suspended-sediment samples were collected by 

observers at a frequency sufficient to determine daily 

mean concentrations according to methods described 

by Porterfield (1972).

Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Ciark Fork basin, Mont.
Results

Water-quality data for samples collected periodically during October 1992 through September 1993 

(water year 1993) are presented in table 4. The types of 

data include instantaneous stream flow, onsite measurements of water-quality properties, and analytical 

results for chemical constituents and suspended sediment. Missing data for anions on March 8,1993 at two 

stations (stations 12323250 and 12323600) were the 

result of incorrect sample preservation in the field. 

Other missing data are described under "Quality Assurance" later in this section.

Daily streamflow and suspended-sediment data 

for water year 1993 at the six daily suspended-sediment 

stations are given in tables 5 to 10. Monthly descriptive statistics for each parameter are provided along 

with totals for the annual or partial-year discharge of 

water and suspended sediment.

Quality Assurance

Quality-assurance procedures used for the collection and field processing of water-quality samples 

are described by Ward and Harr (1990), Edwards and 

Glysson (1988), Knapton (1985), Knapton and Nimick 

(1991), and A.J. Horowitz (U.S. Geological Survey, 

written commun., 1993). Standard procedures used by 

the NWQL for internal sample handling and quality 

assurance are described by Friedman and Erdmann 

(1982), Jones (1987), and Pritt and Raese (1992). 

Quality-assurance procedures used by the Montana 

District sediment laboratory are described by Lambing 

and Dodge (1993).

The quality of analytical results reported for 

water-quality samples was evaluated by quality-control 

samples that were submitted concurrently from the 

field. These quality-control samples consisted of replicates, spikes, and blanks which provide quantitative 

information on the precision and bias of the overall 

field and laboratory process. Each type of qualitycontrol sample was submitted at a proportion equivalent to about 5 percent of the total number of waterquality samples. Therefore, the total number of 

quality-control samples represented about 15 percent 

of the total number of water-quality samples.

In addition to quality-control samples submitted 

from the field, internal quality-assurance practices 

within the laboratory are performed systematically to 

provide quality control of analytical procedures (Pritt 

and Raese, 1992). These internal practices include 

analyses of quality-control samples such as calibration 

standards, standard reference water samples, replicate

samples, deionized-water blanks, or spiked samples at 

a proportion equivalent to at least 10 percent of the 

sample load. The NWQL participates in a blindsample program where standard reference water samples prepared by the USGS Branch of Quality Assurance are routinely inserted into the sample train for 

each analytical method at a frequency proportional to 

the sample load. The NWQL also participates in external evaluation studies twice-yearly with the U.S. Environmental Protection Agency, the Canadian Center for 

Inland Water, and the USGS Branch of Quality Assurance to assess analytical performance.

Replicate samples are two or more samples considered to be essentially identical in composition. 

Analyses of replicate samples indicate the precision 

(reproducibility) of results. Precision is affected by 

numerous sources of variability within the field and 

laboratory environments, including sample collection, 

sample processing, and sample analysis. To provide 

data on precision, replicate samples were obtained in 

the field by splitting a composite stream sample. The 

replicate samples were submitted concurrently for 

analysis. Analyses of field replicates document overall 

precision of environmental data, which is affected by 

the combined variability of field and laboratory processes to which the sample is exposed. Another means 

to evaluate precision is to make replicate analyses of an 

individual sample. Replicate analyses were made in 

the laboratory on a single stream sample selected randomly from tiie group of samples comprising each analytical run. A separate analysis of the sample was made 

at the beginning and end of each analytical run to provide information on laboratory analytical precision 

independent of field collection, processing, and exposure.

Spiked samples are used to evaluate the ability of 

an analytical method to accurately measure a known 

amount of analyte added to a sample. Deionized-water 

blanks and aliquots of stream samples were spiked in 

the laboratory with known amounts of the trace elements analyzed in water samples. Analyses of spiked 

blanks indicate if the spiking procedure and analytical 

method are within control for a water matrix that is presumably free of chemical interference. Analyses of 

spiked aliquots of stream samples indicate if the chemical matrix of ambient stream water interferes with the 

analytical measurement and whether these interferences could contribute significant bias to reported 

trace-element concentrations for stream samples.

Samples of deionized-water blanks were routinely analyzed to identify the presence and magnitude 

of contamination that potentially could bias analytical 

results. The particular type of blank sample routinely 

tested was a "field" blank. Field blanks are aliquots of

WATER-QUALITY DATA
ultra-pure deionized water that are processed through 

the same sampling equipment used to collect stream 

samples and subjected to the same processing (sample 

splitting, filtration, preservation, transportation, and 

laboratory handling) as stream samples. Blank samples 

are shipped to the laboratory with stream samples and 

analyzed for the same constituents.

All water samples were handled in accordance 

with chain-of-custody procedures that provide documentation of sample identity, shipment, receipt, and 

laboratory handling. All samples submitted from a 

sampling episode were stored and analyzed as a group 

independent of other samples submitted to the NWQL. 

Therefore, quality-control data generated to assure the 

quality of environmental data for this program are specific to the analytical results reported herein. Internal 

laboratory quality-control data provide additional evidence of the performance of the analytical process.

Data-quality objectives (table 3) were established for water-quality data as part of the study plan 

for the long-term monitoring program. The objectives 

identify analytical requirements of detectability and 

serve as a guide for identifying questionable data by 

establishing limits for precision and bias of laboratory 

results. Comparisons of quality-control data to objectives are used to evaluate whether sampling and analytical procedures are producing environmentally 

representative data in a consistent manner. Data that 

did not meet the objectives were evaluated for acceptability, and corrective action was taken, when appropriate.

The precision of analytical results for a constituent can be determined by estimating a standard deviation from the differences of several sets of replicate 

measurements. These replicate measurements may 

consist either of individual analyses of a pair of samples considered to be essentially identical (field replicates) or multiple analyses of an individual sample 

(laboratory replicates). The differences in concentration between replicate analyses can be used to estimate 

a standard deviation according to the following equation (Taylor, 1987):

S = (1)

where:

S = standard deviation of the difference in concentration between replicate analyses,

d = difference in concentration between each 

pair of replicate analyses, and

k = number of pairs of replicate analyses.

Precision can also be expressed as a relative standard deviation (RSD), in percent, which is computed 

from the standard deviation and the mean concentration for all the replicate analyses. Expressing precision 

relative to a mean concentration standardizes comparison of precision among individual constituents. The 

RSD, in percent, is calculated according to the following equation (Taylor, 1987):

RSD = Ix (100) (2)

<\>

where:

RSD = relative standard deviation, 

S = standard deviation, and

* = mean of all replicate concentrations.

Paired chemical analyses of field replicates are 

presented in table 11 and the overall precision estimated for each constituent based on these results is 

reported in table 12. Analytical precision for constituents based on replicate analyses of individual samples 

by the laboratory is reported in table 13. Statistics for 

precision of field-replicate analyses were based on the 

values reported in table 11 which are rounded to standard USGS reporting levels for the particular constituent and its analytical method (Timme, 1994). Statistics 

for precision of laboratory-replicate analyses are based 

on unrounded values stored in laboratory data files. 

Concentrations less than the minimum reporting level 

(censored values) were included in the calculations by 

arbitrarily substituting a value of one-half the reporting 

level.

The data-quality objective for precision, based 

on laboratory-replicate analyses, is a maximum relative 

standard deviation of 20 percent. Precision estimates 

for laboratory-replicate analyses were within the 20- 

percent relative standard deviation limits for all constituents (table 13). The precision data, therefore, indicate 

acceptable reproducibility of analytical results. 

Although the data-quality objectives are not directly 

applicable to precision estimated from analyses of field 

replicates owing to the additional potential of variability in the field environment, relative standard deviations estimated from analyses of field replicates also 

were within 20 percent for all constituents except dissolved iron and dissolved lead (table 12). One replicate 

sample pair (Blacktail Creek at Harrison Avenue, 

August 1993) accounted for the exceedance of 20 percent for dissolved iron. Elimination of this replicate 

pair from the data set results in a relative standard deviation of 9.6 percent for dissolved iron. The other element that exceeded 20-percent precision for analyses 

of field replicates was dissolved lead. This exceedance 

resulted from substituting one-half the minimum

Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 3. Data-quality objectives for analyses of water-quality samples collected in the upper Clark Fork basin, 

Montana

[Abbreviations: ug/L, micrograms per liter, uS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter. 

Symbol: --, not determined]

Data-quality objectives

Detectability

Property or constituent

Specific conductance

pH

Hardness

Calcium, dissolved

Magnesium, dissolved

Sodium, dissolved

Potassium, dissolved

Alkalinity, dissolved

Sulfate, dissolved

Chloride, dissolved

Fluoride, dissolved

Silica, dissolved

Arsenic, total recoverable

Arsenic, dissolved

Cadmium, total recoverable

Cadmium, dissolved

Copper, total recoverable

Copper, dissolved

Iron, total recoverable

Iron, dissolved

Lead, total recoverable

Lead, dissolved

Manganese, total recoverable

Manganese, dissolved

Zinc, total recoverable

Zinc, dissolved

Sediment, suspended

Sediment, suspended,

(percent finer than 0.062 mm)

Precision

... , Maximum relative Minimum . . . , , standard deviation reporting of laboratory level, replicate analyses, In units

1

.1

1

.02

.01

.1

.1

1

.1

.1

.1

.1

1

1

1

.1

1

1

10

3

1

.5

10

1

10

3

1

1

|iS/cm

units

mg/L as CaCC>3

mg/L

mg/L

mg/L

mg/L

mg/L as CaCC>3

mg/L

mg/L

mg/L

mg/L

W/L

^g/L

^g/L

W5/L 1

^g/L

^g/L

Hg/L

Hg/L

^g/L

^g/L 1

^g/L

^g/L

^g/L

^g/L

mg/L

percent

in percent

2

5

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

20

--

--

Bias

Maximum 

deviation of 

spike recovery, 

in percent

-

~

~

-

-

-

--

--

-

-

-

-

25

25

25

25

25

25

25

25

25

25

25

25

25

25

-

--

Minimum reporting level prior to March 1993 was 1 |ig/L.

reporting level for several censored values where the 

concentration for the paired replicate sample was at or 

slightly greater than the minimum reporting level. 

Replacing one-half the value with the actual minimum 

reporting level results in a relative standard deviation 

of 8.0 percent for dissolved lead.

Analyses of paired spiked and unspiked samples 

enable calculation of the spike recovery for each trace 

element and thereby provide a measure of the recovery 

efficiency for the analytical method. Spike recovery, in 

percent, was calculated using the following equation:

Spike recovery in percent = spiked sample concentration - unspiked sample concentration x 100

spike concentration (3)

WATER-QUALITY DATA
The data-quality objective for acceptable spike 

recovery of trace elements in water samples was a maximum deviation of 25 percent from a theoretical 100- 

percent recovery of added constituent. If the spike 

recovery for a trace element is outside a range of 75 to 

125 percent, the sample set for the analytical run is 

reanalyzed for the trace element. Results of spike 

recoveries of individual trace elements in spiked 

deionized-water blanks and spiked stream samples are 

presented in tables 14 and 15, respectively. The mean 

spike recovery for all deionized-water and stream samples spiked with trace elements ranged from 93.4 to 

106.5 percent. The 95-percent confidence intervals for 

the mean (Taylor, 1987) of spike recovery for each constituent did not exceed a 25-percent deviation from an 

expected 100-percent recovery. Consequently, spike 

recoveries for each trace element were within the limits 

of data-quality objectives and indicate acceptable analytical performance. However, bias is indicated if the 

confidence interval does not include 100 percent. Confidence intervals for analytical recoveries of dissolved 

arsenic, dissolved copper, total recoverable lead, total 

recoverable manganese, and total recoverable zinc did 

not include 100 percent. For these elements, the bias 

was slightly low in every instance, with mean spike 

recovery ranging from 94.0 to 97.4 percent of complete recovery. Because all identified bias was small 

and mean spike recoveries met data-quality objectives, 

no adjustments were made to analytical results for 

stream samples on the basis of spike recoveries.

Analytical results for field blanks are presented 

in table 16. A field blank with constituent concentrations equal to or less than the minimum reporting level 

for the analytical method indicates that the entire sample collection, processing, and analytical process is 

presumably free of significant contamination. If 

detectable concentrations in field blanks were equal to 

or greater than twice the minimum reporting level (typical measurement precision at the detection level), the 

concentrations were noted. Sporadic, infrequent 

exceedances of twice the minimum reporting level 

probably represent random contamination that is not 

persistent in the process and which is not likely to cause 

significant positive bias in analytical results. However, 

the field blank for the next sample set is evaluated for a 

consistent trend that may indicate systematic contamination. When concentrations for a particular constituent exceeded twice the minimum reporting level in 

field blanks from two consecutive field trips, archived 

blank samples collected for individual components of 

the processing sequence were submitted for analysis in 

order to identify the source of contamination.

Constituent concentrations in field-blanks were 

almost always less than the minimum reporting level.

Exceedances of twice the minimum reporting level 

generally were infrequent and random, thereby indicating no systematic positive bias of reported waterquality data. However, exceedances of twice the minimum reporting level for lead occurred in two consecutive blank samples, which warranted testing for a 

potential source of contamination. Although the two 

consecutive field blanks indicated only low-level lead 

contamination, unusually high concentrations of lead 

and moderately high concentrations of copper relative 

to historic data were noted sporadically in several 

stream samples collected during water year 1993. This 

potential contamination was investigated with a series 

of blank samples collected during several field tests to 

verify if elevated concentrations measured in stream 

samples represented actual environmental conditions 

or were an artifact of contamination. On the basis of 

field notes, all elevated lead concentrations were determined to have occurred in samples collected with the 

D-74TM sampler. The results of tests conducted on 

sampling equipment, field processing, and laboratory 

analyses indicated that elevated concentrations of lead 

and copper resulted from random field contamination. 

The specific source of contamination was determined 

to be the interior metal surface in the vent portal of the 

D-74TM sampler. Leaching of lead and copper apparently occurred during between-site rinsing of the 

D-74TM sampler with 5-percent hydrochloric acid. 

Acid-rinsing of D-74TM samplers was discontinued 

immediately upon confirmation of the source of contamination.

Review of lead and copper data relative to previous baseline concentrations, hydrologic conditions at 

the time of sampling, and results for samples collected 

from nearby stations identified 17 samples for lead and 

7 samples for copper collected from March through 

September 1993 that were potentially affected by contamination. These lead and copper values were deleted 

from the data base and are indicated as dashes in table 

4.

BED-SEDIMENT DATA

Bed-sediment data consist of analyses of solidphase concentrations of trace elements in the fine and 

bulk fractions. Bed-sediment samples were collected 

once-annually during low, stable flow conditions to 

facilitate data comparisons between years.

Methods

Bed-sediment samples were collected using protocols described by E.V. Axtmann (U.S. Geological

8 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Survey, written commun., 1994). Samples were collected using an acid-washed polypropylene scoop from 

the surfaces of exposed streambed deposits near the 

edge of the stream. Samples were collected from both 

sides of the stream whenever possible. Three composite samples of fine-grained bed sediment and one to 

three composite samples of bulk bed sediment were 

collected at each site.

Individual samples of fine-grained bed sediment 

were collected from the surfaces of 3 to 5 randomly 

selected deposits along pool or low-velocity areas. The 

3 to 5 individual samples were combined to form a single composite sample. This collection process was 

repeated three times to obtain three composite samples. 

Each composite sample was wet-sieved onsite through 

a 0.064 mm nylon-mesh sieve using ambient stream 

water. The fraction of bed sediment in each composite 

sample that was finer than 0.064 mm was transferred to 

an acid-washed 500 mL high-density polyethylene bottle and transported to the laboratory on ice.

Individual samples of bulk sediment also were 

collected from the surfaces of 3 to 5 randomly selected 

deposits. Because the streambed at most sampling 

locations is predominantly gravel and cobble, deposits 

were selected where cobbles and gravel could be visually excluded from the samples. The individual samples were composited and, where possible, the 

collection process was repeated to obtain multiple 

composite samples. The material in each composite 

sample was homogenized by stirring in a 1-L, acidwashed, polyethylene beaker. The unsieved, mixed 

material was split into two subsamples using a 

stainless-steel sediment splitter pre-rinsed with ambient stream water. One subsample was archived for 

grain-size analysis. The other subsample was stored in 

an acid-washed polyethylene bottle and transported to 

the laboratory on ice.

Bed-sediment samples were processed at the 

USGS National Research Program laboratory in Boulder, Colo. Bed-sediment samples were oven-dried at 

60 °C and ground using an acid-washed ceramic mortar 

and pestle. Duplicate aliquots of approximately 0.6 g 

of sediment from each composite sample were digested 

using a hot, concentrated nitric acid reflux according to 

methods described by Luoma and Bryan (1981). After 

a digestion period of up to several weeks, the duplicate 

aliquots were evaporated to dryness on a hot plate. The 

dry residue was redissolved with 20 mL of 0.6 N (normal) hydrochloric acid. The reconstituted aliquots then 

were filtered through a 0.45-u,m filter using a syringe 

and in-line disposable filter cartridge. The filtrate was 

subsequently diluted to either a 1:5 or 1:10 ratio with 

0.6 N hydrochloric acid. These final duplicate solutions then were analyzed for cadmium, chromium, copper, iron, lead, manganese, nickel, silver, and zinc 

using Inductively Coupled Argon Plasma Emission 

Spectroscopy (ICAPES) at the USGS National 

Research Program laboratory in Menlo Park, Calif.

Results

Solid-phase concentrations of trace elements 

measured in samples of fine bed sediment and bulk bed 

sediment collected during August 1993 are summarized in tables 17 and 18, respectively. Liquid-phase 

concentrations, in (ig/mL, that were analyzed in the 

reconstituted aliquots of digested bed sediment were 

converted to solid-phase concentrations, in (ig/g, using 

the following equation:

ug/g = (ig/mL x volume of digested sample, in mL 

dry weight of sample, in g x dilution ratio (4)

The reported solid-phase concentrations in table 17 

and 18 represent the means of all analyses of duplicate 

aliquots from each composite sample collected at the 

site. Because the conversion from liquid-phase to 

solid-phase concentration is dependent on both the 

dilution ratio and the dry weight of the sample, minimum reporting levels for some trace elements may 

differ between stations.

Quality Assurance

The protocols for field collection and processing 

of bed-sediment samples are designed to prevent contamination from metal sources. Non-metallic sampling 

and processing equipment were acid-washed and 

rinsed with deionized water prior to the first sample 

collection. Stainless-steel equipment and nylon-mesh 

sieves were washed in a laboratory-grade detergent and 

rinsed with deionized water. All equipment was given 

a final rinse onsite with stream water. Samples were 

collected along an increasing contamination gradient 

from the least contaminated sites (downstream tributaries and mainstem) to the most contaminated sites 

(upstream mainstem) to minimize any effects from 

potential station-to-station carryover contamination. 

Sampling equipment that was reused at each site was 

rinsed between sites with 10-percent nitric acid, deionized water, and stream water. Separate sieves were 

used at each site and therefore did not require betweensite cleaning.

Quality assurance of analytical results for bed 

sediment included laboratory instrument calibration

BED-SEDIMENT DATA
with standard solutions and analysis of quality-control 

samples designed to identify the presence and magnitude of bias (E.V. Axtmann, U.S. Geological Survey, 

written commun., 1994). Quality-control samples consisted of standard reference material and procedural 

blanks. Each type of sample was analyzed in a proportion equivalent to about 10 to 20 percent of the total 

number of bed-sediment samples.

Standard reference materials have certified concentrations of trace elements. Replicate analyses of 

standard reference materials are used to indicate the 

repeatability of measurements and the ability of the 

method to accurately measure a known quantity of a 

constituent. Recovery efficiency of trace-element analyses of standard reference materials for bed sediment is 

summarized in table 19. Two standard reference material samples of agricultural soil were analyzed to test 

recovery efficiency for a range of trace-element concentrations similar to those occurring in the upper 

Clark Fork basin. The digestion process used to analyze bed-sediment samples is not a "total" digestion 

(does not liberate elements associated with crystalline 

lattices); therefore, 100-percent recovery may not be 

achieved for elements strongly bound to the sediment. 

The percent recovery of trace elements in standard reference materials under such conditions serve to indicate which trace elements display strong sedimentbinding characteristics and whether analytical recovery 

is consistent between multiple sets of analyses. 

Although data-quality objectives have not been established for bed sediment, only chromium had a mean 

recovery (53 percent) that was outside a 25-percent 

deviation from complete recovery.

Procedural blanks for bed-sediment samples 

consisted of 0.6 N hydrochloric-acid samples that were 

processed using the same digestion method as that used 

for analysis of bed-sediment samples. After digestion, 

0.6 N hydrochloric acid was added quantitatively to 

obtain the same dilution ratio as that used in the analysis of bed sediment. Procedural blanks, therefore, represent the same chemical matrix as the solution used to 

reconstitute bed-sediment samples. Analytical results 

for procedural blanks indicate the presence and magnitude of potential contamination associated with sample 

handling and analysis in the laboratory environment. 

Results of trace-element analyses of procedural blanks 

for bed sediment are in table 20.

Analytical results of procedural blanks are 

reported as a liquid-phase concentration, in (ig/mL, 

which is equivalent to parts per million. Determination 

of the significance of a detectable blank concentration 

is based on the magnitude of the equivalent solid-phase 

concentration, in (ig/g, relative to the ambient concentration of the trace element in bed-sediment samples.

Because sample weights of individual aliquots may 

vary, the relative significance of blank concentrations 

may differ among samples. If a detectable blank concentration, after conversion to a solid-phase concentration, represents 10 percent or more of the ambient 

solid-phase concentration, then the blank concentration 

is subtracted to remove potential contamination bias. 

The maximum solid-phase bias identified by blank 

samples represented less than 3 percent of the lowest 

ambient trace-element concentration in bed-sediment 

samples. Therefore, no adjustments were made to 

trace-element concentrations in bed-sediment samples 

on the basis of procedural blanks.

BIOLOGICAL DATA

Biological data consist of analyses of solid-phase 

concentrations of trace elements in the whole-body tissue of aquatic benthic insects. Biota samples were collected once-annually at the same stations where bed 

sediment was sampled (table 1). Biota samples were 

collected concurrently with bed-sediment samples to 

facilitate comparisons of results between years and 

between the two media.

Methods

Biota samples were collected using protocols 

described by M.I. Hornberger (U.S. Geological Survey, 

written commun., 1994). Immature stages of aquatic 

benthic insects were collected using a large nylonmesh kick net. A single riffle at each station was sampled repeatedly until an adequate number of individuals was collected to provide sufficient mass for 

analysis. Targeted taxa for collection were Hydropsyche spp., Family Trichoptera; Arctopsyche grandis, 

Family Trichoptera; and Claassenia sabulosa, Family 

Plecoptera. Samples of each taxon were stored separately, by genus, in acid-washed plastic containers. 

Containers were kept on ice in the field while the 

insects were allowed to evacuate the gut contents in 

ambient stream water for a period of six to eight hours. 

Excess water then was drained and insects were frozen 

for transport to the laboratory.

Biota samples were processed and analyzed at 

the USGS National Research Program laboratory in 

Menlo Park, Calif. Insects were thawed and rinsed 

with ultra-pure deionized water to remove paniculate 

matter. The insects then were sorted to their lowest 

possible taxonomic level. Similar-sized individuals 

within each taxon were composited into one to six replicate subsamples, depending on the total number of 

specimens collected at the station. Each subsample

10 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont
consisted of a minimum total dry weight of 50 mg. 

Subsamples were placed in tared scintillation vials and 

oven-dried at 70 °C. Subsamples were weighed to 

obtain a final dry weight and digested by reflux using 

concentrated nitric acid (Cain and others, 1992). After 

digestion, insect samples were evaporated to dryness 

on a hot plate. The dry residue was reconstituted in 0.6 

N hydrochloric acid, filtered through a 0.45-jim filter, 

and analyzed undiluted by ICAPES for calcium, chromium, copper, iron, lead, manganese, nickel, and zinc.

Results

Solid-phase concentrations of trace elements in 

whole-body tissue of aquatic insects collected during 

August 1993 are summarized in table 21. An insufficient number of insects of the targeted taxa were found 

for analysis at Silver Bow Creek at Opportunity during 

the 1993 sampling visit. Liquid-phase concentrations 

analyzed in the reconstituted samples were converted 

to solid-phase concentrations using equation 4. As in 

bed sediment, minimum reporting levels may differ 

between sites as a result of variable sample weights.

Quality Assurance

The protocols for field collection and processing 

of biota samples are designed to prevent contamination 

from metal sources. Non-metallic nets, sampling, and 

processing equipment were employed in all sample 

collection. Equipment was acid-washed and rinsed in 

ultra-pure deionized water prior to the first sample collection. Biota samples were collected concurrently 

with bed sediment samples along an increasing contamination gradient to prevent station-to-station carryover contamination. Nets and any reused equipment 

were thoroughly rinsed in ambient stream water at each 

new station.

Quality assurance of analytical results for biota 

included laboratory instrument calibration with standard solutions and analyses of quality-control samples 

designed to identify the presence and magnitude of bias 

(M.I. Hornberger, U.S. Geological Survey, written 

commun., 1994). Quality-control samples consisted of 

standard reference material and procedural blanks. 

Each type of sample was analyzed in a proportion 

equivalent to about 10 to 20 percent of the total number 

of biota samples.

Recovery efficiency of trace-element analyses of 

standard reference material for biota is summarized in 

table 22. The reference material tested was oyster tissue. Data-quality objectives have not been established

for analytical recovery in biota, but mean percent 

recoveries were within 12 percent of complete recovery for all trace elements, with the exception of lead 

(mean recovery within 26 percent). A low bias is indicated for iron, manganese, nickel, and zinc (confidence 

interval does not include 100 percent). The cause of 

this minor bias is unknown, but no adjustments to 

insect data were warranted.

Results of trace-element analyses of procedural 

blanks for biota are in table 23. Procedural blanks for 

biota were analyzed undiluted at a proportion of one 

blank per site. Analytical results for blanks indicated 

no significant contamination bias, with one exception. 

It was determined that a correction was warranted for 

lead concentrations in biota samples from Rock Creek 

because of the low ambient trace-element concentrations in insects relative to the potential contamination 

bias. Therefore, the blank concentrations for lead were 

subtracted from the original analytical values for Rock 

Creek insect samples, resulting in a decrease in solidphase lead concentrations of 1.2 jig/g for Hydropsy'che, 

0.2 (ig/g for Arctopsyche, and 0.5 (ig/g for Claassenia. 

The adjusted values are reported in table 21. No other 

adjustments for procedural blanks were necessary 

because all other blanks had concentrations less than 10 

percent of ambient solid-phase trace-element concentrations in insects.

STATISTICAL SUMMARIES OF WATERQUALITY DATA

Statistical summaries of water-quality data are 

provided in table 24 for the period of record at each station since 1985. The summaries include the range, 

mean, and median of concentrations and were calculated using standard computer programs within the 

USGS National Water Information System. Documentation of the programs is provided in Maddy and others 

(1989).

SELECTED REFERENCES

Axtmann, E.V., and Luoma, S.N., 1991, Large scale distribution of metal contamination in the fine-grained sediment of the Clark Fork River, Montana: Applied 

Geochemistry, v. 6, p. 75-88.

Cain, D.J., Luoma, S.N., Carter, J.L., and Ferd, S.V., 1992, 

Aquatic insects as bioindicators of trace element contamination in cobble-bottom rivers and streams: Canadian Journal of Fisheries and Aquatic Sciences, v. 49, 

no. 10, p. 2,141-2,154.

Edwards, T.K., and Glysson, G.D., eds., 1988, Field methods 

for measurement of fluvial sediment: U.S. Geological 

Survey Open-File Report 86-531,118 p.

STATISTICAL SUMMARIES OF WATER-QUALITY DATA 11
Fishman, MJ., 1993, Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory-- 

Determination of inorganic and organic constituents in 

water and fluvial sediments: U.S. Geological Survey 

Open-File Report 93-125,217 p.

Fishman, MJ., and Friedman, L.C., 1989, Methods for 

determination of inorganic substances in water and fluvial sediments: U.S. Geological Survey Techniques of 

Water-Resources Investigations, Book 5, Chap. Al, 

709 p.

Friedman, L.C., and Erdman, D.E., 1982, Quality assurance 

practices for the chemical and biological analyses of 

water and fluvial sediments: U.S. Geological Survey 

Techniques of Water-Resources Investigations, Book 5, 

Chap. A6,181 p.

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

Water-Resources Investigations, Book 5, Chap. Cl, 58

PGuy, H.P., and Norman, V.W., 1970, Field methods for measurement of fluvial sediment: U.S. Geological Survey 

Techniques of Water-Resources Investigations, Book 5, 

Chap. Cl, 58 p.

Helsel, D.R., and Conn, T.A., 1988, Estimation of descriptive statistics for multiply censored water quality data: 

Water Resources Research, v. 24, no. 12, p. 1,997- 

2,004.

Jones, B.E., 1987, Quality control manual of the U.S. Geological Survey's National Water Quality Laboratory: 

U.S. Geological Survey Open-File Report 87-457,17 p.

Knapton, J.R., 1985, Field guidelines for collection, treatment, and analysis of water samples, Montana District: 

U.S. Geological Survey Open-File Report 85-409,86 p.

Knapton, J.R., and Nimick, D.A., 1991, Quality assurance 

for water-quality activities of the U.S. Geological Survey in Montana: U.S. Geological Survey Open-File 

Report 91-216,41 p.

Lambing, J.H., 1987, Water-quality data for the Clark Fork 

and selected tributaries from Deer Lodge to Milltown, 

Montana, March 1985 through June 1986: U.S. Geological Survey Open-File Report 87-110,48 p.

____ 1988, Water-quality data (July 1986 through September 1987) and statistical summaries (March 1985 

through September 1987) for the Clark Fork and 

selected tributaries from Deer Lodge to Missoula, Montana: U.S. Geological Survey Open-File Report 88- 

308,55 p.

___1989, Water-quality data (July 1987 through September 1988) and statistical summaries (March 1985 

through September 1988) for the Clark Fork and 

selected tributaries from Galen to Missoula, Montana: 

U.S. Geological Survey Open-File Report 89-229,51 p.

_1990, Water-quality data (July 1988 through September 1989) and statistical summaries (March 1985 

through September 1989) for the Clark Fork and 

selected tributaries from Galen to Missoula, Montana: 

U.S. Geological Survey Open-File Report 90-168,68 p. 

_, 1991, Water-quality and transport characteristics of

suspended sediment and trace elements in streamflow 

of the upper Clark Fork basin from Galen to Missoula, 

Montana, 1985-90: U.S. Geological Survey WaterResources Investigations Report 91-4139,73 p.

Lambing, J.H., and Dodge, K.A., 1993, Quality assurance 

for laboratory analysis of suspended-sediment samples 

by the U.S. Geological Survey in Montana: U.S. Geological Survey Open-File Report 93-131, 34 p.

Luoma, S.N., and Bryan, G.W., 1981, A statistical assessment of the form of trace metals in oxidized estuarine 

sediments employing chemical extractants: Science of 

the Total Environment, v. 17, p. 167-196.

Maddy, D.V., Lopp, L.E., Jackson, D.L, Coupe, R.H., and 

Schertz, T.L., 1989, National Water Information System user's manual, v. 2, Chap. 2, Water-quality system: 

U.S. Geological Survey Open-File Report 89-617, various paging.

Porterfield, George, 1972, Computation of fluvial-sediment 

discharge: U.S. Geological Survey Techniques of 

Water-Resources Investigations, Book 3, Chap. C3,66 

PPritt, J.W, and Raese, J.W., eds., 1992, Quality assurance/ 

quality control manual-National Water Quality Laboratory: U.S. Geological Survey Open-File Report 92- 

495,33 p.

Rantz, S.E., and others, 1982, Computation of discharge: 

U.S. Geological Survey Water-Supply Paper 2175 (2 

v.),631p.

Shields, R.R., Knapton, J.R., White, M.K., Brosten, T.M., 

and Chambers, C.L., 1990, Water resources data, Montana, water year 1990: U.S. Geological Survey Water 

Data Report MT-90-1,540 p.

____1991, Water resources data, Montana, water year 

1991: U.S. Geological Survey Water Data Report MT91-1,528 p.

____1992, Water resources data, Montana, water year

1992: U.S. Geological Survey Water Data Report MT92-1,534 p.

Shields, R.R., White, M.K., Brosten, T.M., and Chambers, 

C.L., 1993, Water resources data, Montana, water year 

1993: U.S. Geological Survey Water Data Report MT93-1,512 p.

Taylor, J. K., 1987, Quality assurance of chemical measurements: Chelsea, Mich., Lewis Publishers, 328 p.

12 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont
Timme, P.J., 1994, National Water Quality Laboratory 1994 Ward, J.R., and Harr, C.A., eds., 1990, Methods for collecServices Catalog: U.S. Geological Survey Open-File tion and processing of surface-water and bed-material

Report 94-304,103 p. samples for physical and chemical analyses: U.S. GeoTTO _ , . , ,«--^T , * - , f logical Survey Open-File Report 90-140,71 p. U.S. Geological Survey, 1977, National handbook of recom- 6 } * ^ F

mended methods for water-data acquisition-Chapter 5, 

Chemical and physical quality of water and sediment: 

193 p.

SELECTED REFERENCES 13
DATA

14 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993

[Abbreviations: ft3/s, cubic feet per second; °C, degrees Celsius; e, instantaneous streamflow estimated from daily mean streamflow; flg/L, 

micrograms per liter; jiS/cm, microsiemens per centimeter at 25 °C; mg/L, milligrams per liter, mm, millimeter; ton/d, tons per day. 

Symbols: <, less than minimum reporting level; , no data]

12323230--BLACKTAIL CREEK AT HARRISON AVENUE, AT BUTTE, MONT

Date

Mar 1993

08...

Apr

12...

26...

May

14...

24...

Jun

06..

Jul

12...

Aug

16..

Stream- Specific 

flow, conductTime Instan- ance, 

taneous onslte 

(fr/s) (uS/cm)

1040

1215

1115

1440

1125

1415

1215

1100

3.1

7.5

9.0

7.9

6.6

7.1

6.6

9.3

320

245

206

240

252

259

282

257

pH, 

onslte 

(standard 

units)

7.7

7.9

7.9

7.8

7.9

7.9

8.2

7.7

Temperature, 

water

5.0

4.0

8.0

17.0

11.0

10.0

12.0

12.0

Hardness, 

total 

(mg/L 

as 

CaCOg)

120

92

73

100

110

110

110

100

Calcium, "?,?£?" Sodium, 

dls- '""' dissolved C °I«IH solved 

C"^' (mS£) <m9/L>

35 8.4 16

26 6.6 11

21 5.1 11

29 6.7 9.4

31 7.3 11

31 7.4 11

33 7.8 11

30 6.7 9.1

Potassium, dissolved 

(mg/L)

3.0

2.3

2.1

2.5

2.3

2.5

2.4

2.5

Alkalinity, 

(mg/L 

as 

CaCOg)

100

79

62

79

86

89

100

98

Date

Mar 1993

08...

Apr

12...

26...

May

14....

24...

Jun

06...

Jul

12..

Aug

16...

Sulfate, dissolved 

(mg/L)

34

28

21

30

29

29

28

20

Chloride, dissolved 

(mg/L)

8.4

8.7

8.9

5.4

5.7

5.3

3.8

4.8

Fluorlde, dissolved 

(mg/L)

0.2

.3

.6

.3

.3

.4

.3

.4

Silica, dissolved 

(mg/L)

27

20

14

24

24

25

25

28

Solids,

sum of 

constituents, 

dissolved 

(mg/L)

192

150

121

155

162

165

171

161

Arsenic, 

total 

recoverable (ug/L)

3

6

10

7

6

5

7

10

A_-J

Cad Arsenic, mlum, . "

dls- total mJKm' 

solved recov- e«i,,I-i *« 'X 3S?

2 <1 <0.1

2 <1 .1

3 <1 <1

5 <1 <.l

4 <1 <1

4 <1 <.l

5 <1 <1

8 <1 <1

Copper, 

total 

recoverable 

(ug/L)

7

28

52

6

6

7

4

7

Copper, dissolved 

(ug/L)

4

4

9

5

3

4

3

5

Date

Mar 1993

08...

Apr

12...

26...

May

14...

24...

Jim

06...

Jul

12...

Aug

16...

Iron, 

total 

recoverable 

(ug/L)

300

1,700

3,800

470

530

520

450

590

Iron, dissolved 

(ug/L)

59

51

44

150

170

160

200

230

Lead, 

total 

recoverable

1

33

47

1

<1

1

<1

1

Lead, dissolved 

(ug/L)

<0.5

1.0

.5

<5

<.5

<5

<5

<5

Manganese, 

total 

recoverable 

(ug/L)

60

130

190

50

60

60

30

30

Manganese, dissolved 

(ug/L)

51

41

50

33

40

36

17

22

Zinc, Zinc, Sedltotal dls- ment, 

recov- solved suserable (ug/L) pended 

(ug/L) (mg/L)

20 5 7

80 9 91

130 11 123

20 5 6

<10 <3 7

10 <3 5

10 9 3

<10 5 4

Sediment discharge, 

suspended 

(ton/d)

0.06

1.8

3.0

.13

.12

.10

.05

.10

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

61

93

95

92

85

90

90

92

TABLE 4 15
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued) 

12323250--SILVER BOW CREEK BELOW BLACKTAIL CREEK, AT BUTTE, MONT.

Date

Mar 1993

08...

Apr

12...

26...

May

14...

24...

Jun

06...

Jul

12...

Aug

16...

Stream- Specific 

flow, conductTime instan- ance, 

taneous onsite 

(fl3/s) (nS/cm)

1340

1430

1245

1300

1355

1545

1315

1225

21

30

37

24

20

21

22

30

535

440

402

435

460

465

526

485

PH, 

onsite (standard 

units)

7.5

7.5

7.4

7.4

7.8

7.6

7.6

7.5

Temperature, 

water <°C)

9.0

3.0

9.0

15.0

15.5

12.5

15.0

14.5

Hardness, 

total 

(mg/L 

as 

CaCOj)

160

130

130

150

150

140

170

160

Calcium, dissolved 

(mg/L)

47

36

37

45

44

42

48

45

Magnesium, dissolved 

(mg/L)

11

8.9

8.3

10

10

9.7

12

11

Sodium, 

dissolved 

(mg/L)

33

23

18

25

27

22

26

22

Potassium, dissolved 

(mg/L)

7.1

5.1

4.5

5.4

5.1

6.3

5.5

5.2

Alkalinity, 

(mg/L as 

CaCOj)

-

71

65

79

78

78

89

96

Date

Mar 1993

08...

Apr

12...

26...

May

14...

24...

Jun

06...

Jul

12...

Aug

16...

Sulfate, dissolved 

(mg/L)

-

70

76

83

75

77

92

81

Chloride, dissolved 

(mg/L)

-

26

16

20

21

20

23

21

Fluoride, dissolved 

(mg/L)

-

.7

.8

.5

.4

.5

.4

.5

Silica, dissolved 

(mg/L)

-

20

17

22

24

22

23

24

Solids, 

sum of 

constituents, dissolved 

(mg/L)

-

234

218

260

255

248

285

269

Arsenic, 

total 

recoverable 

(ug/L)

17

21

39

17

12

11

14

15

Arsenic, dissolved 

(Mg/L)

10

5

6

7

8

7

9

9

Cadmium, 

total 

recoverable (ug/L)

3

4

6

4

2

3

2

3

Cadmium, dissolved 

(ug/L)

2.4

2.4

2.1

2.4

1.9

2.1

2.3

2.6

Copper, 

total 

recoverable 

(Mg/L)

200

360

550

300

130

150

140

190

"sir

solved 

(ug/L)

80

85

65

120

85

90

110

120

Date

Mar 1993

08...

Apr

12...

26...

May

14...

24...

Jun

06...

Jul

12...

Aug

16...

Iron, 

total 

recoverable 

(ug/L)

860

3,900

7,400

2,100

650

700

500

710

Iron, 

dissolved 

(ug/L)

120

31

26

65

76

56

55

93

Lead, 

total 

recoverable 

(ug/L)

18

84

250

35

7

7

3

13

Lead, 

dissolved 

(ug/L)

1.2

.8

2.4

.9

<.5

<.5

<.5

1.4

Manganese, 

total 

recoverable 

(ug/L)

910

860

1,500

880

680

680

620

820

Manganese, dissolved 

(ug/L)

910

690

810

870

670

660

690

780

Zinc, 

total 

recoverable 

(ug/L)

1,000

1,200

1.600

1,100

790

950

850

1,000

Zinc, 

dissolved 

(Mg/L)

900

780

750

930

710

790

800

930

Sediment, 

suspended 

(mg/L)

16

104

162

28

7

6

5

11

Sediment discharge, 

suspended 

(ton/d)

.91

8.4

16

1.8

.38

.34

.30

.89

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

82

89

93

88

91

87

86

91

16 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12323600--SILVER BOW CREEK AT OPPORTUNITY, MONT.

Date

Mar 1993

08...

16...

Apr

12...

26...

May

14...

24...

Jun

07...

Jul

12...

Aug

16...

Time

1530

1100

1645

1430

0745

1530

0635

1430

1340

Streamflow, Instantaneous 

(ft3/s)

e56

e50

51

49

108

92

104

64

50

Specific 

conductance, 

onsite 

(uS/cm)

370

-

395

388

290

282

301

339

377

PH, 

onsite (standard 

units)

7.6

-

8.3

8.7

8.0

8.5

8.0

8.9

8.6

Temperature, 

water

.5

-

5.0

9.0

10.0

15.5

8.5

16.0

15.5

Hardness, 

total 

(mg/L 

as 

CaCOj)

98

-

140

140

110

110

110

130

130

Calcium, dissolved 

(mg/L)

30

-

41

41

34

33

34

40

40

Magnesium, dissolved 

(mg/L)

5.7

-

8.9

8.7

6.5

6.3

6.7

8.1

8.4

Sodium, dissolved 

(mg/L)

23

-

17

18

12

13

13

15

16

Potassium, dissolved 

(mg/L)

5.8

-

4.2

4.6

3.6

19

3.5

3.1

3.8

Alkalinity, 

(mg/L 

as 

CaC03)

..

-

85

84

78

79

78

93

98

Date

Mar 1993

08...

16...

Apr

12...

26...

May

14...

24...

Jun

07...

Jul

12...

Aug

16...

Sulfate, dissolved 

(mg/L)

-

79

77

49

46

50

58

65

Chloride, dissolved 

(mg/L)

--

12

13

7.3

7.4

7.7

9.0

11

Fluoride, dissolved 

(mg/L)

--

.4

.5

.3

.3

.4

.4

.4

Silica, dissolved 

(mg/L)

-

_

22

21

20

19

19

19

23

Solids, 

sum of 

constituents, dissolved

(mg/L)

-

237

235

ISO

176

182

209

227

Arsenic, 

total 

recoverable

140

-

17

16

26

11

16

12

18

Arsenic, dissolved

(Mfl/L)

34

6

7

13

9

7

8

9

Cadmium, 

total 

recoverable

(Kg )

6

2

2

2

1

2

1

2

Cadmium, dissolved

2.0

1.7

.9

.7

1.0

1.4

.9

1.4

Copper, 

total 

recoverable

(Mfl/L)

980

150

140

190

100

180

140

210

Copper, dissolved

180

46

46

49

45

70

60

160

Date

Mar 1993

08...

16...

Apr

12...

26...

May

14...

24...

Jun

07...

Jul

12...

Aug

16...

Iron, 

total 

recoverable

7.600

1.100

890

1.400

780

1.000

570

630

Iron, dissolved

100

19

25

81

51

87

45

49

Lead, 

total 

recoverable

200

-

15

11

26

12

15

8

10

Lead, dissolved

2.3

<.5

2.2

<.5

.8

<.5

<.5

.6

Manganese, 

total 

recoverable

mg «-/

1.200

710

610

450

340

530

430

810

Manganese, dissolved

750

670

570

350

270

500

400

730

Zinc, 

total 

recoverable

(MI/I-)

1.400

610

470

400

260

600

370

420

Zinc, dissolved 

(Mfl/L)

620

370

190

220

110

430

130

180

Sediment, 

suspended 

(mg/L)

215

384

10

10

40

16

16

10

6

Sediment discharge, 

euspended

(ton/d)

33

52

1.4

1.3

12

4.0

4.5

1.7

.81

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

82

77

92

84

65

70

78

60

80

TABLE 4 17
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12323750-SILVER BOW CREEK AT WARM SPRINGS, MONT.

Date

Mar 1993

09...

Apr

12...

26...

May

14...

19...

24...

Jun

07...

Jul

12...

Aug

16...

Time

0830

1800

1620

0930

1250

1740

0745

1535

1440

Streamflow,- 

instan 

taneous 

(ft3/s)

32

78

75

174

347

289

198

149

84

Specificconductance, 

onsite 

(uS/cm)

580

480

474

495

_

361

382

392

476

pH, 

onsite (standard 

units)

9.0

9.1

9.3

8.4

-

8.5

8.0

8.6

8.4

Temperature, 

water

2.0

6.5

12.0

15.0

17.5

17.5

14.0

17.0

18.5

Hardness, 

total 

(mg/L 

as 

CaC03)

250

190

190

210

-

150

160

170

200

Calcium, dissolved 

(mg/L)

74

56

53

60

-

44

48

52

59

Magnesium, dissolved 

(mg/L)

17

13

14

14

_

9.1

9.1

9.7

12

Sodium, dissolved 

(mg/L)

23

16

17

18

-

14

11

12

13

Potassium, dissolved 

(mg/L)

5.0

5.1

5.4

5.3

-

3.9

3.7

3.5

3.4

Alkalinity, 

(mg/L 

as 

CaC03)

96

87

69

90

-

90

89

95

99

Date

Mar 1993

09...

Apr

12...

26...

May

14...

19...

24...

Jun

07...

Jul

12...

Aug

16...

Sulfate, dissolved 

(mg/L)

170

140

150

140

--

81

87

93

130

Chloride, dissolved 

(mg/L)

15

10

6.6

10

--

7.0

5.4

4.9

5.5

Fluoride, dissolved 

(mg/L)

.8

.7

.7

.9

--

.6

.6

.6

.7

Silica, dissolved 

(mg/L)

16

14

15

14

-

13

11

7.6

8.7

Solids,

sum of 

constituents, dissolved

(mg/L)

379

307

303

317

--

227

229

240

292

Arsenic, 

total 

recoverable (ng/L)

13

19

17

17

-

29

23

24

20

Arsenic, dissolved

(Mfl/M

11

14

14

14

--

27

19

23

18

^_j Cadmium, 

total 

recoverable

<l

<1

<l

<l

--

<1

<l

<1

<l

Cadmium, dissolved 

(Mfl/L)

.1

.2

.1

.2

--

.2

.2

.1

<.l

Copper, 

total 

recoverable

24

60

35

60

--

40

32

27

23

Copper, dissolved

(MI/L)

12

23

18

32

-

21

21

20

10

Date

Mar 1993

09...

Apr

12...

26...

May

14...

19...

24...

Jun

07...

Jul

12...

Aug

16...

Iron, 

total 

recoverable

390

420

300

300

-

340

220

140

170

Iron, dissolved

11

14

5

14

-

27

25

15

11

Lead, 

total 

recoverable

3

5

3

2

-

2

<1

<1

1

Lead, dissolved 

(W/L)

<.5

<.5

<.5

<.5

-

<.5

<.5

<.5

<.5

Manganese, 

total 

recoverable 

(W/L)

490

360

270

440

-

220

190

150

190

Manganese, dissolved

370

180

150

330

-

160

140

110

130

Zinc, 

total 

recoverable 

(Mfl/L)

90

130

70

140

-

90

70

40

50

Zinc, dissolved

18

17

9

73

--

31

37

17

16

Sediment, 

suspended 

(mg/L)

8

13

10

8

13

7

4

3

4

Sediment 

discharge, 

suspended 

(ton/d)

.69

2.7

2.0

3.8

12

5.5

2.1

1.2

.91

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

73

97

92

80

76

86

82

82

85

18 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12323770--WARM SPRINGS CREEK AT WARM SPRINGS, MONT.

Date

Mar 1993

09...

Apr

26...

May

13...

19...

Jun

06...

Aug

18...

Time

1020

1720

1450

1225

1750

1200

Streamflow, instantaneous 

(ft3/s)

26

24

93

206

190

97

Specific 

conductance, 

onsite 

(uS/cm)

455

476

251

_

194

257

PH, 

onsite (standard 

units)

8.2

8.6

8.2

_

8.1

8.3

Temperature, 

water

2.5

12.0

13.0

9.5

8.5

11.0

ness, 

total 

(mg/L 

as 

CaC03)

230

230

120

-

94

120

Calcium, dissolved 

(mg/L)

70

70

38

_

29

36

Magnesium, dissolved 

(mg/L)

13

14

7.0

_

5.2

6.6

Sodium, dissolved 

(mg/L)

5.2

5.1

2.5

-

2.1

2.6

Potassium, dissolved 

(mg/L)

4.7

1.8

1.3

-

1.0

1.2

Alkalinity, 

onsite 

(mg/L as 

CaCOa)

97

139

90

--

71

106

Date

Mar 1993

09...

Apr

26...

May

13...

19...

Jun

06...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

110

110

37

-

25

33

Chloride, dissolved 

(mg/L)

.98

1.7

.80

-

.50

.80

Fluoride, dissolved 

(mg/L)

.4

.4

.4

-

.4

.4

Silica, dissolved 

(mg/L)

11

9.4

9.9

_

9.2

11

Solids, 

sum of 

constituents, dissolvsd

(mg/L)

274

296

151

-

115

155

Arsenic, 

total 

recoverable 

(MI/L)

16

5

16

-

4

5

Arsenic, 

dissolved 

(H9/L)

14

4

7

-

4

3

Cadmium, 

total 

recoverable

(Ml

<1

<l

<1

..

<1

<1

Cadmium, dissolved

<1

<l

<1

-

<1

<.l

Copper, 

total 

recoverable

27

6

75

-

10

7

Copper, dissolved

16

3

4

-

4

2

Date

Mar 1993

09...

Apr

26...

May

13...

19...

Jun

06...

Aug

18...

Iron, 

total 

recoverable 

(Mfl/L)

230

70

1.300

-

160

100

Iron, dissolved

30

9

18

--

13

13

Lead, 

total 

recoverable

2

<1

9

--

<1

<1

Lsad, 

dissolved

<.5

<.5

1.8

-

<.5

<.5

Manganese, 

total 

recoverable

(ng/L)

440

190

1,400

--

120

130

Manganese, dissolved

350

110

110

--

74

94

Zinc, 

total 

recoverable

20

<10

60

-

10

<10

Zinc, dissolved

4

3

10

-

7

<3

Sediment, 

suspended 

(mg/L)

10

n

68

32

6

4

Sediment discharge, 

suspended 

(ton/d)

.70

.71

17

18

3.1

1.0

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

88

76

82

75

80

83

TABLE 4 19
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12323800--CLARK FORK NEAR GALEN, MONT.

Data

Nov 1992

16...

Mar 1993

09...

Apr 

13...

27...

May 

14...

19...

24...

Jun

07...

Jul

12...

Aug 

18...

Time

1110

1200

0800

0810

1120

1320

1850

0905

1635

1250

Streamflow, instantaneous 

(ffts)

54

62

98

93

312

541

400

369

263

197

Specific 

conductance, 

onsite 

(uS/cm)

629

555

480

484

390

-

327

309

329

354

pH, 

onsite (standard 

units)

8.4

8.7

8.7

8.7

8.1

-

8.2

8.1

8.4

8.4

Temperature, 

water (°C)

3.0

3.5

3.5

1.0

12.0

15.0

16.0

11.0

16.0

15.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

270

250

200

200

170

-

140

130

140

150

Calcium, dissolved 

(mg/L)

80

75

60

58

50

-

42

41

43

46

Magnesium, dissolved 

(mg/L)

18

16

13

14

11

-

8.2

7.8

7.9

9.1

Sodium, dissolved 

(mg/L)

-

18

14

15

12

-

11

7.5

7.7

8.3

Potassium, dissolved 

(mg/L)

-

5.0

4.3

4.3

3.6

-

3.0

2.4

2.3

2.2

Alkalinity, 

(mg/L 

as 

CaC03)

-

123

98

92

91

-

84

82

90

98

Data

Nov 1992

16...

Mar 1993

09...

Apr

13...

27...

May

14...

19...

24...

Jun

07...

Jul

12...

Aug 

18...

Suifata, dissolved 

(mg/L)

--

160

130

140

97

-

67

62

67

75

Chloride, dissolved 

(mg/L)

--

11

9.0

8.7

6.4

-

5.1

3.2

3.3

3.3

Fluoride, dissolved 

(mg/L)

-

.7

.6

.6

.6

-

.5

.5

.5

.6

Silica, dissolved 

(mg/L)

-

14

10

13

12

-

12

10

8.7

10

Solids, 

sum of 

constituents, dissolved 

(mg/L)

-

364

300

309

247

-

199

184

194

213

Arsenic, 

total 

recoverable 

<WL)

8

15

15

13

23

-

22

15

16

13

Arsenic, dissolved

(WJ/L)

5

12

11

12

12

-

17

13

13

13

Cadmium, 

total 

recoverable (ng/L)

<i

<i

<i

<i

<i

-

<i

<i

<i

<i

Cadmium, dissolved (ng/L)

<i

.1

.2

<.!

<.l

-

.1

<.l

<.!

<.!

Copper, 

total 

recoverable (HS/L)

18

31

47

30

120

-

42

24

17

13

Copper, dissolved 

<W>L)

6

14

19

13

14

-

17

12

11

8

20 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12323800--CLARK FORK NEAR GALEN, MONT.-Continued

Date

Nov 1992

16...

Mar 1993

09...

Apr

13...

27...

May

14...

19...

24...

Jun

07...

Jul

12...

Aug

18...

Iron, 

total 

recoverable

260

350

370

280

1,600

-

410

220

120

120

Iron, dissolved

3

11

13

7

16

--

20

21

12

14

Lead, 

total 

recoverable

3

3

4

2

11

--

3

1

<1

1

MangaLead, nese, 

dis- total 

solved recov- 

(|ig/L) arable

lWf' L)

<1 270

<.5 420

<.5 330

<.5 300

<.5 1,200

..

<.5 270

<.5 170

<.5 120

<.5 130

Manganese, 

dissolved

74

230

150

130

210

--

120

100

74

71

Zinc, 

total 

recoverable

40

70

100

70

170

--

80

40

20

20

Zinc, dissolved

18

14

27

16

39

--

19

25

13

11

Sediment, 

suspended 

(mg/L)

3

8

13

7

75

25

13

5

3

4

Sediment discharge, 

suspended

(ton/d)

.44

1.3

3.4

1.8

63

37

14

5.0

2.1

2.1

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

82

79

91

64

74

66

76

75

84

78

TABLE 4 21
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12324200--CLARK FORK AT DEER LODGE, MONT.

Date

New 1992

16...

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

07...

Jul

12...

Aug

18...

Time

1220

1345

0930

0910

1830

1435

0735

1030

1800

1400

Streamflow, instantaneous 

(ffts)

164

229

215

193

313

572

425

456

396

297

Specific 

conductance, 

onsite 

(uS/cm)

603

570

562

591

506

_

384

353

403

447

pH, 

onsite (standard 

units)

8.4

8.3

8.3

8.3

8.5

_

8.0

8.1

8.6

8.4

Temperature, 

water

4.0

4.5

5.0

2.0

18.0

16.0

13.0

11.0

16.0

16.0

Hardness, 

total 

(mg/L 

as 

CaC03)

270

260

240

260

230

-

170

150

180

200

Calcium, dissolved 

(mg/L)

80

77

71

75

66

_

50

45

54

59

Magnesium, dissolved 

(mg/L)

18

17

16

18

15

_

10

9.1

11

12

Sodium, dissolved 

(mg/L)

..

19

16

18

17

-

14

10

12

13

Potassium, dissolved 

(mg/L)

_

6.3

3.8

4.2

4.5

_

3.3

2.6

2.7

2.8

Alkalinity, 

(mg/L 

as 

CaCOj)

_

143

149

144

120

_

104

103

125

136

Date

Nov 1992

16...

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

07...

Jul

12...

Aug

18...

Sulfate, dissolved 

(mg/L)

--

140

130

140

130

--

79

66

74

90

Chloride, dissolved 

(mg/L)

-

8.9

8.5

8.8

8.4

--

6.1

1.2

4.8

5.1

Fluoride, dissolved 

(mg/L)

--

.6

.6

.6

.7

--

.6

.5

.6

.6

Silica, dissolved 

(mg/L)

~

19

18

19

16

~

14

13

14

17

Solids,

sum of 

constituents, dissolved

(mg/L)

--

374

353

370

330

--

239

209

248

281

Arsenic, 

total 

recoverable 

(H9/L)

11

25

17

16

20

-

28

18

17

16

Areenlc, dissolved 

(Mfl/L)

8

19

11

12

14

--

17

12

15

13

f*ml Cadmium, 

total 

recoverable

<l

<1

<1

<1

<1

--

<1

<1

<1

<1

Cadmium, dissolved 

(MI/L)

<l

<.l

<.l

<.l

<.l

--

<.l

<.l

<.l

<.l

Copper, 

total 

recoverable

(Hfl/L)

21

67

69

39

75

--

85

52

23

20

Copper, dissolved

4

17

10

8

14

--

16

12

11

9

22 Water-quality, bed-sediment, and biological data and statistical aummaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12324200--CLARK FORK AT DEER LODGE, MONT.-Continued

Date

Nov 1992

16...

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

07...

Jul

12...

Aug

18...

Iron, 

total 

recoverable 

(H9/L)

190

1,100

790

500

900

-

1,100

780

210

280

Iron, dissolved

6

34

9

6

<3

-

21

21

11

10

Lead, 

total 

recoverable 

(MI/L)

4

7

7

4

8

-

9

6

2

2

MangaLead, nese, 

dls- total 

solved recov- 

(jig/L) arable 

(W/L)

1 70

<.5 210

<.5 260

<.5 190

<.5 280

<.5 310

<.5 180

.6 80

<.5 80

Manganese, dissolved

28

62

59

51

26

-

28

31

27

22

Zinc, 

total 

recoverable 

(WJ/L)

30

90

100

60

110

-

110

80

30

20

Zinc, dissolved 

(W/L)

18

19

22

21

11

-

15

31

10

8

Sediment, 

suspended 

(mg/L)

8

52

40

20

40

126

46

35

7

12

Sediment discharge, 

suspended 

(ton/d)

3.5

32

23

10

34

195

53

43

7.5

9.6

Sediment, 

suspended 

(percent

than 

0.062

mm)

82

65

68

82

62

54

67

55

82

63

TABLE 4 23
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12324590--UTTLE BLACKFOOT RIVER NEAR GARRISON, MONT

Date

Nov 1992

16...

Mar 1993

11...

Apr

27...

May

13...

19...

Jun

06...

Aug

17...

Time

0930

1200

1045

1115

1130

1915

0735

Streamflow, 

instantaneous

61

71

173

682

637

213

184

Specific 

conductance, 

onsite 

(US/cm)

271

255

218

152

-

231

248

pH, 

onsite 

(standard 

units)

8.2

8.1

8.2

7.9

-

8.3

8.1

Temperature, 

water

2.0

1.0

7.0

10.0

11.5

115

12.0

Hardness, 

total 

(mg/L 

as 

CaCOs)

130

110

98

70

--

100

110

Calcium, 

dissolved 

(mg/L)

37

33

28

20

-

30

32

Magnesium, 

dissolved 

(mg/L)

8.5

7.3

6.7

4.8

--

7.0

7.7

Sodium, 

dissolved 

(mg/L)

-

6.6

4.8

3.4

--

5.4

5.5

Potassium, 

dissolved 

(mg/L)

-

4.5

1.6

1.6

--

1.8

1.9

Alkalinity, 

(mg/L 

as 

CaC03)

-

52

93

64

--

104

118

Date

Nov 1992

16...

Mar 1993

11...

Apr

27...

May

13...

19...

Jun

06...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

-

20

16

10

-

14

11

Chloride, 

dissolved 

(mg/L)

-

3.4

1.5

1.0

-

1.2

1.3

Fluoride, 

dissolved 

(mg/L)

-

.2

.2

.1

-

.2

.2

Silica, 

dissolved 

(mg/L)

-

18

18

17

-

20

21

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

--

124

133

96

-

142

151

Arsenic, 

total 

recoverable (ng/L)

5

7

4

14

-

6

8

Arsenic, 

dissolved (ng/L)

4

6

3

5

-

5

6

Cadmium, 

total 

recoverable (ug/L)

<1

<1

<1

<1

-

<1

<1

Cadmium, 

dissolved

<l

<l

 cl

<1

-

<.l

<.l

Copper, 

total 

recoverable

(ng/L)

<i

3

2

8

-

2

2

Copper, 

dissolved 

(ng/L)

<1

2

<1

3

-

<1

<1

Date

Nov 1992

16...

Mar 1993

11...

Apr

27...

May

13...

19...

Jun

06...

Aug

17...

Iron, 

total 

recoverable

60

160

260

3,200

-

160

330

iron, 

dissolved

4

40

19

69

--

14

26

Lead, 

total 

recoverable

<l

<1

<1

13

--

<1

<1

Lead, 

dissolved

<1

.6

<.5

--

--

<.5

<.5

Manganese, 

total 

recoverable

(W» L)

20

30

40

200

--

30

40

Manganese, 

dissolved

3

12

6

14

--

11

5

Zinc, 

total 

recoverable

(}ig/L)

<10

20

<10

30

--

<10

<10

Zinc, 

dissolved

<3

4

4

4

--

5

4

Sediment, 

suspended 

(mg/L)

2

4

8

166

37

5

13

Sediment 

discharge, 

suspended

(ton/d)

.33

.77

3.7

306

64

2.9

6.5

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

83

78

88

63

58

85

85

24 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12324680--CLARK FORK AT GOLDCREEK, MONT.

Date

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

08...

Jul

13...

Aug

17...

Time

1600

1115

1230

1630

1610

0950

0945

1045

0850

Streamflow, 

instantaneous

e400

398

436

1,080

1,410

1,020

832

824

605

Specific 

conductance, 

onsite 

(jiS/cm)

410

447

430

280

-

305

346

368

375

PH, 

onsite (standard 

units)

8.1

8.5

8.5

8.3

--

8.2

8.3

8.3

8.2

Temperature, 

water

1.0

6.0

8.0

15.0

16.0

11.0

10.0

13.5

13.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

180

190

190

120

--

130

150

160

160

Calcium, 

dissolved 

(mg/L)

52

56

55

36

-

40

45

49

49

Magnesium, 

dissolved 

(mg/L)

11

12

13

8.1

-

8.3

9.3

10

10

Sodium, 

dissolved 

(mg/L)

13

13

13

7.8

--

9.9

10

11

11

Potassium, dissolved 

(mg/L)

6.9

3.3

3.1

2.5

-

2.5

2.6

2.5

2.7

Alkalinity, 

(mg/L 

as 

CaCO3)

118

137

128

89

-

103

121

134

138

Date

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

08...

Jul

13...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

78

84

82

47

-

44

51

44

53

Chloride, 

dissolved 

(mg/L)

6.8

6.1

5.9

3.5

-

3.6

3.5

3.4

3.6

Fluoride, 

dissolved 

(mg/L)

.4

.5

.4

.3

-

.4

.4

.4

.4

Silica, 

dissolved 

(mg/L)

16

18

18

17

-

18

17

18

21

Solids, 

sum of 

constituents, 

dissolved

(mg/L)

255

275

267

176

-

189

211

219

234

Arsenic, 

total 

recoverable

31

11

11

19

-

18

13

13

14

Arsenic, 

dissolved

18

8

9

9

-

11

11

10

10

Cadmium, 

total 

recoverable wig/ )

<i

<i

<i

<i

-

<i

<i

<i

<i

Cadmium, 

dissolved

<.l

<.l

<.l

<1

-

<.l

 cl

<.l

 cl

Copper, 

total 

recoverable

150

34

21

63

-

50

40

-

25

Copper, 

dissolved 

(ug/L)

20

6

4

8

-

12

10

-

6

Date

Mar 1993

09...

Apr

13...

27...

May

13...

19...

25...

Jun

08...

Jul

13...

Aug

17...

Iron, 

total 

recoverable

2,700

470

380

2,500

--

920

540

310

500

Iron, 

dissolved

58

7

5

36

--

22

18

34

15

Lead, 

total 

recoverable

18

4

2

12

--

7

5

-

3

Lead, 

dissolved 

(ug/L)

<.5

<5

<.5

<.5

--

<.5

<.5

--

<.5

Manganese, 

total 

recoverable

' '

470

130

100

250

--

190

130

70

90

Manganese, 

dissolved

35

31

26

24

--

28

21

26

16

Zinc, 

total 

recoverable

180

50

40

110

--

60

50

30

30

Zinc, 

dissolved

21

13

7

7

--

17

14

15

22

Sediment, 

suspended 

(mg/L)

152

21

15

125

103

39

21

10

23

Sediment 

discharge, 

suspended

(ton/d)

164

23

18

365

392

107

47

22

38

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

74

86

89

78

67

78

82

81

78

TABLE 4 25
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12331500--FLINT CREEK NEAR DRUMMOND, MONT.

Date

Nov 1992

16...

Mar 1993

11...

Apr 

13...

27...

May 

15...

19...

25...

Jun

08...

Jul

13...

Aug 

17...

Time

1425

0940

1300

1400

0830

1715

1140

1115

1225

1010

Stream- Specific 

flow, conductinstan- a nee, 

taneous onsite 

(ft3/s) (jiS/cm)

93

81

110

63

374

189

53

148

224

174

351

340

319

238

148

~

329

307

302

313

PH, 

onsite 

(standard 

units)

8.6

8.3

8.7

8.6

7.9

-

8.4

8.3

8.5

8.2

Temperature, 

water

4.0

.5

9.0

8.0

15.0

11.0

9.5

13.0

12.0

Hardness, 

total 

(mg/L 

as 

CaCO3)

170

150

140

160

68

-

160

140

140

140

Calcium, "i?,9"9" d,is- ' TT

?«Sn «>lved 

<m9/L> (mg/L)

45 13

41 12

38 11

42 13

19 4.9

_

43 12

38 11

39 11

39 11

Sodium, *£**-

*L/ ** f±S Swi (m9/L) (mg/L)

..

11 7.8

9.1 2.9

9.8 3.1

4.0 2.0

-

8.6 3.6

7.8 3.1

7.5 2.8

7.8 3.4

Alkalinity, 

(mg/L 

as 

CaCO3)

-

74

141

150

65

~

149

140

145

148

Date

Nov 1992

16...

Mar 1993

-11...

Apr 

13...

27...

May 

15...

19...

25...

Jun

08...

Jul

13...

Aug 

17...

Suifate, 

dissolved 

(mg/L)

-

22

20

22

8.8

-

19

15

12

14

Chloride, dissolved 

(mg/L)

--

5.9

5.2

5.0

1.9

-

4.1

4.1

2.8

3.1

Fluoride, dissolved 

(mg/L)

-

.2

.2

.2

.1

-

.2

.2

.4

.2

Silica, dissolved 

(mg/L)

-

21

20

20

14

-

20

19

19

22

Solids, 

sum of 

constituents, dissolved 

(mg/L)

-

165

191

205

94

-

200

182

182

189

Arsenic, 

total 

recoverable

10

16

13

11

30

-

11

12

13

26

CadArsenic, mium, 

dis- total 

solved recov- 

(ug/L) arable

7 <1

10 <1

8 <1

10 <1

8 <1

-

8 <1

8 <1

9 <1

10 <1

Cad- Copper, 

mium, total 

dis- recovsolved erabie 

(H9/L) (ng/L)

<1 2

<1 5

<1 3

 cl 2

<1 11

<.l 3

 cl 3

<1 10

<1 28

Copper, dissolved

<l

2

<t

<1

3

--

2

1

1

3

26 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12331500--FLINT CREEK NEAR DRUMMOND, MONT.-Continued

Date

Nov 1992

16...

Mar 1993

11...

Apr

13...

27...

May

15...

19...

25...

Jun

08...

Jul

13...

Aug

17

Iron, 

total 

recoverable

240

580

530

300

1,900

-

250

330

330

2,500

Iron, dissolved

7

58

19

10

77

-

29

28

17

40

Lead, 

total 

recoverable

8

9

7

3

36

-

3

5

4

16

MangaLead, nese, 

dis- total 

solved recov- 

(fig/L) arable

IMp"-)

3 70

.7 180

.6 120

<.5 110

1.0 480

..

<.5 120

<.5 130

<.5 200

.6 350

Manganese, dissolved

(Hfl/L)

20

57

34

40

74

-

58

37

32

34

Zinc, 

total 

recoverable

(M/L)

10

40

20

20

110

-

10

20

50

150

Zinc, dissolved 

(Hfl/L)

10

5

3

3

8

-

3

5

4

7

Sediment, 

suspended 

(mg/L)

11

34

27

13

120

49

11

16

15

159

Sediment discharge, 

suspended

(ton/d)

2.8

7.4

8.0

2.2

121

25

1.6

6.4

9.1

75

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

92

85

93

93

78

84

91

87

85

97

TABLE 4 27
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12331800--CLARK FORK NEAR DRUMMOND, MONT.

Date

Mar 1993

09...

Apr

14...

28...

May

15...

19...

26...

Jun

08...

Jul

13...

Aug

17...

Time

1820

0945

0930

1025

1815

1145

1245

1350

1200

Stream- Specific 

flow, conductInstan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

e660

587

550

1,650

1,710

992

985

1,170

907

435

470

462

278

-

371

403

399

429

pH, 

onsite 

(standard 

units)

8.2

8.4

8.4

8.0

--

8.2

8.3

8.4

8.2

Temperature, 

water

1.0

8.0

8.0

13.0

17.0

16.0

11.0

15.0

14.0

Hardness, 

total 

(mg/L 

as 

CaCOj)

190

210

210

120

-

170

180

180

190

Calcium, 

dissolved 

(mg/L)

55

59

61

36

--

50

53

52

55

Magnesium, 

dissolved 

(mg/L)

13

14

15

8.3

--

11

12

12

13

Sodium, 

dissolved 

(mg/L)

13

13

13

7.8

-

13

12

11

13

Potaeeium, 

dissolved 

(mg/L)

7.3

3.5

3.3

2.7

-

3.1

3.4

2.9

3.6

Alkalinity, 

(mg/Lae 

CaC03)

130

150

142

93

--

125

141

150

156

Date

Mar 1993

09...

Apr

14...

28...

May

15...

19...

26...

Jun

08...

Jul

13...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

87

86

90

45

-

58

61

54

38

Chloride, 

dissolved 

(mg/L)

7.1

6.2

5.7

3.4

-

4.6

4.2

4.1

4.5

Fluoride, 

dissolved 

(mg/L)

.4

.4

.4

.3

-

.4

.4

.4

.2

Silica, 

dissolved 

(mg/L)

17

18

17

17

-

20

19

20

23

Solide, 

sum of 

constituents, 

dissolved 

(mg/L)

278

290

291

176

-

235

250

246

244

Arsenic, 

total 

recoverable 

(W/L)

26

12

12

30

-

18

12

12

16

Arsenic, 

dissolved

13

9

10

11

_

13

10

11

12

Cadmium, 

total 

recoverable 

(Hfl/L)

<l

<1

<1

1

-

<1

<l

<l

<l

Cadmium, 

dissolved

<.l

<.l

<.l

<.l

-

.1

<.l

<.l

<.l

Copper, 

total 

recoverable 

(W/L)

100

28

22

140

-

-

-

18

23

Copper, 

dissolved

17

6

4

9

-

-

-

9

5

Date

Mar 1993

09...

Apr

14...

28...

May

15...

19...

26...

Jun

08...

Jul

13...

Aug

17...

Iron, 

total 

recoverable

2,500

560

400

4,000

-

890

490

280

900

Iron, 

dissolved 

(MI/L)

45

7

4

41

--

15

14

10

17

Lead, 

total 

recoverable

19

4

3

40

--

-

-

-

6

Lead, 

dissolved

<.5

<.5

<.5

1.2

--

--

-

-

.8

Manganese, 

total 

recoverable

(Mr 1-)

490

130

110

490

--

170

120

80

130

Manganese, 

dissolved

29

15

15

16

-

22

16

23

16

Zinc, 

total 

recoverable

(M/L)

200

50

40

260

--

70

50

30

40

Zinc, 

dissolved 

(ug/L)

21

11

10

10

-

18

14

7

8

Sediment, 

suspended 

(mg/L)

166

28

19

270

132

40

21

12

42

Sediment 

discharge, 

suspended

(ton/d)

296

44

28

1,200

609

107

56

38

103

Sediment, 

suspended 

(percent 

finer 

than

0.062

mm)

72

85

90

56

62

80

79

86

85

28 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12334510-ROCK CREEK NEAR CLINTON, MONT.

Data

Nwl992

16...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

08...

Aug

17...

Time

1605

1110

1100

1300

1110

1430

1340

Streamflow, 

instantaneous 

(ft*/s)

165

162

290

2.420

2,200

1,340

548

Specific 

conductance, 

onsite 

(uS/cm)

154

145

123

57

-

88

115

pH, 

onsite 

(standard 

units)

8.1

7.8

8.0

7.6

-

7.9

8.3

Temperature, 

water (°C)

4.0

15

6.0

10.0

9.0

9.5

13.5

Hardness, 

total 

(mg/L 

as 

CaCOa)

70

68

55

25

--

41

50

Calcium, 

dissolved 

(mg/L)

18

17

14

6.5

-

11

13

Magnesium, 

dissolved 

(mg/L)

6.2

6.1

4.9

2.2

-

3.4

4.3

Sodium, 

dissolved 

(mg/L)

-

3.5

3.1

1.7

--

2.0

2.5

Potassium, 

dissolved 

(mg/L)

-

1.3

1.1

.80

-

.90

1.0

Alkalinity, 

(mg/L 

as 

CaCOj)

-

67

58

26

-

41

57

Data

Nov 1992

16...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

08...

Aug

17...

Sulfata, 

dissolved 

(mg/L)

-

5.2

4.6

2.0

-

2.3

2.9

Chloride, 

dissolved 

(mg/L)

-

1.0

.70

.50

-

.40

.60

Fluorlde, 

dissolved 

(mg/L)

--

.1

.1

.1

-

<.l

<.l

Silica, 

dissolved 

(mg/L)

-

11

11

11

-

10

11

Solids.

sum of 

constituents, 

dissolved 

(mg/L)

--

85

74

40

-

55

70

Arsenic, 

total 

recoverable 

(ug/L)

<1

1

<1

2

-

<1

2

Arsenic, 

dissolved (ug/L)

<i

<i

<i

<i

_

<i

<i

/*«*«! Cadmium, 

total 

recoverable 

(ug/L)

<1

<1

<1

<1

..

<1

<1

Cadmium, 

dissolved 

(ug/L)

<1

<1

<1

<1

-

<1

<1

Copper, 

total 

recoverable

(ug/L)

<i

<i

<i

12

_

-

1

Copper, 

dissolved 

(ug/L)

<1

<1

<1

6

-

--

<1

Data

Nov 1992

16...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

08...

Aug

17...

Iron, 

total 

recoverable 

(ug/L)

40

60

90

1,200

-

160

130

iron, 

dissolved 

(ug/L)

6

6

13

58

--

41

33

Lead, 

total 

recoverable 

(ug/L)

2

<1

<1

--

-

--

<1

Lead, 

dissolved 

(ug/L)

2

<.5

<.5

--

--

--

<.5

Manganese, 

total 

recoverable 

(ug/L)

10

<10

<10

70

--

20

<10

Mangansse, 

dissolved 

(ug/L)

<l

<l

1

5

-

2

2

Zinc, 

total 

recoverable 

(ug/L)

<10

20

<10

20

--

10

<10

Zinc, 

dissolved 

(ug/L)

<3

<3

3

<3

--

8

4

Sediment, 

suspended 

(mg/L)

2

1

3

108

22

5

6

Sediment 

discharge, 

suspended 

(ton/d)

.89

.44

2.3

706

131

18

8.9

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

70

67

67

56

53

72

79

TABLE 4 29
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued) 

12334550-CLARK FORK ATTURAH BRIDGE, NEAR BONNER, MONT.

Date

Novl992 

17...

Mar 1993

10...

Apr

14...

28...

May

15...

20...

26...

Jun

08...

Jul

13...

Aug

17...

Time

0815

0900

1200

1245

1510

1300

1415

1615

1555

1535

Stream- Specific 

flow, conductinstan- ance, 

tanaous onsite 

(ft3/s) (uS/cm)

645

941

988

980

4,010

4,100

2,810

2,680

2,110

1,520

430

380

364

354

168

--

216

254

303

315

PH, 

onsite (standard 

units)

8.2

8.2

8.5

8.5

7.9

--

8.1

8.4

8.6

8.4

Temperature, 

water

4.0

.5

7.5

8.5

13.0

12.0

15.0

11.0

16.5

15.0

Hardness, 

total 

(mg/L 

as 

CaCOj)

200

170

160

160

73

-

98

110

140

140

Calcium, dissolved 

(mg/L)

55

50

45

45

21

--

28

32

39

39

Magnesium, dissolved 

(mg/L)

14

12

11

12

5.1

--

6.7

7.9

9.4

9.6

Sodium, dissolved 

(mg/L)

12

9.3

9.6

4.3

-

5.8

6.4

8.1

8.5

Potassium, dissolved 

(mg/L)

5.7

15

14

1.7

--

1.8

10

13

17

Alkalinity, 

(mg/L as 

CaCO3)

111

124

117

65

-

77

91

116

119

Date

Nov 1992

17...

Mar 1993

10...

Apr

14...

28...

May

15...

20...

26...

Jun

08...

Jul

13...

Aug

17...

Sulfate, 

dissolved 

(mg/L)

-

68

58

57

21

-

28

32

36

41

Chloride, dissolved 

(mg/L)

-

5.6

4.2

3.8

1.7

-

2.3

2.2

2.6

3.0

Fluoride, dissolved 

(mg/L)

-

.3

.3

.3

.2

--

.2

.2

.3

.3

Silica, 

dissolved 

(mg/L)

-

16

15

15

14

-

14

14

16

18

Solids,

sum of 

constituents, dissolved

(mg/L)

-

236

220

215

108

--

133

151

183

193

Arsenic, 

total 

recoverable

12

15

7

6

15

--

8

6

7

10

Arsenic, 

dissolved 

(W/L)

5

10

5

5

5

-

6

5

7

8

S*«t*J Cadmium, 

total 

recoverable

<1

<1

<1

<1

<1

--

<1

<1

<1

<1

Cadmium, dissolved (ng/L)

<1

<.l

 cl

<.l

 cl

--

<.!

<.!

<.!

<.!

Copper, 

total 

recoverable 

(W/L)

6

50

15

12

76

-

-

16

9

22

Copper, dissolved 

Om/L)

2

12

4

3

7

-

--

6

5

6

30 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued) 

12334550--CLARK FORK ATTURAH BRIDGE, NEAR BONNER, MONT.-Continued

Date

Nov 1992

17...

Mar 1993

10...

Apr

14...

28...

May

15...

20...

26...

Jun

08...

Jul

13...

Aug

17...

Iron, 

total 

recoverable 

(MI/L)

110

1.100

260

240

2400

-

480

290

170

590

Iron, dissolved 

(HS/L)

<3

34

6

5

46

--

190

26

12

14

Lead, 

total 

recoverable

3

8

3

1

27

--

--

2

--

--

MangaLead, nese, 

dis- total 

solved recov- 

(ug/L) arable 

(H9/L)

1 50

<.5 210

<.5 70

<.5 50

.9 280

90

<.5 70

40

90

Manganese, dissolved 

(MI/L)

3

13

8

6

13

-

15

9

8

9

Zinc, 

total 

recoverable

10

100

30

20

150

-

40

30

10

40

Zinc, dissolved 

(MI/L)

6

15

4

8

8

-

9

8

6

6

Sediment, 

suspended 

(mg/L)

6

62

14

12

171

60

26

14

5

31

Sediment discharge, 

suspended 

(ton/d)

10

158

37

32

1.850

664

197

101

28

127

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

87

80

84

85

64

64

72

73

86

88

TABLE 4 31
Table 4. Water-quality data the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12340000--BLACKFOOT RIVER NEAR BONNER, MONT.

Date

Novl992

17...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

09...

Aug

18...

Time

1145

1630

1445

1720

1430

0730

0730

Streamflow, Instantaneous 

(f&s)

500

565

1.390

7,180

6,230

2,780

1,060

Specific 

conductance, 

onsite 

(uS/cm)

260

240

190

140

--

191

246

pH, 

onsite (standard 

units)

8.3

7.8

8.4

8.1

--

8.3

8.3

Temperature, 

water (°C)

4.5

3.0

9.5

10.5

11.0

10.5

13.0

Hardness, 

total 

(mg/L 

as 

CaCOj)

130

110

95

72

--

100

120

Calcium, dissolved 

(mg/L)

33

29

24

19

--

26

31

Magnesium, dissolved 

(mg/L)

12

10

8.4

5.9

--

8.5

11

Sodium, dissolved 

(mg/L)

-

3.2

2.3

1.2

-

1.8

2.5

Potassium, dissolved 

(mg/L)

-

2.8

.80

.60

-

.60

.90

Alkalinity, 

(mg/L as 

CaCOa)

-

120

95

76

~

96

129

Date

Novl992

17...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

09...

Aug

18...

Sulfate, 

dissolved 

(mg/L)

-

5.6

4.5

2.2

-

4.1

5.0

Chloride, 

dissolved 

(mg/L)

-

1.6

.50

.30

-

.30

.60

Fluoride, dissolved 

(mg/L)

-

.1

<.l

<.l

-

<.l

<.l

Silica, 

dissolved 

(mg/L)

-

9.5

8.1

6.8

-

7.4

10

Solids,

sum of 

constituents, dissolved 

(mg/L)

--

134

106

82

-

106

138

Arsenic, 

total 

recoverable 

(WL)

1

3

<1

4

-

1

2

Arsenic, 

dissolved 

(Mfl/L)

1

2

<1

<1

-

<1

<1

/ »_-! Cadmium, 

total 

recoverable 

(W/L)

<1

<1

<1

<1

-

<1

<1

Cadmium, dissolved 

(H9/L)

<1

<1

.1

<1

-

<1

<1

Copper, 

total 

recoverable 

(WI/L)

<1

9

1

12

-

-

1

Copper, 

dissolved 

0*9/1-)

<1

7

<1

3

-

-

<1

Date

Novl992

17...

Mar 1993

10...

Apr

28...

May

15...

20...

Jun

09...

Aug

18...

Iron, 

total 

recoverable 

(H9/L)

50

230

140

2,600

-

140

160

Iron, 

dissolved 

(H9/L)

<3

30

10

30

--

11

7

Lead, 

total 

recoverable 

(H9/L)

<1

-

<1

25

-

-

--

Lead, 

dissolved 

(fig/L)

<1

-

<.5

2

--

-

--

Manganese, 

total 

recoverable 

(MI/L)

10

20

30

180

--

20

10

Manganese, 

dissolved 

(Mfl/L)

<1

6

2

5

--

2

1

Zinc, 

total 

recoverable 

(MI/L)

<10

20

<10

40

--

<10

<10

Zinc, 

dissolved 

(Mfl/L)

<3

6

3

<3

--

4

4

Sediment, 

suspended 

(mg/L)

1

13

8

230

62

8

10

Sediment discharge, 

suspended 

(ton/d)

1.4

20

30

4,460

1,040

60

29

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

76

68

82

83

84

90

91

32 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12340500-CLARK FORK ABOVE MISSOULA, MONT.

Data

Novl992 

17...

Mar 1993

10...

Apr

14...

29...

May

16...

20...

26...

Jun

09...

Jul

14...

Aug

18...

Time

0950

1345

1445

0830

0830

1600

1630

0925

0750

0910

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

1,130

1,500

2,350

2,400

11,400

10,400

6,600

4,850

3,610

2,550

354

325

261

259

153

--

187

221

270

294

PH, 

onsite (standard 

units)

8.2

8.3

8.4

8.3

8.1

--

8.4

8.3

8.3

8.3

Temperature, 

water (°C)

4.0

2.5

7.0

9.0

11.0

12.0

16.5

10.5

15.0

14.5

Hardness, 

total 

(mg/L 

as 

CaCOa)

170

150

120

120

71

--

95

110

130

130

Calcium, dissolved 

(mg/L)

45

42

32

33

19

-

26

29

35

36

Magnesium, dissolved 

(mg/L)

13

12

9.2

9.7

5.6

-

7.3

8.3

9.7

10

Sodium, dissolved 

(mg/L)

7.7

5.3

5.3

2.4

-

3.4

4.1

5.7

6.1

Potassium, dissolved 

(mg/L)

4.5

1.5

1.4

1.0

-

1.1

1.2

1.5

2.0

Alkalinity, 

(mg/L as 

CaC03)

119

105

104

71

--

83

95

116

124

Data

Novl992

17...

Mar 1993

10...

Apr

14...

29...

May

16...

20...

26...

Jun

09...

Jul

14...

Aug

18...

Sulfata, dissolved 

(mg/L)

-

43

24

26

9.3

-

13

17

21

26

Chloride, dissolved 

(mg/L)

--

4.2

2.1

1.9

.90

-

1.4

1.2

1.7

2.1

Fluoride, dissolved 

(mg/L)

--

.2

.2

.2

.1

-

.1

.2

.2

.2

Silica, dissolved 

(mg/L)

-

13

11

11

9.4

_

10

11

12

15

Solids, 

sum of 

constituents, dissolved 

(mg/L)

-

198

148

151

90

-

112

129

156

172

Arsenic, 

total 

recoverable 

(ug/L)

4

10

4

3

7

-

4

4

5

6

Arsenic, dissolved 

(Hfl/L)

4

7

3

2

3

-

3

3

5

5

Cadmium, 

total 

recoverable 

(ufl/L)

<1

<1

<1

<1

<1

-

<1

<1

<1

<1

Cadmium, dissolved 

(ug/L)

<1

<.!

.1

<1

<.l

-

<.l

<1

<1

<1

Copper, 

total 

recoverable 

(Hfl/L)

3

20

8

7

23

-

19

-.

8

8

Copper, dissolved 

(M/L)

1

10

4

2

3

-

9

..

2

2

TABLE 4 33
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)

12340500-CLARK FORK ABOVE MISSOULA, MONT.-Continued

Date

Novl992

17...

Mar 1993

10...

Apr

14...

29...

May

16...

20...

26...

Jun

09...

Jul

14...

Aug

18...

iron, 

total 

recoverable (ng/L)

80

350

170

220

1,800

-

440

230

200

270

Iron, dissolved

3

29

13

27

35

-

16

18

11

14

Lead , _, Manga- TZTT Lead, nese, 

JJJJ. dis- total 

ZfiXL solved recovi,m/i? (Mg/L) arable 

l*ig/L) (jig/L)

<1 <1 30

60

60

60

15 .7 170

60

50

<1 <.5 40

2 <.5 40

Manganese, dissolved

7

19

24

23

9

--

19

15

14

14

Zinc, 

total 

recoverable 

(ug/L)

<10

40

10

20

60

-

20

20

20

10

Zinc, dissolved

<3

7

7

6

7

--

<3

7

5

<3

Sediment, 

suspended 

(mg/L)

2

15

8

9

132

73

26

11

10

12

Sediment discharge, 

suspended 

(ton/d)

6.1

61

51

58

4,060

2,050

463

144

97

83

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

88

91

89

96

85

86

89

93

92

95

34 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1992 through September 1993 (Continued)]

12353000-CLARK FORK BELOW MISSOULA, MONT.

Date

Dec 1992

02...

Feb 1993

03...

Mar

25...

May

04...

25...

Aug

25...

Time

1115

1300

1200

0930

1000

0800

Stream- Specific 

flow, conductinstan- ance, 

taneous onsite 

(ft3/s) (uS/cm)

1,580

1.540

3,880

5,060

14.440

3.970

268

235

207

176

125

243

pH, 

onsite (standard 

units)

7.8

8.3

8.2

8.2

8.0

8.2

Temperature, 

water (°C)

1.0

1.0

8.0

10.0

11.5

13.5

Hardness, 

total 

(mg/L 

as 

CaCOa)

120

130

93

84

57

110

Calcium, 

dissolved 

(mg/L)

34

36

26

23

16

31

Magnesium, 

dissolved 

(mg/L)

8.7

9.5

6.7

6.4

4.2

8.1

Sodium, 

dissolved 

(mg/L)

7.0

7.7

6.1

4.1

2.8

6.1

Potassium, 

dissolved 

(mg/L)

1.8

1.9

2.0

1.2

1.0

1.9

Alkalinity, 

(mg/L as 

CaC03)

115

116

87

76

57

108

Date

Dec 1992

02...

Feb 1993

03...

Mar

25...

May

04...

25...

Aug

25...

Sulfate, 

dissolved 

(mg/L)

27

30

19

14

7.5

18

Chloride, 

dissolved 

(mg/L)

2.9

3.2

2.5

1.5

4.2

1.7

Fluoride, 

dissolved 

(mg/L)

.2

.2

.2

.2

.1

.2

Silica, 

dissolved 

(mg/L)

12

14

11

9.6

9.8

14

Solids,

sum of 

constituents, 

dissolved 

(mg/L)

163

171

126

105

77

145

Arsenic, 

total 

recoverable

(MI/I-)

-

--

6

--

3

4

Arsenic, 

dissolved

(WP/L)

-

-

3

-

2

4

Cadmium, 

total 

recoverable 

(MI/I-)

-

-

<1

-

<1

<1

Cadmium, 

dissolved 

(Ml/I-)

-

--

 cl

--

<.l

<.l

Copper, 

total 

recoverable 

(WP/L)

-

-

18

-

9

7

Copper, 

dissolved 

(MI/L)

-

-

3

--

2

2

Date

Dec 1992

02...

Feb 1993

03...

Mar

25...

May

04...

25...

Aug

25...

Iron, 

total 

recoverable (MI/D

..

-

860

-

510

150

Iron, 

dissolved 

(Ml/I-)

5

--

18

--

28

17

Lead, 

total 

recoverable

(MI/I-)

-

--

4

--

2

<1

Lead, 

dissolved

(Ml/I-)

-

-

<.5

--

<.5

<.5

Manganese, 

total 

recoverable 

(MI/I-)

-

-

120

--

40

20

Manganese, 

dissolved 

(WP/L)

6

--

9

--

11

5

Zinc, 

total 

recoverable 

(MI/L)

-

-

30

-

20

<10

Zinc, 

dissolved 

(WP/L)

..

-

3

-

<3

<3

Sediment, 

suspended 

(mg/L)

1

3

44

18

34

8

Sediment 

discharge, 

suspended 

(ton/d)

4.3

12

461

246

1,320

86

Sediment, 

suspended 

(percent 

finer 

than 

0.062

mm)

93

85

84

78

70

88

TABLE 4 35
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, Montana, March through 

September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter, ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(«3/s)

e30

e32

e32

e34

e36

e40

e50

e56

e60

e56

e50

e45

e50

e56

e56

e50

e56

84

122

82

61

66

91

102

76

83

81

70

65

65

61

1,898

61.2

122

30

Mean 

concentration 

(mg/L)

March

16

16

17

22

29

185

305

274

181

183

140

54

43

140

429

427

S3

195

122

80

62

88

130

140

59

74

63

35

31

28

26

_

119

429

16

Discharge 

(ton/d)

1.3

1.4

1.5

2.0

2.8

20

41

41

29

28

19

6.6

5.8

21

65

58

13

44

40

18

10

16

32

39

12

17

14

6.6

5.4

4.9

4.3

619.6

20

65

1.3

Mean 

streamflow 

(ft3/s)

58

56

53

57

62

57

53

51

51

49

50

51

54

50

48

50

50

53

53

47

47

46

52

51

45

49

51

48

50

59

...

1,551

51.7

62

45

Suspended sediment

Mean 

concentration 

(mg/L)

April

24

21

18

21

30

22

14

15

11

11

10

11

21

14

13

12

10

13

17

12

10

11

15

11

9

10

13

11

11

22

15

30

9

Discharge 

(ton/d)

1993

3.8

3.2

2.6

3.2

5.0

3.4

2.0

2.1

1.5

1.5

1.4

1.5

3.1

1.9

1.7

1.6

1.4

1.9

2.4

1.5

1.3

1.4

2.1

1.5

1.1

1.3

1.8

1.4

1.5

3.5

63.6

2.1

5.0

1.1

Mean 

streamflow 

(«3/s)

58

56

59

100

94

105

115

99

85

79

80

93

97

104

112

111

109

103

100

100

113

108

100

95

81

79

78

81

85

78

71

2,828

91.2

115

56

Suspended sediment

Mean 

concentration 

(mg/L)

May

18

15

14

94

54

115

122

44

26

20

18

30

22

32

37

27

22

20

17

21

32

21

14

15

13

11

12

12

19

15

10

30

122

10

Discharge 

(ton/d)

2.8

2.3

2.2

25

14

33

38

12

6.0

4.3

3.9

7.5

5.8

9.0

11

8.1

6.5

5.6

4.6

5.7

9.8

6.1

3.8

3.8

2.8

2.3

2.5

2.6

4.4

3.2

1.9

250.5

8.1

38

1.9

Mean 

streamflow 

(ft3/s)

84

91

86

76

87

101

102

94

84

85

103

111

97

83

77

150

151

129

109

97

93

113

98

93

86

81

84

83

84

76

2,888

96.3

151

76

Suspended sediment

Mean 

concentration 

(mg/L)

June

30

24

15

10

28

23

18

14

9

10

33

45

17

10

11

124

85

41

29

20

18

46

18

12

11

10

17

18

18

9

...

26

124

9

Discharge 

(ton/d)

6.8

5.9

3.5

2.1

6.6

6.3

5.0

3.6

2.0

2.3

9.2

13

4.5

2.2

2.3

50

35

14

8.5

5.2

4.5

14

4.8

3.0

2.6

2.2

3.9

4.0

4.1

1.8

...

232.9

7.8

50

1.8

36 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 5. Daily streamflow and suspended-sediment data for Silver Bow Creek at Opportunity, 

Montana, March through September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(tt3/s)

74

74

100

84

76

71

84

77

72

69

66

66

62

61

60

57

70

70

62

63

58

57

61

59

78

107

115

96

80

72

68

2,269

73.2

115

57

Mean 

concentration 

(mg/L)

July

7

6

32

12

6

6

18

11

9

8

8

8

7

11

10

8

19

21

7

9

7

6

7

6

51

82

14

28

14

10

7

...

15

82

6

Discharge 

(ton/d)

1.4

1.2

8.6

2.7

1.2

1.2

4.1

2.3

1.7

1.5

1.4

1.4

1.2

1.8

1.6

1.2

3.6

4.0

1.2

1.5

1.1

.92

1.2

.96

11

24

4.3

7.3

3.0

1.9

1.3

101.78

3.3

24

.92

Suspended sediment

Mean Mean 

stream- concenflow tration 

(ft8/*) (mg/L)

65

65

61

57

62

62

60

59

55

51

49

57

88

61

55

51

52

45

50

65

74

114

80

61

54

109

129

94

98

91

82

2,156

69.5

129

45

1993

August

4

4

5

6

7

7

8

8

7

6

6

40

57

15

8

6

14

10

8

16

24

80

17

13

13

91

113

27

23

13

11

22

113

4

Discharge 

(ton/d)

.70

.70

.82

.92

1.2

1.2

1.3

1.3

1.0

.83

.79

6.2

14

2.5

1.2

.83

2.0

1.2

1.1

2.8

4.8

25

3.7

2.1

1.9

27

39

6.9

6.1

3.2

2.4

164.69

5.3

39

.70

Mean 

streamflow 

<ft3/s)

77

78

76

71

67

65

66

60

55

59

57

60

63

63

62

61

59

57

58

58

58

57

55

54

52

51

51

49

49

47

1,795

59.8

78

47

Suspended sediment

Mean 

concentration 

(mg/L)

September

9

9

8

7

7

7

7

7

6

5

5

5

5

5

4

3

4

5

6

6

6

5

5

5

6

6

6

6

6

6

6

9

3

Discharge 

(ton/d)

1.9

1.9

1.6

1.3

1.3

1.2

1.2

1.1

.89

.80

.77

.81

.85

.85

.67

.49

.64

.77

.94

.94

.94

.77

.74

.73

.84

.83

.83

.79

.79

.76

28.94

.96

1.9

.49

TOTAL FOR MARCH-SEPTEMBER 1993: 

STREAMFLOW --15,385 ft3/* 

SEDIMENT DISCHARGE - 1,462.01 tons

TABLE 5 37
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, April 

through September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter, ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean

streamflow

(It3/s)

e97

82

73

73

77

73

80

65

62

67

66

72

77

78

78

77

78

78

79

79

76

76

75

75

75

78

78

73

73

76

...

2,266

75.5

97

62

Mean

concentration

(mg/L)

April

14

14

14

13

13

13

12

13

12

12

10

11

12

11

10

9

9

10

10

7

8

9

8

9

9

9

8

8

9

7

10

14

7

Discharge

(ton/d)

3.7

3.1

2.8

2,6

2.7

2.6

2.6

2.3

2.0

2.2

1.8

2.1

2.5

2.3

2.1

1.9

1.9

2.1

2.1

1.5

1.6

1.8

1.6

1.8

1.8

1.9

1.7

1.6

1.8

1.4

63.9

2.1

3.7

1.4

Mean

streamflow

(ft3/s)

1993

81

78

86

110

126

148

156

159

160

167

156

147

152

183

228

261

315

371

354

338

337

333

317

299

278

253

236

249

266

266

255

6,865

221

371

78

Suspended sediment

Mean

concentration

(mg/L)

May

8

6

8

14

11

10

9

9

9

13

8

7

8

12

14

15

27

24

13

10

9

8

7

7

6

6

6

6

5

6

5

...

10

27

5

Discharge

(ton/d)

1.7

1.3

1.9

4.2

3.7

4.0

3.8

3.9

3.9

5.9

3.4

2.8

3.3

5.9

8.6

11

23

24

12

9.1

8.2

7.2

6.0

5.7

4.5

4.1

3.8

4.0

3.6

4.3

3.4

192.2

6.2

24

1.3

Mean

streamflow

(ft3/s)

247

247

240

206

185

190

196

197

198

197

200

197

194

194

197

207

260

313

300

283

272

269

261

250

238

224

217

224

209

194

6,806

227

313

185

Suspended sediment

Mean

concentration

(mg/L)

June

4

4

4

3

3

3

3

2

1

2

3

3

2

2

2

2

5

6

5

4

3

3

3

3

2

2

2

2

2

2

3

6

1

Discharge

(ton/d)

2.7

2.7

2.6

1.7

1.5

1.5

1.6

1.1

.53

1.1

1.6

1.6

1.0

1.0

1.1

1.1

3.5

5.1

4.1

3.1

2.2

2.2

2.1

2.0

1.3

1.2

1.2

1.2

1.1

1.0

55.73

1.9

5.1

.53

38 Water-quality, bed sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, April 

through September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

185

153

152

165

171

174

173

171

163

159

155

150

146

142

135

133

134

130

130

129

124

122

122

122

132

139

158

174

178

174

172

4,667

151

185

122

Mean 

concentration 

(mg/L)

July

2

2

2

2

2

1

1

1

1

1

2

2

2

2

1

1

1

1

1

1

1

1

1

2

2

2

2

2

2

2

2

2

2

1

Discharge 

(ton/d)

1.0

.83

.82

.89

.92

.47

.47

.46

.44

.43

.84

.81

.79

.77

.36

.36

.36

.35

.35

.35

.33

.33

.33

.66

.71

.75

.85

.94

.96

.94

.93

19.80

.64

1.0

.33

Mean 

streamflow 

(ft3/s)

1993

165

147

135

129

126

120

117

91

87

93

87

101

117

108

100

93

103

100

101

108

109

113

122

120

117

133

143

155

166

169

182

3,757

121

182

87

Suspended sediment

Mean 

concentration 

(mg/L)

August

1

1

1

1

1

1

1

1

1

1

1

1

1

1

2

3

2

2

2

1

1

1

1

1

2

2

2

2

1

1

2

1

3

1

Discharge 

(ton/d)

0.45

.40

.36

.35

.34

.32

.32

.25

.23

.25

.23

.27

.32

.29

.54

.75

.56

.54

.55

.29

.29

.31

.33

.32

.63

.72

.77

.84

.45

.46

.98

13.71

.44

.98

.23

Mean 

streamflow 

(ft3/s)

180

170

152

136

124

117

112

105

94

83

73

71

70

79

84

88

88

87

86

84

83

78

77

79

78

78

78

79

77

82

2,872

95.7

180

70

Suspended sediment

Mean 

concentration 

(mg/L)

September

2

2

2

1

2

2

2

2

1

1

1

1

1

1

2

2

2

2

1

1

1

1

1

1

1

1

1

1

1

1

1

2

1

Discharge 

(ton/d)

0.97

.92

.82

.37

.67

.63

.60

.57

.25

.22

.20

.19

.19

.21

.45

.48

.48

.47

.23

.23

.22

.21

.21

.21

.21

.21

.21

.21

.21

.22

11.27

.38

.97

.19

TOTAL FOR APRIL-SEPTEMBER, 1993: 

STREAMFLOW ~ 27,233 ftVs 

SEDIMENT DISCHARGE - 356.61 tons

TABLE 6 39
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1992 through 

September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter, ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MEM

Mean 

streamflow 

(ft3/s)

92

88

93

111

127

138

144

157

150

137

140

137

136

138

139

144

146

137

135

133

131

131

133

135

137

136

137

138

143

178

182

4,203

136

182

88

Mean 

concentration 

(mg/L)

October

20

22

22

24

24

22

20

19

20

23

22

22

25

25

22

21

22

23

24

25

25

25

26

28

29

30

30

30

25

22

23

24

30

19

Discharge 

(ton/d)

5.0

5.2

5.5

7.2

8.2

8.2

7.8

8.1

8.1

8.5

8.3

8.1

9.2

9.3

8.3

8.2

8.7

8.5

8.7

9.0

8.8

8.8

9.3

10

11

11

11

11

9.7

11

11

270.7

8.7

11

5.0

Mean 

streamflow 

(ft3/s)

1992

168

162

167

166

169

173

180

174

168

164

154

172

172

172

167

164

166

168

164

160

158

158

161

148

el 20

el 20

el 30

el 30

el 30

el 30

4,735

158

180

120

Suspended sediment

Mean 

concentration 

(mg/L)

November

24

26

27

28

31

34

30

28

28

28

30

34

23

17

18

10

11

20

22

21

20

20

21

21

19

18

19

21

24

27

23

34

10

Discharge 

(ton/d)

11

11

12

13

14

16

15

13

13

12

12

16

11

7.9

8.1

4.4

4.9

9.1

9.7

9.1

8.5

8.5

9.1

8.4

6.2

5.8

6.7

7.4

8.4

9.5

300.7

10

16

4.4

Mean 

streamflow 

(ft3/s)

el 30

e!20

el 20

el 10

el 00

el 00

el 10

el 20

el 30

el 30

el 30

el 30

el 20

el 20

el 30

el 30

el 20

el 20

el 20

el 20

el 30

el 30

el 30

e!40

e!40

el 30

e!30

el 20

el 10

el 10

el 10

3,790

122

140

100

Suspended eediment

Mean 

concentration 

(mg/L)

December

29

30

32

31

30

29

29

31

39

31

25

24

26

29

31

32

32

32

31

30

28

27

24

22

22

21

19

18

26

34

34

28

39

18

Discharge 

(ton/d)

10

9.7

10

9.2

8.1

7.8

8.6

10

14

11

8.8

8.4

8.4

9.4

11

11

10

10

10

9.7

9.8

9.5

8.4

8.3

8.3

7.4

6.7

5.8

7.7

10

10

287.0

9.3

14

5.8

40 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft'/S)

e!20

el 30

e!40

e!30

e!20

e!20

e!20

el 30

e!30

e!20

e!20

e!20

el 20

e!20

e!30

e!40

e!40

e!40

e!40

e!50

e!60

e!60

e!60

e!50

e!60

e!70

e!70

e!70

e!70

e!60

e!60

4,370

141

170

120

Mean 

concentration 

(mg/L)

January

35

37

34

26

20

18

19

20

20

20

20

20

20

20

20

21

22

21

20

21

24

25

28

29

27

26

26

26

26

28

37

24

37

18

Discharge 

(ton/d)

11

13

13

9.1

6.5

5.8

6.2

7.0

7.0

6.5

6.5

6.5

6.5

6.5

7.0

7.9

8.3

7.9

7.6

8.5

10

11

12

12

12

12

12

12

12

12

16

291.3

9.4

16

5.8

Mean 

streamflow 

(ft3/s)

1993

e!60

e!50

e!50

e!50

e!50

e!50

e!50

e!60

e!60

e!50

e!40

eHO

e!50

e!50

e!20

ellO

el 20

e!30

e!40

e!40

e!30

e!30

e!40

e!40

e!30

e!30

e!30

e!40

...

...

...

3,940

141

160

110

Suspended sediment

Mean 

concentration 

(mg/L)

February

43

43

42

42

41

40

41

41

39

36

31

24

21

20

20

26

28

22

17

18

22

29

29

25

21

29

34

43

...

...

31

43

17

Discharge 

(ton/d)

19

17

17

17

17

16

17

18

17

15

12

9.1

8.5

8.1

6.5

7.7

9.1

7.7

6.4

6.8

7.7

10

11

9.5

7.4

10

12

16

...

...

...

335.5

12

19

6.4

Mean 

streamflow 

(ft3/s)

e!40

e!40

el 50

el 60

166

204

287

264

245

202

180

168

183

202

221

229

225

237

242

245

252

257

271

257

261

270

278

263

254

240

238

6,931

224

287

140

Suspended sediment

Mean 

concentration 

(mg/L)

March

48

34

38

30

25

95

300

177

68

37

30

33

34

32

37

45

47

49

39

37

41

46

52

48

43

51

53

41

38

37

37

...

56

300

25

Discharge 

(ton/d)

18

13

15

13

11

52

232

126

45

20

15

15

17

17

22

28

29

31

25

24

28

32

38

33

30

37

40

29

26

24

24

1,109

36

232

11

TABLE 7 41
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

228

221

200

197

217

204

200

186

178

178

178

187

209

207

203

199

198

207

211

208

205

194

205

197

190

191

194

189

183

187

5,951

198

228

178

Mean 

concentration 

(mg/L)

April

32

37

27

24

30

28

28

23

21

20

19

20

33

30

26

24

23

25

23

28

23

21

19

17

14

17

17

12

13

15

...

23

37

12

Discharge 

(ton/d)

20

22

15

13

18

15

15

12

10

9.6

9.1

10

19

17

14

13

12

14

13

16

13

11

11

9.0

7.2

8.8

8.9

6.1

6.4

7.6

375.7

13

22

6.1

Mean 

streamflow 

(ft3/s)

1993

195

192

189

222

281

274

304

301

297

283

282

278

294

348

426

469

498

560

566

554

575

594

545

481

427

407

419

449

500

552

495

12,257

395

594

189

Suspended sediment

Mean 

concentration 

(mg/L)

May

16

14

13

35

59

35

61

48

36

31

30

32

36

80

149

158

151

190

154

115

128

116

72

55

47

37

42

61

68

67

52

71

190

13

Discharge 

(ton/d)

8.4

7.3

6.6

21

45

26

50

39

29

24

23

24

29

75

171

200

203

287

235

172

199

186

106

71

54

41

48

74

92

100

69

2,715.3

88

287

6.6

Mean 

streamflow

(ft3/S)

473

554

521

460

403

406

444

425

397

366

408

422

403

372

349

455

575

596

543

503

466

489

470

429

405

373

371

383

398

357

13,216

441

596

349

Suspended sediment

Mean 

concentration 

(mg/L)

June

47

66

47

33

30

30

37

28

20

18

19

20

18

16

14

36

86

83

63

48

38

33

26

18

15

14

14

14

15

16

...

...

32

86

14

Discharge 

(ton/d)

60

99

66

41

33

33

44

32

21

18

21

23

20

16

13

44

134

134

92

65

48

44

33

21

16

14

14

14

16

15

1,244

41

134

13

42 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

347

323

362

392

408

408

401

405

394

397

402

394

385

353

339

340

368

376

351

361

347

344

345

332

343

415

507

491

441

407

390

11,868

383

507

323

Mean 

concentration 

(mg/L)

July

13

10

10

12

13

13

14

14

13

11

9

7

8

10

12

13

15

16

14

12

10

10

11

11

13

22

35

34

29

25

23

15

35

7

Discharge 

(ton/d)

12

8.7

9.8

13

14

14

15

15

14

12

9.8

7.4

8.3

9.5

11

12

15

16

13

12

9.4

9.3

10

9.9

12

25

48

45

35

27

24

496.1

16

48

7.4

Mean 

streamflow 

(ft3/s)

1993

368

336

323

338

340

289

257

240

220

207

204

212

255

261

245

246

278

291

267

280

308

388

367

332

310

344

415

400

447

457

437

9,662

312

457

204

Suspended sediment

Mean 

concentration 

(mg/L)

August

22

22

22

23

135

22

19

18

16

14

14

14

19

17

15

14

12

11

12

19

16

20

18

14

13

22

28

26

32

28

22

23

135

11

Discharge 

(ton/d)

22

20

19

21

124

17

13

12

9.5

7.8

7.7

8.0

13

12

9.9

9.3

9.0

8.6

8.7

14

13

21

18

13

11

20

31

28

39

35

26

620.5

20

124

7.7

Mean 

streamflow

(ft3/S)

426

435

424

409

387

374

356

346

323

309

287

269

287

280

290

291

292

294

302

300

296

289

280

280

285

277

275

268

265

264

9,460

315

435

264

Suspended sediment

Mean 

concentration 

(mg/L)

September

18

15

13

12

12

11

10

10

10

10

9

8

6

6

7

7

7

6

6

5

5

4

4

4

4

4

4

4

4

4

...

...

8

18

4

Discharge 

(ton/d)

21

18

15

13

13

11

9.6

9.3

8.7

8.3

7.0

5.8

4.6

4.5

5.5

5.5

5.5

4.8

4.9

4.1

4.0

3.1

3.0

3.0

3.1

3.0

3.0

2.9

2.9

2.9

...

210.0

7.0

21

2.9

TOTAL FOR WATER YEAR 1993: 

STREAMFLOW-90,383 ft3/s 

SEDIMENT DISCHARGE--8.255.8 tons

TABLE 7 43
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1992 

through September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

444

447

444

439

456

523

548

551

563

568

574

570

574

584

631

659

674

680

672

667

657

646

637

634

630

627

625

629

629

664

698

18,344

592

698

439

Mean 

concentration 

(mg/L)

October

6

6

7

7

8

9

10

10

9

8

8

9

9

10

11

12

12

13

14

14

14

14

12

10

8

7

6

5

6

10

13

...

10

14

5

Discharge 

(ton/d)

7.2

7.2

8.4

8.3

9.8

13

15

15

14

12

12

14

14

16

19

21

22

24

25

25

25

24

21

17

14

12

10

8.5

10

18

24

485.4

16

25

7.2

Mean 

streamflow 

(ft3/*)

698

684

684

673

663

665

664

681

674

659

649

637

649

658

657

653

648

645

646

632

628

617

633

556

511

o420

«400

462

543

496

18,485

616

698

400

Suspended sediment

Mean 

concentration 

(mg/L)

1992

November

12

9

7

6

7

7

7

7

6

6

6

6

6

6

6

6

6

7

7

7

12

23

12

5

5

6

7

8

8

7

8

23

5

Discharge 

(ton/d)

23

17

13

11

13

13

13

13

11

11

11

10

11

11

11

11

10

12

12

12

20

38

21

7.5

6.9

6.8

7.6

10

12

9.4

388.2

13

38

6.8

Mean 

streamflow 

(ft3/*)

535

526

e470

e400

e320

e280

e330

o400

e500

e530

e550

e550

e520

e540

e560

578

550

530

e500

509

561

567

568

588

578

534

563

e500

e400

e350

e370

15.257

492

588

280

Suspended sediment

Mean 

concentration 

(mg/L)

December

6

6

7

7

7

8

8

8

8

8

8

7

7

7

7

7

6

5

4

4

5

12

6

4

4

4

5

5

4

5

8

6

12

4

Discharge 

(ton/d)

8.7

8.5

8.9

7.6

6.0

6.0

7.1

8.6

11

11

12

10

9.8

10

11

11

8.9

7.2

5.4

5.5

7.6

18

9.2

6.4

6.2

5.8

7.6

6.8

4.3

4.7

8.0

258.8

8.3

18

4.3

44 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1992 

through September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

<ft3/s)

e400

e450

e500

e500

e450

e400

e370

e350

e370

e400

e410

e420

e420

e430

e450

e450

e460

e470

e480

eSOO

e520

e550

e520

eSOO

e520

e550

e570

586

584

572

549

14,701

474

586

350

Mean 

concentration 

(mg/L)

January

18

10

3

3

3

3

3

3

3

3

3

3

3

4

5

6

9

11

12

12

12

11

13

20

22

18

16

16

14

11

8

9

22

3

Discharge 

(ton/d)

19

12

4.1

4.1

3.6

3.2

3.0

2.8

3.0

3.2

3.3

3.4

3.4

4.6

6.1

7.3

11

14

16

16

17

16

18

27

31

27

25

25

22

17

12

380.1

12

31

2.8

Mean 

streamflow 

(tt3/s)

1993

534

532

530

523

511

506

516

532

547

548

540

537

547

556

eSOO

e400

e350

e380

e420

e450

e470

e480

e480

e470

e450

e430

e420

e440

...

...

...

13,599

486

556

350

Suspended sediment

Mean 

concentration 

(mg/L)

February

7

7

7

7

6

7

9

9

9

9

9

10

12

11

10

8

7

8

9

9

9

9

9

10

10

8

6

5

...

...

...

...

8

12

5

Discharge 

(ton/d)

10

10

10

9.9

8.3

9.6

13

13

13

13

13

14

18

17

13

8.6

6.6

8.2

10

11

11

12

12

13

12

9.3

6.8

5.9

...

...

...

311.2

11

18

5.9

Mean 

streamflow 

(tt3/s)

e450

e460

e480

506

524

574

751

886

957

940

880

755

701

730

796

1,000

983

915

1,090

1,130

986

971

1,090

1,440

1,330

1,270

1,290

1,290

1,180

1,160

1,120

28,635

924

1,440

450

Suspended sediment

Mean 

concentration 

(mg/L)

March

10

8

5

6

11

17

55

69

67

53

42

25

20

26

49

116

83

47

88

138

55

42

72

182

157

79

74

67

43

39

33

...

57

182

5

Discharge 

(ton/d)

12

9.9

6.5

8.2

16

26

112

165

173

135

100

51

38

51

105

313

220

116

259

421

146

110

212

708

564

271

258

233

137

122

100

5,198.6

168

708

6.5

TABLE 8 45
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1992 

through September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow

(ft3/s)

1,080

1,090

1,110

1,090

1,200

1,200

1,130

1,070

1,050

1,040

1,020

998

1,010

993

976

954

923

954

1,030

1,010

976

975

1.000

1,030

1.010

991

986

974

964

984

30,818

1,027

1,200

923

Mean 

concentration 

(mg/L)

April

33

31

26

27

33

29

21

15

16

18

16

12

11

14

15

14

14

17

18

16

18

18

19

17

19

19

16

13

17

16

._

19

33

11

Discharge 

(ton/d)

96

91

78

79

107

94

64

43

45

51

44

32

30

38

40

36

35

44

50

44

47

47

51

47

52

51

43

34

44

43

1.600

53

1.07

30

Mean 

streamfiow

(ft3/s)

1993

1,010

1,020

1,050

1,280

1,710

1.830

1,930

2,100

1.960

1,820

1,760

2,000

2,520

3,240

3,900

4,300

4,440

4.300

4230

4,180

4.270

4.400

3.970

3,530

3.050

2,840

2,860

2,840

2,930

3.080

2,940

87,290

2,816

4,440

1,010

Suspended sediment

Mean 

concentration 

(mg/L)

May

16

16

18

40

94

98

68

84

64

42

36

43

91

130

159

136

112

77

66

59

59

67

45

38

31

28

28

24

27

32

31

...

60

159

16

Discharge 

(ton/d)

44

44

51

138

434

484

354

476

339

206

171

232

619

1,140

1,670

1,580

1.340

894

754

666

680

796

482

362

255

215

216

184

214

266

246

15,552

502

1,670

44

Mean 

streamflow 

(ft3/s)

2,920

3,330

3,100

2,700

2,550

2,420

2^30

2,660

2,460

2^80

2.420

2,670

2,600

2,340

2,150

2^60

3,140

3.150

2,850

2^40

2,370

2,380

2,480

2,390

2^50

2,070

1,890

1,820

1,900

1,870

~

74,490

2,483

3,330

1,820

Suspended sediment

Mean 

concentration 

(mg/L)

June

26

36

30

23

16

11

16

18

14

13

14

18

16

13

11

12

39

32

22

17

13

11

11

9

8

7

7

7

6

5

...

16

39

5

Discharge 

(ton/d)

205

324

251

168

110

72

109

129

93

80

91

130

112

82

64

73

331

272

169

117

83

71

74

58

49

39

36

34

31

25

3,482

116

331

25

46 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, October 1992 

through September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,720

1,680

1,830

2,030

2,130

2,130

2,140

2,270

2,190

2,140

2,080

2,070

2,090

2,080

2,080

2,030

1.990

2,060

2,040

1,920

1,880

1,790

1,820

1,760

1,690

1.790

2.120

2,200

1.990

1.780

1.690

61,210

1.975

2,270

1,680

Mean 

concentration 

(mg/L)

July

5

5

5

5

5

5

6

6

5

5

6

6

6

5

5

4

4

4

4

4

4

4

4

4

4

5

13

15

14

11

7

~

6

15

4

Discharge 

(ton/d)

23

23

25

27

29

29

35

37

30

29

34

34

34

28

28

22

21

22

22

21

20

19

20

19

18

24

74

89

75

53

32

996

32

89

18

Mean 

streamflow

<ft3/S)

1993

1,590

1.520

1.450

1,390

1.410

1.460

1.370

1,310

1,270

1,170

1,100

1,090

1,130

1,170

1,210

1,330

1.500

1.480

1.400

1,340

1.380

1.540

1,660

1,530

1.430

1.380

1.560

1.640

1.670

1,820

1,820

44.120

1.423

1,820

1.090

Suspended sediment

Mean 

concentration 

(mg/L)

August

6

5

5

4

9

12

10

10

9

6

7

7

7

8

9

21

34

22

12

10

11

25

37

19

14

15

25

26

26

30

27

...

15

37

4

Discharge 

(ton/d)

26

21

20

15

34

47

37

35

31

19

21

21

21

25

29

75

138

88

45

36

41

104

166

78

54

56

105

115

117

147

133

1,900

61

166

15

Mean 

streamflow 

(ft3/s)

1,730

1,680

1,690

1,640

1,600

1.560

1420

1.480

1.440

1.400

1.350

1.340

1,400

1.430

1.420

1.440

1.430

1.410

1.390

1.380

1.400

1,410

1,370

1.340

1,320

1,280

1,250

1,210

1,190

1,180

42,680

1,423

1.730

1.180

Suspended sediment

Mean 

concentration 

(mg/L)

September

22

20

17

16

15

14

13

12

10

9

9

8

8

8

7

7

7

7

7

6

6

5

5

5

6

5

5

5

5

5

...

...

9

22

5

Discharge 

(ton/d)

103

91

78

71

65

59

53

48

39

34

33

29

30

31

27

27

27

27

26

22

23

19

18

18

21

17

17

16

16

16

...

1,101

37

103

16

TOTAL FOR WATER YEAR 1993: 

STREAMFLOW-- 449.629 ft3/s 

SEDIMENT DISCHARGE- 31,653.3 tons

TABLE 8 47
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1992 through 

September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter, ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

etreamflow 

(ft3/s)

454

455

467

456

470

499

494

488

487

488

486

486

497

519

523

518

520

516

511

506

503

498

494

489

488

484

483

484

494

534

543

15,334

495

543

454

Mean 

concentration 

(mg/L)

October

2

2

2

3

2

2

2

2

2

2

2

2

2

1

1

1

2

2

2

2

2

2

2

2

1

1

1

1

1

2

2

2

3

1

Diecharge 

(ton/d)

2.5

2.5

2.5

3.7

2.5

2.7

2.7

2.6

2.6

2.6

2.6

2.6

2.7

1.4

1.4

1.4

2.8

2.8

2.8

2.7

2.7

2.7

2.7

2.6

1.3

1.3

1.3

1.3

1.3

2.9

2.9

73.1

2.4

3.7

1.3

Mean 

streamflow 

(ft3/*)

1992

534

536

522

513

517

511

519

549

550

529

524

520

513

511

508

501

499

505

506

498

489

491

487

425

e350

e320

e300

e370

e450

e450

...

14,497

483

550

300

Suspended sediment

Mean 

concentration 

(mg/L)

November

2

2

1

1

2

2

2

2

2

2

2

2

2

2

2

2

1

1

2

2

4

13

5

3

3

4

4

3

3

2

3

13

1

Discharge 

(ton/d)

2.9

2.9

1.4

1.4

2.8

2.8

2.8

3.0

3.0

2.9

2.8

2.8

2.8

2.8

2.7

2.7

1.3

1.4

2.7

2.7

5.3

17

6.6

3.4

2.8

3.5

3.2

3.0

3.6

2.4

...

101.4

3.4

17

1.3

Suspended sediment

Mean Mean 

stream- concenftew tration 

(ft3/*) (mg/L)

e430

e400

e370

c300

e270

e250

e300

c350

e400

e420

e450

e450

e420

e420

e450

e450

e420

e400

e380

e400

e420

e450

e470

e470

e450

e440

e420

e400

e320

e280

e300

12,150

392

470

250

December

2

2

2

2

2

2

2

2

2

2

2

1

1

1

2

2

2

1

1

2

3

3

3

3

3

3

3

3

3

2

2

2

3

1

Discharge 

(ton/d)

2.3

2.2

2.0

1.6

1.5

1.4

1.6

1.9

2.2

2.3

2.4

1.2

1.1

1.1

2.4

2.4

2.3

1.1

1.0

2.2

3.4

3.6

3.8

3.8

3.6

3.6

3.4

3.2

2.6

1.5

1.6

70.3

2.3

3.8

1.0

48 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

e320

e350

e380

e370

e350

e300

e280

e270

e300

e310

e320

e330

e350

e360

e370

e380

e390

e400

e400

e410

e420

e440

e430

e420

e420

e450

e480

e480

e470

e460

e450

11,860

383

480

270

Mean 

concentration 

(mg/L)

January

2

2

2

2

2

3

3

3

3

3

4

4

5

5

6

14

19

17

14

7

3

3

3

3

4

4

4

4

4

5

5

5

19

2

Discharge 

(ton/d)

1.7

1.9

2.1

2.0

1.9

2.4

2.3

2.2

2.4

2.5

3.5

3.6

4.7

4.9

6.0

14

20

18

15

7.7

3.4

3.6

3.5

3.4

4.5

4.9

5.2

5.2

5.1

6.2

6.1

169.9

5.5

20

1.7

Mean 

streamflow 

(«3/s)

1993

e430

e420

e410

e400

e400

e390

e390

e390

e380

e380

e380

e370

e370

e360

e330

e300

e280

e290

e300

e330

e350

e360

e360

e350

e350

e330

e320

e330

...

...

...

10.050

359

430

280

Suspended sediment

Mean 

concentration 

(mg/L)

February

3

4

5

6

5

5

4

4

3

3

3

3

3

3

4

4

4

4

4

4

4

3

3

2

2

3

4

4

...

...

...

4

6

2

Discharge 

(ton/d)

3.5

4.5

5.5

6.5

5.4

5.3

4.2

4.2

3.1

3.1

3.1

3.0

3.0

2.9

3.6

3.2

3.0

3.1

3.2

3.6

3.8

2.9

2.9

1.9

1.9

2.7

3.5

3.6

...

...

100.2

3.6

6.5

1.9

Mean 

streamflow 

(ft3/*)

e350

e360

e370

e370

e380

e400

e430

e480

e500

521

509

450

432

422

428

469

469

500

551

588

577

576

613

735

806

849

1,040

1,130

1,120

1,130

1,110

18,665

602

1.130

350

Suspended sediment

Mean 

concentration 

(mg/L)

March

3

4

5

6

8

9

9

10

10

12

14

12

8

6

7

10

10

14

24

16

16

19

23

33

28

26

40

30

18

17

13

15

40

3

Discharge 

(ton/d)

2.8

3.9

5.0

6.0

8.2

9.7

10

13

13

17

19

15

9.3

6.8

8.1

13

13

19

36

25

25

30

38

65

61

60

112

92

54

52

39

880.8

28

112

2.8

TABLE 9 49
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,100

1,130

1,170

1,210

1,350

el.500

el,500

1,420

1,430

1,440

1,430

1,400

1,360

1,320

1,270

1,230

1,200

1,230

1,320

1,340

1,330

1,340

1,390

1,440

1,440

1,440

1,420

1,400

1,390

1,410

40,350

1,345

1,500

1.100

Mean 

concentration 

(mg/L)

April

11

11

11

13

14

11

10

8

10

10

9

8

7

7

6

6

7

8

7

6

7

9

11

10

9

9

9

8

9

8

9

14

6

Discharge 

(ton/d)

33

34

35

42

51

45

40

31

39

39

35

30

26

25

21

20

23

27

25

22

25

33

41

39

35

35

35

30

34

30

980

33

51

20

Mean 

streamflow 

(ft3/s)

1993

1,440

1,490

1,640

1,910

2,330

2,500

2,780

2,950

2,880

2.740

2.840

3,570

4,840

5,980

6,870

7,180

7,020

6,680

6,350

6,140

6,100

5,980

5,410

4,720

4,140

3,930

3,940

3,880

3,980

3,990

3,730

129,930

4,191

7,180

1,440

Suspended sediment

Mean 

concentration 

(mg/L)

May

8

9

11

25

43

35

35

34

35

27

25

51

125

175

210

158

124

86

76

65

57

52

44

34

30

24

24

20

20

21

18

...

55

210

8

Discharge 

(ton/d)

31

36

49

129

271

236

263

271

272

200

192

492

1,630

2,830

3,900

3,060

2,350

1,550

1,300

1,080

939

840

643

433

335

255

255

210

215

226

181

24,674

796

3,900

31

Mean 

streamflow 

(ft3/s)

3,900

4,390

4,020

3,600

3,290

3.040

2,940

2.860

2.760

2.590

2,480

2^10

2,510

2.350

2.170

2,080

2.110

2^80

2.410

2.270

2.140

2.130

2.090

2.070

2.010

1.890

1,820

1,820

1,810

1,770

76,110

2.537

4,390

1.770

Suspended sediment

Mean 

concentration 

(mg/L)

June

20

39

28

20

13

9

8

8

9

8

8

8

8

7

7

7

7

11

21

20

18

15

12

10

9

8

9

9

9

8

12

39

7

Discharge 

(ton/d)

211

462

304

194

115

74

64

62

67

56

54

54

54

44

41

39

40

68

137

123

104

86

68

56

49

41

44

44

44

38

2,837

95

462

38

50 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(ft3/s)

1,700

1,630

1,640

1.720

1,720

1.670

1,620

1,580

1,550

1,550

1,530

1,540

1,610

1,590

1,600

1.590

1,600

1.590

1,560

1,520

1,510

1,460

1,410

1,360

1.330

1,330

1,350

1.320

1.250

1,170

1,110

46,710

1,507

1,720

1,110

Mean 

concentration 

(mg/L)

July

6

6

6

6

6

5

5

5

6

6

6

6

6

5

5

4

4

4

4

4

4

4

4

4

4

4

4

4

5

4

4

5

6

4

Discharge 

(ton/d)

28

26

27

28

28

23

22

21

25

25

25

25

26

21

22

17

17

17

17

16

16

16

15

15

14

14

15

14

17

13

12

617

20

28

12

Mean 

streamflow 

(ft3/s)

1993

1.060

1,030

1.010

981

959

987

993

978

943

903

885

856

846

844

857

933

1.070

1,070

1,040

1,010

1,000

1,020

1,030

989

940

911

879

862

907

950

960

29,703

958

1,070

844

Suspended sediment

Mean 

concentration 

(mg/L)

August

3

4

4

4

4

4

4

4

5

4

4

4

3

3

4

5

16

9

5

4

5

6

4

2

2

2

3

3

2

2

2

4

16

2

Discharge 

(ton/d)

8.6

11

11

11

10

11

11

11

13

9.8

9.6

9.2

6.9

6.8

9.3

13

46

26

14

11

13

17

11

5.3

5.1

4.9

7.1

7.0

4.9

5.1

5.2

344.8

11

46

4.9

Mean 

streamflow

(ft3/e)

940

938

971

947

935

941

929

899

865

841

825

829

887

912

914

938

942

930

919

915

915

924

912

901

885

859

844

831

815

795

...

26,898

897

971

795

Suspended sediment

Mean 

concentration 

(mg/L)

Ssptember

3

3

3

3

3

3

3

3

2

2

2

1

1

2

3

3

3

2

2

2

2

1

1

1

1

1

1

1

1

1

...

_

2

3

1

Discharge 

(ton/d)

7.6

7.6

7.9

7.7

7.6

7.6

7.5

7.3

4.7

4.5

4.5

2.2

2.4

4.9

7.4

7.6

7.6

5.0

5.0

4.9

4.9

2.5

2.5

2.4

2.4

2.3

2.3

2.2

2.2

2.1

147.3

4.9

7.9

2.1

TOTAL FOR WATER YEAR 1993: 

STREAMFLOW-- 432.257 ft3/s 

SEDIMENT DISCHARGE- 30,995.8 tons

TABLE 9 51
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1992 through 

September 1993

[Abbreviations: ft3/s, cubic feet per second; e, estimated; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

(«3/s)

901

902

907

908

911

1,020

1,050

1,060

1,060

1,070

1,080

1,070

1,070

1,100

1,140

1,180

1,200

1,210

1,190

1,170

1,170

1.140

1,130

1,120

1,120

1,120

1,110

1,100

1,120

1,190

1,240

33,759

1,089

1,240

901

Mean 

concentration 

(mg/L)

October

2

2

3

3

3

2

2

2

2

2

3

3

3

3

3

3

3

3

3

4

4

3

3

3

3

2

2

2

3

3

3

3

4

2

Discharge 

(ton/d)

4.9

4.9

7.3

7.4

7.4

5.5

5.7

5.7

5.7

5.8

8.7

8.7

8.7

8.9

9.2

9.6

9.7

9.8

9.6

13

13

9.2

9.2

9.1

9.1

6.0

6.0

5.9

9.1

9.6

10

252.4

8.1

13

4.9

Mean 

streamflow 

(«3/s)

1992

1,240

1,230

1,220

1,180

1,210

1,190

1,180

1,220

1,230

1,210

1,190

1,170

1,160

1,180

1,180

1.160

1,140

1,150

1,150

1,140

1,120

1,110

1,120

985

877

e750

e700

851

1,060

1,050

33,353

1,112

1,240

700

Suspended sediment

Mean 

concentration 

(mg/L)

November

3

4

4

4

4

3

2

2

2

2

2

2

2

2

2

2

2

2

2

2

7

18

8

2

2

2

2

2

2

1

3

18

1

Discharge 

(ton/d)

10

13

13

13

13

9.6

6.4

6.6

6.6

6.5

6.4

6.3

6.3

6.4

6.4

6.3

6.2

6.2

6.2

6.2

21

54

24

5.3

4.7

4.1

3.8

4.6

5.7

2.8

...

290.6

9.7

54

2.8

Mean 

streamflow 

(ft3*)

995

951

e850

e700

e600

e550

e600

e700

e900

e950

el .000

el ,000

e950

e950

el ,000

el, 000

e950

e900

e850

e900

e950

el ,000

el, 050

el, 050

1,010

1,010

1,020

e900

e700

e600

e650

27.236

879

1,050

550

Suspended sediment

Mean 

concentration 

(mg/L)

December

1

2

2

2

2

2

1

2

2

2

2

2

2

2

2

2

2

2

2

2

3

3

3

2

2

2

3

3

4

5

6

2

6

1

Discharge 

(ton/d)

2.7

5.1

4.6

3.8

3.2

3.0

1.6

3.8

4.9

5.1

5.4

5.4

5.1

5.1

5.4

5.4

5.1

4.9

4.6

4.9

7.7

8.1

8.5

5.7

5.5

5.5

8.3

7.3

7.6

8.1

11

172.4

5.6

11

1.6

52 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

<ft3/s)

e700

eSOO

e850

e850

eSOO

e700

e650

e600

e650

e700

e700

e750

eSOO

e850

e900

e900

e900

e950

e950

e950

el .000

el ,050

el, 050

el ,000

el, 000

el.100

el ,200

el ,200

el .200

el. 150

el.100

28.000

903

1.200

600

Mean 

concentration 

(mg/L)

January

5

5

4

3

3

4

4

4

3

3

3

2

1

1

1

1

2

2

3

3

3

3

3

4

4

4

4

4

4

4

3

3

5

1

Discharge 

(ton/d)

9.5

11

9.2

6.9

6.5

7.6

7.0

6.5

5.3

5.7

5.7

4.1

2.2

2.3

2.4

2.4

4.9

5.1

7.7

7.7

8.1

8.5

8.5

11

11

12

13

13

13

12

8.9

238.7

7.7

13

2.2

Mean 

streamflow

(ft3/S)

1993

el .050

el ,000

e950

955

952

939

947

932

949

947

927

920

924

941

809

e700

e600

e650

e700

eSOO

e850

e900

e900

e900

e900

e850

eSOO

e850

...

...

...

24,542

876

1,050

600

Suspended sediment

Mean 

concentration 

(mg/L)

February

4

4

5

6

5

4

3

3

4

4

4

4

4

5

5

5

6

8

8

7

6

5

4

3

3

3

3

3

...

...

...

5

8

3

Discharge 

(ton/d)

11

11

13

15

13

10

7.7

7.5

10

10

10

9.9

10

13

11

9.5

9.7

14

15

15

14

12

9.7

7.3

7.3

6.9

6.5

6.9

...

...

295.9

11

15

6.5

Mean 

streamflow 

(ft3/s)

e900

e950

e950

e950

979

1,020

1.200

1.330

1,460

1,490

1.470

1,300

1,200

1.230

1.280

1,490

1,540

1,460

1,620

1.860

1.680

1.610

1.710

2.280

2.270

2,250

2,380

2,570

2,430

2,420

2,350

49,629

1,601

2^70

900

Suspended sediment

Mean 

concentration 

(mg/L)

March

3

3

3

3

3

4

5

12

17

16

15

10

9

9

9

10

20

29

25

31

15

12

12

35

51

30

19

18

15

15

11

...

15

51

3

Discharge 

(ton/d)

7.3

7.7

7.7

7.7

7.9

11

16

43

67

64

60

35

29

30

31

40

83

114

109

156

68

52

55

215

313

182

122

125

98

98

70

2,324.3

75

313

7.3

TABLE 10 53
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

Mean 

streamflow 

<ft3/s)

2,300

2,350

2,430

2,410

2,700

2,810

2,690

2,600

2,580

2,570

2,530

2,480

2,450

2,390

2,320

2,260

2,190

2,240

2,420

2,420

2,360

2,350

2,430

2,530

2,500

2,490

2,460

2,440

2,400

2,440

...

73,540

2,451

2,810

2,190

Mean 

concentration 

(mg/L)

April

10

11

9

9

12

11

8

7

8

7

6

5

4

7

6

7

6

6

7

7

6

5

7

7

7

5

7

6

7

7

...

7

12

4

Discharge 

(ton/d)

62

70

59

59

87

83

58

49

56

49

41

33

26

45

38

43

35

36

46

46

38

32

46

48

47

34

46

40

45

46

...

1,443

48

87

26

Mean 

streamflow 

(ftS/s)

1993

2,500

2,560

2,710

3,230

4,080

4,420

4,800

5,180

4,960

4,680

4,680

5,610

7,410

9,200

10,800

11,600

11,600

11.100

10,600

10,300

10,300

10,400

9,400

8,240

7,210

6,690

6.770

6,630

6,770

6,950

6,570

217,950

7,031

11.600

2,500

Suspended sediment

Mean 

concentration 

(mg/L)

May

6

7

8

13

18

19

21

24

27

22

19

27

68

104

134

129

116

98

82

72

64

63

56

48

36

28

25

25

26

27

26

...

46

134

6

Discharge 

(ton/d)

40

48

59

113

198

227

272

336

362

278

240

409

1.360

2,580

3,910

4,040

3,630

2,940

2,350

2,000

1,780

1,770

1,420

1,070

701

506

457

448

475

507

461

34,987

1,130

4.040

40

Mean 

streamflow

(ft3/s)

6,630

7400

6,980

6,190

5,740

5,380

5,410

5,400

5,140

4,810

4.820

5,020

5.000

4,640

4,310

4,250

4,980

5,180

5,050

4,700

4.450

4,460

4^10

4,400

4,240

3,950

3.720

3,660

3,700

3,650

147,870

4,929

7400

3,650

Suspended sediment

Mean 

concentration 

(mg/L)

June

24

35

30

23

16

12

11

11

11

10

9

10

11

10

10

9

18

22

18

16

15

15

15

13

10

10

12

13

12

11

...

...

15

35

9

Discharge 

(ton/d)

430

709

565

384

248

174

161

160

153

130

117

136

148

125

116

103

242

308

245

203

180

181

183

154

114

107

121

128

120

108

6,253

208

709

103

54 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, October 1992 through 

September 1993 (Continued)

Suspended sediment

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

NUN

Mean 

streamflow 

(ft3/s)

3,460

3,330

3,450

3,660

3,800

3,700

3,700

3.780

3.690

3.550

3.530

3,500

3.640

3,590

3.590

3,510

3,510

3,540

3,540

3.360

3,300

3.180

3.100

3.070

2,910

3.050

3,360

3,470

3.180

2,920

2,750

105.720

3.410

3,800

3,460

Mean 

concentration 

(mg/L)

July

10

10

10

10

11

13

13

13

12

11

10

10

9

10

9

9

9

8

8

8

8

8

9

9

10

11

12

13

12

11

9

10

13

10

Discharge 

(ton/d)

93

90

93

99

113

130

130

133

120

105

95

94

88

97

87

85

85

76

76

73

71

69

75

75

79

91

109

122

103

87

67

2.910

94

133

93

Mean 

streamflow 

(ft3/s)

1993

2,640

2,550

2,450

2.370

2,370

2,450

2,390

2,300

2,260

2,100

2,030

1,980

1.990

2.010

2.070

2.220

2.580

2.580

2,430

2,350

2,360

2,490

2.670

2.520

2.330

2.270

2.330

2,460

2,500

2,690

2,710

73,450

2,369

2,710

2,640

Suspended sediment

Mean 

concentration 

(mg/L)

August

7

6

6

7

8

10

10

8

6

7

8

8

8

8

8

8

10

12

8

6

7

12

14

12

10

9

10

11

11

11

11

...

9

14

7

Discharge 

(ton/d)

50

41

40

45

51

66

65

50

37

40

44

43

43

43

45

48

70

84

52

38

45

81

101

82

63

55

63

73

74

80

80

1.792

58

101

50

Mean 

streamflow 

(ft3/s)

2,620

2J560

2,600

2320

2,460

2,420

2,390

2^70

2^40

2.160

2.100

2.090

2.190

2^60

2^60

2^80

2^80

2£50

2^20

2.190

2^10

2^40

2^00

2,150

2,110

2,040

2,010

1.940

1,930

1,890

...

67,080

2,236

2,620

2,620

Suspended sediment

Mean 

concentration 

(mg/L)

September

11

10

10

9

9

10

10

10

9

9

8

7

6

6

7

7

7

7

6

6

6

5

6

6

6

7

7

7

7

7

...

...

8

11

11

Discharge 

(ton/d)

78

69

70

61

60

65

65

61

54

52

45

40

35

37

43

43

43

43

36

35

36

30

36

35

34

39

38

37

36

36

1,392

46

78

78

TOTAL FOR WATER YEAR 1993: 

STREAMFLOW-- 882,129 ft3/s 

SEDIMENT DISCHARGE- 52,351.3 tons

TABLE 10 55
Table 11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana

[Abbreviations: U,g/L, micrograms per liter, mg/L, milligrams per liter. Symbols: <, less than minimum reporting level; , no data]

Station 

number

12323230 

12323250 

12323600 

12323750

12324680 

12331800

Station name

Cal- Magne- Potas- Sodlum, 

cium, slum, slum, dlsDate Time dls- dis- dis- solved solved solved solved 

(mg/L) 

(mg/L) (mg/L) (mg/L)

Blacktail Creek at Hanison Avenue at Butte 08-16-93 1100 30 6.7 9.1 2.5 

08-16-93 1101 30 6.8 9.5 2.5

Silver Bow Creek below Blacktail Creek at Butte 05-14-93 1300 45 10 25 5.4 

05-14-93 1300 44 10 25 5.4

Silver Bow Creek at Opportunity 03-08-93 1530 30 5.7 23 5.8 

03-08-93 1530 30 5.6 22 5.9

Silver Bow Creek at Warm Springs 04-12-93 1800 56 13 16 5.1 

04-12-93 1800 56 13 16 5.2

06-07-93 0745 48 9.1 11 3.7 

06-07-93 0745 49 9.3 12 3.6

Clark Fork at Goldcreek 04-27-93 1230 55 13 13 3.1 

04-27-93 1230 55 12 13 3.2

Clark Fork near Drummond 05-26-93 1145 50 11 13 3.1 

05-26-93 1145 50 11 12 3.2

Alkalinity, 

(mg/L 

as 

CaC03

98 

100

79 

80

49

87 

86

89 

89

128 

128

125 

126

Sulfate, 

dissolved 

(mg/L)

20 

20

83 

81

69

140 

140

87 

87

82 

84

58 

60

Station

number

12323230

12323250

12323600

12323750

12324680

12331800

Date

08-16-93

08-16-93

05-14-93

05-14-93

03-08-93

03-08-93

04-12-93

04-12-93

06-07-93

06-07-93

04-27-93

04-27-93

05-26-93

05-26-93

Chloride,

dissolved

(mg/L)

4.8

4.8

20

19

..

29

10

10

5.4

5.2

5.9

5.7

4.6

4.5

Fluorlde,

dissolved

(mg/L)

0.4

.4

.5

.5

..

.7

.7

.7

.6

.6

.4

.5

.4

.4

Silica,

dissolved

(mg/L)

28

28

22

22

..

14

14

14

11

11

18

17

20

18

Solids,

sum of 

constituents,

dissolved

(mg/L)

161

162

260

257

..

207

307

307

229

231

267

267

235

235

Arsenic, 

total

recoverable

(WI/L)

10

10

17

17

140

130

19

18

23

23

11

10

18

18

Arsenic,

dissolved

(M9/L))

8

8

7

7

34

34

14

16

19

19

9

8

13

12

Cadmium, Cadmium, total disrecov- solved

eraMe

(WI/L)

<1 <0.1

<1 <1

4 2.4

4 2.1

6 2.0

6 2.2

<1 .2

<1 .2

<1 .2

<1 .2

<1 <1

<1 <1

<1 .1

<1 .1

Copper, 

total

recoverable

(WJ/L)

7

7

300

300

980

1,000

60

57

32

31

21

21

--

Copper,

dissolved

(fig/L)

5

6

120

110

180

180

23

22

21

21

4

5

--

56 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 11. Chemical analyses of field replicates for water samples, upper Clark Fork basin, Montana (Continued)

Station 

Number

Date

Iron, 

total 

recoverablB 

(ug/L)

Iron, 

dissolved

Lead, 

total 

recoverable 

(ug/L)

Lead,

dissolved

(ug/L)

Manganese, 

total 

recoverable 

(ug/L)

Manganese, 

dissolved 

(ug/L)

Zinc, 

total 

recoverable 

(ug/L)

Zinc,

dissolved

(ug/L)

12323230 08-16-93 

08-16-93

590

600

230

300

<0.5 

.6

30

20

22

22

12323250

12323600

12323750

05-14-93 

05-14-93

03-08-93

03-08-93

04-12-93 

04-12-93

2,100

2,100

7,600

7,400

420

450

65

60

100

110

14

10

35

35

200

210

2.3 

2.3

<5

880

880

1,200

1,200

360

360

870

830

750

750

180

170

1,100

1.100

1,400

1,400

130

130

930

890

620

620

17

17

06-07-93 

06-07-93

220

200

25

24

<5 

<5

190

200

140

140

70

70

37

41

12324680 04-27-93 

04-27-93

380

340

100

100

26

25

40

30

12331800 05-26-93 

05-26-93

890

880

15

19

170

160

22

23

70

80

TABLE 11 57
Table 12. Precision of chemical analyses of field replicates for water samples, upper 

Clark Fork basin, Montana

[Abbreviations: mg/L, milligrams per liter, ug/L, micrograms per liter]

Constituent and reporting unit

Calcium, mg/L

Magnesium, mg/L

Sodium, mg/L

Potassium, mg/L

Alkalinity, mg/L as calcium carbonate

Sulfate, mg/L

Chloride, mg/L

Fluoride, \ig/L

Silica, H-g/L

Arsenic, total recoverable, \ig/L

Arsenic, dissolved, p.g/L

Cadmium, total recoverable, \ig/L

Cadmium, dissolved, \ag[L

Copper, total recoverable, \igfL

Copper, dissolved, \ag[L

Iron, total recoverable, \ig/L

Iron, dissolved, \igfL

Lead, total recoverable, \ag[L

Lead, dissolved, jig/L

Manganese, total recoverable, }ig/L

Manganese, dissolved, \ag[L

Zinc, total recoverable, \ig/L

Zinc, dissolved, \ig/L

Number of 

replicate pairs

7

7

7

7

6

6

6

6

6

7

7

7

7

6

6

7

7

6

6

7

7

7

7

Standard 

deviation, 

in units (+/-)

0.38

.28

.48

.06

.76

1.0

.30

.03

.64

2.7

.65

.0

.10

5.8

2.9

55

19

2.9

.17

4.6

11

3.8

11

Relative 

standard 

deviation, 

in percent (+/-)

0.84

2.8

3.0

1.4

.78

1.3

3.1

5.5

3.5

8.1

4.4

.0

14

2.5

5.0

3.2

27

6.9

22

1.1

3.9

.94

4.7

58 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 13. Precision of chemical analyses of laboratory replicates for water samples, upper Clark 

Fork basin, Montana

[Abbreviations: ug/L, micrograms per liter, uS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, milligrams per liter

Property or constituent and reporting unit

Specific conductance, uS/cm

pH, units

Calcium, mg/L

Magnesium, mg/L

Sodium, mg/L

Potassium, mg/L

Alkalinity, mg/L as calcium carbonate

Sulfate, mg/L

Chloride, mg/L

Fluoride, p.g/L

Silica, p.g/L

Arsenic, total recoverable, p.g/L

Arsenic, dissolved, Jig/L

Cadmium, total recoverable, p.g/L

Cadmium, dissolved, p.g/L

Copper, total recoverable, u.g/L

Copper, dissolved, |j.g/L

Iron, total recoverable, |J.g/L

Iron, dissolved, p.g/L

Lead, total recoverable, p.g/L

Lead, dissolved, \ig/L

Manganese, total recoverable, |ig/L

Manganese, dissolved, \ig/L

Zinc, total recoverable, p.g/L

Zinc, dissolved, u.g/L

Number of 

replicate pairs

7

8

8

8

8

7

6

13

11

8

6

8

8

8

8

8

8

8

8

8

7

8

8

8

8

Standard 

deviation, 

in units (+/ )

0.71

.07

.43

.12

.18

.05

.65

.34

.40

.02

.00

.39

.49

.02

.08

.18

.93

22

2.2

.19

.49

4.9

1.1

3.2

3.5

Relative 

standard 

deviation, 

in percent (+/-)

0.2

1.0

1.5

1.7

2.1

1.5

.7

1.2

2.9

6.7

.0

4.2

9.4

2.5

9.6

2.5

9.6

2.4

2.6

3.0

6.4

2.9

1.4

1.1

9.8

Within limits 

of dataquality 

objective

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

TABLE 13 59
Table 14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks

[Abbreviation: |Xg/L, micrograms per liter]

Constituent and reporting unit

Number of 

samples

Mean spike 

recovery, 

in percent

95-percent 

confidence 

interval for 

spike recovery, 

in percent

Within limits 

of dataquality 

objective

Arsenic, total recoverable, \LgfL 

Arsenic, dissolved, (ig/L 

Cadmium, total recoverable, (J.g/L 

Cadmium, dissolved, jo.g/L 

Copper, total recoverable, (ig/L 

Copper, dissolved, jo.g/L 

Iron, total recoverable, )ig/L 

Iron, dissolved, (J.g/L 

Lead, total recoverable, p.g/L 

Lead, dissolved, (J-g/L 

Manganese, total recoverable, (J.g/L 

Manganese, dissolved, (J.g/L 

Zinc, total recoverable, (J.g/L 

Zinc, dissolved, (J.g/L

102.6

94.0

97.0

93.4

101.7

99.5

94.0

103.3

100.5

105.8

96.9

95.6

96.3

106.5

95.8-109 

89.6-98.4 

93.5-101 

85.9-101 

94.4-109 

95.9-103 

90.0-98.0 

92.4-114 

95.2-106 

99.5-112 

96.3-97.5 

82.2-109 

94.1-98.5 

99.7-113

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes

60 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data,upper Clark Fork basin, Mont.
Table 15. Recovery efficiency for trace-element analyses of laboratory-spiked stream samples, 

upper Clark Fork basin, Montana

[Abbreviation: ug/L, micrograms per liter]

Constituent

Number of 

samples

Mean spike 

recovery, 

in percent

95-percent 

confidence 

interval for 

spike recovery, 

in percent

Within limits 

of dataquality 

objective

Arsenic, total recoverable, \Lg/L 

Arsenic, dissolved, ng/L 

Cadmium, total recoverable, Hg/L 

Cadmium, dissolved, |j,g/L 

Copper, total recoverable, |j,g/L 

Copper, dissolved, \ig/L 

Iron, total recoverable, |j,g/L 

Iron, dissolved, |ig/L 

Lead, total recoverable, \ig/L 

Lead, dissolved, \ig/L 

Manganese, total recoverable, \igfL 

Manganese, dissolved, \ig/L 

Zinc, total recoverable, |ig/L 

Zinc, dissolved, [ig/L

99.9

95.2

98.1

97.1

97.2

97.4

94.6

102.2

96.0

104.7

95.7

100.2

95.7

105.7

96.5-103

92.0-98.3

95.2-101

92.3-102

92.3-102

95.8-99.0

86.7-103

94.4-110

93.0-99.0

98.5-111

92.1-99.3

96.4-104

92.2-99.2

93.4-118

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes

TABLE 15 61
Table 16. Chemical analyses of field blanks for water samples

[Abbreviations: °C, degrees Celsius; flg/L, micrograms per liter; fiS/cm, microsiemens per centimeter at 25 °C; mg/L, 

milligrams per liter. Symbols: <, less than minimum reporting level; , no data]

Date

Specific 

conductTime ance, 

onsite 

(fiS/cm)

PH,

onsite

(standard

units)

Calcium,

dissolved

(mg/L)

Magnesium, 

dissolved 

(mg/L)

Sodium,

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Alkalinity, 

(mg/L as 

CaCOg)

Sulfate,

dissolved

(mg/L)

Nov 1992

16...

Mar 1993

08...

Apr 

12...

Jun

08...

Jul

12...

Aug 

16...

1305

1000 1

0800 4

0600 1

0730 1

0730 1

--

6.8

5.4

5.2

4.4

5.5

<0.10

<.02

.03

<.02

<02

<02

<0.10

<.01

<.01

<.01

<.01

<.01

--

<0.2

<2

<.2

<2

<2

-

<0.1

<.l

<.l

<.l

<.l

_

<1.0 0.3

2.5 <.l

1.1 <.l

1.3 <.l

2.8 <.l

Chloride, 

Date dissolved 

(mg/L)

Ruoride, 

dissolved 

(mg/L)

Silica, 

dissolved 

(mg/L)

Arsenic, 

total 

recoverable 

(M4/L)

Arsenic, 

dissolved 

(MI/L)

Cadmium, 

total 

recoverable 

(Ml/L)

Cadmium, 

dissolved 

(Ml/L)

Copper, 

total 

recoverable 

(Ml/L)

Copper, 

dissolved

Nov 1992

16... 

Mar 1993

08... 

Apr

12... 

Jun

08... 

Jul

12... 

Aug

16...

0.2 <0.1 0.1 <1 <1 <.l

Date

Iron,

total

recoverable

(Ml/L)

Iron,

dissolved

(Ml/L)

Lead,

total

recoverable

(ng/L)

Lead,

dissolved

(R9/L)

Manganese,

total

recoverable

(Ml/L)

Manganese,

dissolved

(M9/L)

Zinc,

total

recoverable

(M4/L)

Zinc,

dissolved

(H.Q/L)

Nov 1992

16... 

Mar 1993

08...

Apr

12...

Jun

08...

Jul

12...

Aug 

16...

10

10

20

20

<10

<3

<3

<3

<3

<3

<1 <5 <10 <1 <1

<1 <.5 10 <1 <1

<1 <.5 10 <1 <1

2 2.4 <10 <1 <1

2 1.4 <10 <1 <1

0 <3

0 <3

0 <3

0 4

0 9

62 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 17. Trace-element analyses of fine bed sediment, upper Clark Fork basin, Montana, August 1993

[Abbreviations: fig/g, micrograms per gram of dry sample weight. Fine sediment is material less than 0.064 millimeter in diameter. 

Concentrations are the mean of all analyses for duplicate aliquots from each composite sample]

Station

number 

(fig. 1)

Number

of cornStation name 

posite

CadmiumChromium

samples

12323600

12323750

12323800

12324200

12324680

12331500

12331800

12334510

12334550

12340000

12353000

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

dark Fork at Goldcreek

Flint Creek near Drummond

dark Fork near Drummond

Rock Creek near Clinton

dark Fork at Turah Bridge, near Bonner

Blackfoot River near Bonner

dark Fork below Missoula1

3

3

3

3

3

3

3

3

3

3

3

29.3

12.2

13.2

5.6

6.2

3.2

4.2

<.8

3.9

<.8

1.9

24.2

12.8

22.1

19.5

31.6

21.1

30.8

19.3

26.7

15.3

18.8

Copper

4,570

769

1,520

992

1.030

73

614

15

498

25

225

Concentration, in ng/g

Iron

37,500

20,800

29,900

26,800

26.400

22,400

24,700

18,000

22,400

15,800

21,040

Lead

1,030

99

191

177

152

240

135

16

115

20

58

Manganese

1,680

8,150

12,200

1,480

1,180

3,050

1,940

423

1,410

535

991

Nickel

16.3

16.5

23.2

15.0

17.0

11.6

15.7

12.7

15.9

12.7

14.1

Sliver

19.6

.9

4.2

4.1

3.7

7.8

3.5

<.5

2.9

<.5

1.5

Zinc

6,850

2,010

2,580

1,230

1,320

727

1,100

58

1,010

71

486

Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 17 63
Table 18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1993

[Abbreviations: |ig/g, micrograms per gram of dry sample weight. Concentrations are the mean of all analyses for duplicate aliquots for 

each composite sample]

Station

number

Number

of cornStation name 

posite

CadmiumChromium

samples

12323600

12323750

12323800

12324200

12324680

12331500

12331800

12334510

12334550

12340000

12353000

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Clark Fork near Galen

Clark Fork at Deer Lodge

Clark Fork at Goldcreek

Flint Creek near Drummond

Clark Fork near Drummond

Rock Creek near Clinton

Clark Fork at Turah Bridge, near Bonner

Blackfoot River near Bonner

Clark Fork below Missoula1

1

3

1

3

1

1

1

1

3

1

3

6.7

1.2

1.5

2.4

2.4

.3

1.8

<.8

.5

<.8

.5

9.6

9.9

4.2

16.1

23.4

4.9

16.9

6.6

6.9

6.7

8.6

Copper

831

111

223

383

370

19

276

4

122

14

77

Concentration,

iron

18,700

9,160

9,930

17,900

18,600

8,630

15,900

6,380

10,700

10,300

10,200

Lead

248

33

41

85

72

51

61

5

30

8

19

, in |ig/g

Manganese

671

543

1,280

998

649

1,150

820

91

487

179

351

Nickel

6.0

8.0

4.9

10.2

12.4

5.8

11.0

4.8

6.4

7.6

7.1

Silver

3.9

<.5

.7

1.6

1.6

3.9

1.7

.1

.3

<.5

.4

Zinc

2,050

303

498

599

676

190

621

16

345

33

172

Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

64 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 19. Recovery efficiency for trace-element analyses of standard reference materials for bed sediment

[Abbreviations: ug/g, micrograms per gram of dry sample weight; SRM, standard reference material. Symbol: , recovery could not be determined because 

all analyses were less than the analytical detection limit of 0.8 ug/g for cadmium and 0.5 jig/g for silver]

Constituent

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Number of 

measurements

5

5

5

5

5

5

5

5

5

9

9

9

9

9

9

9

9

9

Certified concentration

(H9/9)

SRM sample 2709

0.38

130

34.6

35,000

18.9

538

88

.41

106

SRM sample 2711

41.7

47.0

114

28,900

1,160

638

20.6

4.63

350

Mean SRM recovery 

(percent)

--

54.8

76.9

79.1

97.3

87.1

84.9

90.0

96.9

51.6

88.2

75.4

101

80.2

80.6

77.5

93.1

95-percent confidence 

interval for SRM 

recovery 

(percent)

-

49.0-60.6

70.9-82.9

75.9-82.3

94.0-101

85.5-88.7

83.1-86.7

-

87.0-93.0

95.2-98.6

46.3-56.9

85.5-90.9

71.2-79.6

99.1-103

78.2-82.2

77.8-83.4

72.5-82.5

90.9-95.3

TABLE 19 65
Table 20. Trace-element analyses of procedural blanks for bed sediment

[Abbreviation: fig/mL, micrograms per milliliter. Dilution ratio is the proportion of initial volume of digested sample aliquot to final volume of solution after 

addition of 0.6 N hydrochloric acid. Symbol: <, less than]

Sample 

designation

A

A

B

B

C

C

D

D

E

E

F

F

G

G

H

H

I

I

Dilution 

ratio

1:5

1:10

1:5

1:10

1:5

1:10

1:5

1:10

1:5

1:10

1:1

1:5

1:1

1:5

1:1

1:5

1:1

1:5

Trace-element concentration, in fig/mL

Cadmium

<0.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

Chromium

<0.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

<.004

.006

<.004

<.004

<.004

<.004

<.004

<.004

Copper

0.014

<.006

.012

<.006

<.006

<.006

<.006

<.006

<.006

<.006

.021

<.006

.014

<.006

.010

<.006

.023

<.006

Iron

0.060

<.055

<.055

<.055

<.055

<.055

<.055

<.055

<.055

<.055

<.055

.175

<.055

.106

<.055

.072

<.055

<.055

Lead

<0.011

<.on

<.on

<.on

<.on

<.on

<.on

<.on

<.011

<.on

<.on

<.on

<.on

<.on

<.on

<.on

<.on

<.on

Manganese

<0.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

Nickel

<0.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

<.005

Silver

<0.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

<.003

Zinc

<0.003

<.003

<.003

<.003

<.003

<.003

<,003

<.003

<.003

<.003

.037

.025

.032

<.003

.023

<.003

.026

<.003

66 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 21. Trace-element analyses of aquatic insects, upper Clark Fork basin, Montana, 

August 1993

[Abbreviations: |Xg/g, micrograms per gram of dry sample weight. Analyses are of whole-body tissue. 

Composite samples made by combining similar-sized insects into a sample of sufficient mass for analysis. 

Concentrations for insect samples composed of two or more composite samples are the means of all analyses]

Number Concentration, in [ig/g

Taxon

Hydropsyche cockerelli

Hydropsyche morosa group

Chematopsyche sp.

Hydropsyche cockerelli

Hydropsyche occidentalis

Hydropsyche tana

Hydropsyche cockerelli

Hydropsyche occidentalis

Hydropsyche cockerelli

Arctopsyche grandis

Claassenia sabulosa

Hydropsyche occidentalis

Hydropsyche tana

Arctopsyche grandis

Hydropsyche cockerelli

Hydropsyche occidentalis

Claassenia sabulosa

Hydropsyche cockerelli

Arctopsyche grandis

Claassenia sabulosa

Hydropsyche cockerelli

Hydropsyche occidentalis

Hydropsyche morosa group

Arctopsyche grandis

Claassenia sabulosa

Hydropsyche occidentalis

Hydropsyche morosa group

Arctopsyche grandis

Claassenia sabulosa

Hydropsyche cockerelli

Hydropsyche occidentalis

Arctopsyche grandis

Claassenia sabulosa

Cad- Chro- Copposite Iron Lead 

mium mium per 

samples

12323600 Silver Bow Creek at Opportunity

(insufficient number of insects obtainable for analysis)

12323750 Silver Bow Creek at Warm Springs

2 2.0 0.7 96.9 784 5.2

1 2.3 1.4 47.6 619 5.1

1 3.6 .9 117 725 5.0

12323800 Clark Fork near Galen

2 2.6 3.1 176 1,390 8.0

1 1.5 6.6 82.4 786 4.0

1 3.2 4.6 156 1,890 12.4

12324200 Clark Fork at Deer Lodge

3 1.6 2.1 81.8 568 6.1

1 2.7 16.5 49.4 1,030 <4.6

12324680 Clark Fork at Gold creek

3 2.0 3.2 66.8 636 5.3

1 6.6 2.3 39.9 387 3.8

1 .6 1.6 66.6 209 1.0

12331500 Flint Creek near Drummond

1 1.0 17.6 <1.7 1,940 24.0

1 .3 10.3 5.4 1,320 15.3

6 .5 3.1 16.3 1,740 13.5

12331800 Clark Fork near Drummond

2 1.2 1.6 44.4 513 6.9

1 1.0 8.1 13.3 424 3.0

1 1.2 3.3 45.5 252 1.3

12334510 Rock Creek near Clinton

1 .3 2.3 17.6 652 .6

2 .3 2.4 10.5 513 <.3

3 .2 1.5 28.5 94.6 .07

12334550 Clark Fork at Turah Bridge, near Bonner

1 1.4 8.0 26.4 905 4.4

2 .9 2.4 40.5 1,090 7.9

1 1.1 4.6 26.8 986 6.6

2 1.7 1.9 23.2 569 3.5

2 1.4 1.7 45.1 113 .9

12340000 Blackfoot River near Bonner

1 .1 1.5 20.6 1,060 1.2

1 .3 1.9 10.2 948 1.1

1 .1 1.1 13.4 483 1.5

1 .05 .7 48.3 113 .6

12353000 Clark Fork below Mlssoula1

5 .6 3.1 35.8 1,150 2.8

1 .5 3.5 30.5 731 1.9

1 .9 2.7 17.1 343 1.8

2 .7 1.1 51.9 112 .4

Manganese

1,160

1,100

1,110

1,760

2,860

2,360

632

1,960

608

1,080

179

1,450

1,180

1,280

549

619

156

215

277

24.4

788

1,440

1,320

722

79.6

452

496

360

45.2

627

667

525

52.4

Nickel

0.7

<.4

.9

2.9

3.5

3.6

.9

12.9

1.3

1.0

.4

6.8

3.1

1.6

.6

1.7

1.1

1.4

1.4

.6

2.6

1.0

1.7

.6

.4

1.1

1.6

.7

.3

1.3

1.3

.8

.3

Zinc

261

284

242

285

278

349

168

297

196

309

166

195

139

240

175

173

211

144

161

255

224

230

231

236

217

150

167

136

197

169

159

169

203

'Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 21 67
Table 22. Recovery efficiency for trace-element analyses of standard reference material for biota

[Abbreviations: SRM, standard reference material; Jig/g, micrograms per gram of dry sample weight]

95-percent confidence

Number of Certified concentration Mean SRM recovery interval for SRM 

Constituent

measurements (1^9/9) (percent) recovery

(percent)

SRM sample 156(Ta

Cadmium 7 4.15 94.9 88.9-101 

Chromium 7 1.43 93.1 67.8-118 

Copper 7 66.3 100 96.5-103 

Iron 7 539 89.7 86.9-92.5 

Lead 7 12.3 126 81.1-171 

Manganese 7 2.25 90.9 87.1-94.7 

Nickel 7 .37 88.6 78.0-99.2 

Zinc 7 830 92.1 89.0-95.2

68 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 23. Trace-element analyses of procedural blanks for biota

[Blanks were not diluted prior to analysis. Abbreviation: (ig/mL, micrograms per milliliter. Symbol: <, less than]

Sample 

designation

Dilution

Trace-element concentration,

ratio Cadmium Chromium Copper Iron Lead

Manganese

Nickel Zinc

A 1:1

B 1:1

C 1:1

D 1:1

E 1:1

F 1:1

G 1:1

H 1:1

I 1:1

J 1:1

<0.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

<.006

0.047

.060

.063

.092

.053

.068

.057

.078

.006

.007

0.022

.025

.014

<.006

<.006

<.006

<.006

<.006

.013

<.006

<0.055

.151

.146

.279

.161

.252

.226

.348

.079

<.055

0.038

.011

<.011

<.011

<.011

<.011

<.on

<.011

.012

.036

<0.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

<.023

0.019

.016

.009

.026

.014

.018

.017

.024

<.005

<.005

0.033

<.003

.004

.020

<.003

.034

<.003

<.003

.019

<.003

TABLE 23 69
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993

[Abbreviations: ft3/s, cubic feet per second; °C, degrees Celsius; ug/L, micrograms per liter; uS/cm, microsiemens per centimeter at 25 °C; mg/L,

milligrams per liter, mm, millimeter; ton/d, tons per day. Symbols: <, less than minimum reporting level1 ; , indicates insufficient data 

greater than minimum reporting level to compute statistic]

Property or constituent and reporting unit

Number of 

samples

Maximum

Minimum

12323230-BLACKTAIL CREEK AT HARRISON AVENUE. AT BUTTE.

Mean

MONT.

Median

Water-quality period of record: March 1993-September 1993

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (jiS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCQ^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCC^)

Sulfate, dissolved (mg/L as SO4)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (Hg/L)

Arsenic, dissolved (|J.g/L)

Cadmium, total recoverable (Hg/L)

Cadmium, dissolved (p-g/L)

Copper, total recoverable (p.g/L)

Copper, dissolved (p.g/L)

Iron, total recoverable (|ig/L)

Iron, dissolved (p.g/L)

Lead, total recoverable (Hg/L)

Lead, dissolved (u,g/L)

Manganese, total recoverable (^ig/L)

Manganese, dissolved (p.g/L)

Zinc, total recoverable (Hg/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

9.3

320

17

8.2

120

35

8.4

16

3

100

34

8.9

.6

28

192

10

8

<1

.1

52

9

3,800

230

47

1.0

190

51

130

11

123

3

95

3.1

206

4

7.7

73

21

5.1

9.1

2.1

62

20

3.8

.2

14

121

3

2

<1

<.l

4

3

300

44

<1

<.5

30

17

<10

<3

3

.05

61

7.4

258

9.9

7.9

102

30

7.0

11

2.4

87

27

6.4

.4

23

160

7

4

-

-

15

5

1,040

133

211

--

76

36

234

26

31

.67

87

7.8

254

10.5

7.9

105

30

7.0

11

2.4

87

28

5.5

.3

24

161

6

4

<1

<.l

7

4

525

155

1

<.5

60

38

10

5

6

.12

91

70 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323250--SILVER BOW CREEK BELOW BLACKTAIL CREEK. AT BUTTE. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (p.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (pg/L)

Arsenic, dissolved (p.g/L)

Cadmium, total recoverable (p.g/L)

Cadmium, dissolved (p.g/L)

Copper, total recoverable (pg/L)

Copper, dissolved (p.g/L)

Iron, total recoverable (p.g/L)

Iron, dissolved (p.g/L)

Lead, total recoverable (pg/L)

Lead, dissolved (pg/L)

Manganese, total recoverable (p.g/L)

Manganese, dissolved (p.g/L)

Zinc, total recoverable (pg/L)

Zinc, dissolved (p.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

8

8

8

8

8

8

8

8

8

7

7

7

7

7

7

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

March 1993-Septeraber 1993

37

535

15.5

7.8

170

48

12

33

7.1

96

92

26

.8

24

285

39

10

6

2.6

550

120

7,400

120

250

2.4

1,500

910

1,600

930

162

16

93

20

402

3.0

7.4

130

36

8.3

18

4.5

65

70

16

.4

17

218

11

5

2

1.9

130

65

500

26

3

<.5

620

660

790

710

5

.30

82

26

468

11.7

7.5

149

43

10

24

5.5

79

79

21

.5

22

253

18

8

3

2.3

252

94

2,100

65

52

2.1

869

760

1,060

824

42

3.6

88

23

462

13.5

7.5

150

44

10

24

5.3

78

77

21

.5

22

255

16

8

3

2.3

195

87

785

60

16

.8

840

735

1,000

795

13

.90

88

TABLE 24 71
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12323600--SILVER

Number of 

samples

Maximum Minimum Mean Median

BOW CREEK AT OPPORTUNITY. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (p-S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as SQ^)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (p.g/L)

Arsenic, dissolved (M-g/L)

Cadmium, total recoverable (fig/L)

Cadmium, dissolved (p.g/L)

Copper, total recoverable (p.g/L)

Copper, dissolved (M-g/L)

Iron, total recoverable (u.g/L)

Iron, dissolved (p.g/L)

Lead, total recoverable (p.g/L)

Lead, dissolved (p.g/L)

Manganese, total recoverable (M-g/L)

Manganese, dissolved (fig/L)

Zinc, total recoverable (p.g/L)

Zinc, dissolved (p.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

7

8

8

8

8

8

8

8

8

7

7

7

7

7

7

8

8

8

8

8

8

8

8

8

8

8

8

8

8

9

9

9

March 1993-September 1993

108

395

16.0

8.9

140

41

8.9

23

5.8

98

79

13

.5

23

237

140

34

6

2.0

980

180

7,600

100

200

2.3

1,200

750

1,400

620

384

52

92

49

282

.5

7.6

98

30

5.7

12

2.9

78

46

7.3

.3

19

176

11

6

1

.7

100

45

570

19

8

<.5

340

270

260

110

6

.81

60

74

343

10

8.3

121

37

7.4

16

3.9

85

60

9.6

.4

20

206

32

12

2

1.2

261

82

1,750

57

37

-

635

530

566

281

78

12

76

64

354

9.5

8.4

120

37

7.4

15

3.7

84

58

9.0

.4

20

209

16

8

2

1.2

165

54

945

50

13

<.5

570

535

445

205

16

4.0

78

72 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

123237SO--SILVER

Number of 

samples

Maximum Minimum Mean Median

BOW CREEK AT WARM SPRINGS. MONT.

Water-quality period of record: March 1993-September 1993

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (}4.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (u.g/L)

Arsenic, dissolved (jig/L)

Cadmium, total recoverable (jig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable (jig/L)

Copper, dissolved (jig/L)

Iron, total recoverable (jig/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (jig/L)

Lead, dissolved (jig/L)

Manganese, total recoverable (p.g/L)

Manganese, dissolved (jxg/L)

Zinc, total recoverable (}4.g/L)

Zinc, dissolved (jig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

9

8

9

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

9

9

9

347

580

18.5

9.3

250

74

17

23

5.4

99

170

15

.9

16

379

29

27

<1

.2

60

32

420

27

5

<.5

490

370

140

73

13

12

97

32

361

2.0

8.0

150

44

9.1

11

3.4

69

81

4.9

.6

7.6

227

13

11

<1

<.l

23

10

140

5

<1

<.5

150

110

40

9

3

.69

73

158

455

13.3

8.7

190

56

12

15

4.4

89

124

8.0

.7

12

286

20

18

--

2.1

38

20

285

15

22

--

289

196

85

27

8

3.4

84

149

475

15.0

8.5

190

54

12

15

4.4

90

135

6.8

.7

13

297

20

16

<1

.1

33

20

300

14

2

<.5

245

155

80

17

8

2.1

82

TABLE 24 73
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

12323770--WARM SPRINGS CREEK

Maximum Minimum Mean Median

AT WARM SPRINGS. MONT.

Water-quality period of record: March 1993

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (jj.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCOj)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (|J£/L)

Arsenic, dissolved (u.g/L)

Cadmium, total recoverable (jJ.g/L)

Cadmium, dissolved (p.g/L)

Copper, total recoverable (jig/L)

Copper, dissolved (jig/L)

Iron, total recoverable (p.g/L)

Iron, dissolved (u.g/L)

Lead, total recoverable (u.g/L)

Lead, dissolved (p.g/L)

Manganese, total recoverable (p.g/L)

Manganese, dissolved Qig/L)

Zinc, total recoverable (jJ.g/L)

Zinc, dissolved (u.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

6

5

6

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

6

6

6

206

476

13.0

8.6

230

70

14

5.2

4.7

139

110

1.7

.4

11

296

16

14

<1

<.l

75

16

1,300

30

9

1.8

1,400

350

60

10

68

18

88

-September 1993

24 106

194

2.5 9.4

8.1

94

29

5.2

2.1

1.0

71

25

.5

.4

9.2

115

4

3

<1

<.l

6

2

70

9

<1

<.5

120

74

<10

<3

4 21

.71 6.8

75 81

95

--

10.2

--

-

--

--

--

--

--

--

--

--

--

--

--

--

-

--

--

--

--

--

--

--

--

--

--

--

10

2.0

81

74 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12323800--CI

Number of 

samples

Maximum Minimum Mean Median

,ARK FORK NEAR GALEN. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s) 48

Specific conductance, onsite (u,S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved sob'ds, calculated (mg/L)

Arsenic, total recoverable (u,g/L)

Arsenic, dissolved (^ig/L) 

Cadmium, total recoverable (jJg/L)

Cadmium, dissolved (Hg/L)

Copper, total recoverable (H-g/L)

Copper, dissolved (u,g/L)

Iron, total recoverable (u.g/L)

Iron, dissolved (H-g/L) 

Lead, total recoverable (u,g/L) 

Lead, dissolved (^.g/L)

Manganese, total recoverable (Hg/L)

Manganese, dissolved (|J.g/L)

Zinc, total recoverable (u,g/L)

Zinc, dissolved (|J.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

38

49

37

36

36

36

8

8

8

8

8

8

8

8

36

36 

36

36

35

36

36

36 

36 

36

36

36

36

36

50

50

49

July 1988-September 1993

626 14

720

22.5

8.8

370

110

22

18

5.0

123

160

11

.7

14

364

60

30 

3

1

240

50

9,200

110 

28 

3

1,400

360

360

110

338

338

97

220

.0

7.5

96

29

5.7

7.5

2.2

82

62

3.2

.5

8.7

184

3

4 

<1

<.l

11

3

90

3 

<1 

<.5

80

33

20

3

2

.15

64

170

467

9.2

8.3

208

62

13

12

3.4

95

100

5.9

.6

11

251

18

12 

2.5

--

46

13

799

20 

26 

2.5

373

144

79

24

23

20

80

94

482

9.0

8.2

215

61

14

12

3.3

91

86

5.8

.6

11

230

15

12 

<1

<1

31

10

315

11 

3 

<1

300

125

60

15

8

2.1

79

TABLE 24 75
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12324200--CL

Number of 

samples

Maximum

,ARK FORK AT DEER LODGE.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (|j.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3 )

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (jJ.g/L)

Arsenic, dissolved (jJ.g/L)

Cadmium, total recoverable (|J.g/L)

Cadmium, dissolved (jxg/L)

Copper, total recoverable (|ig/L)

Copper, dissolved (ju.g/L)

Iron, total recoverable (|ig/L)

Iron, dissolved (u.g/L)

Lead, total recoverable (|ig/L)

Lead, dissolved (|ig/L)

Manganese, total recoverable (|ig/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (|ig/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

102

86

102

51

43

43

43

8

8

9

8

8

8

8

8

53

53

53

53

52

53

53

53

53

53

53

53

53

53

103

103

94

Minimum

, MONT.

Mean Median

March 1985-September 1993

1,920

642

23.0

8.6

270

81

18

19

6.3

149

140

8.9

.7

19

374

200

39

5

2

1,500

120

29,000

150

200

6

4,600

400

1,700

230

2,250

8,690

99

23

262

.0

7.4

120

37

7.2

10

2.6

103

66

1.2

.5

13

209

8

7

<1

<.l

12

4

60

<3

<1

<.5

30

1

10

3

2

.29

40

264

519

9.2

8.1

220

65

14

15

3.8

126

106

6.5

.6

16

300

26

14

2.8

-

125

14

2,830

217

217

21

413

49

155

21

95

228

72

196

547

10

8.1

230

69

14

15

3.5

125

110

7.2

.6

16

305

17

12

<1

<1

51

10

790

10

6

<1

210

31

70

15

22

11

74

76 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12324S90--LITTLE BL

Number of 

samples

Maximum Minimum Mean Median

ACKFOOT RIVER NEAR GARRISON. MONT.

Water-quality period of record: March 1985-September 1993

Streamflow, instantaneous (ft /s)

Specific conductance, onsite (^.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3 )

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCC>3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (|J.g/L)

Arsenic, dissolved (|J.g/L)

Cadmium, total recoverable (|ig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable (|ig/L)

Copper, dissolved (|ig/L)

Iron, total recoverable (|J.g/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (|ig/L)

Lead, dissolved (M-g/L)

Manganese, total recoverable (M-g/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (|J.g/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

48

38

49

37

32

32

32

6

5

5

5

5

5

6

5

37

37

37

37

36

37

37

37

37

37

37

37

37

37

50

50

50

2,080

300

16.0

8.5

140

43

9.2

6.6

4.5

118

20

3.4

.2

21

151

17

7

2

1

45

7

25,000

120

25

6

1,100

30

140

24

1,410

7,920

95

28

120

.0

7.0

51

14

3.3

3.4

1.6

52

10

1.0

.1

17

96

4

3

<1

<.l

1

<1

20

<3

<1

<.5

<10

1

<10

<3

1

.08

49

313

219

7.1

7.9

100

29

6.8

5.1

-

--

--

-

--

18

--

7

5

2.4

-

7

22

2,040

236

25

2.8

2 115

8

223

25

76

237

74

186

215

7.0

7.9

99

28

6.8

5.3

--

--

-

-

--

18

-

6

5

<1

<1

6

2

330

26

1

<1

30

6

10

4

10

4.4

78

TABLE 24 77
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12324680--CI

Number of 

samples

Maximum Minimum Mean Median

,ARK FORK AT GOLDCREEK MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (|iS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3 )

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (|ig/L)

Arsenic, dissolved (u,g/L)

Cadmium, total recoverable (|4.g/L)

Cadmium, dissolved (u,g/L)

Copper, total recoverable (|4.g/L)

Copper, dissolved (u,g/L)

Iron, total recoverable (|4.g/L)

Iron, dissolved (|4,g/L)

Lead, total recoverable (u.g/L)

Lead, dissolved (|J.g/L)

Manganese, total recoverable (u,g/L)

Manganese, dissolved ((J-g/L)

Zinc, total recoverable (u,g/L)

Zinc, dissolved (|4.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

9

8

9

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

7

7

8

8

7

7

8

8

8

8

9

9

9

March 1993-September 1993

1,410

447

16.0

8.5

190

56

13

13

6.9

138

84

6.8

.5

21

275

31

18

<1

<.l

150

20

2,700

58

18

<.5

470

35

180

22

152

392

89

398

280

1.0

8.1

120

36

8.1

7.8

2.5

89

44

3.4

.3

16

176

11

8

<1

<.l

21

4

310

5

2

<.5

70

16

30

7

10

18

67

826

370

10.3

8.3

160

48

10

11

3.2

121

60

4.5

.4

18

228

16

11

-

-

55

9

1,040

24

7

--

179

26

69

13

57

131

79

828

371

11.0

8.3

160

49

10

11

2.6

124

52

3.6

.4

18

226

13

10

<1

<.l

40

8

520

20

5

<.5

130

26

50

14

23

47

78

78 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12331500-FLINT CREEK NEAR DRUMMOND. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (^.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (jig/L)

Arsenic, dissolved (jig/L)

Cadmium, total recoverable (u.g/L)

Cadmium, dissolved (jJ-g/L)

Copper, total recoverable (H-g/L)

Copper, dissolved (|ig/L)

Iron, total recoverable (H-g/L)

Iron, dissolved (ng/L)

Lead, total recoverable (H-g/L)

Lead, dissolved (H-g/L)

Manganese, total recoverable (|J.g/L)

Manganese, dissolved (jig/L)

Zinc, total recoverable (jJ-g/L)

Zinc, dissolved (M-g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

56

47

56

44

37

37

37

9

8

8

8

8

8

9

8

44

44

44

44

43

44

44

44

44

44

44

44

44

44

58

58

58

March 1985-September 1993

892

501

19.0

8.8

260

73

20

11

7.8

150

22

5.9

.4

22

205

50

20

3

<1

32

7

7,200

190

87

7

1,600

120

290

27

556

904

98

4.2

135

.0

7.5

60

17

4.3

4.0

2.0

65

8.8

1.9

.1

14

94

7

5

<1

<.l

1

<1

70

4

<1

<.5

50

19

<10

<3

3

.03

28

167

311

9.1

8.2

152

41

12

8.1

3.6

126

17

4.0

.2

19

176

19

10

2.4

~

9

22

1,310

35

214

21

274

46

254

28

59

52

82

111

307

9.5

8.2

150

39

12

7.8

3.1

143

17

4.1

.2

20

185

16

9

<1

<1

7

2

580

26

9

<1

150

40

30

6

26

8.8

85

TABLE 24 79
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12331800--CL

Number of 

samples

Maximum Minimum Mean Median

ARK FORK NEAR DRUMMOND. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (|iS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (|4.g/L)

Arsenic, dissolved (Hg/L)

Cadmium, total recoverable (|4.g/L)

Cadmium, dissolved (|4.g/L)

Copper, total recoverable (Hg/L)

Copper, dissolved (|4.g/L)

Iron, total recoverable (Hg/L)

Iron, dissolved (u.g/L)

Lead, total recoverable (|ig/L)

Lead, dissolved (|4.g/L)

Manganese, total recoverable (M-g/L)

Manganese, dissolved (|4.g/L)

Zinc, total recoverable (p.g/L)

Zinc, dissolved (M-g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

9

8

9

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

8

6

6

8

8

5

5

8

8

8

8

9

9

9

March 1993-September 1993

1,710

470

17.0

8.4

210

61

15

13

7.3

156

90

7.1

.4

23

291

30

13

1

.1

140

17

4,000

45

40

1.2

490

29

260

21

270

1,200

90

550

278

1.0

8.0

120

36

8.3

7.8

2.7

93

38

3.4

.2

17

176

12

9

<1

<.l

18

4

280

4

3

<.5

80

15

30

7

12

28

56

1,020

406

11.4

8.3

181

52

12

12

3.7

136

65

5.0

.4

19

251

17

11

-

-

55

8

1,250

19

-

-

215

19

92

12

81

276

77

985

416

13.0

8.2

185

54

12

13

3.4

142

60

4.5

.4

18

248

14

11

<1

<.l

26

8

725

14

--

--

130

16

50

10

40

103

80

80 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12334510-ROCK CREEK NEAR CLINTON. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (u,S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCC^)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (u.g/L)

Arsenic, dissolved (|ig/L)

Cadmium, total recoverable (|ig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable (|±g/L)

Copper, dissolved (M-g/L)

Iron, total recoverable (|ig/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (|±g/L)

Lead, dissolved (|ig/L)

Manganese, total recoverable Qig/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (|±g/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

49

40

49

39

31

31

31

5

5

5

5

5

5

5

5

37

37

37

37

35

36

37

37

35

35

37

37

37

37

49

49

49

March 1985-September 1993

3,010

155

18.0

8.6

90

23

8.0

3.5

1.3

67

5.2

1.0

.1

11

85

2

1.0

3

1

41

6

2,100

110

19

5

90

8

60

15

157

1,280

95

113

55

.0

6.9

25

6.5

2.2

1.7

.8

26

2.0

.4

<.l

10

40

<1

<1

<1

<.l

<1

<1

40

5

<1

<.5

<10

<1

<10

<3

1

.31

35

850

105

7.9

7.8

51

13

4

--

-

-

-

--

-

--

-

2.9

-

2.6

-

26

1 2

400

35

24

22

221

22

213

23

21

100

70

521

97

9.0

7.8

50

13

4

-

-

--

--

-

-

-

--

<1

<1

<1

<1

4

1

200

35

2

<1

20

1

<10

<3

6

9.8

72

TABLE 24 81
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum

12334550--CLARK FORK AT TURAH BRIDGE. NEAR BONNER.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (uJS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (u.g/L)

Arsenic, dissolved (jJ-g/L)

Cadmium, total recoverable (u.g/L)

Cadmium, dissolved (u.g/L)

Copper, total recoverable (u.g/L)

Copper, dissolved (u.g/L)

Iron, total recoverable (u.g/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (u.g/L)

Lead, dissolved (|J.g/L)

Manganese, total recoverable Qig/L)

Manganese, dissolved (u.g/L)

Zinc, total recoverable Qig/L)

Zinc, dissolved (u.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

106

81

105

52

42

42

42

8

8

9

8

8

8

8

8

51

51

51

51

49

50

51

51

48

48

51

51

51

51

106

106

95

Mean

MONT.

Median

March 1985-September 1993

9,370

483

22.0

8.7

210

59

14

12

5.7

124

68

5.6

.3

18

236

110

17

4

1

500

25

19,000

190

100

7

2,000

31

1,100

39

1,370

34,700

98

37

160

.0

7.4

67

19

4.8

4.3

1.7

65

21

1.7

.2

14

108

5

4

<1

<.l

3

2

70

<3

<1

<.5

10

1

<10

<3

3

.80

27

1,630

323

9.1

8.1

144

41

10

8.0

2.6

100

42

3.2

.2

15

180

12

6

2.6

-

60

6

1,940

227

215

2.9

213

8

2113

210

72

803

71

999

340

9.5

8.1

145

42

10

8.3

2.3

111

38

2.8

.3

15

188

8

5

<1

<1

24

5

550

14

7

<1

90

7

40

8

20

57

72

82 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

Number of 

samples

12340000-BLACKFOOT RIVER

Maximum Minimum Mean Median

NEAR BONNER. MONT.

Water-quality period of record: March 1985 -September 1993

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (jiS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCC^)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (u\g/L)

Arsenic, dissolved (u\g/L)

Cadmium, total recoverable (u\g/L)

Cadmium, dissolved (p.g/L)

Copper, total recoverable (u\g/L)

Copper, dissolved (u\g/L)

Iron, total recoverable (u\g/L)

Iron, dissolved (|ig/L)

Lead, total recoverable (|ig/L)

Lead, dissolved (u\g/L)

Manganese, total recoverable (jig/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (u\g/L)

Zinc, dissolved (u\g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

80

57

80

40

33

33

33

5

5

5

5

5

5

5

5

40

40

40

40

38

39

40

40

37

37

40

40

40

40

80

80

78

10,300

294

20.5

8.7

140

37

13

3.2

2.8

129

5.6

1.6

.1

10

138

4

2

2

1

34

7

3,600

100

25

8

180

11

60

15

271

7,540

98

344

131

.0

7.5

55

14

4.9

1.2

.6

76

2.2

.3

<.l

6.8

82

<1

<1

<1

<.l

1

<1

40

<3

<1

<.5

<10

<1

<10

<3

1

1.1

42

2,450

205

8.8

8.1

99

25

8.7

-

--

-

-

-

--

~

-

21

2.8

2.5

~

10

22

698

222

27

21

243

23

215

25

32

527

77

1,020

205

8.5

8.2

95

24

8.4

-

-

--

-

--

--

--

-

1

<1

<1

<1

8

2

270

15

4

<1

20

2

10

3

8

22

80

TABLE 24 83
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12340500--CL

Number of 

samples

Maximum

ARK FORK ABOVE MISSOUL

Minimum

A. MONT.

Water-quality period of record: October 1989-September 1993

Streamflow, instantaneous (f^/s) 49 13,100 798

Specific conductance, onsite (jxS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCGj)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (fig/L)

Arsenic, dissolved (jig/L)

Cadmium, total recoverable (jig/L)

Cadmium, dissolved (jig/L)

Copper, total recoverable (jig/L)

Copper, dissolved (jig/L)

Iron, total recoverable (jig/L) 

Iron, dissolved (jig/L) 

Lead, total recoverable (u.g/L) 

Lead, dissolved (jig/L)

Manganese, total recoverable ()ig/L)

Manganese, dissolved (jig/L) 

Zinc, total recoverable Qig/L) 

Zinc, dissolved (jig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

40

50

29

29

29

29

8

8

8

8

8

8

8

8

29

29

29

29

27

28

29 

29

24 

24

29

29 

29 

29

50

50

50

399

19.5

8.6

170

46

13

7.7

4.5

124

43

4.2

.2

15

198

10

7

<1

.1

31

10

3,000 

44 

15 

1

170

24 

60 

16

144

4,740

98

152

.0

7.9

61

14

5.6

2.4

1.0

71

93

.9

.1

9.4

90

2

1

<1

<.l

2

1

70 

<3 

<1 

<.5

20

7 

<10 

<3

2

6.1

76

Mean

4,110

262

8.7

8.2

122

33

9.5

5.0

1.8

102

22

1.9

.2

12

144

4

3

-

-

10

3

555 

219 

23 

2.7

56

14 

220 

26

24

600

89

Median

2,110

270

8.2

8.2

120

33

9.7

5.3

1.4

104

22

1.8

.2

11

149

4

3

<1

<1

8

2

250 

16 

2 

<1

40

14 

20 

6

9

51

89

84 Water-quality, bed-sediment, and biological data and statistical summaries of water-quality data, upper Clark Fork basin, Mont.
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1993 (Continued)

Property or constituent and reporting unit

12353000-CL

Number of 

samples

Maximum Minimum Mean Median

ARK FORK BELOW MISSOULA. MONT.

Water-quality period of record:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (jlS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCO3)

Calcium, dissolved (mg/L)

Magnesium, dissolved (mg/L)

Sodium, dissolved (mg/L)

Potassium, dissolved (mg/L)

Alkalinity (mg/L as CaCO3)

Sulfate, dissolved (mg/L as S04)

Chloride, dissolved (mg/L)

Ruoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (u,g/L)

Arsenic, dissolved (u,g/L)

Cadmium, total recoverable (u,g/L)

Cadmium, dissolved (u,g/L)

Copper, total recoverable (M-g/L)

Copper, dissolved (u,g/L)

Iron, total recoverable (u.g/L)

Iron, dissolved (u,g/L)

Lead, total recoverable (p.g/L)

Lead, dissolved (u,g/L)

Manganese, total recoverable (u,g/L)

Manganese, dissolved (u,g/L)

Zinc, total recoverable Qo.g/L)

Zinc, dissolved (jo.g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

52

52

52

52

52

52

52

52

52

51

52

52

52

52

52

3

29

3

29

3

29

3

34

3

29

3

34

3

29

52

52

51

March 1985-September 1993

19,800

320

20.5

8.8

150

42

11

8.5

2.5

135

34

4.7

.3

15

194

6

6

<1

2

18

9

860

34

4

5

120

18

30

24

85

4,540

93

869

108

.0

7.1

48

13

3.7

2.2

.6

47

6

.3

<.l

5.8

63

3

1

<1

<.l

7

1

150

4

<1

<.5

20

3

<10

<3

1

4.3

35

4,530

225

8.5

8.0

106

29

7.9

5.7

1.6

95

20

2.4

2.2

12

135

-

2

--

-

-

4

-

15

-

2.8

-

7

-

27

15

313

73

2,680

242

8.2

8.0

115

32

8.6

6.2

1.8

101

19

2.5

.2

12

146

--

2

-

<1

--

3

--

15

--

<1

--

6

--

6

10

70

78

Multiple minimum reporting levels during the period of record may result in varying values identified with a less-than (<) symbol. 

2Value is estimated by using a log-probability regression to predict the values of data less than the minimum reporting level (Helsel and 

Cohn, 1988).

U.S. GOVERNMENT PRINTING OFFICE: 1994 - 573-191 / 80057 REGION NO. 8 TABLE 24 85