WATER-QUALITY, BED-SEDIMENT, AND BIOLOGICAL 

DATA (OCTOBER 1994 THROUGH SEPTEMBER 1995) 

AND STATISTICAL SUMMARIES OF DATA FOR 

STREAMS IN THE UPPER CLARK FORK BASIN, 

MONTANA

By Kent A. Dodge, Michelle I. Hornberger, and Ellen V. Axtmann

U.S. GEOLOGICAL SURVEY 

Open-File Report 96-432

Prepared in cooperation with the

U.S. ENVIRONMENTAL PROTECTION AGENCY

Helena, Montana 

September 1996
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Gordon P. Eaton, Director

For additional information write to:

District Chief 

U.S. Geological Survey 

Federal Building, Drawer 10076 

Helena, Montana 59626-0076

Copies of this report may be purchased from:

U.S. Geological Survey 

Branch of Information Services 

Box 25286 

Denver, Colorado 80225-0286
CONTENTS

Page

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

Introduction.................................................................................................................................^ 1

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

Water-quality data................................................................................................................................................................. 4

Methods..................................................................................................................................................................... 4

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

Quality assurarce...................................................................^ 5

Bed-sediment data................................................................................................................................................................. 9

Methods.........................................................._ 9

Results..........................................................................^ 10

Quality asstirance....................................................................................................................... 10

Biological data...............................................................................................................................« 11

Methods............................................................................................................................................ 11

Results..........................................................^ 11

Quality assiirance............................................................................................................^ 11

Statistical summaries of data..........................................................................................................» 12

Selected references...................................................................................^ 13

Data....................................................................................................................................................................................... 15

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,

Monlana......................................................................................................................................^ 7

4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995.......... 16

5.-10. Daily streamflow and suspended-sediment data, October 1994 through September 1995, for

5. Silver Bow Creek at Opportunity, Montana........................................................................................... 32

6. Silver Bow Creek at Warm Springs, Montana....................................................................................... 36

7. Clark Fork at Deer Lodge, Montana....................................................................................................... 40

8. Clark Fork at Turah Bridge, near Bonner, Montana............................................................................... 44

9. Blackfoot River near Bonner, Montana.................................................................................................. 48

10. Clark Fork above Missoula, Montana.................................................................................................... 52

11. Chemical and suspended-sediment analyses of field replicates for water samples, upper Clark Fork

basin, Montana...................................................................................................................................... 56

12. Precision of chemical and suspended-sediment analyses of field replicates for water samples, upper

Clark Fork basin, Montana.......................................................................................................................... 60

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

Montana.......................................................................................................................................^ 61

14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks....................... 62

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

Fork basin, Montana.................................................................................................................................... 63

16. Chemical analyses of field blanks for water samples...................................................................................... 64

CONTENTS III
TABLES-Continued

Page

Table 17. Trace-element analyses of fine-grained bed sediment, upper Clark Fork basin, Montana, August 1995........ 67

18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1995.................... 68

19. Recovery efficiency for trace-element analyses of standard reference materials for bed sediment................. 69

20. Trace-element analyses of procedural blanks for bed sediment....................................................................... 70

21. Trace-element analyses of biota, upper Clark Fork basin, Montana, August 1995......................................... 71

22. Recovery efficiency for trace-element analyses of standard reference material for biota............................... 72

23. Trace-element analyses of procedural blanks for biota.................................................................................... 73

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

through September 1995.............................................................................................................................. 74

25. Statistical summary of the fine-grained bed-sediment data for the upper Clark Fork basin, Montana,

August 1986 through August 1995.............................................................................................................. 90

26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, August 1993

through August 1995 ................................................................................................................................... 94

27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through

August 1995................................................................................................................................................. 98

CONVERSION FACTORS AND ABBREVIATED WATER-QUALITY UNITS

Multiply ____ _____By___________ To obtain

cubic foot per second (ft3/s) 0.028317 cubic meter per second

foot (ft) 03048 meter (m)

gallon (gal) 3.785 liter (L)

gallon (gal) 3,785 milliliter (ml)

inch (in.) 25.4 millimeter (mm)

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

mile (mi) 1.609 kilometer

ounce (oz) 28.35 gram (g)

part per million 1 microgram per gram (M-g/g)

square mile (mi2) 2.59 square kilometer

ton per day (ton/d) 907.2 kilogram per day

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

°F = 9/5(°C) + 32 

Abbreviated water-quality units used in this report:

(ig/g micrograms per gram

H-g/L micrograms per liter

M-g/mL micrograms per milliliter

|iS/cm microsiemens per centimeter at 25 degrees Celsius

mg/L milligrams per liter

Water-year definition:

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

iv Water-quality, bad-sediment, and biological data (October 1994 through September 1995) and statistical summaries of date for straams 

in the Upper Clark Fork Basin, Montana
Water-Quality, Bed-Sediment, and Biological Data 

(October 1994 through September 1995) and Statistical 

Summaries of Data for Streams in the Upper Clark Fork 

Basin, Montana

By Kent A. Dodge, Michelle I. Hornberger, and Ellen V. Axtmann

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. 

Sampling stations were located on the Clark Fork 

and major tributaries. Water-quality data were 

obtained periodically at 16 stations during October 

1994 through September 1995 (water year 1995). 

Data for 12 bed-sediment and 11 biological stations were obtained in August 1995. The primary 

constituents analyzed were trace elements associated with tailings from historical mining and 

smelting activities.

Water-quality data include concentrations 

of major ions, trace elements, and suspended sediment in stream samples collected periodically during water year 1995. Daily values of streamflow, 

suspended-sediment concentration, and suspended-sediment discharge are given for six stations. Bed-sediment data include trace-element 

concentrations in the fine-grained and bulk fractions. Biological data include trace-element concentrations in whole-body tissue of aquatic benthic 

insects. Quality-assurance data are reported for 

analytical results of water, bed sediment, and 

biota. Statistical summaries of water-quality, bedsediment, and biological data are provided for the 

period of record at each station since 1985.

INTRODUCTION

The Qark 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 6,000-mi2 Qark 

Fork basin above Missoula include irrigation, stock 

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

primarily are 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. Tailings have been eroded 

and transported downstream since the late 1800's and 

redeposited in stream channels, on flood plains, and in 

Warm Springs Ponds and Milltown Reservoir. The 

river continues to erode, transport, and redeposit sediment along the stream channel and flood plain, 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. A long-term data base was considered necessary to detect trends over time in order to evaluate the 

effectiveness of remediation. Water-quality data have 

been collected by the U.S. Geological Survey (USGS) 

at selected sites in the upper Qark Fork basin since 

1985 (Lambing, 1987,1988,1989,1990, and 1991;

Abstract
Bo»e from U.S. Geological Survey State 

base map, 1=1,000,000, 

1966

12340500 

12353000 \ M,,ltown

EXPLANATION

12324200 STATION AND NUMBER 

Streamflow gaging 

A Continuous record 

A Periodic measurement 

Water quality, bed sediment, biota 

J7 Periodic water quality 

V-Daily suspended sediment 

VOnce - annual bed sediment 

"V Once-annual biota

10 20 MILES

10 20 KILOMETERS

Figure 1. Location of study area.

Lambing and others, 1994,1995). Trace-element data 

for bed sediment and biota (aquatic benthic insects) 

have been collected intermittently since 1986 at 

selected sites as pan of studies on bed-sediment contamination and bioaccumulation of metals conducted 

by the USGS National Research Program (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 to provide systematic, long-term monitoring.

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

12 bed-sediment and 11 biological stations in the upper 

Clark Fork basin collected from October 1994 through 

September 1995 (water year 1995). Quality-assurance 

data are presented for water quality, bed sediment, and 

biota. Statistical summaries also are provided for 

water-quality, bed-sediment, and biological data collected since 1985.

SAMPLING LOCATIONS AND TYPES OF 

DATA

Sampling stations in the upper Gark Fork basin 

are located on both the Clark Fork mainstem and major

2 Watar-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for atraam* 

In the Upper Clark Fork Baaki, Montana
tributaries from Butte to below Missoula (fig. 1). 

Mainstem sites were selected to divide the upper Gark 

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 for major hydrologic sources in the upper basin and to provide reference comparisons to the mainstem for bed sediment 

and biota. Water-quality data were obtained periodically at 16 stations; daily suspended-sediment data

were obtained at 6 of these stations. Data for 12 bedsediment and 11 biological stations were obtained 

once-annually (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 1995 are listed in tables 4 

through 23 at the back of the report. Statistical summaries of water-quality, bed-sediment, and biological data 

collected since 1985 are given in tables 24-27 at the 

back of the report.

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 Dnimmond

Clark Fork near Dnimmond

Rock Creek near Clinton

Clark Fork at Turah Bridge,

nearBonner

Blackfoot River near

Bonner

Clark Fork above Missoula

Clark Fork below Missoula3

Continuousrecord 

 treamfiow

«

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

03/85-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

03/93P

03/85-P

03/85-P

03/85-P

07/86-P

03/85-P

Dally 

suspended 

sediment

03/93-P

04/93-P

-

-

03/85-08/86,

04/87-P

~

«

~

03/85-P

07/86-03/87,

06/88-P

07/86-03/87,

06/88-P

~

Fine-grained 

bed sediment2

07/92-P

07/92-P

08/95

08/87, 08/91-P

08/86, 08/87,

08/90-P

08/86, 08/87,

08/94

07/92-P

08/86, 08/89,

07/92-P

08/86, 08/87,

08/91-P

08/86, 08/87,

08/89, 08/91-P

08/86, 08/91-P

08/86, 08/87,

08/91, 08/93-P

~

08/86, 08/90-P

Bulk 

bed 

sediment2

~

--

08/93-P

08/93,

08/95

08/95

08/93-P

08/93-P

08/94

08/93-P

08/93-P

08/93-P

08/93-P

08/93-P

08/93-

08/94

08/93-P

Biota2

07/92, 08/94-P

07/92-P

08/95

08/87, 08/91-P

08/86, 08/87,

08/90-P

08/87, 08/94

07/92-P

08/86, 07/92-P

08/86, 08/87,

08/91-P

08/87, 08/91-P

08/86, 08/91-P

08/86, 08/87,

08/91, 08/93

08/86, 08/90-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.

2Laboratory analyses of trace elements.

3Bed sediment and biota sampled about 30 miles downstream from water-quality station to conform to previous sampling location.

SAMPLING LOCATIONS AND TYPES OF DATA
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 on 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 USGS (1977),

Knapton (1985), and Edwards and Glysson (1988). 

These methods provide a vertically and laterally discharge-weighted 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-81 and 

D-74TM) which are either constructed of plastic or 

equipped with nylon nozzles and coated with a nonmetallic 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 procedures described by Horowitz 

and others (1994), Ward and Hair (1990), USGS 

(1977), and Knapton (1985). 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 constituents listed in table 2 by the USGS National Water Quality Laboratory (NWQL) in Arvada, Colo. The trace 

elements arsenic, cadmium, copper, iron, lead, manganese, and zinc were analyzed for both dissolved and 

total-recoverable concentrations. Analytical methods

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

Conatltuent

Hardness 

Calcium

Magnesium

Sodium

Potassium

Alkalinity

Sulfate

Chloride

Fluoride

Silica

Dissolved solids

Arsenic

Cadmium

Copper

Iron

Lead

Manganese

Zinc

Suspended 

sediment

Bad 

sediment

Constituent

Cadmium 

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Biota

Constituent

Cadmium 

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

4 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
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 sand-silt 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 

(table 1), suspended-sediment samples were collected 

2 to 7 times per week. These samples were collected 

by local contracted observers using the depth-integration method at a single vertical near mid-stream. The 

samples were analyzed for suspended-sediment concentration and were used to determine daily mean suspended-sediment concentrations according to methods 

described by Porterfield (1972).

Results

Water-quality data for samples collected periodically during October 1994 through September 1995 

(water year 1995) are presented in table 4. The types 

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

results for chemical constituents and suspended sediment.

Daily streamflow and suspended-sediment data 

for water year 1995 at the six daily suspended-sediment 

stations are given in tables 5 through 10. Monthly 

descriptive statistics for each parameter are provided 

along with totals for the annual 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 Horowitz and others (1994), Ward and 

Harr (1990), Edwards and Glysson (1988), Knapton 

and Nimick (1991), and Knapton (1985). 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 from the field and analyzed concurrently in the laboratory with routine samples. 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 at 

the NWQL 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 Technical Development and Quality Systems are routinely inserted into 

the sample line for each analytical method at a frequency proportional to the sample load. The laboratory 

also participates in external evaluation studies twiceyearly with the U.S. Environmental Protection Agency, 

the Canadian Center for Inland Water, and the Branch 

of Technical Development and Quality Systems 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 for samples exposed to all sources of 

variability combined, replicate samples were obtained 

in the field by splitting a composite stream sample. 

Analyses of these field replicates indicate the reproducibility of environmental data that are affected by the 

combined variability potentially introduced by field 

and laboratory processes.

Analytical precision was evaluated by excluding 

field sources of variability. Replicate analyses were 

made of an individual sample selected randomly in the 

laboratory from the 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 possible effects on precision caused by 

field collection and processing of samples.

WATER-QUALITY DATA
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 same 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.

Blank samples of deionized water 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 

deionized water that are certified as trace-element free 

and are processed through the sampling equipment 

used to collect stream samples. These blanks are then 

subjected to the same processing (sample splitting, filtration, preservation, transportation, and laboratory 

handling) as stream samples. Blank samples are analyzed for the same constituents as those of stream samples to identify whether any detectable concentrations 

exist.

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 discrete sample group, independent of other samples submitted to the NWQL. Therefore, statistical 

descriptions of quality-control data generated for this 

program are directly applicable to the analytical results 

for stream samples reported herein.

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

for the expanded long-term monitoring program that 

was initiated in 1993. 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 data-quality 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):

ri _

2k 0)

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 = -xlOO (2)

where

RSD= relative standard deviation,

S - standard deviation, and

x = mean of all replicate concentrations.

Paired analyses of field replicates are presented 

in table 11. The precision estimated for each constituent based on these paired results, which include the 

combined sources of field and laboratory variability is 

reported in table 12. Statistics for precision of fieldreplicate 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). Analytical precision for 

chemical constituents based on replicate laboratory 

analyses of individual samples, which includes only 

laboratory sources of variability, is reported in table 

13. Statistics for analytical precision of laboratoryreplicate analyses are based on unrounded values

6 Watar-quallty, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for atraama 

In tha Uppar Clark Fork Baaln, Montana
Table 3. Data-quality objectives for analyses of water-quality samples collected in the upper Clark Fork basin, 

Montana

[Abbfeviations: Ug/L, micrograms per liter; uS/cm, microsiemens per centimeter at 25 degrees Celsius; mg/L, minignms per liter. 

Symbol: , not determined]

Data-quality objectives

DetectabllUy

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

Minimum Maximum relative 

w±Z standard devtation 

toJS of laboratory

In unite replicate analyses, m uniis h p^^,

1

.1

1

.1

.1

.1

.1

1

.1

.1

.1

.1

1

1

1

.1

1

1

10

3

1

5

10

1

10

3

1

1

liS/cm

standard units

mg/L as CaCO3

mg/L

mg/L

mg/L

mg/L

mg/L as CaCO3

mg/L

mg/L

mg/L

mg/L

*ig/L

W/L

W/L

W/L

Jig/L

W/L

Hg/L

HS/L

HS/L

W/L

HS/L

Hg/L

Hg/L

Hg/L

mg/L

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 reoo very, 

In percent

~

~

«

~

-

«

«

25

25

25

25

25

25

25

25

25

25

25

25

25

25

«

«

WATER-QUALITY DATA
stored in laboratory data files. Concentrations less 

than the minimum repotting level (censored values) 

were included in the calculations by arbitrarily substituting a value of one-half the reporting level.

The data-quality objective for analytical 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 for stream samples.

Data-quality objectives for precision are not 

directly applicable to field replicates because of the 

additional potential for variability resulting from field 

sampling and processing. However, a statistical calculation of precision for the field replicates is provided in 

table 12 to illustrate overall reproducibility of environmental data that incorporates both field and laboratory 

sources of variability. Relative standard deviations 

estimated from differences in analytical results 

between field replicates were within 20 percent for all 

constituents, except dissolved iron.

The large relative standard deviation for dissolved iron was the result of the November 28 sample 

being processed through two different types of filters as 

part of a test of new USGS protocols. Apparently, colloidal iron is retained more effectively on flat membrane filters compared to the convoluted surface of 

capsule filters recommended in the new protocols. 

Other elements displayed no discernible difference 

between filters. If this sample were omitted, the relative standard deviation of dissolved iron would be ± 6.6

percent. Because detection of long-term trends could 

be affected by converting to new equipment having 

different sampling characteristics, it was decided to 

continue usage of the flat membrane filters.

Analyses of an unspiked sample and a spiked aliquot of the same sample 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 equation 3 (see below).

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 At the laboratory, a spiked deionized-water blank and a spiked aliquot of a stream sample were prepared and analyzed 

along with the original unspiked sample. The differences between the spiked and unspiked sample concentrations were determined and used to compute recovery 

according to equation 3. If the spike recovery for a 

trace element was outside a range of 75 to 125 percent, 

the entire sample set and spiked samples were reanalyzed for that particular trace element until recoveries 

were within acceptable limits. Results of recovery efficiency for 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 deionized-water 

samples spiked with trace elements ranged from 93.8 to 

106.8 percent. The mean spike recovery for spiked 

stream samples ranged from 97.4 to 104.7 percent. The 

95-percent confidence intervals (Taylor, 1987) for the 

mean of spike recovery for each constituent did not

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

spike concentration

(3)

8 Watar-quality, bad-ssdimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical summarias of data for straams 

in tha Uppar Clark Fork Basin, Montana
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 for stream samples. Bias is indicated, however, 

if the confidence interval does not include 100 percent. 

The confidence interval for analytical recovery of dissolved zinc in spiked stream samples was 101-108 percent Because the 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. Analytical results from the 

field blank for the next sample set is evaluated for a 

consistent trend that may indicate systematic contamination. Sporadic, infrequent exceedances of twice the 

minimum reporting level probably represent random 

contamination or instrument calibration error that is not 

persistent in the process and which is not likely to cause 

significant positive bias in analytical results. However, 

if concentrations for a particular constituent exceed 

twice the minimum reporting level in field blanks from 

two consecutive field trips, blank samples are collected 

from individual components of the processing 

sequence and are 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. There were no occurrences of concentrations greater than the minimum reporting level in two 

consecutive blank samples.

BED-SEDIMENT DATA

Bed-sediment data consist of analyses of solidphase concentrations of trace elements in the finegrained and bulk fractions. Bed-sediment samples are 

collected once-annually during low, stable flow conditions to facilitate data comparisons between years.

Methods

Bed-sediment samples were collected in August 

1995 using protocols described by E.V. Axtmann (U.S. 

Geological Survey, written commun., 1994). Samples 

were collected using an acid-washed polypropylene 

scoop from the surfaces of streambed deposits in lowvelocity areas 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 composite sample of bulk bed sediment were collected at each site.

Individual samples of fine-grained bed sediment 

were collected from the surfaces of three to five randomly selected deposits along pool or low-velocity 

areas. The three to five 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 wetsieved 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 bed sediment also 

were collected from the surfaces of three to five randomly selected deposits. Because the streambed at 

most sampling locations is predominantly gravel and 

cobble, deposits were selected where cobbles and 

gravel could be seen and, therefore, excluded from the 

samples. Bulk bed-sediment samples generally are 

composed of particles smaller than about 10 mm in 

diameter. The individual unsieved samples were composited and stored in acid-washed polyethylene bottles 

that were transported to the laboratory on ice.

Bed-sediment samples were processed at the 

USGS National Research Program laboratory in Boulder, Colo. Fine-grained and bulk 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 fine-grained bed sediment sample were 

digested using a hot, concentrated nitric acid reflux 

according to methods described by Luoma and Bryan 

(1981). Triplicate aliquots were analyzed from each 

composite sample of bulk bed sediment. After a digestion period of up to several weeks, the 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-pm filter using a syringe and inBED-SEDIMENTDATA
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 solutions then were analyzed for cadmium, chromium, copper, iron, manganese, nickel, and zinc using Inductively Coupled Argon 

Plasma Emission Spectroscopy (ICAPES) at the USGS 

National Research Program laboratory in Menlo Park, 

Calif. Lead and silver were analyzed in undiluted 

digests by flame atomic absorption (AA) at the USGS 

National Research Program laboratory in Boulder, 

Colo.

Results

Solid-phase concentrations of trace elements 

measured in samples of fine-grained bed sediment and 

bulk bed sediment collected during August 1995 are 

summarized in tables 17 and 18, respectively. Liquidphase concentrations, in ug/mL, that were analyzed in 

the reconstituted aliquots of digested bed sediment 

were converted to solid-phase concentrations, in u.g/g, 

using the following equation:

ug/g = ugAnL 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 are the means of all analyses of replicate 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 and among years.

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 was acid-washed and rinsed 

with deionized water prior to the first sample collection. Nylon-mesh sieves were washed in a laboratorygrade detergent and rinsed with deionized water. All 

equipment was given a final rinse onsite with stream 

water. 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 

between-site cleaning. Samples were collected along 

an increasing concentration gradient from the downstream tributaries and mainstem to the upstream tributaries and mainstem to minimize any effects from 

potential station-to-station carryover contamination.

Quality assurance of analytical results for bed 

sediment included laboratory instrument calibration 

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 materials 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 (SRM) 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 materials consisting of agricultural soils representing low 

and high concentrations of trace elements were analyzed to test recovery efficiency for a range of concentrations generally 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, elements with mean recoveries 

outside a 25-percent deviation from complete recovery 

were chromium and lead for the low-concentration 

range (SRM 2709), and chromium for the high-concentration range (SRM 2711). Mean recoveries were low 

for these elements, indicating that the digestion during 

sample preparation did not release all of the element 

from the solid-phase matrix.

Procedural blanks for bed-sediment samples 

consisted of the same reagents used for sample digestion and reconstitution. Concentrated nitric acid used

10 Watar-quallty, bad-sadlmant, and biological data (Octobar 1994 through Saptombar 1995) and statistical summarlas of data for straams 

In tha Uppar Clark Fork Basin, Montana
for sample digestion was heated and evaporated to dryness. After evaporation, 0.6 N hydrochloric acid was 

added quantitatively to the dry residue 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 reagents used to digest and 

reconstitute bed-sediment samples. Analytical results 

for procedural blanks can 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 M-g/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. 

Almost all procedural blanks had concentrations less 

than analytical detection levels. 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. Insect samples are collected once-annually at the same stations where bedsediment samples are collected (table 1). Biota samples are collected concurrently with bed-sediment samples to facilitate comparisons of results between years 

and between concentrations in bed sediment and biota.

Methods

Insect samples were collected using protocols 

described by M.I. Homberger (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 (caddisflies); Arctopsyche grandis, Family Trichoptera; and Claassenia 

sabulosa, Family Plecoptera (stoneflies). Samples of 

each taxon were stored separately, by genus, in acidwashed 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.

Insect 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. When large numbers of specimens were collected from a station, similar-sized individuals were composited into replicate subsamples. 

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-um filter, 

and analyzed undiluted by 1C APES for cadmium, 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 1995 are summarized in table 21. The variability in the number of composite samples between species and between sites reflects the difference in insect 

abundance, with number of composite samples increasing with abundance of insects. 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. In general, the smaller the biological sample 

weight (a function of insect abundance), the higher the 

minimum reporting level. Therefore, higher minimum 

reporting levels do not necessarily imply a higher traceelement concentration in tissue.

Two genera of Hydropsyche were collected for 

this study: Hydropsyche occidentails and Hydropsyche morosa group. Two species of Hydropsyche 

were identified within the morosa group (//. cockerelli 

and H. tana). Results of analyses are listed for the individual species within the morosa group where positive 

identification was possible. In some instances (as

BIOLOGICAL DATA 11
noted at the individual station), a sample was not positively identifiable as H. cockerelli although it could be 

identified as belonging to the morosa group. These 

samples are most likely H. cockerelli based on a distinct head pattern. However, the small size of the insect 

made it difficult to determine the precise species. 

Hydropsyche samples that could not be identified 

clearly to the species but had morosa characteristics 

were listed separately as H. morosa group.

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 concentration gradient to prevent station-to-station carryover contamination. Nets and equipment were 

thoroughly rinsed in ambient stream water at each new 

mainstem station. New nets and depuration chambers 

were used for the tributary stations.

Quality assurance of analytical results for biota 

samples 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 for 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 recoveries were within 10 percent of complete recovery for 

all trace elements, with the exception of chromium 

(mean recovery within 20 percent). A low bias is indicated for iron, manganese, and zinc (confidence interval does not include 100 percent) and a high bias is 

indicated for cadmium and chromium. The cause of 

this minor bias is unknown, and 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 consisted of the same reagents used to digest and 

reconstitute tissue of aquatic insects. The blanks were 

analyzed undiluted at a proportion of one blank per

site. No adjustments for procedural blanks were necessary because all blanks had concentrations that, when 

converted to solid-phase concentrations, were less than 

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

STATISTICAL SUMMARIES OF DATA

Statistical summaries of water-quality, bed-sediment, and biological data are provided in tables 24-27 

for the period of record at each station since 1985. The 

summaries include the period of record, number of 

samples, maximum, minimum, mean, and median of 

concentrations.

Statistical summaries of water-quality data (table 

24) are based on results of samples collected periodically during the station's period of record. Statistical 

summaries of bed-sediment (table 25 and 26) and biological data (table 27) are based on results of samples 

collected once-annually during the indicated years. 

Because not all stations were sampled for bed sediment 

and biota every year, these data do not represent a consecutive annual record.

Sample sizes and statistics for bed-sediment data 

are based on the annual mean concentrations determined from the combined results of composite samples 

for a given year. Therefore, sample sizes for bed sediment represent the number of years sampled. Sample 

sizes and statistics for biological data are based on individual analyses for each composite sample collected in 

individual years rather than the annual mean concentration. Biota sample sizes therefore reflect differences in 

species abundance and the statistics describe the full 

range of variability in trace-element assimilation 

among species. Consequently, a sample size greater 

than one can be generated for a single year. The abundance of aquatic insects at a particular site in a given 

year limits the biomass of the sample which, in turn, 

may result in different taxa analyzed between years or 

in variable analytical detection limits. Where minimum reporting levels vary between years, statistical 

summaries are provided only as a general indication of 

the range of detection.

The presence or absence of insect species at a 

given site can vary between years and may result in different taxa being analyzed in the long-term period of 

record. Because Hydropsyche insects were not sorted 

to the species level during 1986-89, statistics for stations sampled during those years are based on the 

results of all Hydropsyche species combined. At some 

sites, statistics for the Hydropsyche morosa group are 

based on the combined results for two or more species.

12 Watar-quality, bad-sadimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical summarias of data for straams 

in tha Uppar Clark Fork Basin, Montana
The biological statistical summary table shows 

samples listed separately as H. cockerelli and H. 

morosa group. This is a slightly different format from 

the biological summary table for the 1994 water year 

(Lambing and others, 1995), where these H. cockerelli 

and H. morosa group samples were combined for the 

statistical summary. Table 27 also includes samples 

listed as H. species. In addition, some Hydropsyche 

samples in recent years were not identifiable to the species or group level; therefore, these samples were 

grouped into H. spp. Hydropsyche were not sorted by 

species during the earlier part of the study (1986-1989).

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, DJ., 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.

Fishman, M J., 1993, Methods of analysis by the U.S. Geological Survey National Water Quality LaboratoryDetermination of inorganic and organic constituents in 

water and fluvial sediments: U.S. Geological Survey 

Open-File Report 93-125,217 p.

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

PFriedman, 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 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.

Horowitz, A.J., Demas, C.R., Fitzgerald, K.K., Miller, T.L., 

and Rickert, D.A., 1994, U.S. Geological Survey protocol for the collection and processing of surface-water 

samples for the subsequent determination of inorganic

constituents in filtered water U.S. Geological Survey 

Open-File Report 94-539,57 p.

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 (October 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 (October 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.

Lambing, J.H., Hornberger, M.I., Axtmann, E.V., and 

Dodge, K.A., 1995, Water-quality, bed-sediment, and 

biological data (October 1993 through September 

1994) and statistical summaries of data for streams in 

the upper Clark Fork basin, Montana: U.S. Geological 

Survey Open-File Report 95-429,104 p.

Lambing, J.H., Hornberger, M.I., Axtmann, E.V., and Pope, 

D.A., 1994, 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: U.S. Geological Survey OpenFile Report 94-375,85 p.

SELECTED REFERENCES 13
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.

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., 

631 p.

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

Timme, PJ., 1994, National Water Quality Laboratory 1994 

Services Catalog: U.S. Geological Survey Open-File 

Report 94-304,103 p.

U.S. Geological Survey, 1977, National handbook of recommended methods for water-data acquisition Chap. 5, 

Chemical and physical quality of water and sediment: 

Office of Water Data Coordination, 193 p.

Ward, J.R., and Harr, C.A., eds., 1990, Methods for collection and processing of surface-water and bed-material 

samples for physical and chemical analyses: U.S. Geological Survey Open-File Report 90-140,71 p.

14 Water-quality, bad-sadlmant, and biological data (Oetobar 1994 through Saptembar 1995) and statistical summariM of data for straams 

in tha Uppar Clark Fork Basin, Montana
DATA

DATA 15
Table 4. Water-quality data for the upper Clark Fork basin, Montana, Octobr 1994 through September 1995

[Abbreviations: fta/s, cubic feet per second; °C, degrees Celsius; E, estimated; Jig/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 level; --, no data

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

Date

Novl994

28...

FA 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Stream- Specific 

flow, conductTime Instan- ance, 

tansous oneite 

(ftj/s) (jiS/cm)

1105

1000

1000

1505

1310

1055

1230

1005

1055

0930

6.0

4.3

5.7

11

10

49

42

85

18

7.5

302

318

338

236

241

194

177

186

236

292

oneite (standard 

units)

7.3

7.7

7.9

7.9

7.9

7.7

7.9

7.8

7.9

7.8

Temperature, 

water

co

4.0

4.0

4.0

7.0

6.0

5.5

95

12.0

15.0

13.5

Hardnew, 

total 

(mg/L 

as 

CaCOj)

130

120

130

88

95

74

71

77

100

120

Calcium, 

dissolved 

(mg/L)

36

35

36

25

27

21

20

22

29

34

Magneeium, dissolved 

(mg/L)

8.6

9.1

8.9

6.2

6.7

5.2

5.0

5.3

6.9

8.1

Sodium

12

13

18

11

9.2

7.8

6.4

6.8

7.4

9.8

*dS? 

(mg/L)

2.8

6.4

2.9

2.4

2.7

3.5

2.4

3.7

2.5

2.7

Alkalinity 

(mg/Lae 

CaCOj)

104

101

98

71

77

57

59

65

95

109

Date

Novl994

28...

FA 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Sulfate, 

dissolved 

(mg/L)

34

34

33

22

26

27

19

19

15

25

Chloride, 

dissolved 

(mg/L)

6.5

10

18

12

8.3

3.8

2.8

2.8

3.5

5.3

Fluoride, diseoived 

(mg/L)

0.30

.30

.30

.40

.40

.30

.30

.30

.30

.30

Silica, 

dissolved 

(mg/L)

28

26

27

21

20

20

23

24

27

27

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

191

195

203

143

147

123

114

123

149

178

Arsenic, 

total 

recoverable (W/L)

2

4

3

6

4

9

9

17

18

11

Arsenic, 

dissolved 

(W/L)

2

2

2

3

3

5

8

13

12

7

Cadmium, 

total 

recoverable

<1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Cadmium, diesolved

<0.1

cl

cl

cl

cl

cl

cl

cl

cl

cl

Copper, 

total 

recov- 

 rable

5

8

7

9

8

14

10

18

5

4

eolved

1

6

2

4

5

7

7

10

4

3

Date

Novl994

28...

FA 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Iron, 

total 

recoverable

590

590

550

1,100

480

1,800

680

1,800

920

620

Iron, dissolved 

(W/L)

58

190

71

160

130

230

170

290

330

200

Lead, 

total 

recoverable 

(W/L)

<1

1

4

9

3

4

1

4

1

<1

Lsad, dissolved

<0.5

c5

c5

.6

c5

c5

c5

c5

c5

c5

Manganese, 

total 

recoverable 

(W/L)

70

90

70

60

50

70

30

60

60

60

Mangeness, 

dissolved

61

76

51

38

43

21

19

25

39

45

Zinc, 

total 

recoverable

<10

20

10

20

<10

20

<10

10

<10

<10

Zinc, dissolved

<3

8

6

6

<3

3

<3

9

<3

<3

Ssdlment, 

suspended 

(mg/L)

7

10

14

20

25

50

15

74

7

2

ft 1« 99QImenl diecharge, 

suspended 

(ton/d)

0.11

.12

.22

.59

.68

6.6

1.7

17

.34

.04

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

91

92

95

94

72

60

60

50

92

93

16 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

in the Upper Clark Fork Basin, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued) 

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

Data

Novl994

28...

Febl995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Stream- Specific 

flow, conductTime inetan- ance, 

taneous onstte 

(fta/s) (uS/cm)

1240

1210

1150

1355

1215

1245

1355

1150

1230

1100

19

21

23

35

26

65

54

93

35

25

487

480

555

691

478

309

300

265

409

500

pH, 

onsite (standard 

units)

7.5

7.5

7.4

7.5

7.6

7.6

7.7

7.6

7.5

7.5

Temperature, 

water <"C)

7.5

7.5

7.5

8.0

7.0

8.0

12.0

12.5

17.0

15.5

Hardness, 

total 

(mg/L

C«COj)

150

150

170

160

150

100

98

97

140

170

Calcium, dissolved 

(mg/L)

43

42

47

44

43

29

28

28

42

47

Magnesium, dissolved 

(mg/L)

11

11

12

11

11

7.2

6.8

6.5

9.6

12

Sodium, dissolved 

(mg/L)

28

29

36

66

25

15

14

12

20

26

Potassium, dissolved 

(mg/L)

5.7

6.8

5.8

9.8

14

7.8

8.0

7.6

4.8

5.0

Alkalinity 

(mg/L

CaCOj)

90

89

81

81

%

69

70

74

94

103

Date

Novl994

28...

Febl995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Sulfate, diesolved 

(mg/L)

69

71

88

86

80

50

43

35

62

87

Chloride, diesolved 

(mg/L)

20

24

30

88

18

9.4

9.0

6.7

15

19

Fluoride, dissolved 

(mg/L)

0.40

.40

.40

.60

.40

.40

.40

.40

.60

.40

Silica, dissolved 

(mg/L)

26

24

25

22

21

21

23

24

26

25

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

258

263

294

378

271

182

175

165

238

285

Arsenic, 

total 

recoverable 

<W/L)

22

18

22

23

12

22

18

28

22

18

Arsenic, dissolved 

(WP/L)

8

5

10

8

9

7

9

13

11

10

Cadmium, 

total 

recoverable 

(WP/L)

4

3

2

4

2

2

1

2

3

3

Cadmium, dissolved 

(«P/L)

0.5

1.3

1.6

2.5

1.9

.9

.9

.5

2.2

2.9

Copper, 

total 

recoverable 

(«P/L)

220

170

170

290

110

160

91

150

150

190

°ar

solved 

(Hfl/L)

22

45

50

50

71

53

50

42

70

100

Date

Novl994

28...

Fcb 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Iron, 

total 

recoverable 

(WP/L)

2,600

1,500

1,200

4,200

740

2,500

1,100

2^00

1,200

760

Iron, dissolved 

<W/L)

130

230

57

45

110

190

170

270

140

49

Lead, 

total 

recoverable 

(WP/L)

48

34

21

110

9

48

16

60

28

7

Lead, dissolved 

(W/L)

<0.5

2.0

<.5

.9

<.5

1.5

1.2

2.2

.8

<.5

Manganese, 

total 

rscoverabis 

(WP/L)

780

740

980

1,000

590

490

320

350

710

770

Manganese, dissolved 

(W/D

670

680

970

790

580

300

270

210

640

740

Zinc, 

total 

recoverable 

0*9/1-)

1,200

900

730

1,200

770

530

380

350

870

1,100

Zinc, dissolved 

(ng/L)

580

670

600

850

710

330

320

200

710

960

Sediment, 

suspended 

(mg/L)

64

31

32

125

12

94

99

25

11

QA*|| 9SOIment discharge, 

suspended 

(ton/d)

3.3

1.8

2,0

12

.84

16

25

2.4

.74

Sediment, 

euspended 

(percent 

finer than 

0.062 mm)

88

78

80

76

71

48

42

60

58

TABLE 4 17
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12323600--SILVER BOW CREEK AT OPPORTUNITY, MONT.

Data

Novl994

28...

Feb 1995

06...

Mar

09...

Apr

10...

28...

Mty

08...

22...

Jun

05...

Jul

11...

Aug

07...

Stream- Specific 

flow, conductTime Instan- ance, 

taneous onsHe 

(ft3/.) (|iS/em)

1430

1330

1350

1225

1050

1400

1505

1405

1350

1215

E33

62

51

75

63

189

173

315

155

49

403

441

471

342

370

266

239

219

289

403

PH, 

onstts (standard 

units)

8.1

8.1

8.0

8.4

8.4

7.9

8.2

7.8

8.1

8.7

Temperature, 

water <°C)

0.5

5.0

45

5.0

4.5

7.0

11.5

10.0

14.0

18.0

Hardness, 

total 

(mg/L

CaCOs)

150

150

160

120

140

98

93

88

110

150

Calcium, dissolved 

(mg/L)

44

44

46

36

40

29

28

27

32

43

Magnesium, dissolved 

(mg/L)

9.8

9.0

10

7.8

8.6

6.2

55

4.9

6.3

9.4

Sodium,

diSSOlved

(mg/L)

20

26

26

16

17

12

9.1

8.1

13

19

Potassium, di«-

-.. -. .J OfVfjQ

(mg/L)

4.4

6.4

4.4

4.7

6.5

4.1

3.1

3.6

4.2

4.0

AlkaUM!*** iinny 

(mg/L 

as 

CaCOs)

103

84

87

87

94

68

73

64

82

105

Date

Novl994

28...

Feb 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Sulfate, dissolved 

<mg/L)

63

73

72

55

62

46

32

32

39

72

Chloride, dissolved 

(mg/L)

13

24

23

9.7

11

5.6

4.3

3.2

5.8

12

Fluerid., dissolved 

(mg/L)

0.50

.70

50

.40

.40

.30

.30

.30

.40

.40

Silica, dissolved 

(mg/L)

23

22

22

21

21

21

20

18

21

24

SOiMM|

sum or constHuerrte, 

dissolved 

(mg/L)

240

257

257

204

224

166

147

136

172

248

Arsenic, 

total wcov* 

arable 

(HO/L)

16

34

22

22

16

44

22

100

92

22

Arsenic, dissolved 

(Mg/L)

8

14

8

7

8

9

11

11

20

9

Csdmlum, 

total 

recovarable 

(M/L)

1

3

2

2

2

3

1

4

4

3

Cadmium,

diSSOrVOd

(W/L)

0.7

1.4

1.5

1.1

1.2

1.2

.6

1.2

1.9

1.7

Copper, 

total rscov* 

erable 

(MO/L)

92

300

170

160

100

320

120

560

560

260

°3r

solved (ngfl.)

25

63

35

30

33

66

38

100

120

80

Date

Novl994

28...

Feb 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Iron, 

total 

recoverable 

(MO/L)

980

£200

1300

1,700

830

3,700

1,400

7,900

4,600

810

Iron, dissolved 

(HO/L)

21

120

11

27

27

150

170

210

52

22

Lead, 

total 

racovarable 

(MO/L)

16

62

34

39

17

87

29

190

150

11

Lead, dissolved 

(MO/L)

<0.5

2.3

<5

.7

<5

2.1

2.0

2.7

<5

<5

Manganese, 

total 

recoverable 

(MO/L)

620

810

770

480

490

610

230

600

870

700

Manganese, dissolved 

(MO/L)

490

670

730

420

460

390

190

310

620

650

Zinc, 

total 

recoverable 

(MO/L)

640

740

590

460

480

630

240

700

930

630

Zinc, dissolved 

(MO/L)

390

400

370

250

340

320

130

260

310

260

Sediment, 

suspended 

(mg/L)

24

53

26

28

19

176

39

258

201

10

O-.JI 99QIRMTlt discharge, 

susBMldAli

(ton/d)

2.1

8.9

3.6

5.7

3.2

90

18

219

84

1.3

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

70

84

90

90

72

52

66

71

79

92

18 Water-quality, bed-»edlment, and biological data (October 1994 through September 1995) and atatlatlcal summaries of data for streams 

in the Upper Clark Fork Basin, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12323750-SILVER BOW CREEK AT WARM SPRINGS. MONT.

Date

Novl994

28...

Febl995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Tim*

1530

1445

1500

1050

0900

1515

1600

1725

1525

1340

Stream- Specific 

flow, eonductInstan- anca, 

taneous onslta 

(ft*/a) OiS/cm)

48

121

81

114

121

195

303

452

219

E85

595

519

514

515

491

472

348

353

281

364

PH, 

oneHe 

(standard 

unite)

8.8

8.9

8.8

8.7

8.7

8.7

8.9

8.6

8.3

9.0

Temperature, 

water <°Q

3.0

5.5

3.0

5.5

8.0

10.0

14.0

13.5

165

20.0

Hardness, 

total 

(mg/L

CeCOa)

250

220

220

220

210

200

140

150

120

150

Calcium, dissolved 

(mg/L)

73

62

66

67

61

59

44

46

36

45

Magnesium, dissolved 

(mg/L)

17

15

14

14

13

13

8.5

9.1

6.7

9.9

Sodium, dissolved 

(mg/L)

23

22

18

18

17

17

13

11

8.2

10

Potassium, dissolved 

(mg/L)

8.3

5.6

5.3

4.9

4.9

4.8

3.5

3.8

2.6

2,9

Alkalinity 

(mg/L

as 

CaCOa)

130

119

101

113

106

109

97

95

85

91

Date

Nwl994

28...

Febl995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

Sulfata, dissolved 

(mg/L)

160

120

130

130

120

110

67

75

44

CNorWe, disaolvad 

(mg/L)

12

13

12

11

10

9.2

5.3

4.2

2.9

Fluorida, disaolvad (mg/L)

1.0

.80

.70

.80

.80

.70

.50

JO

JO

Silica, dissolved 

(mg/L)

10

13

12

11

6.3

8.5

15

15

15

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

382

323

319

325

297

288

215

222

167

Arsenic, 

total 

recoverable 

(MO/L)

17

14

17

13

12

14

29

48

39

Arsenic, dissolved 

(WP/L)

14

8

11

9

9

12

28

35

30

Cadmium, 

total 

recoverable 

(WP/L)

<1

<1

<1

<1

<1

<1

<1

<1

<1

Cadmium, dissolved 

(WP/L)

<0.1

.1

.2

<.!

<1

<1

<1

<1

<1

Copper, 

total 

recoverable 

(WP/L)

13

19

56

16

14

14

29

70

16

°ar

solved 

(W/L)

8

12

25

11

10

8

17

13

8

Data

Novl994

28...

Feb 1995

06...

Mar

09...

Apr

10...

28...

May

08...

22...

Jun

05...

Jul

11...

Aug

07...

Iron, 

total 

recoverable 

(WP/L)

450

430

750

290

360

340

400

3,000

440

180

Iron, dissolved 

(W/L)

4

6

35

8

15

10

17

21

23

11

Load, 

total 

recoverable 

(WP/L)

<1

2

14

2

1

1

3

12

2

<1

Lead, dissolved 

(WP/L)

<0.5

<.5

.7

<.5

<J

<.5

<.5

<J

<5

<5

Manganese, 

total 

recoverable 

(WP/L)

130

250

310

100

130

170

110

310

190

80

Manganess, disA^tluAjJ OIWQ (WP/L)

81

200

220

65

95

110

73

76

120

46

Zinc, 

total 

recoverable 

(Wt/L)

40

70

100

40

30

30

50

70

40

<10

Zinc, dissolved 

(WP/L)

7

13

27

14

4

6

9

16

5

6

Sediment, 

suspended 

(mg/L)

4

4

12

3

6

7

14

229

10

4

Sediment discharge, 

suspended 

(ton/d)

0.52

1.3

2,6

.92

2.0

3.7

11

279

5.9

.92

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

91

73

96

82

92

63

72

77

95

90

TABLE 4 19
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

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

Data

Novl984

28...

Mar 1995

09...

Apr

28...

May

22...

Jun

05...

Aug

07...

Straam- SpacHIc 

flow, conductTlma Inatan* anca, 

tanaoua onaita 

(ft3/*) OiS/cm)

1650

1530

0930

1635

1545

1410

36

39

26

106

333

43

382

428

457

253

172

283

PH, 

onaita (standard 

unHa)

8.2

8.5

8.3

8.4

7.4

8.4

Tamparatura, 

watar

1.0

4.0

5.0

11.5

7.0

15.0

Hardnaaa, 

total 

(mgA

CaCOj)

200

230

230

120

80

130

Calcium, dissolved 

(mg/L)

60

68

69

37

25

40

Magnesium, 

dissolved 

(mgA)

12

14

14

6.9

4.3

7.5

Q^tWIaUM OOQHJflL

dlssotvsd 

(mg/L)

4.4

5.0

5.0

25

2.0

3.0

Potaaalum, 

dlaaoivad 

(mgA)

1.6

1.7

1.7

1.1

1.3

1.2

AlkaUnity 

(mgA 

aa 

CaCO*)

136

138

147

96

61

106

Data

Novl994

28...

Mar 1995

09...

Apr

28...

May

22...

Jun

OS...

Aug

07...

Sulfata, dlaaolvad 

(mg/L)

64

85

89

31

24

35

Chlorida, dissolved

1.2

3.6

1.9

.80

.60

.90

Fluorlda, dlaaoivad

0.50

50

50

.40

.40

.40

Silica, dissolved 

(mg/L)

12

10

9.7

9.5

8.4

11

Solids, 

aumof conatHuanta, 

dissolved 

(mgA)

238

271

279

147

103

163

Araanlc, 

total 

rocov 

araMa

3

5

4

7

23

8

Arsenic, dissolved

3

4

4

5

8

5

Cadmium, 

total 

racovaraMa

<1

<1

<1

<1

<1

<1

Cadmium, dlsaolvad

<0.1

<1

<1

<1

<1

<1

Copper, 

total 

racovaraMa 

(Mg/L)

5

9

4

19

88

7

"SET'

aoivad

1

2

2

3

9

3

Data

NOT 1994

28...

Mar 1995

09...

Apr

28...

May

22...

Jun

OS...

Aug

07...

Iron, 

total 

racovaraMa

80

140

60

380

1,300

90

ISM&M iron, dlsaolvad 

Oig/L)

6

4

6

9

26

7

Laad, 

total 

racovaraMa 

(Mg/L)

<1

1

<1

2

14

<1

Laad, dlaaolvad

<0.5

<5

<5

<5

<5

<5

Manganaaa, 

total 

recoverable (Mg/L)

400

450

470

320

330

170

Manganese, 

dissolved

350

370

450

110

65

140

Zinc, 

total 

recoverable 

(ugA)

<10

20

<10

20

50

<10

Zinc, dissolved

<3

6

<3

<3

<3

<3

Sa* ma««t nWrn,

auapandad 

(mg/L)

3

16

8

20

81

4

SadlIVMHlt dlscharga, 

auapandad 

(ton/d)

0.29

1.7

56

5.7

73

.46

Sadlmant, 

auapandad 

(percent 

finer than 

0.062mm)

81

83

83

76

77

64

20 Watar-quallty, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for atraama 

In tha Uppar Clark Fork Baaln, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12323800--CLARK FORK NEAR GALEN, MONT.

Date

Novl994

29...

Febl995

06...

Mar

09...

Apr

10...

26...

May

09...

22...

Jun

05...

06...

Jul

11...

Aug

07...

Time

0815

1620

1730

1700

1415

0705

1800

1900

0935

1645

1530

Stream- Specific 

flow, conductinstan- ancs, 

taneous onsite 

(ft*/s) (uS/cm)

84

153

122

145

129

227

372

832

1,050

400

126

532

501

502

522

476

457

329

292

308

246

341

PH, 

onsite (standard 

units)

8.2

8.9

8.5

8.6

8.7

8.4

8.8

8.4

8.4

8.3

9.0

TMflpST*

ature, 

water 

CO

1.0

6.0

4.0

7.5

10.0

8.5

13.5

10.0

9.5

16.0

19.5

HardDQGSi 

total 

(mg/L

CaCOt)

240

220

220

230

210

200

140

130

130

100

150

Calcium, dissolved 

(mg/L)

70

64

67

69

62

59

43

39

40

32

44

Magnesium, dissolved 

(mg/L)

15

15

14

15

13

12

8.1

7.3

7.4

5.9

9.1

Sodium, dissolved 

(mg/L)

16

19

15

16

15

15

10

15

8.4

5.7

8.1

Potassium, dissolved 

(mg/L)

5.9

4.8

4.4

4.3

4.2

4.3

3.0

2.8

3.3

2.0

25

Alkalinity 

(mg/L

C*CO,)

136

124

112

120

114

114

97

83

86

79

98

Date

Novl994

29...

Febl995

06...

Mar

09...

Apr

10...

26...

May

09...

22...

Jun

05...

06...

Jul

11...

Aug

07...

Sulfata, diseolved 

(mg/L)

120

110

120

130

110

100

60

57

61

34

68

Chloride, dissolved 

(mg/L)

8.7

11

10

10

8.9

8.0

4.5

3.0

3.3

2.0

3.3

Ruonde. dissolved 

(mg/L)

0.80

.80

.60

.80

.70

.60

.50

.50

.50

.40

.60

Silica, dissolved 

(mg/L)

10

12

11

11

8.1

9.4

13

13

14

12

14

Solid*, 

sum of 

constituents, 

dissolved 

(mg/L)

328

311

309

328

290

277

200

180

190

141

208

Arsenic, 

total 

recoverable 

(W/L)

11

12

14

12

12

14

26

38

47

27

25

Arsenic, dissolved (W/L)

9

10

9

7

11

12

24

21

27

19

21

Cadmium, 

total 

recoverable 

(W/L)

<1

<1

<1

<1

<1

<1

<1

<1

1

<1

<1

Cadmium, dissolved 

(W/L)

<0.l

<1

.1

 cl

 cl

 cl

 cl

 cl

.2

 cl

<1

Copper, 

total 

recoverable 

(MO/D

8

18

43

17

16

22

34

86

150

19

9

°ar

solved 

(W/L)

6

10

19

9

9

8

14

13

25

6

6

Date

Novl994

29...

Febl995

06...

Mar

09...

Apr

10...

26...

May

09...

22...

Jun

05...

06...

Jul

11...

Aug

07

Iron, 

total 

recoverable 

Oig/L)

270

380

600

340

250

420

530

2,100

2,900

360

120

Iron, dissolved (WP/L)

5

4

21

7

17

10

15

22

29

16

10

Lead, 

total 

recoverable (cg/L)

<1

2

10

2

2

2

3

10

17

2

<1

Lead, dissolved 

(WD

<05

<5

<.5

c5

<.5

<.5

<.5

<.5

<5

<5

<.5

Mangansss, 

total 

recoverable 

(W/L)

200

270

330

170

180

250

200

390

500

150

90

llangansss, dissolved

(Mfl/L)

160

170

220

110

110

110

68

64

74

76

52

Zinc, 

total 

recoverable 

(Mfl/L)

30

60

70

30

20

40

50

80

180

30

<10

Zinc, dissolved 

<W/L)

8

10

18

11

7

4

6

9

18

5

<3

SedlMkAB^ mvni, 

suspended 

(mg/L)

4

6

10

6

5

11

18

130

162

11

3

f> ii 9VQIment dischargs, 

sue-

 kAMjJ^jJ pOfnJOQ

(ton/d)

0.91

2J5

3.3

2.3

1.7

6.7

18

292

459

12

1.0

Sediment, 

impended 

(percent finer than 

0.082 mm)

88

74

90

73

83

69

77

82

71

76

76

TABLE 4 21
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12324200--CLARK FORK AT DEER LODGE, MONT.

Date

Novl994

29...

Febl995

07...

Mar

10...

Apr

10...

26...

May

08...

24...

Jun

06...

Jul

11...

Aug

07...

Time

0920

0800

0705

1810

0730

1700

1045

1200

1815

1810

Stream- Specific 

flow, conduetInstsn- ance, 

taneoue onelte 

(ft3/.) OiS/cm)

E210

262

252

262

229

340

437

1,120

500

133

535

513

505

550

548

564

373

410

305

427

PH, 

onaite (standard 

unite)

8.2

8.3

8.2

8.6

8.3

8.4

8.3

8.0

8.5

8.7

Temperature, 

water

0.5

4.0

4.0

7.5

5.5

10.5

11.0

9.0

17.0

19.0

Hardness, 

total 

(mg/L

CaCO,)

250

230

230

250

240

250

160

180

140

180

Calcium, diesolved 

(mg/L)

72

67

69

73

71

74

48

52

41

54

Magnealum, dissolved 

(mg/L)

16

15

15

16

16

17

9.5

11

8.0

11

Sodium, dissolved 

(mg/L)

17

18

16

18

17

17

12

13

8.6

14

Potassium, dissolved 

(mg/L)

4.2

4.2

3.6

4.0

4.0

4.3

3.1

4.4

2.4

3.2

Alkalinity 

(mg/L

aa 

CaCOt)

161

144

140

149

147

144

112

101

102

137

Date

Novl994

29...

Fet>1995

07...

Mar

10...

Apr

10...

26...

May

08...

24...

Jun

06...

Jul

11...

Aug

07...

Sulfate, dissolved 

(mg/L)

110

100

no

120

120

130

66

98

44

75

Chloride, dissolved 

(mg/L)

7.7

9.2

8.8

9.8

9.1

8.0

5.2

52

3.1

5.9

FlUOride, dissolved 

<mg/L)

0,70

.70

.70

.70

.70

.70

.50

.60

.50

.70

Silica, dissolved 

(mg/L)

18

16

16

15

11

13

15

16

15

21

Solid., 

sum of 

constituents, 

dissolved 

(mg/L)

342

317

323

346

337

350

227

261

184

267

Arsenic, 

total 

recoverable 

(W/L)

9

18

20

14

13

24

28

100

32

25

Arsenic, dissolved 

(W/L)

8

8

8

9

10

13

19

33

21

22

Cadmium, total 

recoverable

<l

<1

<1

<1

<1

<1

<1

3

<1

<1

Cadmium, dissolved 

(W/L)

0.1

<1

<1

<.!

<1

<.!

<1

.1

<1

<1

Copper, 

total 

recoverable

13

62

83

38

32

76

80

600

42

32

Cjg.,

solved 

(ng/1.)

4

7

9

8

8

9

14

33

10

17

Date

Novl994

29...

Fcd> 1995

07...

Mar

10...

Apr

10...

26...

May

08...

24...

Jun

06...

Jul

11...

Aug

07...

Iron, 

total 

recoverable 

(W/L)

250

1,000

1,300

600

490

1,300

1,100

8,500

520

230

Iron, dissolved

5

9

16

8

8

7

17

48

8

7

Lssd, 

total 

recoverable

1

8

12

4

4

9

8

79

4

1

Leed, dissolved (eg/I)

<0.5

<.s

<5

<5

<5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable 

(W/L)

90

230

250

130

140

280

240

1,100

130

80

Mangeness, dissolved 

(W/L)

52

34

51

41

50

25

19

130

18

43

Zinc, 

total 

recoverable

30

80

100

40

40

90

70

510

40

10

Zinc, dissolved

9

10

18

12

9

5

11

36

4

12

Seolment, 

suspended 

(mg/L)

10

44

57

27

25

72

46

462

23

6

ment discharge, 

suspended 

(ton/d)

5.7

31

39

19

15

66

54

1,400

31

2.2

Sediment, 

suepended 

(percent 

finer than 0.062 mm)

77

68

71

60

73

53

59

58

62

85

22 Water-quality, bed-ssdlment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12324590-LITTLE BLACKFOOT RIVER NEAR GARRISON, MONT.

Dat*

Novl994

29...

Mar 1995

10...

Apr

26...

May

09...

Jun

07...

Aug

07...

Tim*

1035

0815

0840

0845

1745

1700

Stream- Specific 

now, conductmstan- anca, 

tanaous onsit* 

(ft3/«) OiS/cm)

E56

154

144

411

1,030

76

279

235

222

163

175

273

PH, 

onsHe (standard 

units)

8.2

8.2

8.2

8.0

8.0

8.4

Temperature, 

water (*C)

0.5

25

35

55

7.0

19.0

Hardness, 

total 

(mg/L

as 

CaCOj)

130

100

100

74

79

120

Calcium, "XSKT" Mm slum, dis- solved i i <"*" > SSS

39 8.8

30 7.3

30 7.0

21 5.2

23 5.3

35 8.0

Sodium, dissofved 

(mcyL)

6.6

6.3

5.0

3.7

45

5.9

Potassium, dissolved 

(mg/L)

2,0

2.9

1.7

1.5

1.9

2.2

Alkalinity 

(mgl

CaCO-J

125

100

100

69

78

131

Dat*

Nwl994

29...

Mar 1995

10...

Apr

26...

May

09...

Jun

07...

Aug

07...

Sulfat*. dissolved 

(mg/L)

14

16

14

11

10

12

Chloride, dissolved 

(mg/L)

1.6

2.8

1.7

1.1

1.3

1.5

Fluorid*, dissolved 

(mg/L)

0.20

.20

.20

.20

.20

.20

Silica, dissolved 

(mg/L)

21

17

17

17

18

23

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

168

143

137

102

111

166

Arsenic, 

total 

recovarable 

G-g/L)

4

7

4

5

11

7

CadArsMiiCy nnluiHi 

die- total 

solved recov- 

(ug/L) erabl* d-g/M

4 <1

6 <1

4 <1

4 <1

6 <1

6 <1

Caddis-' 

solved 

(WJ/L)

<0.1

<1

<1

<1

<1

<1

Coppar, 

total 

recoverable 0-g/L>

<1

4

1

2

6

1

solved 0-g/L)

<1

2

1

2

3

2

Dat*

Novl994

29...

Mar 1995

10...

Apr

26...

May

09...

Jun

07...

Aug

07...

Iron, 

total 

recoverable

50

770

220

1,000

2.400

100

Iron, dissolved G-g/L)

4

120

17

86

62

5

Lead, 

total 

recoverable

<1

2

<1

3

5

<1

Lead, dissolved 

<W/L)

<05

<5

<.5

<5

<5

<5

Manganese, 

total rscov* 

arable

(W

10

50

10

80

100

20

Manganese, 

dissolved

6

6

6

5

13

10

Zinc, -»_.. 

total *jj£

 " COV- *»*u«a»H

 aTfthaat vOIWa 

"* *" / ILfl/L.)

<10 <3

10 4

<10 <3

10 <3

20 <3

<10 <3

Sediment, 

suspended 

(mg/L)

2

36

9

56

123

3

0 II aeat-

*discharge, 

suspended

(ton/d)

0.30

15

3.5

62

342

.62

suspended 

(percent 

finer than 

0.062 mm)

90

89

87

59

68

89

TABLE 4 23
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12324680--CLARK FORK AT GOLDCREEK, MONT.

Date

Novl994

29...

Febl995

07...

Mar

10...

Apr

11...

26...

May

09...

24...

Jun

06...

Jul

12...

Aug

08...

Time

1135

1010

0920

1555

0945

0950

0900

1430

1705

1800

Stream- Specific 

flow, conductInetan- ance, 

taneoue onalte 

(t?/a) (jiS/em)

E290

481

529

458

430

934

1,150

3,920

1.020

280

496

432

400

448

435

350

257

264

315

398

PH, 

onsite (standard 

units)

8.2

8.3

8.2

8.7

8.5

8.2

8.2

8.0

8.3

8.7

Temperature, 

water

0.5

3.0

4.0

7.0

5.0

7.5

9.0

7.0

17.5

16.5

Hardness, 

total 

(mg/L

CaCOj)

230

190

180

210

200

150

110

110

140

170

Calcium, dissolved 

(mg/L)

68

56

52

59

57

43

33

33

41

51

Magnesium, dissolved 

(mg/L)

15

13

11

14

13

10

6.9

7.1

8.6

11

Sodium, dissolved 

(mg/L)

15

14

12

17

13

10

6.9

7.9

9.3

12

Potassium, dissolved 

(mg/L)

3.9

4.1

3.9

3.4

3.3

18

11

3.4

10

18

Alkalinity 

<mg/L

aa 

CaCOj)

163

137

127

140

139

109

93

98

122

151

Data

Novl994

29...

Febl995

07...

Mar

10...

Apr

11...

26...

May

09...

24...

Jun

06...

Jul

12...

Aug

08...

Sulfate, dissolved 

(mg/L)

88

70

65

82

79

61

31

37

32

51

Chloride, dissolved 

(mg/L)

6.1

6.8

6.1

7.2

6.3

4.4

15

16

19

4.4

Fluoride, dissolved 

(mg/L)

0.60

.50

.40

50

50

.40

.30

<10

.40

.50

Silica, dissolved

19

17

17

16

14

16

16

16

18

23

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

313

264

244

283

269

213

155

166

187

246

Arsenic, 

total 

recoverable 

(Mfl/L)

8

13

17

11

9

17

16

75

25

17

Arsenic, dissolved

7

9

8

7

8

8

11

17

14

14

Cadmium, 

total 

recoverable 

(Mfl/L)

<1

<1

<1

<1

<1

<1

<1

2

<1

<1

Cadmium, dissolved

<0.1

<.!

<1

<1

<1

<.!

<1

<1

<1

<1

Copper, 

total 

recoverable 

(Mfl/L)

11

40

76

27

19

58

43

440

54

10

solved 

(MO"-)

3

6

9

6

5

6

7

23

9

7

Date

Novl994

29...

Febl995

07...

Mar

10...

Apr

11...

26...

May

09...

24...

Jun

06...

Jul

11..

Aug

08

Iron, 

total 

recoverable 

(Mg/L)

280

730

1,700

520

330

1,600

1,000

12,000

2,100

90

Iron, dieeolved 

(Mfl/L)

<3

22

30

7

9

30

30

73

16

<3

Lead, 

total 

recoverable 

(Mfl/L)

1

5

11

3

3

8

6

73

9

<1

Lead, dissolved

<0.5

<5

<5

<5

<5

<.5

<.5

<5

<.5

<5

Manganese, 

total 

recoverable

lMg/LJ

90

160

220

90

80

220

120

1,100

210

30

Manganaee, dissolved

24

19

22

18

22

12

12

43

22

17

Zinc, 

total 

recoverable 

(Mfl/L)

30

60

100

30

30

70

60

510

70

<10

Zinc, dissolved (Mg/L)

4

9

13

5

5

<3

7

16

<3

4

Sediment, 

suspended 

<mg/L)

14

28

78

20

16

83

54

752

119

2

QaHI. 9vQIment diecharge, 

suspended

(ton/d)

11

36

111

25

19

209

168

7,960

328

1.5

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

79

83

78

78

85

66

55

58

93

93

24 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

in the Upper Clark Fork Baain, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12331500--FLINT CREEK NEAR DRUMMOND, MONT.

Oat*

Novl994

29...

Feb 1995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Tim*

1245

0945

1030

1430

1105

1100

1430

1820

1515

1640

Stream- Specific 

flow, conductinstan- anca, 

taneous onsits 

(ft3/s) OiS/cm)

El 00

534

229

113

114

268

186

505

437

42

341

189

243

299

301

217

204

224

337

413

PH, 

onsne (standard 

units)

8.3

8.1

8.2

8.6

8.5

8.3

8.5

8.1

8.2

8.6

Temperature, 

water (°C)

1.0

.5

3.5

5.5

5.0

8.0

11.0

6.0

15.0

14.5

Hardness, 

total 

(mg/L 

as 

CaCOa)

160

70

110

140

140

94

94

99

150

190

Calcium, dissolved 

(mg/L)

44

18

28

38

38

25

26

27

40

50

Magnesium, dissolved 

(mg/L)

13

6.0

9.0

12

12

7.7

7.1

7.7

13

15

Sodium, dissolved 

(mg/L)

8.8

3.9

6.9

7.3

7.4

5.9

4.3

5.6

8.8

10

Potassium, dissolved 

(mg/L)

3.0

7.1

5.4

2.5

2.6

2.8

1.7

3.5

4.5

4.0

Alkalinity 

(mg/L 

as 

CaCOa)

159

74

106

143

143

96

95

100

160

199

Oats

Novl994

29...

Feb 1995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Sulfata, dissolved 

(mg/L)

18

6.5

12

14

14

13

8.6

11

12

20

Chloride, dissolved 

(mg/L)

3.6

5.7

5.1

3.7

4.1

2.6

1.8

2.8

3.6

4.6

Fluorids, dissolved 

(mg/L)

0.20

<.10

.10

.20

.20

.10

.10

.10

.20

.20

Silica, dissolved 

(mg/L)

22

11

16

18

16

17

13

15

22

25

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

208

103

146

182

180

132

120

133

200

248

Arsenic, 

total 

recoverable 

<W/L)

10

44

57

11

11

20

15

28

36

13

Arsenic, dissolved

(W/L)

7

17

11

7

8

8

7

10

14

11

Cadmium, 

total rscoV" 

arable 

(W/L)

<1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Cadmium, dissolved 

(W/L)

<0.1

<.!

<.!

<.!

<.!

<1

<.!

<.!

<.!

<.!

Copper, 

totsl 

recoverable 

(W/L)

3

15

20

2

2

8

6

9

9

2

Copper, dissolved 

(W/L)

<1

5

4

<1

1

3

2

3

3

1

Date

Novl994

29...

Feb 1995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Iron, 

total 

recoverable 

(W/L)

420

2,500

2,700

260

330

1,300

690

1.100

1,200

120

iron, dissolved 

<w/L)

10

240

110

11

13

110

29

51

41

8

Lead, 

total 

recoverable 

(W/L)

6

41

54

3

4

14

10

20

20

1

Lead, dissolved 

(W/L)

<0.5

2.3

1.1

<5

<.5

<.5

<.5

.6

<.5

<.5

Manganess, 

total 

recoverable 

(W/L)

140

610

680

70

90

250

160

300

400

70

Manganess, dissolved 

(W/L)

26

71

25

32

33

30

25

48

64

43

Zinc, 

total 

recoverable 

(W/L)

30

120

140

10

10

50

30

50

60

<10

Zinc, dissolved 

(W/L)

<3

18

8

8

<3

<3

<3

4

<3

4

Sedlfnwit| 

suspended 

(mg/L)

26

168

191

11

17

82

39

90

108

4

Sediment discharge, 

suspended 

(ton/d)

7.0

242

118

3.4

5.2

59

20

123

127

.45

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

76

70

83

84

87

80

77

68

68

96

TABLE 4 25
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12331800-CLARK FORK NEAR DRUMMOND, MONT.

Date

NOT 1994

30...

Febl995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Time

0900

1230

1245

1305

1215

1300

1225

1645

1335

1515

Stream- Specific 

Now, conductinstan- anca, 

taneous oneite 

(ft3/*) (uS/cm)

505

2.370

749

598

582

1,180

1500

3300

1540

344

499

233

429

459

450

351

287

281

364

506

PH, 

oneite (standard 

unite)

8.4

8.0

8.2

8.3

8.5

8.2

8.2

8.2

8.3

8.5

Temperature, 

water

25

15

5.0

6.0

8.0

10.0

11.0

8.0

165

16.5

Hardness, 

total 

(mg/L 

as 

CaCOj)

240

91

200

210

210

150

120

120

160

220

Calcium, 

(mjL)

68

26

56

60

59

43

36

36

46

65

Magnesium, dissolved 

(mgA)

16

6.4

14

15

14

11

8.1

7.8

11

15

Sodium, dissolved 

(mgA)

14

5.6

12

13

12

9.8

7.4

8.1

10

14

Potessium,

(mgA)

3.8

10

3.5

3.3

3.2

3.1

2.3

3.4

3.1

3.7

AlkaUnity 

(mgA.

aa 

CaCO,)

169

81

142

150

149

114

100

103

143

178

Date

NOT 1994

30...

Febl995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Sulfate, dissolved 

(mg/L)

85

25

68

78

79

57

39

35

38

80

Chloride, dissolved

5.9

4.9

6.1

6.3

5.9

4.1

2.8

2.7

3.5

5.3

Fluoride, dissolved 

(mg/L)

0.50

.20

.40

50

50

.30

.30

.30

.40

50

Silica, dissolved 

(mg/L)

19

10

18

16

14

16

16

17

20

24

Solid*, 

sum of 

constituents, 

dissolved 

(mgA)

314

137

263

282

277

213

172

172

218

314

Arsenic, 

total 

recoverable

9

30

31

11

11

24

18

62

27

16

Arsenic, dissolved

8

12

9

7

9

10

11

19

15

14

Cadmium, 

total rtcov* 

arable

<1

<1

<1

<1

<1

<1

<1

2

<1

<1

Cadmium, dte-

 - - 

eonrvo

<0.1

 cl

 cl

 cl

 cl

 cl

 cl

 cl

 cl

 cl

Copper, 

total 

recoverable

15

97

100

22

19

86

57

360

51

8

aolved

2

14

6

5

5

6

9

21

9

6

Date

NOT 1994

30...

Febl995

02...

Mar

10...

Apr

11...

26...

May

09...

23...

Jun

06...

Jul

12...

Aug

08...

Iron, 

total 

recoverable

320

3,700

2,700

440

380

2.600

1,400

8,800

1,200

80

Iron, dissolved

<3

140

14

6

7

34

23

54

12

4

Lead, 

total 

recoverable

2

26

28

3

3

15

9

56

10

<1

Lead, dissolved

<0.5

.9

<5

<5

<5

<5

<5

.6

<5

<5

Manganese, 

total 

recovarable

(WW

90

550

400

70

80

320

170

880

220

30

Manganess, dissolved

13

50

12

16

15

15

14

34

22

15

Zinc, 

tots! 

recoverable

30

210

170

30

30

140

80

490

80

<10

Zinc, dissolved 

<M«/L)

5

18

10

7

4

4

6

16

7

8

Se*

suspended 

(mg/L)

16

222

155

22

18

147

77

530

73

2

discharge, 

sus-

(ton/d)

22

1,420

313

36

28

468

312

4,720

304

1.9

suspended 

(percent 

finer than 

0.062mm)

88

63

77

76

86

66

62

63

70

91

26 Watar-quality, bsd-ssdimant, and biological data (Octobsr 1994 through September 1995) and statistical summaries of data for straams 

in the Upper Clark Fork Basin, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12334510-ROCK CREEK NEAR CLINTON, MONT.

Data

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Jun

07...

Aug

08...

Time

1020

1430

1745

0920

1500

1350

Stream- Specific 

flow, conductinstan- anea, 

taneoue onshe 

(ft'/e) OiS/om)

183

406

323

1,030

2,510

383

150

124

121

85

71

128

onsHe (standard 

units)

8.3

8.2

7.9

7.8

7.7

8.4

Temperature, 

water (°C)

2.0

3.0

8.0

7.0

6.0

14.5

Hardness, 

total 

(mg/L

CaCO))

69

58

55

38

33

57

Calcium, iJg*- 

die- ^JjJJ'

8OlV0fl AJtiuAjJ < " « > (SStf

18 5.9

15 5.0

14 4.8

9.6 3.3

8.6 2.7

15 4.7

Sodium, dissolved 

(mg/L)

3.3

2.8

2.9

2.3

1.6

25

Potassium, dissolved 

(mg/L)

1.2

1.6

1.1

1.0

1.1

1.0

Unity 

(mg/L

as 

CaCO))

74

59

58

39

34

63

Data

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Jun

07...

Aug

08...

Sulfata, 

dissolved 

(mg/L)

4.5

3.7

3.9

3.3

2.2

4.3

Chloride, 

dissolved 

(mg/L)

0.60

1.0

.70

.50

.40

.40

Ruoride, diesolved 

(mg/L)

0.20

.10

.10

.10

 clO

.10

Silica, 

dissolved 

(mg/L)

12

9.9

11

12

9.7

9.7

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

90

75

73

56

47

75

Arsenic, 

total 

recoverable 

(Mg/L)

<1

<1

<1

<1

1

<1

CadAreenlc, mlum, 

die- total 

solved reeov- 

(|ig/L) erabto 

(Mg/L)

<1 <1

1 <1

<1 <1

<1 <1

<1 <1

<1 <1

Cadmium, dlasolved

<0.1

 cl

<.!

 cl

<.!

 cl

Copper, 

total 

recoverable

<1

<1

3

7

4

<1

solved

<1

<1

<1

2

1

<1

Date

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Jun

07...

Aug

08...

Iron, 

total 

recoverable 

(Mg/L)

20

130

90

340

500

60

Iron, dissolved G>g/L)

8

28

17

70

49

12

Lead, 

total 

recoverable 

(Mg/L)

<1

<1

1

1

1

<1

Lead, dissolved

<0.5

<.5

<.5

<.5

<5

 c5

Manganese, 

total 

recoverable 

(ug/L)

<10

<10

<10

20

50

<10

Mangadiesolved

<1

<1

<1

2

3

2

total' *jjf 

recov- _ _ I..-.I rahi* soivea

ESS <M«vg

<10 <3

<10 4

<10 <3

<10 <3

<10 <3

<10 4

Sedlment, 

suspended 

(mg/L)

1

5

5

16

45

1

Sedlment discharge, 

suspended

(ton/d)

0.49

5.5

4.4

44

305

1.0

Sediment, 

euspended 

(percent 

finer than 

0.062 mm)

86

89

76

78

53

86

TABLE 4 27
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued) 

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

Date

Novl994

30...

Febl995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

11..

Aug

08...

Tim*

1200

1050

0900

1040

1515

1130

1010

0815

0850

1215

Stream- Specific 

flow, conductInstan- anca, 

tanepus onsite 

(ft3/*) (us/cm)

695

1,040

1,180

980

1,000

2,330

3,220

6,950

2,640

734

408

371

340

353

353

243

195

210

275

323

PH, 

onsite (standard 

units)

8.4

8.4

8.3

8.3

8.4

8.1

8.1

8.0

8.2

8.6

Temperaturs, 

water (°C)

3.0

3.0

5.0

5.0

10.0

10.0

9.0

6.5

15.0

15.0

Hardness, 

total 

(mg/L 

aa 

CaCOa)

190

170

150

160

160

110

82

90

120

140

Calcium, dissolved 

(mg/L)

54

47

43

44

45

30

23

26

35

39

Magnesium, dissolved 

(mg/L)

14

12

11

12

11

7.8

5.9

6.0

8.5

10

Sodium, 

dissolved 

(mg/L)

11

10

9.3

9.2

9.2

6.4

4.8

5.8

7.1

7.8

Potassium, dissolved 

(mg/L)

3.0

3.6

3.3

2.4

2.5

2.1

1.6

2.7

2.0

2.2

Alkalinity 

(mg/L 

as 

CaCO,)

146

128

116

121

123

85

72

79

109

121

Data

Novl994

30...

Febl995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

12...

Aug

08...

Sulfate, dissolved 

(mg/L)

62

53

48

52

54

32

20

25

24

40

Chloride, dissolved 

(mg/L)

4.2

4.7

4.5

3.7

4.1

2.3

1.7

1.9

2.1

2.7

Flueride, dissolved 

<mg/L)

0.40

.40

.30

.30

.30

.20

.20

.20

.30

.30

Silica, 

dissolved 

(mg/L)

16

16

15

15

12

14

13

14

16

15

Solids, 

sum of 

constituents, 

dissolved 

(mg/L)

252

223

204

211

212

146

113

129

160

190

Arsenic, 

total 

recoverable 

(Mg/L)

5

11

17

7

8

12

10

33

14

8

Arsenic, dissolved 

(Mfl/L)

5

7

7

4

6

7

6

12

9

7

Cadmium, 

total 

recoverable 

(ug'L)

<1

<1

<1

<1

<1

<1

<1

1

<1

<1

Cadmium, dissolved 

(Mg/L)

<0.1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Copper, 

total 

recoverable (ng/L)

6

37

60

12

13

43

30

180

32

4

Cgpr.

^ | 1

VOIWQ (wjrt->

2

5

9

3

4

5

6

14

6

2

Data

Novl994

30...

Fet>1995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

12...

Aug

08...

Iron, 

total 

recoverable 

(Mg/L)

120

710

1,500

280

290

1,400

760

4,900

840

60

Iron, 

dissolved 

(M^L)

<3

20

27

9

6

41

35

56

22

4

Lead, 

total 

recoverable 

(WL)

<1

5

14

2

2

8

6

33

5

<1

Lead, 

dissolved 

(WL)

<0.5

<5

<5

<5

<5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable 

(Mg/L)

30

130

230

270

50

170

120

580

130

20

Manganese, dissolved 

(Mg/L)

3

9

6

6

5

6

7

13

11

7

Zinc, 

total 

recoverable 

(Mg/L)

10

60

100

20

20

70

50

270

50

<10

Zinc, 

dissolved 

(Mg/L)

<3

9

8

6

4

<3

4

10

6

5

Sediment, 

suspended 

(mg/L)

6

30

74

13

14

77

64

325

46

2

Sediment discharge, 

suspended 

(ton/d)

11

84

236

34

38

484

556

6.100

328

4.0

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

90

88

89

86

92

68

49

63

80

91

28 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

in tha Upper Clark Fork Basin, Montana
Tabto 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12340000-BLACKFOOT RIVER NEAR BONNER, MONT.

Date

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Jun

07...

Aug

08...

Tim*

1320

1050

1330

1540

1045

1030

StrMm- Specific 

flow, conductinatan- anca, 

taneoua onsKs 

(f?/s) (uS/em)

472

869

1,360

3,410

6,440

779

263

215

203

181

168

253

onaita (standard 

untta)

8.6

8.6

8.4

8.3

8.2

8.6

Tamparatura, 

watar (°C)

10

4.0

8.0

11.0

7.0

15.0

Hardness, 

total 

<mg/L

aa 

CaCO,)

140

110

100

86

83

120

Calcium, diaaolvad 

(mg/L)

36

29

26

22

22

31

Magnaslum, dissolved (mam

12

10

9.0

7.6

6.9

11

Sodium, dtea»r»ii«aifi aKNWu

(mgA)

3.3

2.8

2J

1.9

2.0

2J

Potassium, 

die-

^.^.t- -I VOIWQ

(mo/L)

0.90

.90

.80

.70

.80

.70

Alkalinity 

(mg/L

CaCOj)

140

111

105

92

86

131

Date

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Inn

07...

Aug

08...

Sulfata,

dissolved

(mg/L)

5.5

5.0

4.2

5.3

4.3

5.8

CHorida, die-

^^.a- -J

WOiwWo

(mg/L)

0.70

1.0

.80

.40

.40

.50

Ruerida, 

diaaolvad 

(mg/L)

0.10

<10

<10

<10

<10

<10

Silica, diaaolvad 

(mg/L)

9.4

7.6

75

8.1

7.4

8.1

aumoi 

constituents, 

diaaolvad 

(mg/L)

152

123

114

101

95

138

Arsenic, 

total 

recoverable 

(|ig/L)

<l

1

<l

1

2

<1

Arsenic, 

diaaolvad 

(WJ/L)

1

1

<1

<1

1

1

Cadmium, 

total 

recovarable 

(MJ/L)

<1

<1

<1

<1

<1

<1

Cadmium, dieA«*I.JAjJ OffVMI

(W^U

<0.1

<.!

<1

<1

<1

<1

copper, 

total 

recoverable 

(HO/L)

<1

1

<1

4

15

<1

IT'

solved 

(M/L)

<1

<1

<1

1

1

<1

Data

Novl994

30...

Mar 1995

11...

Apr

25...

May

10...

Jun

07...

Aug

08...

Iron, 

total 

recoverable 

(W/L)

20

170

110

1,000

1,200

SO

Iron, 

diaaolvad 

(W/L)

<3

14

10

22

22

<3

Laad, 

total 

recoverable 

<W/L)

<1

<1

<1

2

2

<1

l£d, diaaolvad 

(W/L)

<0.5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable 

(WJ/L)

<10

<10

20

90

60

<10

Manganess, 

diaaolvad 

(fifl/L)

<1

2

2

3

2

2

Zinc, 

total 

recoverable 

(|ig/L)

<10

<10

<10

10

<10

<10

Zinc, 

diaaolvad 

(MJ/L)

<3

<3

<3

<3

<3

<3

Se<HIfMVIt,

auapended 

<mg/L)

1

6

8

70

99

4

Sedi-

 MAaa* ifwni discharge, 

auapandad 

(ton/d)

1.3

14

29

644

1,720

8.4

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

88

94

87

91

83

95

TABLE 4 29
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12340500-CLARK FORK ABOVE MISSOULA, MONT.

Date

Novl994

30...

Febl995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

12...

Aug

08...

Tims

1450

1315

1230

0815

1130

1330

0800

1235

1120

0830

Stream- Specific 

flow, conductInstan- ance, 

taneoue onsHs

1,210

1580

2,190

2,410

2.360

5,760

7,620

13,100

4,810

1,720

350

319

297

260

274

208

179

191

253

283

o£its (standard 

units)

8.4

8.4

8.4

8.3

8.3

8.2

8.2

8.1

8.3

8.5

Temperature, 

water (*C)

2.0

2.5

5.0

55

8.5

10.0

9.5

7.0

16.0

17.0

Hardtotal 

(mg/L

CaCOj)

170

150

140

120

130

94

83

90

120

130

Calcium, diesolved 

(mg/L)

45

40

38

32

35

25

22

25

32

34

Magnesium, dissolved 

(mg/L)

13

11

11

9.5

10

7.6

6.7

6.6

8.8

10

Sodium, die-

 ^|«._.J OIWQ

(mgA.)

7.8

7.7

6.7

5.4

55

3.7

2.9

4.0

5.1

5.2

Potassium, die-

.»._ . ..».J CMWCI

(mg/L)

2.1

3.8

2.0

1.5

1.5

1.3

1.0

1.8

1.5

1.4

Unity 

(mgA

CaCO*)

143

121

118

108

114

89

82

83

101

123

Data

Novl994

30...

Febl995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

12...

Aug

08...

Sulfats, dissolved 

<mg/L)

39

34

31

23

25

16

11

15

16

22

Chloride, dissolved 

(mg/L)

2.8

3.6

3.1

2.2

2.4

1.3

1.0

1.2

15

1.6

Fluoride, dissolved 

(mg/L)

0.30

.30

.30

.20

.20

<10

.10

.10

.20

.20

Silica, dissolved 

(mg/L)

13

14

12

11

96

11

96

11

13

11

Solids, 

sum of 

constrtuenta, 

dissolved 

(mg/L)

209

187

175

150

158

119

104

115

139

159

Arsenic, 

total 

recovarable 

(W/L)

3

7

6

3

3

6

5

18

10

6

Arsenic, diesolved 

(ug/L)

3

5

5

2

3

3

3

7

6

4

Cadmium, 

total 

recoverable 

(ug/L)

<1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Cadmiunig dissolved 

(ug/L)

<0.1

<1

<1

<1

<1

<1

<1

<1

<1

<1

Copper, 

total 

recoverable 

(ug/L)

5

13

18

7

7

16

22

110

23

5

solved 

(W/D

3

4

3

2

2

3

3

8

4

2

Date

Novl994

30...

Febl995

08...

Mar

11...

Apr

11...

25...

May

10...

23...

Jun

07...

Jul

12...

Aug

08...

Iron, 

total

ItCOV*

arable 

(ug/L)

60

380

450

190

180

890

700

3,100

680

140

Iron, dissolved 

(Mg/L)

<3

30

11

15

11

30

26

45

16

6

Lead, 

total

ItCOV*

arable

<1

2

4

1

2

4

4

16

4

<1

 2* 

dissolved 

(W/L)

<0.5

<5

<5

<5

<5

<5

<5

<5

<5

<5

Manganese, 

total 

recoverable (W/L)

20

70

70

30

40

100

60

300

120

30

Manganess, dissolved 

(MO/L)

7

14

22

21

26

19

17

23

39

18

Zinc, 

total 

recovarable 

(W/L)

<10

30

30

20

10

30

30

160

40

<10

Zinc, diesolved 

(ug/L)

<3

3

8

6

3

<3

4

11

<3

5

Sediment, 

suspended 

(mg/L)

2

12

18

8

10

54

45

186

36

6

q- -II 9eOH

ment discharge, 

suspended 

(ton/d)

6.5

51

106

52

64

840

926

6580

468

28

Sediment, 

suspended 

(percent 

finer than 

0.062 mm)

94

99

98

%

92

95

89

80

91

97

30 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 4. Water-quality data for the upper Clark Fork basin, Montana, October 1994 through September 1995 (Continued)

12353000-CLARK FORK BELOW MISSOULA, MONT.

Data

Octl994

18...

Dec

20...

Febl995

21...

Apr

18...

Jun

16...

Aug

08...

23...

Time

1115

1045

1130

1115

0920

1000

1000

Stream- Specific 

flow, conductInatan- anca, 

taneoua oneite 

(ft3/*) (uS/cm)

1.730

1,850

5,710

3.950

16,500

2.610

2.420

315

267

178

188

115

233

224

pH, 

onaita (atandard 

unit*)

8.3

7.8

7.9

8.2

7.5

8.0

8.0

Temperature, 

water

9.0

1.5

2.0

8.0

13.0

16.0

8.5

Hardnaaa, 

total 

(mg/L

CaCO,)

140

120

78

90

53

100

Calcium, JJJdla- aolved ««IIJ«H

<"*«-> S$L)

41 10

34 9.2

22 5.6

25 6.7

15 3.8

_

28 7.8

Sodium, dlaaolved 

(mg/L)

7.6

7.0

4.4

4.8

2.7

5.6

Potaaalum, diaaolvad 

(mg/L)

2.4

1.8

1.9

1.3

.90

1.8

AHcaHnHy 

(mgH 

aa 

CaCO,)

131

112

69

84

54

101

Data

Octl994

18...

Dec

20...

Febl995

21...

Apr

18...

Jun

16...

Aug

08...

23...

Sulfata, dteeorvod 

(mg/L)

28

25

13

15

9.8

12

Chloride, di*- 

aolved 

(mg/L)

3.0

2.7

2.2

1.8

.80

2.0

Ruoride, dleaolved 

(mg/L)

0.20

.20

.10

.20

<10

.20

Silica, di*- 

aolved 

(mg/L)

15

13

11

10

9.9

12

Solid*, 

eumof conetHuente, 

dissolved 

(mg/L)

179

153

107

114

70

127

Araenlc, 

total 

recoverable

3

-

6

3

3

-

CadAraenic, mlum, 

die- total 

aolved recovOig/L) arable

<1 <1

..

3 <1

2 <1

2 <1

Cadmium, dlaaolved

<0.1

~

<1

<1

<1

~

-

Copper, 

total 

recoverable

4

-

25

4

12

~

-

C3ff"r>

aolved

2

~

6

2

4

-

Date

Octl994

18...

Dec

20...

Febl995

21...

Apr

18...

Jun

16...

Aug

08...

23...

Iron, 

total

roCOV"

arable 

(W/L)

140

-

1,600

180

580

~

-

Iron, dleaolved 

(ug/L)

16

-

47

26

93

-

Lead, 

total 

recoverable

<1

-

4

<1

2

-

Lead, dleaolved

0.5

-

<5

<5

<5

-

Manganeaa, 

total 

recoverable

30

..

110

20

60

--

-

Manganeee, dleaolved

5

-

7

11

8

-

Zinc, 7,_. 

total ZJ~-

JJJJ: aolvad

9iaaim (ufl/L)

10 <10

..

40 10

20 <10

20 <10

_

--

Sedlment, 

auapended 

(mg/L)

5

3

52

9

42

4

3

Sediment diecharge, 

auapended

(ton/d)

23

15

802

96

1,870

28

20

ttm aeoimeni, Muut !

euapended 

(percent 

mar than 

0.062 mm)

88

91

79

87

62

91

90

TABLE 4 31
Table 5. Daily streamflow and suspended-sediment data for Silver Bow at Opportunity, Montana, October 1994 through 

September 1995

[Abbreviations: ft?/», cubic feet per second; mg/L, milligrams per liter; ton/d, tons per day. Symbol: , no data]

Suspended eedlment u^... u^...

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

strsam-

* now

(ft3/.)

28

29

31

30

30

29

29

29

29

33

34

36

33

32

45

36

36

37

36

36

35

36

36

34

34

36

41

53

45

41

42

1.091

35

53

28

Mean 

concentration 

(mg/L)

October

11

11

10

10

9

9

10

12

14

14

13

12

13

15

33

25

20

20

20

14

13

12

12

12

12

12

13

22

16

14

14

14

33

9

Discharge 

(ton/d)

0.83

.86

.84

.81

.73

.70

.78

.94

1.1

1.2

1.2

1.2

1.2

1.3

4.0

2,4

1.9

2.0

1.9

1.4

1.2

1.2

1.2

1.1

1.1

1.2

1.4

3.1

1.9

1.5

1.6

43.79

1.4

4.0

.70

 t reamflow

(ft3/.)

49

43

39

43

40

40

39

38

39

36

36

36

35

33

37

35

34

31

30

32

32

31

32

32

32

32

33

33

34

40

1.076

36

49

30

Suspended sediment 

u_..

Mean 

concentration 

(mg/L)

1994

November

16

19

16

16

15

14

15

15

15

16

18

20

22

25

26

27

27

28

29

29

30

33

30

23

18

16

20

24

25

62

23

63

14

Diecharge 

(ton/d)

2.1

2.2

1.7

1.8

1.6

15

1.6

15

1.5

1.6

1.7

1.9

2.1

2.2

2.6

2.6

25

2.3

2.3

25

2.6

2.8

2.6

2.0

1.6

1.4

1.8

2.1

2.3

6.7

65.7

22

6.8

1.4

at reamflow 

(ft'/s)

49

41

39

38

36

33

32

31

32

30

31

30

31

32

34

37

40

45

50

49

49

47

48

45

42

40

40

41

39

36

31

1.198

39

50

30

Suspended dimwit

Mean 

concerttrafion 

<mg/L)

December

79

42

34

33

28

20

14

10

10

10

10

10

10

9

8

8

7

8

10

22

20

14

12

11

11

11

11

34

16

13

12

19

81

7

Diecharge 

(ton/d)

10

4.6

3.6

3.4

2.7

1.8

1.2

.84

.86

.81

.84

.81

.84

.78

.73

.80

.76

.97

1.4

2.9

2.6

1.8

1.6

1.3

1.2

1.2

1.2

3.8

1.7

1.3

1.0

59.34

2.0

11

.73

32 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summariea of data for streams 

in the Upper Clark Fork Basin, Montana
Table 5. Daily streamflow and suspended-sediment data for Silver Bow at Opportunity, Montana, October 1994 through 

September 1995 (Continued)

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

Maan . 

atraamflow 

(ft3/.)

30

29

29

28

28

30

30

35

40

50

70

80

80

76

70

66

64

56

54

42

40

38

37

40

42

45

46

47

45

45

60

1,472

48

80

28

Suspended aadimant

Maan 

concant ration 

(mg/L)

January

12

11

11

12

12

13

14

14

14

15

16

16

17

18

18

17

16

16

17

18

18

19

19

19

20

22

23

23

23

23

57

18

57

11

DJaeharga 

(ton/d)

.97

.86

.86

.91

.91

1.1

1.1

1.3

1.5

2.0

3.0

3.5

3.7

3.7

3.4

3.0

2.8

2.4

2.5

2.0

1.9

1.9

1.9

2.1

2.3

2.7

2.9

2.9

2.8

2.8

9.2

74.91

2.4

9.2

.86

Maan 

atraamflow 

(ft3/*)

100

160

120

90

73

68

64

65

64

61

45

40

35

33

32

32

35

40

150

400

300

120

79

73

73

69

59

54

2434

90

400

32

Suapandad aadimant

Maan 

concontratlon 

(mg/L)

1995

Fabruary

121

200

130

106

61

52

40

27

22

23

24

26

27

28

29

30

31

31

31

34

260

180

70

52

56

38

32

17

63

260

17

Diaeharga 

(ton/d)

33

86

42

26

12

9.5

6.9

4.7

3.8

3.8

2.9

2.8

2.6

24

25

2.6

2.9

3.3

13

37

211

58

15

10

11

7.1

5.1

2.5

6194

22

211

2.5

Maan - 

atraamflow 

(ll»/a)

52

47

47

45

44

42

40

45

57

100

151

110

83

75

82

80

74

72

69

67

71

69

67

65

61

62

62

59

60

57

62

2,077

67

151

40

Suapandad aadimant

Maan 

eoncantratlon 

(mg/L)

March

31

53

14

21

35

30

44

36

40

185

235

80

45

40

50

39

34

26

21

26

29

26

28

20

23

21

18

18

16

20

22

43

235

14

Diaeharga 

(ton/d)

4.4

6.7

1.8

2.6

4.2

3.4

4.8

4.4

6.2

50

%

24

10

8.1

11

8.4

6.8

5.1

3.9

4.7

5.6

4.8

5.1

3.5

3.8

3.5

3.0

2.9

2.6

3.1

3.7

308.1

9.9

%

1.8

TABLES 33
Table 5. Daily streamflow and suspended-sediment data for Silver Bow at Opportunity, Montana, October 1994 through 

September 1995 (Continued)

Suapandad aadimant 

u._ _. 

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

attaain* 

flew 

(ft3/*)

64

66

66

70

77

81

84

88

80

79

75

74

79

89

79

71

75

69

74

82

73

71

75

68

73

67

69

68

72

68

--

2,226

74

89

64

 Wwl

concentration 

(mg/L)

April

16

16

15

21

30

33

29

32

24

40

33

20

20

31

25

22

21

16

15

21

22

16

17

17

21

16

17

22

29

22

23

40

15

Discharge 

(ton/d)

2.8

2.9

Z7

4.0

6,2

7.2

6,6

7.6

5.2

8.5

6,7

4.0

4.3

7.4

5.3

4.2

4.3

3.0

3.0

4.6

4.3

3.1

3.4

3.1

4.1

2.9

3.2

4.0

5.6

4.0

138.2

4.6

8.5

2.7

at reamflow 

<«*> >

1995

68

70

83

80

83

168

206

204

191

190

229

261

260

222

196

189

192

201

202

195

190

179

168

158

149

146

139

132

129

136

140

5,156

166

261

68

Suapandad aedMnent

Maan 

concentration 

<mg/L)

Hay

29

34

55

46

45

362

219

160

70

51

81

166

130

85

64

55

54

66

65

51

46

46

38

30

29

25

22

21

20

24

30

72

362

20

Diacharga 

(ton/d)

5.3

6,4

12

9.9

10

164

122

88

36

26

50

117

91

51

34

28

28

36

35

27

24

22

17

13

12

9.9

8.3

7.5

7.0

8.8

11

1,117.1

36

164

5.3

Maan - 

atraamflow 

(fl3*)

147

151

174

320

330

447

412

356

334

322

311

300

296

290

281

270

258

238

244

224

199

204

179

160

149

142

156

143

135

125

7,297

243

447

125

Suapandad sediment

Maan 

cone antratlon 

(mgt)

Juna

40

43

48

225

220

410

250

165

120

105

102

90

79

67

61

64

62

61

42

43

35

31

29

25

27

29

47

29

24

22

86

410

22

Discharge 

(ton/d)

16

18

23

194

196

495

278

159

108

91

86

73

63

52

46

47

43

39

28

26

19

17

14

11

11

11

20

11

8.7

7.4

&211.1

74

495

7.4

34 Water-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and atatiatkal aummariaa of data for atraama 

In tha Upper Clark Fork Bat In, Montana
Table 5. Daily streamflow and suspended-sediment data for Silver Bow at Opportunity, Montana, October 1994 through 

September 1995 (Continued)

Suspended sediment

u_._ u_._

Day

l

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

MTN

at reamflow 

(ft3/*)

119

111

111

108

102

100

96

90

93

136

180

187

213

174

136

120

110

103

98

94

88

84

79

76

71

69

65

58

65

105

78

3,319

107

213

58

concentration 

<mg/L)

July

20

19

18

17

14

15

17

18

30

330

330

340

563

129

47

33

27

22

18

19

16

14

13

12

11

10

10

9

30

90

19

75

563

9

Discharge 

(ton/d)

6.4

5.7

5.4

5.0

3.9

4.1

4.4

4.4

75

121

160

172

324

61

17

11

8.0

6.1

4.8

4.8

3.8

3.2

2.8

2.5

2.1

1.9

1.8

1.4

5.3

26

4.0

991.3

32

324

1.4

streamflow 

(ft3/*)

68

61

57

58

56

52

48

47

48

47

45

41

43

42

41

43

49

49

46

42

42

38

37

36

38

39

31

31

30

28

28

1,361

44

68

28

Suspended sediment

Mean 

concerttratlon 

<mg/L)

1995

August

16

16

16

19

17

13

11

10

10

10

10

11

11

10

10

10

14

11

10

9

10

10

10

11

11

11

11

11

11

10

10

12

19

9

Diecharge 

(ton/d)

2.9

2.6

2.5

3.0

2.6

1.8

1.4

1.3

1.3

1.3

1.2

1.2

1.3

1.1

1.1

1.2

1.9

15

1.2

1.0

1.1

1.0

1.0

1.1

1.1

1.2

.92

.92

.89

.76

.76

44.15

1.4

3.0

.76

Mean 

streamflow 

(ft3/*)

29

28

27

28

53

36

37

93

69

62

51

48

50

46

46

44

44

45

47

61

50

48

47

46

47

44

42

41

44

43

_.

1,396

46

93

27

*3uapendet

Mean 

concen* 

tratlon 

(mg/L)

September

10

9

9

25

180

148

150

225

70

60

23

14

21

13

12

12

12

12

21

76

15

14

13

12

12

11

10

10

9

9

._

41

225

9

1 sediment

Discharge 

(ton/d)

.78

.68

.66

1.9

26

14

15

56

13

10

3.2

1.8

2.8

1.6

1.5

1.4

1.4

15

2.7

13

2.0

1.8

1.6

15

1.5

1.3

1.1

1.1

1.1

1.0

182.92

6.1

56

.66

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW--30.203 ft3* 

SEDIMENT DISCHARGE-5,856.11 tons

TABLE 5 35
Table 6 . Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1994 

through September 1995

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

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/*)

28

27

26

26

25

25

26

27

30

30

27

28

32

37

46

48

49

50

52

51

56

53

52

51

51

52

49

46

53

58

62

1,273

41

62

25

Suspended sediment

Mean 

concentration 

(mg/L)

October

4

3

3

3

3

3

4

4

4

4

4

4

3

3

3

3

3

3

3

3

5

3

3

3

3

5

5

3

3

3

6

4

6

3

Diecharge 

(ton/d)

0.30

.22

.21

.21

.20

.20

.28

.29

.32

.32

.29

.30

.26

.30

.37

.39

.40

.41

.42

.41

.76

.43

.42 -

.41

.41

.70

.66

.37

.43

.47

1.0

12.16

.39

1.0

.20

at reamflow

1994

57

57

56

61

54

56

56

57

56

56

54

54

57

57

57

45

49

52

51

48

46

48

45

44

45

48

49

48

50

50

_.

1363

52

61

44

Suspended sediment

Mean 

concentration 

(mg/L)

NOVMflDeM*

4

4

4

7

6

6

6

6

5

4

4

4

4

4

7

6

8

10

10

7

5

5

5

5

5

5

5

4

4

4

5

10

4

Diecharge 

(ton/d)

0.62

.62

.60

1.2

.87

.91

.91

.92

.76

.60

58

58

.62

.62

1.1

.73

1.1

1.4

1.4

.91

.62

.65

.61

59

.61

.65

.66

52

34

34

23.04

.77

1.4

.52

Mean 

streamflow 

(ft3/*)

52

55

59

60

59

57

57

56

51

49

48

47

47

48

47

45

46

49

52

53

52

52

53

53

54

56

55

57

60

56

55

1,640

53

60

45

Suspended aediment

Mean 

concen* 

tratlon 

(mg/L)

December

4

5

5

5

4

4

4

4

4

5

5

5

5

5

4

4

4

4

3

3

3

4

5

6

5

4

3

3

4

4

5

4

6

3

Discharge 

(ton/d)

036

.74

.80

.81

.64

.62

.62

.60

55

.66

.65

.63

.63

.65

51

.49

50

53

.42

.43

.42

36

.72

.86

.73

.60

.45

.46

.65

.60

.74

18.83

.61

.86

.42

36 Water-quality, bed-sediment, and biological data (Octobar 1994 through Saptambar 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1994 

through September 1995 (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 

streamttmmmt now («*/ >

52

47

44

42

39

39

39

39

39

43

46

49

53

55

56

56

56

57

53

50

50

50

48

47

45

44

47

48

49

48

49

1.479

48

57

39

Mean 

concertt ration 

<mg/L)

January

5

6

6

7

7

7

7

7

7

7

6

6

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

5

6

7

5

Discharge 

(ton/d)

.70

.76

.71

.79

.74

.74

.74

.74

.74

.81

.75

.79

.72

.74

.76

.76

.76

.77

.72

.68

.68

.68

.65

.63

.61

59

.63

.65

.66

.65

.66

22.01

.71

.81

.59

Mean 

streamflow 

(ft3/*)

1995

54

90

153

163

143

121

107

92

77

61

57

55

53

52

53

55

57

59

64

90

149

171

163

150

135

127

121

113

2,785

100

171

52

Suspended sediment

Mean 

concentration 

<mg/L)

February

5

8

12

13

9

5

6

10

11

12

12

12

12

12

12

13

14

14

14

15

18

14

11

8

10

15

18

18

...

12

18

5

Discharge 

(ton/d)

.73

1.9

5.0

5.7

3.5

1.6

1.7

2.5

2.3

2.0

1.8

1.8

1.7

1.7

1.7

1.9

2.2

2.2

2.4

3.6

7.2

6.5

4.8

3.2

3.6

5.1

5.9

5.5

...

...

...

89.73

3.2

7.2

.73

Mean 

streamflow 

(fl3/s)

106

97

90

88

87

84

83

81

81

84

92

110

120

117

107

102

100

97

93

93

88

90

90

85

84

83

82

81

81

81

82

2,839

92

120

81

Suspended sediment

Mean 

concentratton 

(mg/L)

March

14

12

14

15

14

11

12

11

10

11

13

10

10

11

13

10

9

8

8

8

7

7

14

8

6

6

6

7

7

5

3

10

15

3

Discharge 

(ton/d)

4.0

3.1

3.4

3.6

3.3

2.5

2.7

2.4

2.2

2.5

3.2

3.0

3.2

3.5

3.8

2.8

2.4

2.1

2.0

ZO

1.7

1.7

3.4

1.8

1.4

1.3

1.3

1.5

1.5

1.1

.66

75.06

Z4

4.0

.66

TABLE 6 37
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1994 

through September 1995 (Continued)

u... u^..

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

atraam-

* - now

(ft3/*)

82

80

80

88

100

104

108

112

114

114

112

110

109

113

112

111

109

107

108

115

116

114

114

114

110

111

111

121

125

124

~-

3,248

108

125

80

Maan 

coneantnrtlon 

<mg/L)

April

3

4

4

4

5

5

5

4

3

3

4

4

5

4

3

4

4

3

4

3

3

3

3

4

3

3

4

5

4

3

...

4

5

3

Dtoeharga 

(ton/d)

.66

.86

.86

.95

1.4

1.4

13

1.2

.92

.92

1.2

1.2

1.5

1.2

.91

1.2

1.2

.87

1.2

.93

.94

.92

.92

1.2

.89

.90

1.2

1.6

1.4

1.0

...

33.05

1.1

1.6

.66

 traain-

< ---, now

(fl»/a)

123

121

123

125

124

140

171

196

203

204

211

242

298

310

304

298

291

302

317

306

270

305

303

308

314

307

303

290

276

284

309

7,678

248

317

121

Suspended aacHmant

u...

Maan 

concan* 

tratton 

(maH)

1906

May

5

3

3

3

5

8

6

7

8

8

7

28

58

42

34

24

17

31

30

28

23

17

14

14

13

12

12

8

8

9

11

16

58

3

Dtoeharga 

(ton/d)

1.7

.98

1.0

1.0

1.7

3.0

2.8

3.7

4.4

4.4

4.0

18

47

35

28

19

13

25

26

23

17

14

11

12

11

9.9

9.8

6.3

6.0

6.9

9.2

375.78

12

47

.98

atraam-

* - now

(ft3*)

323

334

391

405

463

677

661

555

533

509

468

457

491

477

468

450

451

442

457

452

441

429

403

365

343

324

315

311

301

284

...

12,980

433

677

284

Suapandad aadbnant

Maan 

concantratfon 

(mg/g

Juna

13

17

34

42

155

165

93

43

74

70

51

44

24

20

18

17

14

15

21

15

13

12

11

10

9

11

15

19

14

12

...

36

165

9

Dtoeharga 

(ton/d)

11

15

36

46

194

302

166

64

106

96

64

54

32

26

23

21

17

18

26

18

15

14

12

9.9

8.3

9.6

13

16

11

9.2

...

1.453.0

48

302

8.3

38 Watar-quallty, bad-aadlmant, and biological data (Oetobar 1994 through Saptambar 1995) and statistical summarlas of data for ttraama 

In tha Uppar Clark Fork Bat In, Montana
Table 6. Daily streamflow and suspended-sediment data for Silver Bow Creek at Warm Springs, Montana, October 1994 

through September 1995 (Continued)

Suspended sediment

U___ M~-

Day

1

2

3

4

5

6

7

8

9

10

11

12

13

14

IS

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

TOTAL

MEAN

MAX

MIN

stream- 

<**/»)

266

250

235

231

223

201

1S9

238

214

208

220

221

224

209

203

201

200

198

196

192

184

175

163

154

144

108

91

89

92

108

108

5,735

185

266

89

Mssn 

concertt ration 

(mg/L)

July

12

11

9

9

8

8

14

18

14

11

15

19

16

18

12

11

11

10

10

9

8

7

7

7

6

6

6

6

6

7

7

10

19

6

DisCrMfgS

(ton/d)

8.6

7.4

5.7

5.6

4.8

4.3

7.1

12

8.1

6.2

8.9

11

9.7

10

6.6

6.0

5.9

5.3

5.3

4.7

4.0

3.3

3.1

19

13

1.7

1.5

1.4

1.5

2.0

2.0

168.9

5.4

12

1.4

Stream*

flow

<**/»)

1996

106

106

105

104

95

91

85

70

64

59

61

59

57

58

56

55

59

58

58

57

58

54

54

50

50

49

45

45

41

38

39

1,986

64

106

38

Suspended sediment 

u_~.

Mean 

ooocon* 

tratfon 

(mg/L)

August

8

8

8

8

8

6

4

4

5

5

5

4

4

4

4

4

4

4

4

4

4

4

4

4

4

4

3

3

3

2

2

5

8

2

DisCharge

(ton/d)

13

13

13

12

11

1.5

.92

.76

.86

.80

.82

.64

.62

.63

.60

.59

.64

.63

.63

.62

.63

.58

.58

.54

.54

.53

.36

.36

.33

.21

.21

27.33

.88

13

.21

Straamflow

<**/»)

41

42

43

44

48

47

48

78

88

88

88

83

83

84

83

87

87

83

86

93

86

82

79

77

77

76

73

69

68

70

2,181

73

93

41

Suspended sediment

Mean 

conosntration 

(mg/L)

September

3

4

4

4

4

4

7

18

21

11

7

5

5

5

4

4

4

4

7

5

4

3

3

3

3

3

3

4

4

5

-

5

21

3

Diecharge 

(lon/d)

.33

.45

.46

.48

52

51

.91

3.8

5.0

16

1.7

1.1

1.1

1.1

.90

.94

.94

.90

1.6

1.3

.93

.66

.64

.62

.62

.62

.59

.75

.73

.95

-

33.75

1.1

5.0

.33

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW-45,387 ft3* 

SEDIMENT DISCHAROE-2,332.64 torn

TABLE 6 39
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1994 

through September 1995

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

Suapandad aadimant

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

Maan 

atraamflow 

(ft*/*)

116

109

110

134

152

152

153

154

152

149

148

153

154

162

187

211

210

209

205

205

219

214

214

207

204

204

208

208

202

200

203

5^08

178

219

109

Maan 

concwv 

tration 

(mg/L)

Octobar

13

12

11

17

26

24

20

16

13

13

15

17

18

20

21

22

23

22

20

20

20

20

20

20

20

20

18

16

15

16

17

_

26

11

Dtocharga 

(ton/d)

4.1

3.5

3.3

6.2

11

9.8

8.3

6.7

5.3

5.2

6.0

7.0

15

8.7

11

13

13

12

11

11

12

12

12

11

11

11

10

9.0

8.2

8.6

9.3

277.7

9.0

13

3.3

Maan 

atraam 

flow 

(ft8/*)

214

219

216

210

200

200

210

210

215

229

226

222

222

215

206

208

205

180

170

170

170

160

170

170

180

180

190

200

210

220

5.997

200

229

160

Suapandad aadimant

Uaan 

 ooncsn* 

tration 

(mg/L)

1994

Novambar

18

18

18

18

19

19

18

18

17

17

17

18

19

20

20

22

23

24

25

26

27

28

27

24

20

18

16

14

12

20

...

...

28

12

Dtecharga 

(ton/d)

10

11

10

10

10

10

10

10

9.9

11

10

11

11

12

11

12

13

12

11

12

12

12

12

11

9.7

8.7

8.2

7.6

6.8

12

. 

316.9

11

13

6.8

Uaan 

atraamflow 

(ft8/*)

248

234

223

221

210

190

180

170

170

170

180

180

170

170

180

165

186

189

191

192

208

198

210

203

191

192

197

209

202

197

193

6.019

194

248

165

Suapandad aadimant

concentration 

(mg/L)

Dacambar

25

23

22

21

20

19

18

17

18

20

22

22

21

20

19

18

18

22

26

27

27

28

28

28

28

27

26

25

26

28

31

_

~

31

17

Dtecharga 

(ton/d)

17

15

13

13

11

9.7

8.7

7.8

8.3

9.2

11

11

9.6

9.2

9.2

8.0

9.0

11

13

14

15

15

16

15

14

14

14

14

14

15

16

379.7

12

17

7.8

40 Watar-quality, bad-sadimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for straams 

in tha Uppar Clark Fork Basin, Montana
Table 7. Daily streamfbw and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1994 

through September 1995 (Continued)

Suapandad aadimant

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

atraanv

** now

(fl*/a)

160

150

145

140

140

140

150

160

170

180

211

188

194

204

205

195

193

187

190

178

160

150

150

150

160

164

177

180

170

170

187

5,298

171

211

140

Maan 

concan* 

tratlon 

(mg/L)

January

32

31

30

26

24

26

30

34

35

35

35

37

45

55

50

43

36

31

30

36

45

50

48

44

39

33

28

24

21

21

22

_

55

21

Dtecharga 

(ton/d)

14

13

12

9.8

9.1

9.8

12

15

16

17

20

19

24

30

28

23

19

16

15

17

19

20

19

18

17

15

13

12

9.6

9.6

11

501.9

16

30

9.1

Maan

atraam-

** now

(If/a)

1995

250

279

279

299

293

274

258

244

226

207

180

150

130

120

130

160

187

204

235

255

294

309

303

293

288

280

267

252

_

...

-~

6,646

237

309

120

Suspended sediment

Maan 

concan* 

tratlon 

(mg/l)

February

46

64

63

60

56

51

35

20

18

17

16

16

19

23

27

38

57

74

85

88

90

84

64

48

42

38

36

34

-

_

90

16

Dte- 

(ton/d)

31

48

47

48

44

38

24

13

11

9.5

7.8

6.5

6.7

75

95

16

29

41

54

61

71

70

52

38

33

29

26

23

-

894.5

32

71

6.5

Maan 

atraamflow 

(«*/ )

220

210

210

200

200

210

211

215

233

251

249

256

271

267

265

251

243

237

233

226

226

221

227

215

208

206

202

202

200

203

210

6,978

225

271

200

Suapandad aadimant

Mean 

concan* 

tratlon

March

34

38

38

31

31

37

47

44

42

49

38

45

41

42

34

29

26

25

23

30

29

23

22

23

23

26

22

18

18

27

22

_

49

18

Diacharga 

(ton/d)

20

22

22

17

17

21

27

26

26

33

26

31

30

30

24

20

17

16

14

18

18

14

13

13

13

14

12

9.8

9.7

15

12

600.5

19

33

9.7

TABLET 41
Table 7. Daily streamflow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1994 

through September 1995 (Continued)

Suapandad aadimant

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

Maan 

atraamflew 

(fl»/»)

207

202

207

213

237

243

248

251

261

265

271

257

248

249

242

238

233

228

230

246

266

262

246

243

241

237

241

247

256

241

7,256

242

271

202

Maan 

concentration 

(mg/y

April

18

14

13

15

18

32

29

37

28

27

21

23

23

22

29

19

20

17

17

22

24

30

23

20

21

34

25

20

25

20

_

37

13

Dtecharga 

(ton/d)

10

7.6

7.3

8.6

12

21

19

25

20

19

15

16

15

15

19

12

13

10

11

15

17

21

15

13

14

22

16

13

17

13

-

451.5

15

25

7.3

Maan 

atraamflow 

(«*/»)

1995

239

249

279

264

247

287

355

349

356

361

386

389

459

459

449

432

418

423

460

471

407

450

437

439

436

423

415

391

386

387

455

11,958

386

471

239

Suapandad aadimant

Maan 

concantratlon 

(mg/L)

aa^..- My

18

20

37

25

25

46

89

76

63

74

84

74

179

113

93

75

68

74

86

83

56

53

58

45

42

43

36

36

33

35

71

_

...

179

18

Dteeharga 

(ton/d)

12

13

28

18

17

36

85

72

61

72

88

78

222

140

113

87

77

85

107

106

62

64

68

53

49

49

40

38

34

37

87

2,098

68

22

12

Maan 

at reamnow 

(«*/»)

487

508

543

722

718

1,060

1,180

1.010

877

800

725

686

731

761

775

775

762

778

802

799

725

699

664

616

586

582

623

663

635

532

21,824

727

1,180

487

SuapandM

Maan 

concantratlon 

(mg/L)

Juna

86

96

114

147

143

311

221

130

102

96

95

81

85

85

82

80

78

73

61

64

56

49

43

38

35

39

43

39

31

31

_

._

311

31

iaadtonant

Diacharga 

(ton/d)

113

132

167

287

277

890

704

355

242

207

186

150

168

175

172

167

160

153

147

138

110

92

77

63

55

61

72

70

53

45

-

5,688

190

890

45

42 Water-quality, bed-sediment, and biological data (October 1994 through Saptambar 1995) and statistical *ummarlas of data for ttraamt 

In tha Uppar Clark Fork Basin, Montana
Table 7. Daily streamfiow and suspended-sediment data for Clark Fork at Deer Lodge, Montana, October 1994 

through September 1995 (Continued)

impended sediment Suspended sedlrnent

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

MMn

StreamflOW 

(ft3/S)

489

501

503

497

434

427

422

468

464

444

4%

503

571

569

509

485

473

442

435

427

410

408

379

334

314

271

236

213

207

249

244

12,824

414

571

207

MMn 

concent ratten 

(mg/L)

July

30

27

26

24

21

20

22

24

25

24

23

26

33

28

21

26

12

11

12

13

14

15

16

15

9

7

8

10

11

14

11

__

33

7

Discharge 

(ton/d)

40

37

35

32

25

23

25

30

31

29

31

35

51

43

29

34

15

13

14

15

15

17

16

14

7.6

5.1

5.1

5.8

6.1

9.4

7.2

695.3

22

51

5.1

Mean 

strMmft nOW

(ft3/s)

1995

226

187

180

176

167

153

139

122

114

108

103

95

92

92

92

82

87

94

89

83

79

76

79

83

96

88

83

69

67

59

55

3,315

107

226

55

MMn 

concentration 

(mg/L)

August

7

7

6

6

6

6

6

6

6

6

5

5

4

4

4

4

4

4

4

4

4

4

4

5

5

5

6

6

7

8

7

_ .

8

4

Discharge 

(ton/d)

4.3

3.5

2.9

2.9

2.7

2.5

2.3

2.0

1.8

1.7

1.4

1.3

.99

.99

.99

.89

.94

1.0

.96

.90

.85

.82

.85

1.1

1.3

1.2

1.3

1.1

1.3

1.3

1.0

49.08

1.6

4.3

.82

streamflow 

(*3/»)

58

64

66

115

135

120

122

238

323

289

261

241

230

236

237

233

226

219

226

272

256

248

269

261

256

247

242

241

240

243

~

6.414

214

323

58

Suspended Mdiment

MMn 

concentratton 

(mg/L)

September

6

5

8

29

30

22

36

121

88

36

23

18

16

16

15

14

12

11

11

12

10

10

12

10

8

7

7

7

7

7

...

...

~

121

5

Diecharge 

(ton/d)

.94

.86

1.4

9.0

11

7.1

12

78

77

28

16

12

9.9

10

9.6

8.8

7.3

6.5

6.7

8.8

6.9

6.7

8.7

7.0

5.5

4.7

4.6

4.6

4.5

4.6

-~

378.70

13

78

.86

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW-100,037 ft3/i 

SEDIMENT DISCHAROE-12.331.78 tons

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

October 1994 through September 1995

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

Suapandad aadbnant

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

Maan 

at NM inflow 

<ft*/a)

465

474

478

490

518

543

566

581

587

598

602

632

687

703

744

796

812

817

841

830

823

829

818

796

783

772

759

810

862

823

800

21.639

698

862

465

Maan 

concentration 

(mo'L)

October

12

10

9

8

8

9

9

10

10

11

11

14

21

21

22

22

22

22

22

20

17

13

11

11

11

11

11

11

11

10

9

_.

22

8

Diacharge 

(ton/d)

15

13

12

11

11

13

14

16

16

18

18

24

39

40

44

47

48

49

50

45

38

29

24

24

23

23

23

24

26

22

19

818

26

50

11

Maan 

atiaamflow 

(ft1*)

1984

864

925

870

821

801

821

819

787

737

791

795

788

777

765

741

724

739

675

617

684

701

635

626

695

728

712

671

669

665

686

_.

22,329

744

925

617

Suapandad aadimant

Maan 

cone wi* 

tratten 

(mg/L)

November

10

13

10

6

5

5

5

5

5

6

6

7

7

7

6

6

6

6

6

7

7

7

9

11

11

8

6

5

5

6

...

_

13

5

DiaCnaWQt}

(ton/d)

23

32

23

13

11

11

11

11

9.9

13

13

15

15

14

12

12

12

11

10

13

13

12

15

21

22

15

11

9.0

9.0

11

._

422.9

14

32

9.0

Maan 

atiaani* 

flow 

(«*/ )

760

817

771

703

648

646

657

684

662

662

656

625

646

660

574

625

713

672

699

642

642

644

582

619

689

663

690

682

679

641

587

20.640

666

817

574

Suapandad aadimant

Maan 

cone an* 

tratkxi 

(mg/L)

Daeambar

9

12

9

7

6

5

5

4

4

4

4

5

6

6

6

9

16

13

10

8

7

7

6

5

5

5

8

9

10

9

7

16

4

Diacharge 

(ton/d)

18

26

19

13

10

8.7

8.9

7.4

7.1

7.1

7.1

8.4

10

11

9.3

15

31

24

19

14

12

12

9.4

8.4

9.3

9.0

15

17

18

16

11

411.1

13

31

7.1

44 Watar-quallty, bed-sediment, and biological data (Octobar 1994 through Saptambar 1995) and statistical summarias of data for straams 

in tha Uppar Clark Fork Basin, Montana
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, 

October 1994 through September 1995 (Continued)

Suapandad Mdimant

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

streamat now 

(ft / )

499

372

320

300

320

350

400

450

500

550

600

650

700

700

811

895

733

678

665

631

617

521

490

447

465

497

591

613

599

543

597

17,104

552

895

300

Maan 

concant ration 

(mg/L)

January

4

3

4

4

4

4

4

3

3

4

9

22

31

15

20

23

14

13

12

12

11

10

10

9

8

8

8

8

8

8

21

 .

31

3

Dtoeharga 

(ton/d)

5.4

3.0

3.5

3.2

3.5

3.8

4.3

3.6

4.1

5.9

15

39

59

28

44

56

28

24

22

20

18

14

13

11

10

11

13

13

13

12

34

537.3

17

59

3.0

Maan 

streammt now

(ft*/»)

1996

1,450

3,680

1.910

1,360

1310

1,230

1,120

1,030

938

887

757

675

450

350

400

500

600

700

796

1,280

1,570

1,260

1,120

1,050

1,060

1.070

1.010

924

 .

...

. 

30.487

1,089

3,680

350

Suapandadaediment *»pandad Mdimant

Maan 

ooncantration 

(mg/L)

February

87

211

94

46

55

57

58

31

21

19

19

20

22

24

26

25

20

15

22

71

134

70

48

36

29

26

24

17

-

_

-

211

15

Diacnanja 

(ton/d)

341

2,100

485

169

195

189

175

86

53

46

39

36

27

23

28

34

32

28

47

245

568

238

145

102

83

75

65

42

5,696

203

2,100

23

Maan 

streammt now

/ifcSiflki |n TV}

818

762

781

850

791

785

760

739

787

930

1,170

1,090

1,010

970

962

973

938

911

912

902

901

894

874

860

840

822

801

786

772

753

764

26,908

868

1,170

739

Maan 

ooncantration 

(mg/L)

March

15

15

15

14

10

9

13

11

11

25

66

39

24

17

18

17

14

13

11

10

10

9

8

8

6

4

4

4

4

4

4

_

...

66

4

Dtocharga 

(ton/d)

33

31

32

32

21

19

27

22

23

63

208

115

65

45

47

45

35

32

27

24

24

22

19

19

14

8.9

8.7

8.5

8.3

8.1

8.3

1,094.8

35

208

8.1

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

October 1994 through September 1995 (Continued)

Suspended aadimant Suspended ssdimsni

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 

strea inflow

768

769

767

767

801

869

898

966

1,020

1,010

982

958

950

1,010

1,060

1,040

1,010

991

995

1.000

1,010

1,000

998

994

994

996

968

952

955

954

-

28.452

948

1.060

767

Mean 

concentration 

(mg/L)

April

5

6

8

9

13

15

14

18

21

15

13

14

16

16

18

12

12

13

17

14

7

8

17

14

14

12

12

13

12

12

-

_.

_.

21

5

Discharge 

(ton/d)

10

12

17

19

28

35

34

47

58

41

34

36

41

44

52

34

33

35

46

38

19

22

46

38

38

32

31

33

31

31

-

1.015

34

58

10

Mean 

streamflow 

(tf/a)

1905

949

961

1,020

1.080

1,080

1,140

1,780

2,320

2,360

2.340

2,520

2,920

3.240

3,160

2,880

2,790

2,780

2,960

3,210

3,340

3.340

3.320

3,250

3.130

3.010

2,890

2,770

2^60

2,490

2,630

2,880

77,100

2,487

3,340

949

Mean 

concentration 

<mg/L)

May

12

13

15

18

21

25

134

146

96

77

85

115

136

114

81

72

67

76

83

82

73

68

65

59

49

46

42

40

36

40

49

...

...

146

12

Diecharge 

(ton/d)

31

34

41

52

61

77

644

915

612

486

578

907

1,190

973

630

542

503

607

719

739

658

610

570

499

398

359

314

276

242

284

381

14,932

482

1,190

31

Mean 

streamflow 

(*3/a)

3,320

3.630

3.820

4.890

5,780

6,340

6,880

5,870

5,090

4,560

4.130

3.920

4.000

4.180

4,320

4,350

4,370

4.260

4,280

4,310

3.810

3,540

3.360

3.120

2,920

2,820

2,850

2,860

2,720

2,500

...

122.800

4,093

6,880

2,500

Suspended sediment

Mean 

concentration 

(mg/L)

June

65

79

90

200

225

205

280

155

105

85

72

64

61

63

63

61

60

60

56

49

41

35

33

33

28

24

24

23

21

21

-

_

._

280

21

Diecharge 

(ton/d)

583

774

928

2.640

3^10

3^10

5,200

2,460

1,440

1,050

803

677

659

711

735

716

708

690

647

570

422

335

299

278

221

183

185

178

154

142

-

31,408

1,050

5,200

142

46 Water-quality, bad-aadimant, and biological data (Octobar 1994 through September 1995) and statistical aummariaa of data for atraama 

In the Upper Clark Fork Basin, Montana
Table 8. Daily streamflow and suspended-sediment data for Clark Fork at Turah Bridge, near Bonner, Montana, 

October 1994 through September 1995 (Continued)

Suspended aadimant

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

Maan 

atraamflow 

(f!3/s)

2,320

2,180

2,240

2,420

2,290

2,130

2,180

2,120

2,090

2,210

2,380

2,670

3,000

2.960

2,660

2,390

2,220

2,050

1.920

1.780

1,680

1,630

1^50

1,470

1,380

1,290

1,230

1,150

1,080

1,110

1,160

60,940

1,966

3,000

1,080

concant ration 

(mg/L)

July

22

20

20

23

20

16

16

17

17

17

23

47

60

51

31

21

18

16

14

13

11

10

9

8

7

6

6

6

6

8

8

_

60

6

Dtocharga 

(ton/d)

138

118

121

150

124

92

94

97

%

101

148

339

486

408

223

136

108

89

73

62

50

44

38

32

26

21

20

19

17

24

25

3^19

114

486

17

Maan 

atraamflow 

(ft'/s)

1995

1,110

1,040

992

922

884

843

783

753

747

703

683

666

663

644

622

647

695

679

652

629

607

583

569

574

545

532

513

499

501

490

490

21,260

686

1,110

490

Suapandad aadimant

Maan 

concentration 

(mg/L)

August

6

5

5

5

4

3

2

2

4

5

5

5

5

5

5

5

5

5

5

4

4

4

5

5

5

5

5

5

5

5

5

_

6

2

Dtocharga 

(ton/d)

18

14

13

12

9.5

6.8

4.2

4.1

8.1

9.5

9.2

9.0

9.0

8.7

8.4

8.7

9.4

9.2

8.8

6.8

6.6

6.3

7.7

7.7

7.4

7.2

6.9

6.7

6.8

6.6

6.6

262.9

8.5

18

4.1

Maan 

straanv 

flow 

(Il3/a)

490

491

480

473

516

613

624

783

1,220

1,200

1,150

1,050

981

947

939

931

923

918

923

1,040

1,080

1,040

1.030

1,020

998

984

982

974

974

968

26,742

891

1.220

473

Suapandad sadimant

Maan 

concan* 

t ration 

(mg/L)

Saptambar

5

5

5

6

7

11

9

16

43

28

14

9

8

8

8

9

9

10

10

13

12

11

10

9

8

9

10

10

10

10

...

_

...

43

5

Diacharga 

(ton/d)

6.6

6.6

6.5

7.7

9.8

18

15

34

142

91

43

26

21

20

20

23

22

25

25

37

35

31

28

25

22

24

27

26

26

26

...

869.2

29

142

6.5

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW-476,401 ft*/« 

SEDIMENT DISCHARGE-60,986.2 tons

TABLE 8 47
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1994 

through September 1995

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

Suepended eediment

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 

at reamflow

383

401

424

410

404

396

393

391

394

393

405

412

409

413

425

430

428

417

411

413

427

426

425

421

419

418

439

490

527

502

499

13.145

424

527

383

cone ent rat Ion 

(mg/L)

October

3

3

3

3

2

2

2

2

2

2

2

2

1

2

2

2

2

2

2

2

2

2

1

1

1

1

1

2

2

2

3

_

3

1

Diecherge 

(ton/d)

3.1

3.2

3.4

3.3

12

11

11

11

11

11

12

12

1.1

12

13

13

13

13

12

12

13

13

1.1

1.1

1.1

1.1

1.2

16

18

17

4.0

69.3

12

4.0

1.1

Meen 

at reamflow 

(ft»/a)

1994

595

598

578

548

540

525

519

516

510

512

519

521

513

506

488

491

490

440

452

494

443

360

340

464

526

480

458

454

436

461

...

14,777

493

598

340

Suepended eediment

Meen 

ooncoo* 

tret ten 

(mg/L)

NOVMVIDOr

3

3

3

3

2

2

2

2

2

2

1

1

1

1

1

1

1

2

2

2

2

2

2

2

1

1

1

1

1

1

...

...

...

3

1

Diecherge 

(ton/d)

4.8

4.8

4.7

4.4

19

18

18

18

18

18

1.4

1.4

1.4

1.4

1.3

1.3

1.3

14

14

17

14

1.9

1.8

15

1.4

1.3

1.2

1.2

1.2

1.2

68.7

13

4.8

1.2

Meen

Mf^MMVt*

flow

(*'/»)

512

511

514

457

424

392

400

410

430

420

400

380

380

390

400

430

500

490

480

450

420

400

380

400

420

450

470

480

470

450

400

13410

436

514

380

Suepended

Meen 

concentration 

(mg/L)

December

3

3

3

4

8

5

3

3

3

3

3

3

3

3

3

4

4

3

3

2

1

1

2

2

2

2

2

2

2

2

2

_

._

8

1

-ii _»

DieCffMFQa)

(ton/d)

4.1

4.1

4.2

4.9

92

5.3

3.2

3.3

34

3.4

3.2

3.1

3.1

3.2

3.2

4.6

5.4

4.0

3.9

14

1.1

1.1

11

12

13

14

15

16

15

14

12

104.7

3.4

9.2

1.1

48 Watar-quallty, bad-aadlmant, and biological data (Oetobar 1994 through Saptambar 1995) and atatiatlcal aummarlaa of data for atraama 

In tha Uppar Clark Fork Basin, Montana
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1994 

through September 1995 (Continued)

Suspended aadlment

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

Item 

at reamflow 

(«'/ )

350

300

250

200

220

250

280

300

350

400

450

500

550

580

600

600

550

500

480

450

430

400

350

300

350

400

450

450

430

400

400

12.520

404

600

200

Mean 

concentration 

(mg/L)

January

2

2

4

5

5

4

3

2

3

4

5

8

17

9

4

5

4

3

2

2

2

2

2

2

3

3

3

3

3

3

3

_

17

2

Diecharge 

(ton/d)

1.9

1.6

2.7

2.7

3.0

2.7

2.3

1.6

2.8

4.3

6.1

11

25

14

6.5

8.1

5.9

4.1

2.6

2.4

2.3

2.2

1.9

1.6

2.8

3.2

3.6

3.6

3.5

3.2

3.2

142.4

4.6

25

1.6

Mean 

 traa inflow 

(«'/ )

1996

500

1.440

1,600

1.220

949

822

771

692

633

590

467

373

300

250

300

350

400

450

550

1,060

1480

1.510

1,350

1,180

1,210

1,200

1.110

990

...

...

...

23,847

852

1.600

250

Suapandad aadlmant

Maan 

concentration 

(mg/g

February

7

13

19

12

8

7

6

6

6

6

5

5

5

5

4

4

3

2

5

24

30

22

22

27

31

24

16

10

_.

_.

-

_

31

2

Discharge 

(ton/d)

9.5

51

82

40

20

16

12

11

10

9.6

6.3

5.0

4.1

3.4

3.2

3.8

3.2

2.4

7.4

69

128

90

80

86

101

78

48

27

_.

_.

-

1,006.9

36

128

2.4

Mean 

atreamflow 

(ft»/e)

876

858

890

896

815

811

790

759

764

776

878

991

988

956

973

1,000

999

997

1,010

1,020

1,060

1,090

1,070

1.070

1.050

1,040

1,010

1,000

999

985

976

29.397

948

1.090

759

Suspended sediment

Mean 

concentration 

(mg/L)

March

6

5

6

6

3

4

4

4

4

5

6

8

9

7

7

6

6

6

8

6

6

8

8

7

5

4

4

4

6

7

6

_

...

9

3

Dtocharge 

(ton/d)

14

12

14

15

6.6

8.8

8.5

8.2

8.3

10

14

21

24

18

18

16

16

16

22

17

17

24

23

20

14

11

11

11

16

19

16

469.4

15

24

6.6

TABLE 0 49
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1994 

through September 1995 (Continued)

Suapandad aadimant

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

Maan 

atraamflow

971

971

966

986

1,030

1,120

1,200

1,320

1,400

1,420

1,400

1380

1.370

1,450

1,500

1,480

1,440

1,400

1.380

1.410

1,390

1,360

1,370

1.360

1,360

1,350

1,350

1340

1330

1320

39,124

1.304

1,500

966

Maan 

cone antration 

(mg/L)

April

7

6

6

6

9

10

10

15

14

11

10

10

9

10

10

7

8

7

8

8

13

15

8

9

7

6

7

7

6

6

-

15

6

Dtecharga 

(ton/d)

18

16

16

16

25

30

32

53

53

42

38

37

33

39

40

28

31

26

30

30

49

55

30

33

26

22

26

25

22

21

942

31

55

16

Maan 

atraamflow 

(«*/ )

1995

1,290

1350

1.470

1,540

1.650

1.860

2,470

3,060

3,310

3370

3,560

3,910

4,170

3,990

3.690

3,570

3,750

4,230

4,520

4,540

4,550

4,470

4,320

4,160

4,040

3.840

3,580

3.400

3,490

3,910

4,510

105,570

3,405

4,550

1,290

AuiunHf |IM

Maan 

concantration 

(mg/L)

May

6

7

10

10

11

19

42

73

91

74

62

61

57

54

38

29

27

37

50

43

37

35

27

23

20

18

14

13

15

25

52

_

_

91

6

tdMdliMnt

Dte- 

(ton/d)

21

26

40

42

49

95

280

603

813

673

596

644

642

582

379

280

273

423

610

527

455

422

315

258

218

187

135

119

141

264

633

10,745

347

813

21

Suapandad aadimant

atraamflow 

(ft*/a)

5,000

5,220

5,460

5,870

6,050

6,440

6370

5,610

4,860

4360

4,040

3,980

4,150

4,380

4,430

4,490

4.480

4,280

4,090

3,950

3,600

3,310

3,180

3,020

2,910

2,870

2,810

2,720

2^60

2390

-

126.880

4,229

6,440

2,390

Maan 

concant rat km 

(mg/L)

June

67

72

77

97

95

108

105

86

49

37

32

37

43

46

47

47

45

41

32

28

28

27

21

16

15

18

15

12

10

10

-

_ .

108

10

Dte- 

(ton/d)

904

1,010

1,140

1,540

1,550

1.880

1.810

1300

643

436

349

398

482

544

562

570

544

474

353

299

272

241

180

130

118

139

114

88

69

65

18,204

607

1,880

65

50 Watar-quallty, bad-aadimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical summariaa of data for straams 

In tha Uppar Clark Fork Basin, Montana
Table 9. Daily streamflow and suspended-sediment data for Blackfoot River near Bonner, Montana, October 1994 

through September 1995 (Continued)

SiMDMMtod dimwit

Day

1

2

3

4

S

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

UMO 

 traamflow 

<«*/ )

2,240

2,150

2,140

2,120

2,050

1,960

1,990

1.890

1,840

1,850

1,860

1,940

1.970

2,070

1,940

1,820

1,700

1,600

1,500

1,420

1.360

1,330

1,300

1,250

1,190

1,130

1,110

1.060

1,030

1.010

998

50,818

1,639

2,240

998

Mean 

concwv* 

tratlon 

<mg/L)

July

10

9

7

7

8

8

8

8

8

8

9

10

10

11

8

6

7

8

8

12

15

13

10

8

5

6

6

6

6

6

5

15

5

Dtocharg* 

(len/d)

60

52

40

40

44

42

43

41

40

40

45

52

53

61

42

29

32

35

32

46

55

47

35

27

16

18

18

17

17

16

13

1,148

37

61

13

MMUI 

 traamflow

<«*/ )

1995

961

915

878

852

828

797

780

773

778

773

767

739

736

740

727

727

791

794

773

743

719

6rO

678

676

669

669

660

647

634

621

615

23,156

747

961

615

Swp»nd«d dimwit

Mean 

ooncwitration 

<mg/LJ

August

5

5

5

5

4

4

4

4

5

5

5

5

6

6

6

6

5

4

3

3

3

3

3

3

3

3

3

3

3

2

2

__

6

2

Dt»- 

charg* 

(ton/d)

13

12

12

12

8.9

8.6

8.4

8.3

11

10

10

10

12

12

12

12

11

8.6

6.3

6.0

5.8

5.6

55

5.5

5.4

5.4

5.3

5.2

5.1

3.4

3.3

259.6

8.4

13

3.3

UMn 

 traamflow

<««/ )

598

583

573

570

601

601

611

700

799

816

781

727

683

655

636

635

600

592

599

614

607

600

5%

5%

592

585

578

587

593

594

18,902

630

816

570

Suspended Mdimwit

Mean 

concentration 

<mg/L)

Soptembw

2

2

2

2

3

2

3

4

6

5

5

4

3

3

4

5

4

4

3

2

1

1

1

1

1

2

2

2

3

3

_.

_.

6

1

Dtocharg* 

(ton/d)

3.2

3.1

3.1

3.1

4.9

3.2

4.9

7.6

13

11

11

7.9

5.5

5.3

6.9

8.6

6.5

6.4

4.9

3.3

1.6

1.6

1.6

1.6

1.6

3.2

3.1

3.2

4.8

4.8

~

150.5

5.0

13

1.6

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW--471.646 ft3* 

SEDIMENT DTSCHARGE--33.310.5 tons

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

October 1994 through September 1995

tAbbreviations: ft3/s, cubic feet per second; mg/L, milligrams per liter, ton/d, torn 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/*)

867

892

923

929

944

960

974

979

1,020

1.000

1,020

1,060

1,100

1,130

1,170

1,230

1,260

1.250

1,260

1.250

1.250

1,260

1.250

1,240

1,210

1,200

1,210

1,280

1,410

1,350

1,290

35.168

1.134

1,410

867

Mean 

cone ent ration 

(mg/g

October

4

4

5

5

4

4

4

4

6

6

6

6

6

6

7

7

8

8

7

5

5

4

4

4

4

4

5

5

5

5

6

_

8

4

Diecharge 

(ton/d)

9.4

9.6

12

13

10

10

11

11

17

16

17

17

18

18

22

23

27

27

24

17

17

14

13

13

13

13

16

17

19

18

21

503.0

16

27

9.4

Mean 

at reamflow 

(ft3/*)

1994

1,450

1,520

1,450

1,380

1,340

1.350

1,350

1,320

1,270

1,290

1,320

1,310

1.300

1,280

1.260

1,220

1,240

1,150

1,050

1,200

1,180

1,030

994

1,050

1,310

1,270

1,190

1,120

1,130

1,180

37,504

1,250

1,520

994

Suspended sediment

Mean 

concentration 

(mg/L)

NOVWHDM*

6

5

4

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

3

4

4

6

9

7

5

3

2

2

...

_

...

9

2

Diecharge 

(ton/d)

23

21

16

11

11

11

11

11

10

10

11

11

11

10

10

9.9

10

9.3

8.5

9.7

9.6

11

11

17

32

24

16

9.1

6.1

6.4

...

377.6

13

32

6.1

Mean 

at reamflow 

(ft3/*)

1,270

1,340

1,310

1,220

1,050

1.000

1.000

1,050

1,100

1,050

1,000

950

950

1.000

1,050

1,070

1,240

1,230

1,220

1,170

1,050

1,000

950

1,000

1,050

1,100

1.170

1,240

1,180

1,110

1,000

34,120

1,101

1,340

950

Suspandad aadiinant

Maan 

concentration 

(mg/L)

December

4

5

4

3

2

3

4

4

4

4

3

2

2

2

2

3

3

3

4

4

3

3

4

5

5

5

4

3

4

5

5

5

2

Diecharge 

(torVd)

14

18

14

9.9

5.7

8.1

11

11

12

11

8.1

5.1

5.1

5.4

5.7

8.7

10

10

13

13

8.5

8.1

10

13

14

15

13

10

13

15

13

331.4

11

18

5.1

52 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, 

October 1994 through September 1995 (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»/a)

800

700

600

500

550

600

700

800

900

1,000

1.100

1,300

1/400

1,380

1,370

1.440

1,230

1.140

1,130

1,050

1,000

900

800

750

800

927

1.060

1.050

1.030

983

1.000

29.990

967

1,440

500

Maan 

concentration 

<mg/L)

January

6

6

5

5

4

4

5

5

5

5

6

7

7

6

7

16

9

4

4

5

5

5

6

7

8

8

8

7

7

7

8

_

16

4

Discharge 

(ton/d)

13

11

8.1

6.8

5.9

65

95

11

12

13

18

25

26

22

26

62

30

12

12

14

13

12

13

14

17

20

23

20

19

19

22

535.8

17

62

5.9

Maan 

at reamHow 

(ft3/a)

1995

1,850

4.430

2.930

2.390

2,110

1,980

1,850

1,700

1,580

1,490

1.260

1,000

800

600

700

900

1,000

1.200

1.400

2.000

2.780

2^40

2,260

2.110

2,240

2,240

2,090

1.880

. 

. 

--

51.110

1.825

4.430

600

Suependedeediment

Mean 

concentration 

<mg/L)

February

27

168

58

26

18

18

18

12

9

7

5

4

5

5

5

5

5

5

6

15

47

37

28

22

19

15

11

8

-

_

168

4

Discharge 

(ton/d)

135

2.010

459

168

103

96

90

55

38

28

17

11

11

8.1

9.5

12

13

16

23

81

353

234

171

125

115

91

62

41

4,575.6

163

2.010

8.1

Mean 

at reamflow 

(ft»/s)

1,650

1,550

1,610

1,730

1,590

1.560

1,550

1,490

1,510

1,590

2.020

2.070

2.010

1,920

1,920

1,960

1,920

1,880

1.880

1,870

1,900

1,920

1.900

1.880

1,850

1,810

1,760

1,740

1,720

1,710

1,700

55,170

1,780

2.070

1.490

Suspended sediment

Mean 

concentration 

(mg/L)

March

8

7

6

8

7

8

7

8

8

11

19

21

17

13

11

11

10

10

10

10

9

8

8

7

7

7

7

5

5

6

7

_ .

21

5

Discharge 

(ton/d)

36

29

26

37

30

34

29

32

33

47

104

117

92

67

57

58

52

51

51

50

46

41

41

36

35

34

33

23

23

28

32

1,404

45

117

23

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

October 1994 through September 1995 (Continued)

Suapandad aadimant

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

MOST

Maan 

at r«a inflow 

(f!3/a)

1,690

1,690

1,690

1,700

1,770

1,890

2.010

2^50

2,410

2,390

2,350

2^20

2^70

2,390

2.530

2,480

2.420

2,340

2,340

2,370

2,320

2,330

2,330

2300

2,300

2^10

2,260

2^50

2,220

2^20

66.140

2,205

2^30

1,690

Maan 

coneent rat km 

(mg/LJ

April

9

8

8

9

9

9

9

14

10

9

9

9

10

10

10

10

8

9

11

10

8

7

7

8

9

8

9

9

7

6

-

_

14

6

Dieeharga 

(ton/d)

41

37

37

41

43

46

49

85

65

58

57

56

61

65

68

67

52

57

69

64

50

44

44

50

56

50

55

55

42

36

1.600

53

85

36

Maan 

strea inflow 

(tf/a)

1995

2,190

2^30

2,420

2,540

2,690

2,920

4,150

5,310

5,630

5,670

5,980

6.820

7,250

7,170

6.560

6,370

6,460

7,130

7.700

7,840

7,790

7,740

7.570

7,250

7,030

6,730

6,370

5.910

5,920

6,480

7,240

181,060

5,841

7,840

2,190

Suapandad aadimant

Maan 

concentration 

(mg/L)

May

7

8

9

10

9

11

19

41

52

54

51

62

65

66

52

44

41

44

57

57

55

47

42

36

29

26

23

22

17

19

30

_..

...

66

7

Diaeharga 

(ton/d)

41

48

59

69

65

87

213

588

790

827

823

1,140

1,270

1,280

921

757

715

847

1,190

1,210

1.160

982

858

705

550

472

396

351

272

332

586

19,604

632

1,280

41

Mean 

etreamflow 

(«3/a)

8,220

8,790

9,130

10,400

11,500

12,300

13,000

11 .500

10,100

8,970

8.150

7.880

8,060

8,480

8,640

8.750

8.740

8,470

8.250

8,140

7,390

6,810

6,440

6.090

5.760

5.600

5.580

5.550

5.250

4.860

-

246.800

8,227

13,000

4,860

Suapandad aadimant

Maan 

concentration 

(mg/L)

June

45

53

55

92

121

123

181

136

88

71

50

53

56

53

50

49

48

43

37

34

31

27

23

21

17

14

14

16

16

14

_

181

14

Diecharge 

(ton/d)

999

1,260

1.360

2,580

3.760

4,080

6,350

4,220

2,400

1,720

1,100

1,130

1,220

1,210

1,170

1.160

1.130

983

824

747

619

496

400

345

264

212

211

240

227

184

42.601

1,420

6,350

184

54 Watar-quality, bed-sediment, and biological data (October 1994 through Saptambar 1995) and statistical summarlaa of data for straams 

in tha Upper Clark Fork Basin, Montana
Table 10. Daily streamflow and suspended-sediment data for Clark Fork above Missoula, Montana, 

October 1994 through September 1995 (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

 t reamflow 

(ft8/.)

4,540

4.350

4,370

4,530

4,350

4.110

4,120

4.060

3.890

4,060

4,190

4,520

4,900

4,960

4.600

4,200

3.910

3,650

3.460

3,230

3,030

2,990

2,840

2,740

2^00

2^50

2^50

2^30

2.180

2.080

2^00

111,590

3.600

4.960

2,080

Mean 

concentration 

(mg/L)

July

12

10

11

11

11

11

11

10

10

12

13

26

28

25

20

17

13

12

11

11

11

11

12

12

13

12

11

8

7

8

9

_.

28

7

Diecharge 

(ton/d)

147

117

130

135

129

122

122

110

105

132

147

317

370

335

248

193

137

118

103

96

90

89

92

89

88

83

67

48

41

45

53

4,098

132

370

41

Mean 

at reamflow 

(ft8/*)

1995

2,120

2,020

1,950

1,910

1,820

1,810

1,750

1,720

1,680

1.650

1,600

1,560

1,550

1,530

1.490

1.470

1,590

1.580

1,530

1,450

1,360

1,360

1300

1,290

1,250

1,210

1,200

1,170

1,120

1,120

1,100

47,260

1^25

2,120

1,100

Suspended sediment

Mean 

concentration 

(mg/L)

August

9

8

7

7

6

6

6

6

7

6

6

5

5

5

5

4

5

4

4

4

4

4

4

4

4

4

4

4

4

4

4

_ 

9

4

Discharge 

(ton/d)

52

44

37

36

29

29

28

28

32

27

26

21

21

21

20

16

21

17

17

16

15

15

14

14

13

13

13

13

12

12

12

684

22

52

12

Mean 

streamflow 

(ft'/s)

1.090

1.070

1,040

1,030

1,060

1,180

1,210

1,420

1,890

1.980

1,910

1,810

1,630

1460

1430

1420

1400

1,460

1,480

1490

1,650

1.630

1.600

1480

1460

1430

1420

1440

1440

1440

--

44,650

1,488

1.980

1.030

Suspended sediment

Mean 

concentration 

(mg/L)

September

4

4

4

4

4

3

4

5

7

8

6

4

3

4

4

4

4

4

4

4

4

4

4

4

4

4

4

5

5

5

...

...

8

3

Discharge 

(ton/d)

12

12

11

11

11

9.6

13

19

36

43

31

20

13

17

17

16

16

16

16

17

18

18

17

17

17

17

16

21

21

21

...

539.6

18

43

9.6

TOTAL FOR WATER YEAR 1995: 

STREAMFLOW-940462 ft3* 

SEDIMENT DISCHARGE-76,854.0 tons

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

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

Station 

Station ram* 

number

1 2323230 Blacktail Creek it Hanison Avenue, it Butte

12323250 SOver Bow Creek below Blacktail Creek, at Butte

12323750 SUver Bow Creek at Warn Springs

12324200 d«k Forfeit Deer Lodge

12324680 CUricFakitGoldcreek

12331 800 CUric Fofk near Dnmunond

12334550 CUric ForitttTuimh Bridge, near Bomer

12340500 OaikFcric above ftffivoula

Date

11-28-941

11-28-94

03-09-95

03-09-95

06-05-95

06-05-95

02-07-95

02-07-95

04-26-95

04-26-95

04-11-95

04-11-95

05-10-95

05-10-95

05-23-95

05-23-95

Tim*

1105

1110

1150

1155

1725

1730

0800

0805

0945

0950

1305

1310

1130

1135

0800

0805

Hardnaaa total 

(mg/Laa 

C*CO,)

130

120

170

160

150

160

230

230

200

200

210

210

110

100

83

85

Calcium, 

dte- 

 on/ad 

(mg/L)

36

35

47

46

46

47

67

66

57

57

60

59

30

29

22

23

llagneMUffllt

dteaelvad 

(mg/L)

8.6

8.5

12

12

9.1

9.2

15

15

13

13

15

15

7.8

7.7

6.7

6.7

56 Water-quality, bed-sediment, and biological data (Oetobar 1994 through September 1995) and statistical summariaa of data for atraama 

in the Upper Clark Fork Basin, Montana
Table 11. Chemical and suspended-sediment analyses of field replicates for water samples, upper Clark Fork basin, Montana 

(Continued)

Station

number

12323230

12323600

12323770

12324200

12324680

12331800

12334550

12340500

Date

11-28-94'

11-28-94

03-09-95

03-09-96

06-05-95

06-05-95

02-07-95

02-07-95

04-26-95

04-26-95

04-11-95

04-11-95

05-10-95

05-10-95

05-23-95

05-23-95

Sodium, 

dissolved

(mg/L)

12

12

36

36

11

11

18

18

13

13

13

13

6.4

6.3

2.9

2.9

Potassium,

dto*

solved

(mg/L)

2.8

2.8

5.8

5.6

3.8

3.9

4.2

4.1

3.3

3.3

3.3

3.3

2.1

2.1

1.0

1.0

Alkalinity,

(mg/L as

CaCOj)

104

103

81

81

95

95

144

144

139

138

150

150

85

85

82

82

SlMfats,

dissolved

(mg/L)

34

34

88

88

75

75

100

100

79

79

78

78

32

31

11

10

dissolved

(mg/L)

6.5

6.8

30

31

4.2

4.2

9.2

9.2

6.3

6.5

6.3

6.3

2.3

2.3

1.0

.90

Fiuoride,

dissolved

(mg/L)

0.3

.3

.4

.4

J5

5

.7

.7

J5

.5

J5

5

2

.3

.1

.1

Silica, 

dissolved

(mg/L)

28

28

25

25

15

15

16

16

14

13

16

16

14

13

9.6

9.6

Solids,

sum of

constituents,

dissolved

(mg/L)

191

189

294

294

222

223

317

315

269

268

282

281

146

143

104

103

Arsenic,

total

recoverable

<xg/i.)

2

2,

22

23

48

49

18

18

9

9

11

11

12

12

5

6

TABLE 11 57
Table 11. Chemical and suspended-sediment analyses of field replicates for water samples, upper Clark Fork basin, Montana 

(Continued)

Station 

numbar

Data

Araante, 

dteCadmium, 

total 

racovaraMa 

Oxg/L)

Cadmium,

dtesolvad 

(W/L)

Coppar, 

total

Coppar,

dtesolvad

Iron, 

total 

raeovaraMa

Iron, 

diaaolvad

total

raeovarabla 

(WP/U

12323230 11-28-94' 

11-28-94

590

580

58

110

12323600

12323770

12324200

12324680

03-09-95 

03-09-96

06-05-95 

06-05-95

02-07-95 

02-07-95

04-26-95 

04-26-95

10

10

35

34

1.6 

1.6

170

160

70

70

62

60

19

20

50

52

13

13

7

7

5

5

1,200

1.100

3,000

3,000

1.000

1,000

330

340

57

56

21

16

21

24

12

12

8

7

3

2

12331800 04-11-95 

04-11-95

22

22

440

440

12334550

12340500

05-10-95 

05-10-95

05-23-95 

05-23-95

43

40

22

21

1,400

1,300

700

730

41

42

26

26

58 Wat«f-quality, bad-sadinwnt, and biological data (Octobar 1994 through Saptembar 1995) and statistical summarias of data for straams 

in th« Uppar Clark Fork Basin, Montana
Table 11. Chemical and suspended-sediment analyses of field replicates for water samples, upper Clark Fork basin, Montana 

(Continued)

Station

number

12323230

12323600

12323770

12324200

12324680

12331800

12334550

12340500

Date

11-28-941

11-28-94

03-09-95

03-09-96

06-05-95

06-05-95

02-07-95

02-07-95

04-26-95

04-26-95

04-11-95

04-11-95

05-10-95

05-10-95

05-23-95

05-23-95

Lead,

dieeolved

(W/L)

<0.5

.5

.5

.5

.5

.5

S

5

5

 5

.5

.5

.5

5

.5

.5

Manganeee,

total

recoverable

(uo/L) IPW"

70

80

980

990

310

290

230

220

80

90

70

70

170

170

60

40

llanganeea,

dteeolved

(W/L)

61

60

970

960

76

77

34

34

22

22

16

16

6

6

17

17

Zinc, 

total

recoverable

(W/L)

<10

<10

730

730

70

80

80

80

30

20

30

40

70

70

30

30

Zinc,

dieeolved

(W/L)

<3

<3

600

600

16

7

10

10

5

<3

7

8

<3

3

4

<3

Sediment,

impended

(mg/L)

7

10

32

32

229

223

44

44

16

15

22

22

77

78

45

45

Sediment,

impended 

diameter,

percent

finer than

0.062mm

91

71

80

84

77

78

68

68

85

86

76

76

68

67

89

89

^ssolved constituents for the 11 -28-94 sample were collected through two different types of filters as part of a USGS test of new sampling protocols.

TABLE 11 59
Table 12. Precision of chemical and suspended-sediment analyses of field replicates for water 

samples, upper Clark Fork basin, Montana

[Abbreviations: Mg/L, micrograms per liter; mg/L, milligrams per liter, mm, millimeter]

Constituent and reporting unit

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

Chloride, dissolved, mg/L

Fluoride, dissolved, mg/L

Silica, dissolved, mg/L

Arsenic, total recoverable, ug/L

Arsenic, dissolved, ug/L

Cadmium, total recoverable, |ig/L

Cadmium, dissolved, ug/L

Copper, total recoverable, ug/L

Copper, dissolved, ug/L

Iron, total recoverable, ug/L

Iron, dissolved, ug/L

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

Sediment, suspended, mg/L

Sediment, suspended, percent finer than 0.062 mm

Number of 

replicate palra

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

Standard 

deviation, 

In unlta (+/-)

0.66

.04

.02

.06

.35

35

.27

.02

35

.43

.56

.0

.0

2.7

.75

36

13

.84

.0

8.7

25

4.3

2.5

1.7

5.4

Relative 

atandard 

deviation, 

In percent (+/-)

1.5

.4

.1

1.8

.3

.6

3.2

4.9

2.0

2.7

5.7

.0

.0

5.3

6.6

3.4

42

11

.0

3.6

1.7

3.3

3.1

2.9

6.9

60 Water-quality, bed-sediment, and biological data (Octobar 1994 through September 1995) and atatiatical summaries of data for streams 

in the Upper Clark Fork Baain, Montana
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, jiS/cm

pH, standard units

Calcium, dissolved, mg/L

Magnesium, dissolved, mg/L

Sodium, dissolved, mg/L

Potassium, dissolved, mg/L

Alkalinity, mg/L as CaCO}

Sulfate, dissolved, mg/L

Chloride, dissolved, mg/L

Fluoride, dissolved, mg/L

Silica, dissolved, mg/L

Arsenic, total recoverable, M-g/L

Arsenic, dissolved, fig/L

Cadmium, total recoverable, fig/L

Cadmium, dissolved, M-g/L

Copper, total recoverable, \ig/L

Copper, dissolved, M-g/L

Iron, total recoverable, M-g/L

Iron, dissolved, M-g/L

Lead, total recoverable, \LgJL

Lead, dissolved, M-g/L

Manganese, total recoverable, [Lg/L

Manganese, dissolved, M-g/L

Zinc, total recoverable, ^ig/L

Zinc, dissolved, M-g/L

Number off 

replicate pairs

10

10

10

10

10

11

10

10

10

10

10

10

10

10

10

10

10

10

11

10

10

10

10

10

10

Standard 

deviation, 

In unite (+/ )

4.4

.05

.68

.09

.12

.11

.42

.13

.13

.01

.07

.33

.28

.01

.01

5.2

1.3

15

1.7

.71

.04

3.6

4.1

4.2

3.5

Relative 

standard 

deviation, 

In percent (+/ )

1.3

.6

1.6

.9

1.0

3.5

.4

.4

2.1

2.6

.4

1.6

3.5

1.3

2.9

5.1

5.7

1.3

5.4

2.9

16

1.7

2.8

2.5

5.3

Within limits 

off 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 61
Table 14. Recovery efficiency for trace-element analyses of laboratory-spiked deionized-water blanks 

[Abbreviation: |ig/L, micrognuns per liter]

Constituent and reporting unit

Arsenic, total recoverable, jig/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, |ig/L

Iron, dissolved, jig/L

Lead, total recoverable, |ig/L

Lead, dissolved, jig/L

Manganese, total recoverable, Jig/L

Manganese, dissolved, Hg/L

Zinc, total recoverable, Hg/L

Zinc, dissolved, Jig/L

Number off 

aamplaa

8

8

8

8

8

8

8

8

8

8

8

8

8

8

Mean aplke 

recovery, 

In percent

106.8

103.9

1013

100.0

97.6

102.7

102.2

93.8

100.8

1023

96.5

98.5

101.5

102.3

95-percent 

confidence 

Interval for 

apike recovery, 

In percent

103-110

99.1-109

97.5-105

97.3-103

92.3-103

101-105

97.8-107

87.9-99.7

96.6-105

97.7-107

92.0-101

93.1-104

97.1-106

97.1-108

Within Hmlta 

off dataquality 

objective

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

62 Water-quality, bed-eedlment, and biological data (Octobar 1994 through September 1995) and statistical aummariea of data for atreama 

in the Upper Clark Fork Basin, Montana
Table 15. Recovery efficiency for trace-element analyses of laboratory-spiked stream samples, 

upper Clark Fork basin, Montana

[Abbreviation: ug/L, microgrems per liter]

Constituent

Arsenic, total recoverable, H-g/L

Arsenic, dissolved, p.g/L

Cadmium, total recoverable, p.g/L

Cadmium, dissolved, H-g/L

Copper, total recoverable, p.g/L

Copper, dissolved, p.g/L

Iron, total recoverable, H-g/L

Iron, dissolved, H-g/L

Lead, total recoverable, |ig/L

Lead, dissolved, M-g/L

Manganese, total recoverable, |ig/L

Manganese, dissolved, |ig/L

Zinc, total recoverable, |ig/L

Zinc, dissolved, p.g/L

Number of

 ample*

8

8

8

8

8

8

8

8

8

8

8

9

8

9

Mean spike

recovery,

in percent

102.2

103.8

102.9

101.3

98.0

99.8

99.5

101.4

100.0

102.9

97.4

103.8

101.1

104.7

95-percent

confidence

interval for

 pike recovery,

In percent

97.1-107

94.6-113

98.0-108

96.7-106

92.7-103

96.2-103

96.1-103

96.2-107

96.7-103

98.6-107

92.9-102

99.0-109

99.1-103

101-108

Within limit*

of dataquality

objective

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

TABLE 15 63
Table 16. Chemical analyses of field blanks for water samples

[Abbreviations: °C, degrees Celsias; Mg/L, micrograms per liter; US/cm, microtiemens per centimeter at 25 °C; mg/L, milligrams per liter. 

Symbols: <, less than minimum reporting level]

Date

Specific 

conductTime

onsite 

(|iS/cm)

PH,

onsite

(standard

units)

Calcium,

dissolved

(mg/L)

Magnesium, 

dissolved 

(mg/L)

Sodium,

dissolved

(mg/L)

Potassium,

dissolved

(mg/L)

Alkalinity 

(mg/Lae 

CaCO*)

Sulfate,

dteeolved

(mg/L)

Novl994

28... 

Febl995

03... 

Mar

10... 

Apr

10...

25... 

May

09...

23... 

Jun

06... 

Jul

11...

1830

1000

1100

1900

1630

1415

1330

2015

1450

5.5

5.6

5.7

5.8 

5.8

5.8 

5.8

5.6 

5.8

<0.02 

<02 

<02

<02 

<02

.07 

<02

<02 

<02

<0.01 <0.02 

<02 

<.02

<.02 

<.02

<.02 

<.02

<.02 

<.02

1.6

1.1

1.1 

1.1

1.1 

\5

1.3

1.1

0.2

64 Water-quality, bed-sediment, and biologicai data (October 1994 through September 1995) and statistical summaries of data for streams 

in the Upper Clark Fork Basin, Montana
Table 16. Chemical analyses of field blanks for water samples (Continued)

Araanic,

Cadmium, Coppar,

Ruorida, Silica, total Araanic, Cadmium,

total total

D&to dtooolvtd flMttolvMi diftftolvftd rscov* dtesolvtd dtooolvtd dissolved

FMovwfeblt r+cov> nbto

(mg/L) (mg/L) (rog/L) arabla (Mg/L) . _ (jig/L) . _ (|ig/L)

Nov 1994 

28...

Febl995

03...

Mar

10...

Apr

10...

25...

May

09...

23...

Jun

06...

Jul

11...

<0.1 <0.

 cl <

 cl <

 cl <

 cl <

 cl <

 cl <

 cl -c

 cl -c

.1 <0.1 <1 <1

,1 <.! <1 <1

,1 <.! <1 <1

,1 <.! <1 <1

,1 .2 <1 <1

,1 .1 <1 <1

,1 .1 <1 <1

1 .2 <1 <1

1 <.! <1 <1

<1 <0.1

<1 <.!

<1 <.!

<1 <.!

<1 <.!

<1 <.!

<1 <.!

<1 <.!

<1 <.!

<1 <1

<1 <1

<1 <1

<1 <1

<1 <1

<1 <1

3 <1

1 <1

<1 <1

TABLE 16 65
Table 16. Chemical analyses of field blanks for water samples (Continued)

	MangaIron, Lead, Zinc,

Iron, Lead, noae, Manganeee, Zinc,

total total total

Date diaaolved diaaolved total diaaolved diaaolved

recoverable recoverable recoverable

Gig/L) t ^ ftig/L) recoverable Oig/L) ^^^

Novl994

28... <10 <3 <1 <O.S <10 <1 <10 <3 

Febl99S

03... <10 <3 <1 .6 <10 <1 <10 <3 

Mar

10... <10 <3 <1 <.5 <10 <1 <10 <3 

Apr

10... <10 & <1 <.5 <10 <1 <10 <3

25... <10 <3 <1 <.5 <10 <1 <10 <3 

May

09... <10 <3 <1 <.5 <10 <1 <10 <3

23... <10 <3 <1 <3 <10 <1 <10 <3 

Jun

06... <10 <3 <1 <5 <10 <1 <10 <3 

Jul

11... <10 <3 <1 <-5 <10 <1 <10 <3

66 Water-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statistical summarias of data for straams 

In the Upper Clark Fork Basin, Montana
Table 17. Trace-element analyses of fine-grained bed sediment, upper Clark Fork basin, Montana, August 1995

[Fine-grained sediment is material less than 0.064 millimeter in diameter. Concentrations are the mean of all analyses for duplicate aliquot* from each 

composite sample. Abbreviation: Hg/g, micrograms per gram of dry sample weight. Symbol: <, less than]

Station 

number

(flg-D

12323600

12323750

12323770

12323800

12324200

12324680

12331500

12331800

12334510

12334550

12340000

12353000

Number

of corn- Station name 

poaite

aamplaa

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Warm Springs Creek at Warm Springs

dark Fork near Galen

dark Fork at Deer Lodge

dark Fork at Goldcreek

Flint Creek near Drummond

dark Fork near Drummond

Rock Creek near Clinton

dark Fork at 1\irah Bridge, near Bonner

Blackfoot River near Bonner

dark Fork below Missoula1

3

3

3

3

3

3

3

3

3

3

3

3

Concentration, In ug/g

Cadmium

36.7

6.0

3.9

7.5

9.0

5.8

4.5

4.8

<1.1

3.4

<1.1

1.9

Chromium

30.1

22.9

33.4

30.9

35.4

37.8

26.0

34.0

26.3

19.2

22.0

25.6

CopP«r

6.280

259

892

1,220

1,480

829

63

579

15

317

23

194

Iron

41,200

19,500

21,900

28,500

31,700

27,500

24,800

26,100

20,900

17,200

19,100

21,100

Lead

899

58

85

133

186

120

168

114

10

70

13

48

not*

2,460

7,230

8,790

4.890

2,440

1,730

3,910

2,780

269

1,130

672

1,740

Nick*!

14.5

14.4

21.9

17.7

16.8

16.4

13.5

15.9

13.7

11.6

12.5

13.4

SHvar

17.8

1.0

3.2

3.7

5.5

3.2

5.6

3.3

<.3

1.8

<.3

1.2

Zinc

9390

620

421

1,370

1,610

1,160

674

1,170

51

786

73

463

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

TABLE 17 67
Table 18. Trace-element analyses of bulk bed sediment, upper Clark Fork basin, Montana, August 1995

[Bulk bed sediment collected in this study generally is material smaller than about 10 millimeters in diameter. Concentrations are die mean of all analyses for 

triplicate aliquots for each composite sample. Abbreviation: Jig/g, nucrograms per gram of dry sample weight Symbol: <, less than]

Station 

number 

(flg.1)

12323600

12323750

12323770

12323800

12324200

12324680

12331500

12331800

12334510

12334550

12353000

Station name

Silver Bow Creek at Opportunity

Silver Bow Creek at Warm Springs

Warm Springs Creek at Warm Springs

dark Fork near Galen

dark Fork at Deer Lodge

dark Fork at Goldcreek

Flint Creek near Drummond

dark Fork near Drummond

Rock Creek near Clinton

dark Fork at Itoah Bridge, near Bonner

dark Fork below Missoula1

Number 

of composite 

samples

1

1

1

1

1

1

1

1

1

1

1

Concentration, In fig/g

Cadmium

8.5

<1.1

1.0

4.0

3.1

3.4

3.2

1.8

<1.1

<1.1

<1.1

Chromium

12.7

10.1

9.7

14.8

12.1

20.3

11.0

23.1

8.9

9.1

5.4

Cop976

42

205

542

449

471

40

235

5

75

28

Iron

19,700

12300

8,980

22,500

15,700

19,600

15,000

16,600

8,960

9,530

6,890

Lead

221

11

34

79

74

71

120

44

5

21

10

Manganese

745

830

2,650

1,540

1,050

749

2,440

1,210

145

234

381

Nickel

6.8

5.5

7.8

8.8

8.3

12.0

8.0

10.3

5.7

6.8

4.5

Sliver

3.4

<.3

.9

1.6

1.4

1.5

5.1

1.2

<.3

<.3

<.3

Zinc

2,270

137

148

6%

619

6%

429

497

20

281

101

1Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

68 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

in the Upper Clark Fork Basin, Montana
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 O.S ug/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

9

9

9

9

8

9

9

9

9

8

8

8

8

8

8

8

8

8

Dilution ratio

1:5

1:5

1:5

1:5

1:1

1:5

1:5

1:1

1:5

1:10

1:10

1:10

1:10

1:5

1:10

1:10

1:1

1:10

Certified 

concentration

(Mfl/g)

SRM sample 2709

0.4

130

35

35,000

19

538

88

.4

106

SRM sample 2711

41.7

47.0

114

28,900

1,160

638

20.6

4.6

350

Mean SRM 

recovery (percent)

~

69.0

79.9

88.3

61.1

93.0

87.3

115

93.4

104

61.2

88.6

81.0

99.2

83.3

77.9

82.5

94.1

95-percent confidence 

Interval for SRM 

recovery 

(percent)

61.5-76.5

72.4-87.4

83.4-93.2

58.4-63.8

88.5-97.5

83.2-95.2

94.1-135

87.4-99.4

102-106

54.5-67.9

87.5-89.7

77.0-85.0

98.3-100.1

82.2-84.4

73.2-82.6

80.0-85.0

93.3-94.9

TABLE 19 69
Table 20. Trace-element analyses of procedural blanks for bed sediment

[Abbreviation: llg/mL. micrograrns per milliliter. Dilution ratio is die proportion of initial volume of concentrated nitric acid used as a digesting 

reagent to final volume of solution after addition of 0.6 N hydrochloric acid used for reconstituting dried residue. Symbols: <, less than; . no data]

Sample 

Identification

A 

A 

A

B 

B 

B

C 

C 

C

D 

D 

D

E 

E 

E

F 

F 

F

G 

G 

G

H 

H 

H

Dilution 

ratio

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

1:1 

1:5 

1:10

Cadmium

<0.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

<.007 

<.007

Chromium

<0.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

Cop0.012 

<.010

<.010 

<.010

<.010 

<.010

<.010 

<.010

<.on

<.010

<.010 

<.010

<.010 

<.010

<.010 

<.010

-

<0.057 

<.057

<.057 

.062

<.057 

<.057

<.057 

<.057

<.057 

<.057

<.057 

<.057

<.057 

<.057

<.057 

<.057

Lead

<0.02

<.02

<.02

<.02

<.02

<.02

<.02

<.02

tration, in pg/mL

Manganese

<0.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

<.002 

<.002

Nickel

<0.005 

<.005

<.005 

<.005

<.005 

<.005

<.005 

<.005

<.005 

<.005

<.005 

<.005

<.005 

<.005

<.005 

<.005

Silver Zinc

<0.01 

<0.012 

<.012

<.012 

<.012

<.012 

<.012

<.012 

<.012

<.012 

<.012

<.012 

<.012

<.012 

<.012

<.012 

<.012

70 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In tha Upper Clark Fork Basin, Montana
Table 21. Trace-element analyses of biota, upper Clark Fork basin, Montana, 

August 1995

[Analyses are of whole-body tissue of aquatic insects. Composite samples made by combining similar-sized insects 

of the same species into a sample of sufficient mass for analysis. Concentrations for biota samples composed of two or 

more composite samples are the means of all analyses. Abbreviations: u.g/g, micrograms per gram of dry sample weight. 

Symbol: <, less than minimum reporting level]

Number Concentration, in ug/g

Taxon

Hydropsyche cockerelli 

Hydropsyche tana

Hydropsyche cockerelli 

Arctopsyche grandis

Hydropsyche cockerelli 

Hydropsyche occidentalis

Hydropsyche cockerelli 

Hydropsyche occidentalis

Arctopsyche grandis 

Claassenia sabulosa

Hydropsyche cockerelli 

Hydropsyche occidentalis 

Hydropsyche sp.

Arctopsyche grandis 

Hydropsyche cockerelli 

Hydropsyche occidentalis

Arctopsyche grandis 

Claassenia sabulosa

Hydropsyche cockerelli 

Hydropsyche occidentalis

Arctopsyche grandis 

Claassenia sabulosa

Hydropsyche cockerelli 

Hydropsyche occidentalis

Arctopsyche grandis 

Claassenia sabulosa

Hydropsyche cockerelli 

Hydropsyche occidentalis

Claassenia sabulosa

Hydropsyche cockerelli 

Hydropsyche occidentalis

of cornCad- Chro- Coppoaite Iron Lead 

mium mium per 

 ample*

12323600 Silver Bow Creek at Onnortunitv

1 6.3 3.1 439 689 21.7 

1 9.2 2.0 456 875 21.0 

12323750 Silver Bow Creek at Warm Spr^ngp

4 .6 1.0 36.9 783 2,6 

12323770 Warm Spriim Creek at Warm Springs

1 2.4 1.9 98.8 684 5.6

12323800 Clark Fork near Galen

2 1.5 1.7 89.7 1,250 7.8 

4 1.1 1.7 71.7 1,200 6.6 

123242QO Clark Fork at Deer Lodge

1 1.3 3.2 104 1,360 16.6 

5 1.4 2.1 104 1,360 10.7

12324680 Clark Fork at Goldcreek

2 2.3 .8 29.6 361 2.3 

2 1.6 .8 56.3 161 1.4

2 1.7 1.0 46.6 602 5.8 

4 1.4 1.0 41.3 698 4.6 

1 1.2 1.3 34.4 540 5.8

12331500 Flint Creek nfar IDpimmOOd

6 .4 2.1 16.2 1,650 9.2 

1 <.5 1.0 9.5 9% 7.2 

1 .9 4.1 26.4 2^50 29.2

12331800 C'ar'c Fork near DrUIDinQDd

5 1.5 .8 25.9 386 3.3 

4 1.6 .7 71.5 122 .9

4 1.5 1.3 58.8 891 6.5 

1 1.5 1.6 51.1 972 8.7

12334510 Rock Creek near Clinton

4 .2 1.2 9.9 625 .4 

3 .3 .6 37.6 85.8 .4

1 <.3 .9 13.1 609 <1.5 

1 <.3 .9 9.6 752 <2.0 

12334550 Clark Fork at Turah Bridge, near Bonner

4 1.0 1.3 28.7 729 3.0 

4 1.0 .6 61.8 92.7 .6

3 .8 1.5 40.7 890 5.3 

3 .7 1.5 39.6 880 5.0

123530QQ CLlrk Fork hdnw Missoula*

3 .7 .6 42.9 102 .8

4 .5 1.7 32.2 1,260 2,4 

1 .6 1.7 27.6 1,050 3.5

Manganeae

180 

307

670 

2,280

1310 

2,180

686 

1,690

665 

86.6

552 

819 

625

1,190 

401 

2,690

555

132

754 

1,220

250 

33.4

258 

262

513 

96.5

554 

680

77.5

590 

790

Nickel

0.7 

.7

.9 

2.3

1.8 

1.3

2.4 

1.5

.3 

.3

1.0 

1.1 

.8

1.4 

.9 

3.6

.3 

.3

1.1 

2.4

1.1 

.3

.9 

.9

.7 

.1

.8 

.7

.2

1.3 

1.4

Zinc

871 

1,010

158 

222

189 

178

197 

232

206 

231

141 

148 

128

203 

85 

243

173 

262

175 

196

131 

185

99 

99

169 

196

158 

167

183

142 

151

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

TABLE 21 71
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

measurement* (MQ/9) (percent) recovery

______________________________________________________________(percent)____

SRM sample 1586 a

Cadmium 12 4.1S 104 102-106

Chromium 12 1.43 120 115-125

Copper 12 66.3 100 97.1-103

Iron 12 539 93.8 92.0-95.6

Lead 12 .37 109 91.1-127

Manganese 12 12.3 92.9 91.5-94.3

Nickel 12 2.25 103 85.0-121

Zinc 12 830 97.0 95.5-98.5

72 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 23. Trace-element analyses of procedural blanks for biota

[Procedural blanks were not diluted prior to analysis. Abbreviation: ug/mL, micrograms per milliliter. Symbol: <, less than]

Station 

number

12323600 

12323750 

12323770 

12323800

12324200 

12324680

12331500

12331800

12334510

12334550 

12353000

Station Oil 

name r

ution

 do Cadmium

Silver Bow Creek at Opportunity 1 : 1 <0.003 

Silver Bow Creek at Warm Springs 1 :1 <.003 

Warm Springs Creek at Warm Springs 1 : 1 <.003 

Clark Fork near Galen 1 : 1 <.003

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 Banner 

Clark Fork below Missoula

:1 <.003 

:1 <.003

:1 <.003

:1 <.003

:1 <.003

:1 <.003 

:1 <.003

Trace-element concentration, In jig/mL

Chromium Copper

0.021 

.009 

.011 

.013

.013 

.014

.011

.012

.017

.014 

.014

<0.002 

<.002 

<.002 

<.002

<.002 

<.002

<002

<.002

<.002

<.002 

<.002

Iron

<0.35 

<35 

.47 

<35

<35 

<35

<35

<35

<35

<35 

<35

Lead

<0.02 

<.02 

<.02 

<.02

<.02 

<.02

<.02

<.02

<.02

<.02 

<02

Manganeee

0.017 

<003 

.019 

.010

.004 

.007

<003

.005

.004

<003 

.004

Nickel Zinc

<0.004 <0.01 

<.004 <01 

<.004 <01 

<004 <.0l

<.004 <.01 

<004 <.01

<004 <01

<.004 <01

<004 <01

<004 <.01 

<.004 <.01

TABLE 23 73
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995

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

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

greater than minimum reporting level to compute statistic]

Property or constituent and reporting unit

Number of 

samples

Maximum

Minimum Mean Median

12323230--BLACKTAFL TREEK AT HARRJSON AVENUE. AT BUTTE. MONT.

Period of record for water-quality data: March

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (fiS/cm)

Temperature, water (°C)

pH, oasite (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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable ()ig/L)

Arsenic, dissolved ftig/L)

Cadmium, total recoverable ()ig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable ()ig/L)

Copper, dissolved (|0.g/L)

Iron, total recoverable (Hg/L)

Iron, dissolved (jig/L)

Lead, total recoverable (|ig/L)

Lead, dissolved ()ig/L)

Manganese, total recoverable ()ig/L)

Manganese, dissolved (jig/L)

Zinc, total recoverable ()ig/L)

Zinc, dissolved (u\g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

85

340

17.0

8.2

140

39

9.7

18

6.4

117

36

18

.6

32

208

18

13

<1

.1

52

10

3,800

360

47

1

190

99

130

11

123

17

95

1993-September 1995

3.1

177

2.5

7.3

71

20

5.0

6.4

2.0

57

15

2.8

.2

14

114

2

2

<1

<.l

2

1

260

24

<1

<.5

30

17

<10

<3

2

.04

50

15

256

8.4

7.8

102

29

7.0

10

2.8

87

26

6.5

.3

24

159

7

5

--

--

10

4

861

169

25

--

66

42

217

25

20

1.3

84

8.2

254

7.5

7.8

100

30

7.0

10

2.6

89

26

5.6

.3

24

161

6

4

<1

<.l

7

4

595

170

1

<.5

60

40

10

5

8

.16

90

74 Water-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and atatlatleal aummarlaa of data for atraama 

in tha Uppar Clark Fork Basin, Montana
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

123232SO-SILVER BOW CREEK BELOW BL

Maximum Minimum Mean Median

ACKTAIL CREEK. AT BUTTE. MONT.

Period of record for water-quality data: March 1993-September 1995

Streamflow, instantaneous (ft3/s) 28 93 15

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 CaCQj)

Sulfate, dissolved (mg/L)

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 (|ig/L)

Cadmium, dissolved (|ig/L)

Copper, total recoverable (|ig/L)

Copper, dissolved (U-g/L)

Iron, total recoverable (u.g/L)

Iron, dissolved (u.g/L)

Lead, total recoverable (|ig/L) 

Lead, dissolved (|ig/L)

Manganese, total recoverable (jig/L)

Manganese, dissolved (|ig/L)

Zinc, total recoverable (|lg/L)

Zinc, dissolved (|ig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

28

28

28

28

28

28

28

28

27

27

27

27

27

27

28

28

28

28

28

28

28

28

28 

28

28

28

28

28

27

27

27

691

17.0

7.8

170

48

12

66

35

133

96

88

.8

28

378

39

13

6

6.2

550

120

7,400

270

250 

2.4

1,600

1,700

2,200

2,200

162

25

93

265

1.5

7.3

97

28

6.5

12

4.0

65

35

6.7

.3

17

165

10

5

1

.5

85

22

310 1

26

3 

<.5

320

210

350

200

3

.14

42

31

462

10.4

7.5

142

41

9.9

25

9.0

87

72

22

.5

23

256

18

8

3

2.0

189

71

,630

109

36 

2.9

771

694

911

722

38

4.1

81

26

470

9.0

7.5

150

42

10

25

6.0

89

75

20

.4

23

258

18

8

2

1.9

155

68

1,150

102

18 

.8

720

675

885

710

19

1.5

86

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323600--SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for water-quality data: March 1993 -September 1995 

Streamflow, instantaneous (ft3/s) 30 315 26 85

Specific conductance, onsite (jiS/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 CaCGj)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable Qig/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 (p.g/L)

Iron, dissolved (u.g/L)

Lead, total recoverable (u,g/L) 

Lead, dissolved (u,g/L)

Manganese, total recoverable (p.g/L)

Manganese, dissolved (u,g/L)

Zinc, total recoverable (u,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)

29

29

29

29

29

29

29

29

28

28

28

28

28

28

29

29

29

29

29

29

29

29

29 

29

29

29

29

29

30

30

30

593

18.0

8.9

200

54

15

26

16

117

190

24

.8

28

374

170

34

49

41

3,900

450

8,600

210

260 

2.7

10,000

9,300

15,000

13,000

384

219

92

219

0.0

7.2

88

27

4.9

8.1

2.9

60

32

3.2

.2

15

136

11

1

1

.5

79

25

290

3

7 

<.5

230

190

230

110

6

.42

52

363

9.0

8.2

130

38

8.2

17

5.2

88

65

11

.4

21

220

34

10

4

2.6

345

77

1,960

62

47 

2.8

927

815

1,040

727

63

21

76

57

370

9.0

8.2

130

40

8.4

16

4.2

86

62

11

.4

21

226

18

9

2

1.2

150

57

980

44

17 

<.5

610

500

520

310

20

3.8

78

76 Water-quality, bad-sadlmant, and biological data (Oetobar 1994 through Saptembar 1995) and statistical summarlM of data for streams 

in tha Uppar Clark Fork Basin, Montana
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

12323750--SILVER BOW CREEK

Maximum Minimum Mean Median

AT WARM SPRINGS. MONT.

Period of record for water-quality data: March

Streamflow, instantaneous (ft3/s) 30 452

Specific conductance, onsite (MS/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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (Mg/L)

Arsenic, dissolved (Mg/L)

Cadmium, total recoverable (Mg/L)

Cadmium, dissolved (Mg/L)

Copper, total recoverable (Mg/L)

Copper, dissolved (Mg/L)

Iron, total recoverable (Mg/L)

Iron, dissolved (Mg/L) 

Lead, total recoverable (Mg/L)

Lead, dissolved (Mg/L)

Manganese, total recoverable (Mg/L)

Manganese, dissolved (Mg/L)

Zinc, total recoverable (Mg/L)

Zinc, dissolved (Mg/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

28

29

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28 

28

28

28

28

28

28

30

30

29

614

22.0

9.3

260

78

19

23

8.3

130

210

15

1.2

20

396

48

35

<1

.2

70

32

3,000

35 

14

.7

570

500

180

73

229

279

97

1993-September 1995

24

281

2.0

8.0

120

36

6.7

8.2

2.6

69

44

1.3

.5

6.3

167

12

8

<1

<.l

10

7

130

3

<.5

80

34

10

3

2

.26

63

147

461

11.9

8.8

194

57

13

16

4.5

99

119

7.9

.7

12

290

21

18

-

2.1

28

14

462

13 

22

-

227

144

69

15

15

13

82

118

475

13.5

8.8

195

58

13

17

4.4

%

120

7.5

.7

12

294

20

16

<1

<.l

23

12

350

11 

1

<.5

195

115

65

10

7

1.9

82

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

12323770- WARM SPRINGS CREEK

Maximum Minimum Mean Median

AT WARM SPRINGS. MONT.

Period of record for water quality data: March 1993-September 1995

Streamflow, instantaneous (ft3/s) 18 333 2.8

Specific conductance, onsite (iiS/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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (Mg/L)

Arsenic, dissolved (Mg/L)

Cadmium, total recoverable (Mg/L)

Cadmium, dissolved (Mg/L)

Copper, total recoverable (Mg/L)

Copper, dissolved (M-g/L)

Iron, total recoverable (Mg/L)

Iron, dissolved (Mg/L) 

Lead, total recoverable (Mg/L)

Lead, dissolved (M-g/L)

Manganese, total recoverable (Mg/L)

Manganese, dissolved (Mg/L) 

Zinc, total recoverable (Mg/L) 

Zinc, dissolved (Mg/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

17

18

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17

17 

17

17

17

17 

17 

17

18

18

18

795

16.0

8.6

420

130

22

7.4

4.7

147

270

3.6

.6

13

536

23

14

<1

<.l

88

16

1,400

30 

14

1.8

1,400

570 

60 

10

90

73

88

172

.5

7.4

80

25

4.3

1.8

.9

61

20

.5

.3

8.4

103

3

3

<1

<.l

4

1

40

4 

<1

<.5

120

65 

<10 

<3

3

.14

57

97

342

8.2

8.2

170

52

9.8

3.6

1.6

108

66

13

A

10

210

8

5

~

-

23

4

376

12 

23

-

358

198 

217 

23

24

10

76

84

283

8.8

8.3

130

40

7.5

3.0

13

106

37

1.0

.4

10

163

6

4

<1

<.l

9

3

140

9 

<1

<.5

320

110 

10 

<3

12

1.4

77

78 Water-quality, bed-aedlment, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for atraama 

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12323800--CLARK FORK NEAR GALEN. MONT.

Period of record for water-quality data: July 1988-September 1995

Streamflow, instantaneous (ft3/s) 71 1,050 14

Specific conductance, onsite (uS/cm)

Temperature, water (t)

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 CaCOj)

Sulfate, dissolved (mg/L)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (ug/L) 

Cadmium, total recoverable (Mg/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L) 

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)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

59

70

58

57

57

57

29

29

29

29

29

29

29

29

57

57 

57

57

56

57

57

57 

57 

57

57

57

57

57

71

71

70

720

22.5

9.0

370

110

22

19

5.9

136

220

11

1.1

17

428

60

30 

3

1

240

50

9,200

110 

28 

3

1,400

360

360

110

338

459

97

220

.0

7.5

96

29

5.7

3.6

2.0

79

34

2.0

.4

8.1

141

3

4

<.l

8

3

90

3

80

33

10

3

2

.12

64

192

453

9.6

8.4

201

60

13

12

3.6

103

99

6.4

.6

12

261

18

13 

2.4

2.1

41

12

717

18 

25 

2.4

324

134

69

18

23

26

79

117

469

9.8

8.4

200

61

13

13

3.3

98

100

6.4

.6

12

266

15

12

<1

25

9

330

10 

2

270

110

50

12

8

2.2

79

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum

12324200-CLARK FORK AT DEER LODGE

Minimum

.MONT.

Mean Median

Period of record for water-quality data: March 1985-September 1995

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (jiS/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)

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 (M-g/L)

Cadmium, dissolved (jig/L)

Copper, total recoverable (M-g/L)

Copper, dissolved (|0.g/L)

Iron, total recoverable (jig/L)

Iron, dissolved (M-g/L)

Lead, total recoverable (M-g/L)

Lead, dissolved (jig/L)

Manganese, total recoverable (M-g/L)

Manganese, dissolved (jig/L)

Zinc, total recoverable (ug/L)

Zinc, dissolved 0*g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

123

106

122

71

63

63

63

28

28

29

28

28

28

28

28

73

73

73

73

72

73

73

73

73

73

73

73

73

73

123

123

114

1,920

642

23.0

8.7

270

81

18

25

6.3

182

140

12

.7

34

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

8.6

2.4

101

44

1.2

.1

11

184

8

7

<1

<.l

11

4

271

510

9.4

8.2

217

64

14

15

3.7

133

98

7.0

.6

17

297

25

14

2.7

--

112

13

60 2,350

<3

<1

<.5

30

1

10

3

2

.29

40

216

215

2.7

359

47

134

18

88

207

72

123

536

10.0

8.2

230

67

14

15

3.6

141

98

7.2

.6

16

312

17

12

<1

<1

50

9

730

9

5

<1

210

32

70

14

24

11

73

80 Water-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for straamc 

in ttta Upper Clark Fork Baain, Montana
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995 (Continued)

Property or constituent and reporting unit

12324590--LITTLE BL

Number off 

samples

Maximum Minimum Mean Median

ACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for water-quality data: March 1985-September 1995

Streamflow, instantaneous (ft3/s) 62 2,080 21

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)

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 (u.g/L)

Cadmium, dissolved (|ig/L) 

Copper, total recoverable (u.g/L) 

Copper, dissolved (u.g/L)

Iron, total recoverable Oig/L) 

Iron, dissolved (u.g/L) 

Lead, total recoverable (u.g/L) 

Lead, dissolved (u.g/L) 

Manganese, total recoverable (u.g/L)

Manganese, dissolved (M-g/L) 

Zinc, total recoverable (U£/L) 

Zinc, dissolved Oig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

50

61

49

44

44

44

18

17

17

17

17

17

18

17

49

49 

49

49 

48 

49

49 

49 

49 

48 

49

49 

49 

49

62

62

62

300

22

8.5

140

43

9.4

7.3

4.5

141

20

3.4

.2

23

182

17

7 

2

1 

45 

7

25,000 

120 

25 

6 

1,100

30 

140 

24

1,410

7,920

95

120

.0

7.0

51

14

3.3

3.4

13

52

9.8

.8

.1

17

96

4

3 

<1

<.l 

<1 

<1

20 

<3 

<1 

<5 

<10

1 

<10 

<3

1

.08

49

298

220

7.2

7.9

101

29

6.8

5.2

2.0

97

13

1.5

.2

19

135

7

5 

2.4

26 

22

1,670 

236 

24 

2.6 

295

8 

219 

24

66

200

75

178

216

7.0

8.0

100

30

7.0

5.3

1.8

100

14

1.3

.2

18

137

6

5 

<1

<1 

3 

2

330 

23 

1 

<1 

30

6 

10 

4

10

4.4

80

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum Mean Median

12324680-CLARK FORK AT GOLDCREEK MONT.

Period of record for water-quality data: March 1993-September 1995

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)

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 (M-g/L)

Cadmium, dissolved (p.g/L)

Copper, total recoverable (|ig/L)

Copper, dissolved (M-g/L)

Iron, total recoverable (p.g/L)

Iron, dissolved (lig/L)

Lead, total recoverable (M-g/L)

Lead, dissolved (fig/L)

Manganese, total recoverable fyig/L)

Manganese, dissolved (p.g/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)

29

28

29

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

27

27

28

28

27

27

28

28

28

28

29

29

29

3,920

496

20.0

8.7

230

68

15

19

6.9

172

88

7.2

.6

25

313

75

18

2

<.l

440

23

12,000

73

73

<.5

1,100

43

510

22

752

7,960

93

87

257

.0

8.0

110

33

6.9

6.9

2.0

89

31

2.5

.1

14

155

8

6

<1

<.l

8

3

752

379

8.9

8.3

167

49

11

12

3.1

128

59

4.7

.4

18

234

16

10

~

-

54

8

60 1,240

<3

<1

<.5

30

11

10

<3

2

.94

52

219

28

--

174

22

70

29

67

364

78

529

399

8.0

8.3

175

52

11

12

3.0

131

56

4.4

.4

18

245

14

10

<1

<.l

34

6

540

14

4

<.5

125

22

50

7

23

38

79

82 Water-quality, bad-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

12331500^FLINT CREEK NEAR

Maximum Minimum Mean Median

DRUMMOND. MONT.

Period of record for water-quality data: March 1985-September 1995

Streamflow, instantaneous (f^/s) 78 892 4.2

Specific conductance, onsite (jj.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)

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 (ug/L)

Cadmium, dissolved (Mg/L)

Copper, total recoverable (ug/L) 

Copper, dissolved (Mg/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L) 

Lead, total recoverable (fig/L) 

Lead, dissolved (Mg/L)

Manganese, total recoverable (ug/L)

Manganese, dissolved (Mg/L) 

Zinc, total recoverable (Mg/L) 

Zinc, dissolved (Mg/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

67

76

64

57

57

57

29

28

28

28

28

28

29

28

64

64 

64

64

63 

64

64

64 

64 

64

64

64 

64 

64

78

78

78

507

21.0

8.8

260

73

20

15

7.8

237

32

6.5

.4

32

318

57

20 

3

<1

32 

7

7,200

240 

87 

7

1,600

120 

290 

27

556

904

98

135

.0

7.5

60

17

4.3

3.8

1.0

65

6.5

1.5

.1

11

94

7

5

<1

<.l

1 

<1

70 1

4 

<1 

<.5

50

15 

<10 

<3

3

.03

28

172

306

8.7

8.2

146

40

11

7.5

3.4

134

15

3.7

.2

19

177

19

10 

2.3

-

8 

22

,140

38 

214 

21

255

44 

249

27

57

50

81

114

301

9.0

8.3

140

39

12

7.5

3.0

142

14

3.6

.2

19

182

15

9 

<1

<1

7 

2

580

26 

9

<5

155

40 

30 

4

28

8.8

84

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

through September 1995 (Continued)

Property or constituent and reporting unit

12331800-CL

Number of 

samples

ARK FORK NEAR

Period of record for water-quality data:

Streamflow, instantaneous (ft3/s) 29

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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (Mg/L)

Arsenic, dissolved (Mg/L)

Cadmium, total recoverable (Mg/L)

Cadmium, dissolved (Mg/L)

Copper, total recoverable (Mg/L)

Copper, dissolved (Mg/L)

Iron, total recoverable (Mg/L) 

Iron, dissolved (Mg/L)

Lead, total recoverable (Mg/L)

Lead, dissolved (Mg/L)

Manganese, total recoverable (Mg/L)

Manganese, dissolved (Mg/L) 

Zinc, total recoverable (Mg/L)

Zinc, dissolved (Mg/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

28

29

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

28

26

26

28 

28

24

24

28

28 

28

28

29

29

29

Maximum Minimum Mean Median

DRUMMOND. MONT.

March 1993-September 1995

3300 149 1,010

630

21.0

8.5

300

83

22

20

10

199

130

7.8

.5

24

410

62

19

2

.2

360

21

8,800 

140

56

1.2

880

50 

490

21

530

4,720

91

233

1.0

8.0

91

26

6.4

5.6

2.1

81

25

2.7

.2

10

137

8

7

<1

<.l

5

1

50

<3

<1

<.5

20

8

3

2

1.9

53

409

10.0

8.3

185

53

13

12

3.7

140

65

4.8

.4

19

253

18

11

--

-

54

7

1,370 

220

211

--

201

17 

289

9

81

379

74

846

432

10.0

83

195

56

13

12

3.4

144

64

4.6

.4

18

266

14

10

<1

<.l

26

6

650 

10

5

<.5

125

15 

50

8

30

76

75

84 Water-quality, bad-aadlmant, and biological data (October 1994 through Saptambar 1995) and statistical summariaa of data for atraama 

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number off 

samples

Maximum Minimum Mean Median

12334S10-ROCK CREEK NEAR CLINTON. MONT.

Period of record for water-quality data: March 1985-September 1995

Streamflow, instantaneous (ft3/s) 61 3,010 113

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 CaCOj)

Sulfate, dissolved (mg/L)

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 (U£/L) 

Copper, total recoverable (u,g/L) 

Copper, dissolved (u.g/L)

Iron, total recoverable (u,g/L)

Iron, dissolved (u,g/L)

Lead, total recoverable (u.g/L) 

Lead, dissolved (u,g/L) 

Manganese, total recoverable Cig/L) 

Manganese, dissolved (u,g/L)

Zinc, total recoverable Cig/L) 

Zinc, dissolved (u,g/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

52

61

51

43

43

43

17

17

17

17

17

17

17

17 

49 

49 

49

49 

47 

48

49

49

47 

47 

49 

49

49 

49

61

61

61

155

18

8.6

90

23

8.0

3.5

1.6

75

5.2

1.0

.2

13

90 

2 

1 

3

1 

41 

6

2,100

110

19 

5 

90 

8

60 

15

157

1,280

95

55

.0

6.9

25

6.5

2.2

1.6

.8

26

2.0

3

<.l

9.7

40

:;'

20

5

<10

<10 

<3

1

31

35

836

107

7.8

7.9

51

13

4.4

2.6

1.1

53

3.6

.6

2.1

11

68 

2.8 

21 

2.5

25 

21

344

33

2.8 

219 

22

23

18

88

71

515

102

8.0

7.9

55

14

4.7

25

1.1

58

3.7

.6

.1

11

73

3 

1

160

33

1

10 

1

<3

5

8.9

74

TABLE 24 85
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995 (Continued)

Property or constituent and reporting unit

12334550--CLARK FORK

Number of 

samples

Maximum Minimum Mean Median

AT TURAH BRIDGE. NEAR BONNER. MONT.

Period of record for water-quality data: March 1985-September 1995

Streamflow, instantaneous (ft3/s) 126 9,370 296 1,660

Specific conductance, onsite (uS/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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable fyig/L)

Arsenic, dissolved (Mg/L) 

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L) 

Iron, dissolved (ug/L) 

Lead, total recoverable (ug/L) 

Lead, dissolved (ug/L)

Manganese, total recoverable (Mg/L)

Manganese, dissolved (ug/L) 

Zinc, total recoverable (ug/L) 

Zinc, dissolved (ug/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

101

125

72

62

62

62

28

28

29

28

28

28

28

28

71

71 

71

71

69

70

71 

71 

67 

67

71

71 

71 

71

126

126

115

483

22.0

8.7

210

59

14

12

5.7

146

68

5.6

.4

19

252

110

17 

4

1

500

25

19,000 

190 

100 

7

2,000

31 

1,100 

39

1,370

34,700

98

160

.0

7.4

67

19

4.8

4.3

1.6

65

20

1.7

.2

12

108

5

4 

<1

<.l

3

2

60 

<3 

<1 

<.5

10

1 

<10 

<3

2

3.5

27

320

9.1

8.2

142

40

10

8.0

2.5

108

42

3.1

.3

15

185

12

6 

2.5

--

51

6

1,610 

225 

212 

2.6

186

8 

295 

29

68

749

72

1,020

340

9.5

8.2

150

42

11

8.4

2.4

116

41

3.0

.3

15

196

8

5 

<1

<1

23

5

530 

14 

5 

<1

90

7 

40 

7

22

61

72

86 Water-quality, bed-sediment, and biological data (October 1994 through September 1995) and statistical summaries of data for streams 

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

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum Minimum M-n Median

12340000--B LACK FOOT RIVER NEAR BONNER. MONT.

Period of record for water-quality data:

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (u.S/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCCVj)

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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable (ug/L)

Arsenic, dissolved (p.g/L)

Cadmium, total recoverable (ug/L)

Cadmium, dissolved (ug/L)

Copper, total recoverable (ug/L)

Copper, dissolved (ug/L)

Iron, total recoverable (ug/L)

Iron, dissolved (ug/L)

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)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

92

69

92

52

45

45

45

17

17

17

17

17

17

17

17

52

52

52

52

49

50

52

52

48

48

52

52

52

52

92

92

90

March 1985 -September 1995

10,300

294

20.5

8.7

140

37

13

3.4

2.8

140

6.6

1.6

.1

12

154

4

2

2

1

34

7

3,600

100

25

8

180

11

60

15

271

7,540

98

344 2,420

131

.0

7.5

55

14

4.9

1.2

.5

76

1.1

.3

<.l

6.8

82

<1

<1

<1

<.l

<1

<1

20

<3

<1

<.5

<10

<1

<10

<3

1

1.1

42

207

8.7

8.2

101

26

9.0

2.4

.9

109

4.7

.6

-

8.6

119

21

2.8

2.5

~

28

22

611

220

26

21

240

23

213

24

30

495

78

1,020

205

8.5

8.2

100

26

8.5

25

.8

105

5.0

5

<.l

8.1

114

1

<1

<1

<1

6

2

240

14

2

<1

20

2

<10

<3

8

22

81

TABLE 24 87
Table 24. Statistical summary of water-quality data for the upper Clark Fork basin, Montana, March 1985 

through September 1995 (Continued)

Property or constituent and reporting unit

Number of 

samples

Maximum

12340500--CLARK FORK ABOVE MTSSOUl

Minimum

,A. MONT.

Mean Median

Period of record for water-quality data: July 1986-September 1995

Streamflow, instantaneous (ft3/s)

Specific conductance, onsite (uS/cm)

Temperature, water (°C)

pH, onsite (standard units)

Hardness, total (mg/L as CaCQj)

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)

Chloride, dissolved (mg/L)

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable fyig/L)

Arsenic, dissolved (u.g/L)

Cadmium, total recoverable fyig/L)

Cadmium, dissolved fyig/L)

Copper, total recoverable fyig/L)

Copper, dissolved fyig/L)

Iron, total recoverable (u.g/L)

Iron, dissolved fyig/L)

Lead, total recoverable fyig/L)

Lead, dissolved fyig/L)

Manganese, total recoverable fyig/L)

Manganese, dissolved (}ig/L)

Zinc, total recoverable fyig/L)

Zinc, dissolved fyig/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

92

69

89

49

49

49

49

28

28

28

28

28

28

28

28

49

49

49

49

47

48

49

49

44

44

49

49

49

49

92

92

87

15,100

399

19.5

8.6

170

46

13

7.8

4.5

143

43

4.2

.3

16

209

18

7

<1

.1

110

10

3,100

45

16

1

300

39

160

16

297

7,670

99

720 3,810

145

.0

7.9

61

14

5.6

2.4

.9

71

9.3

.9

<.l

9.4

90

2

1

<1

<.l

2

1

60

<3

<1

<.5

10

7

<10

<3

2

6.1

44

265

9.1

8.3

123

33

9.6

5.3

1.7

108

23

1.9

2.2

12

152

5

3

--

--

13

3

520

218

23

2.7

58

16

223

25

30

674

88

2,040

275

8.5

83

130

34

9.7

5.4

1.5

111

23

1.8

.2

11

154

4

3

<1

<.l

8

2

250

16

2

<.5

40

14

20

4

10

55

90

88 Water-quality, bed-eetfment, and biological data (Octobar 1994 through September 1995) and atetietical eummariee of data for atraama 

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

through September 1995 (Continued)

Property or constituent and reporting unit

12353000--CL

Number of 

samples

Maximum

ARK FORK BELOW MISSOUL

Period of record for water-quality data:

Stream flow, instantaneous (ft3/s) 64

Specific conductance, onsite QiS/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)

Chloride, dissolved (mg/L) 

Fluoride, dissolved (mg/L)

Silica, dissolved (mg/L)

Dissolved solids, calculated (mg/L)

Arsenic, total recoverable Qlg/L) 

Arsenic, dissolved (jig/L)

Cadmium, total recoverable (M-g/L)

Cadmium, dissolved (jig/L)

Copper, total recoverable (M-g/L)

Copper, dissolved (M-g/L)

Iron, total recoverable (jig/L)

Iron, dissolved Qig/L) 

Lead, total recoverable (M-g/L) 

Lead, dissolved (M-g/L)

Manganese, total recoverable (^g/L)

Manganese, dissolved (jig/L)

Zinc, total recoverable (U£/L) 

Zinc, dissolved (flg/L)

Sediment, suspended concentration (mg/L)

Sediment, suspended discharge (ton/d)

Sediment, suspended (percent finer than 0.062 mm)

64

64

64

64

64

64

64

64

63

64

64 

64

64

64

11 

37

11

37

11

37

11

42 

10 

35

11

42

11 

37

64

64

63

Minimum

A. MONT,

Mean

March 1985-September 1995 

19,800 869 4,650

320

20.5

8.8

150

42

11

8.5

3.4

135

34

4.7 

3

15

194

6 

6

<1

2

25

9

1,600

93 

4 

5

120

18

40

24

85

4,540

93

108

.0

7.1

48

13

3.7

2.2

.6

47

6

.3 

<.l

5.8

63

2 

<1

<1

<.l

2

1

90

4 

<1 

<.5

20

3

<10 

<3

1

4.3

35

223

8.4

8.0

104

29

7.8

5.7

1.6

95

19

2.4 

2.2

12

134

3 

22

-

-

9

3

417

19 

22 

2.6

45

8

18 

2?

16

330

75

Median

2,680

242

8.2

8.0

110

32

8.4

6.2

1.8

101

18

2.5 

.2

12

144

3 

2

<1

<1

7

3

180

17 

<1 

<1

30

6

20 

4

9

70

79

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

fyalue Is estimated by using a log-probability regression to predict the values of data less than the minimum reporting level (Heteel and Cohn, 1988).

TABLE 24 80
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1995

[Fine-grained bed sediment is material feu than 0.064 miltimeter in diameter. Concentrations are in micrograrrw per gram dry 

weight. Symbols: <, fess than minimum reporting level; -, indicates either too few samples or insufficient data greater 

than the minimum reporting level to compute statistic. Number of samples represents the number of years that the constituent 

was analyzed, with each year represented by a single mean concentration of composite samples. Values for single samples are 

arbitrarily listed in the "Mean" column]

Number of MaxlConatituent 

samples mum

Minimum Mean Median

1232HOO..SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for fine-grained bed-sediment data: 1992-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

4

3

4

4

4

4

3

4

4

38.2

30.1

6.280

41.200

1.030

3,200

16.3

19.6

9390

27.1 32.8

24.2 273

4,560 5.110

34,400 38,200

752 879

1,680 2.440

14.5 15.6

13.7 16.4

6.850 8,230

33.0

27.6

4.790

38.600

866

2,440

16.0

16.1

8,340

12323750-SILVFR BOW CREEK AT WARM SPRINGS. MONT.

Period of record for fine-grained bed-sediment data: 1992-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

4

3

4

4

4

4

3

4

4

12.2

22.9

769

26,000

99

17.700

16.5

1.3

2,220

6.0 9.3

12.8 17.5

259 570

19,500 21,700

58 78

7,230 10,400

14.4 15.6

.3 .9

620 1.580

9.4

16.7

626

20,600

78

8,370

15.8

1.0

1,730

1232770--WARM SPRINGS CREEK AT WARM SPRINGS. MONT.

Period of record for fine-grained bed-sediment data: 1995

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

1

1

1

1

1

1

1

1

1

_

-

_

-

3.9

33.4

892

21,900

85

8,790

21.9

3.2

421

-

12323800--CLARK FORK NEAR GALEN. MONT.

Period of record for fine-grained bed-sediment data: 1987, 1991-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

6

3

6

6

6

6

3

6

6

IIMM* mrtfi klnlAMteal data ffVHnh*r 1

20.1

30.9

2300

39,800

235

15.600

23.2

5.5

3,560

OOA MtmiMih 9*nl

7.5 13.1

22.1 25.4

1,220 1,460

22,600 29300

116 158

4,890 11,000

17.7 20.9

2.8 3.8

1370 2,380

*mh*r Iftftjn anil *tati*tte*l *um

12.6

23.3

1,250

28,100

139

12,300

21.8

3.7

2,460

marlM «f «bta I nr mi

In the Upper Clark Fork Basin, Montana
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1995 (Continued)

Number of MaxiConstituent 

samples mum

Minimum Mean Median

12324200-CLARK FORK AT DEER LODGE. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1990-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

8

3

8

8

8

8

8

8

8

9.0

35.4

4,180

31,700

242

6,020

16.8

7.9

1,730

5.1 7.2

19.5 27.8

837 1,680

22,600 27,400

121 167

1,460 2,820

15.0 15.7

2.4 4.5

977 1,390

7.6

28.4

1,130

27,600

164

2,380

15.3

4.4

1,420

12324590-LnTLE BLACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1994

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

1

3

3

3

3

1

3

3

.9

_

85

26,400

53

2,700

.9

180

.2 .6

22.1

38 54

16,100 22,100

37 43

907 1,550

13.6

<.5 .4

161 170

.7

..

40

23,800

40

1,040

«

<.5

170

12324KO--CLARK FORK AT GOLDCREEK. MONT.

Period of record for fine-grained bed-sediment data: 1992-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

4

3

4

4

4

4

3

4

4

6.2

37.8

1,030

27,500

152

2,610

17.0

3.7

1,320

5.4 5.8

31.6 33.8

653 811

20,500 24,500

93 118

1,180 1,990

15.0 16.1

2.3 3.0

1,120 1,200

5.8

31.9

779

25,000

114

2,090

16.4

3.0

1,180

12331500-FLINT CREEK NEAR DRUMMOND. MONT.

Period of record for fine-grained bed-sediment data: 1986, 1989, 1992-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

6

3

6

6

6

6

3

5

6

4.5

26.0

73

28,100

240

5,510

13.5

7.8

727

<1.0 1 2.6

21.1 23.8

55 62

21,100 23,800

151 189

2,710 3,860

11.7 12.6

5.0 6.3

610 668

2.8

24.3

60

23,200

185

3,740

12.5

6.4

673

TABLE 25 91
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1995 (Continued)

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

Number of MaxlConstituent Minimum Mean

samples mum

12331800--CLARK FORK NEAR DRUMMOND. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1991-95

7 5.4 4.1 4.7

3 34.0 17.0 27.0

7 614 469 549

7 26,100 16,500 21,900

7 135 85 104

7 2,780 1,220 1,970

3 15.9 14.0 15.2

7 3.5 2.1 2.9

7 1,230 1,030 1,120

12334510--ROCK CREEK NEAR CLINTON. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 89, 1991-95

8 <1.2 <.3 -1

3 26.3 16.5 20.7

8 15 3 12

8 21,400 13,100 17,600

8 16 <3 *8

8 598 126 311

3 13.7 10.8 12.4

7 <.7 <.3 -1

8 58 36 48

1 2334550--CLARK FORK AT TURAH BRIDGE. NEAR BONNER. MONT.

Period of record for fine-grained bed-sediment data: 1986, 1991-95

6 5.2 3.1 3.8

3 26.7 15.3 20.4

6 561 300 387

6 23,200 15,100 18,400

6 115 62 80

6 1,670 671 1,140

3 15.9 11.6 13.2

6 2.9 1.3 2.0

6 1,160 775 909

12340000-BLACKFOOT RIVER NEAR BONNER. MONT.

Period of record for fine-grained bed-sediment data: 1986-87, 1991, 1993-95

6 <1.2 <.3 -1

3 22.0 15.1 175

6 25 16 21

6 19,100 12,400 15,900

6 20 9 12

6 672 298 490

3 12.7 11.7 12.3

6 <.7 <.3 -1

6 73 54 63

Median

4.8

30.1

551

23,200

102

1,940

15.7

2.9

1,120

*<.6

193

14

17,800

10

274

12.7

*<.5

50

35

19.2

322

17,200

72

1,200

12.0

2.0

861

*<.6

15.3

22

15,500

11

492

12.5

*<.5

62

92 Watar-quality, bad-aadimant, and biological data (Octobar 1994 through Saptambar 1995) and atatiatical aummariaa of data for atraama 

in the Uppar Clark Fork Baain, Montana
Table 25. Statistical summary of fine-grained bed-sediment data for the upper Clark Fork basin, Montana, 

August 1986 through August 1995 (Continued)

Number of 

Constituent 

samples

Maximum

Minimum Mean Median

12353000--CLARK FORK BELOW MISSOULA. MONT.2

Period of record for fine-grained bed-sediment data: 1986, 1990-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

7

3

7

7

7

7

3

7

7

2.6

25.6

293

21,100

58

2,530

14.1

2.1

675

1.1

18.8

98

14,500

33

752

13.3

.4

319

1.7

22.0

166

18,600

42

1,540

13.6

1.1

432

1.7

21.5

138

19,500

38

1,340

13.4

1.2

409

'Value determined by arbitrarily substituting one-half of the detection level for censored (<) values, when both 

uncensored and censored values are used in determining the mean. When all data are below the detection level, the 

median is determined by ranking the censored values in order of detection level. No mean is reported when all values 

are below the detection level.

2Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 25 93
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, 

August 1993 through August 1995

[Bulk bed sediment is material smaller than about 10 mm in diameter. Concentrations are in micrognms per gram dry weight 

Symbols: <, less than minimum reporting level; , indicates either too few samples or insufficient data greater than the minimum 

reporting level to compute statistic. Number of samples represents the number of yean that the constituent was analyzed, with 

each year represented by a single mean concentration of composite samples. Values for single samples are arbitrarily 

listed in the "Mean" column]

Number of Maxk 

Constttuent 

samples mum

Minimum Mean Median

12323600--SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

12.7

14.9

1,550

27,200

300

1,670

8.9

4.8

3,420

6.7 9.3

9.6 12.4

831 1,120

18,600 21,800

221 256

671 1,030

6.0 7.2

3.4 4.0

2,050 2,580

8.5

12.7

976

19,700

248

745

6.8

3.9

2,270

12323750--STLVER BOW CREEK AT WARM SPRINGS. MONT.

Period of record for bulk bed-sediment data: 1993, 1995

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

2

2

2

2

2

2

2

2

2

1.2

10.1

111

12,300

33

830

8.1

<.5

303

<1.1 .9

9.9 10.0

42 76

9,160 10,700

11 22

543 686

5.5 6.8

<.3 --1

137 220

-

~

12327700--WARM SPRINGS CREEK AT WARM SPRINGS. MONT.

Period of record for bulk bed-sediment data: 1995

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

1

1

1

1

1

1

1

1

1

-

-

-

1.0

9.7

205

8,980

34

2,650

7.8

.9

148

-

--

12323800--CLARK FORK NEAR GALEN. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

6

6.0

18.4

685

25,900

87

5,410

12.5

1.6

1,280

1.5 3.8

4.2 12.5

223 483

9,930 19,400

41 69

1,280 2,740

4.9 8.7

.7 1.3

498 825

4.0

14.8

542

22,500

79

1,540

8.8

1.6

696

94 Water-quality, bed-sediment, and biological data (Octobar 1994 through September 1995) and statistical summaries of data for straams 

in the Upper Clark Fork Basin, Montana
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, 

August 1993 through August 1995 (Continued)

Number of MaxlConstltuent 

samples mum

Minimum Mean Median

12324200-CLARK FORK AT DEER LODGE. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

3.1

16.1

449

17,900

85

2,060

10.2

1.6

619

2.0 2.5

12.1 13.8

281 371

13,200 15,600

45 68

998 1,370

7.7 8.7

<.7 1 1.1

456 558

2.4

13.3

383

15,700

74

1,050

83

1.4

599

12324S90--LITTLE BLACK FOOT RIVER NEAR GARRISON. MONT.

Period of record for bulk bed-sediment data: 1994

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

1

1

1

1

1

1

1

1

1

~

~

~

~

~

-

<1.2

14.7

19

15,600

12

420

8.6

<.7

73

--

--

..

--

J23^4fipO~CLARK FORK AT GOLDCREEK. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

3.4

23/4

471

19,600

72

1,190

12.4

1.6

696

2.3 2.7

17.6 20.4

282 374

15,500 17,900

46 63

649 863

9.1 11.2

<7 H.2

549 640

2.4

20.3

370

18,600

71

749

12.0

1.5

676

12331500-FLINT CREEK NEAR DRUMMOND. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

3.2

11.0

40

15,000

120

3,200

8.0

5.1

429

.3 1.7

4.9 8.7

19 28

8,630 12,300

51 83

1,150 2,260

5.8 6.6

3.3 4.1

190 301

1.7

10.3

25

13,400

79

2,440

6.0

3.9

284

TABLE 26 95
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, 

August 1993 through August 1995 (Continued)

Number off

Constituent

samples

MaxiMinimum Mean

mum

Median

1 2331 800--C LARK FORK NEAR DRUMMOND. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

1.8 1.5 1.7

23.1 13.8 17.9

276 173 228

16,600 14,100 15,500

61 35 47

1,210 711 915

11.0 9.0 10.1

1.7 .5 1.1

621 434 517

1.8

16.9

235

15,900

44

820

10.3

1.2

497

12334510-ROCK CREEK NEAR CIJNTON. MONT.

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

<1.2 <.8 -1

10.8 6.6 8.8

9,840 

745

6380 8,390

555

195 91 144

6.2 4.9 5.6

<.7 .1 1 .2

29 16 22

Vcl.1

8.9

5

8,960

5

145

5.7

<3

20

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

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

3

3

3

3

3

3

3

3

3

1.8 .5 1.0

15.5 6.9 10.5

182 75 126

13,200 9,530 11,100

37 21 29

487 234 378

8.8 6.4 73

<.7 <3 .3

510 281 379

<1.1

9.1

122

10,700

30

414

6.8

.3

345

12340000--BLACKFOOT RIVER NEAR BONNER. MONT.

Period of record for bulk bed-sediment data: 1993-94

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Silver

Zinc

2

2

2

2

2

2

2

2

2

<1.2 <.8 -1

17.7 6.7 12.2

19 14 16

16,600 10300 13,400

10 8 9

305 179 242

9.8 7.6 8.7

<.7 <.5 -- 1

58 33 46

-

-

-

-

-

96 Watar-quality, bad-sadiment, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for straama 

in the Upper Clark Fork Baaln, Montana
Table 26. Statistical summary of bulk bed-sediment data for the upper Clark Fork basin, Montana, 

August 1993 through August 1995 (Continued)

Constituent

Number of 

samples

Maximum

Minimum Mean Median

12353WQ"CLARK FORK BELOW MTSSQULAi MONT,2

Period of record for bulk bed-sediment data: 1993-95

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Silver

Zinc

3

3

3 

3

3

3 

3

3

3

<1.2

8.7

77 

10,200

19

381 

7.1

.5

172

.5

4.4

22 

6,160

8

223 

3.5

<.3

88

*.6

6.2

42 

7,750

12

318 

5.0

1 3

120

<l.l

5.4

28 

6,890

10

351 

4.5

<.7

101

'Value determined by arbitrarily substituting one-half of the detection level for censored (<) values, when both 

uncensored and censored values are used in determining the mean. When all data are below the detection level, the 

median is determined by ranking the censored values in order of detection level. No mean is reported when all values 

are below the detection level.

2Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

TABLE 26 97
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995

[Concentrations are in imcrograms per gram dry weight Symbol*: <, leu than minimum reporting level; , indicates either 

too few samples or insufficient data greater than the minimum reporting level to compute statistic, or element not analyzed 

Number of composite samples represents the total of all individual composite samples collected for every year that the constituent 

was analyzed. Values for single samples are arbitrarily listed in the "Mean" column. Because Hydropsyche insects were not sorted to 

the species level during 1986-89, statistics for stations sampled during those years are based on the results of all Hydropsyche species 

combined. At some sites, statistics for the Hydropsyche morasa group are based on the combined results for two 

or more species]

Number of 

Constituent composite 

samples

MaxlMinimum 

mum

Mean Median

12323600--SILVER BOW CREEK AT OPPORTUNITY. MONT.

Period of record for biological data: 1992, 94-95

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

5

5

5 

5

5

5 

5

5

63 4.1

8.0 1.0

462 269 

1,180 689

21.7 19.0

718 180 

2.1 .7

898 749

4.9

3.7

365 

931

20.3

460 

1.4

818

4.7

3.1

333 

953

20.1

434 

1.6

805

Hvdropsvfhe tana

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

6

6

6 

6

6

6 

6

9.2 4.8

11.5 .9

456 10.5 

1,520 857

21.0 15.6

969 307 

1.8 .7

6 1,070 760 

12323750-STLVER BOW CREEK AT WARM SPRINGS.

6.8

4.5

236 

1,100

18.6

634 

1.4

961 

MONT.

6.9

1.8

298 

1,050

18.3

675 

1.6

1,020

Period of record for biological data: 1992-95

Hvdropsvche cockeretti

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

10

10

10 

10

10

10 

10

10

2.1 .5

13 J5

96.9 25.1 

1,240 553

5.6 3

2,450 528 

1.8 .7

276 118

1.1

.8

56.1 

810

2.9

1,240 

1.0

197

.9

.8

513 

758

2.9

1,160 

.9

197

Hvdropsvche occidentalis

Cadmium

Chromium

Copper 

Iron 

Lead

Manganese 

Nickel

Zinc

3

3

3 

3 

3

3 

3

3

1.1 .4

.9 .3

46.5 38.6 

1,040 372 

<3.6 <2.3

2,250 1,780 

1.5 .7

202 149

.8

.6

41.5 

803 

h.6

2,060 

1.0

184

.9

.7

39.4 

998 

1.7

2,140 

.9

201

98 Watar-quality, bad-aadimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical aummariaa of data for atraama 

In tha Uppar Clark Fork Basin, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Number of

MaxlConstltuent composite Minimum Mean

mum

samples

12323750--SILVER BOW CREEK AT WARM SPRINGS. MONT.-Continued

Period of record for biological data: 1992-95

Hvdropsvche spp.

1 -- - 23

1 - -- 1.4

1 - - 47.6

1 - » 619

1 - -- 5.1

1 - -- 1,100

1 - - <.4

1 - ..284

1M23770--WARM SPRINGS CREEK AT WARM SPRINGS. MONT.

Period of record for biological data: 1995

Arctopsvche pnutdis

1 - -- 2.4

1 - - 1.9

1 - - 98.8

1 ~ ..684

1 - - 5.6

1 ~ - 2,280

1 ~ - 2.3

1 ~ - 222

12323800--CLARK EORK NEAR GALEN. MONT.

Period of record for biological data: 1987, 1991-95

Hvdropsvche cockereOi

10 2.7 13 1.8

10 33 .8 1.5

10 181 80.5 105

10 1,500 901 1,180

10 93 1.2 6.5

10 2,950 1,410 2,130

10 3.1 1.0 1.6

10 299 174 228

Hvdropsvche morosa group

5 32 2.4 2.5

5 4.6 1.8 2.6

5 185 156 173

5 1,890 1,360 1,510

5 12.4 7.1 8.5

5 3,960 2,360 3,500

5 3.6 1.9 2.3

5 349 292 309

Median

-

«

-

-

-

--

~

~

1.8

1.2

98.8

1,170

7.5

2,140

1.5

230

2.4

2.2

175

1,430

7.9

3,860

2.1

303

TABLE 27 99
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Number of 

Constituent composite 

samples

Maximum

Minimum Mean Median

12323800--CLARK FORK NEAR GALENr MONT.-Continned

Period of record for biological data: 1987, 1991-95

Hvdropsvche occidentaUs

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

12

12

12

12

12

12

12

12

1.6

6.6

84.1

1,300

8.0

4,070

35

278

1.0

.7

66.7

642

1.6

1.2

1.8

75.5

991

5.1

1,980 2,930

1.1

170

1.7

211

1.2

1.5

74.5

1,060

5.0

2,920

1.6

205

Hvdropsvche spp.

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

4

0

4

4

4

0

0

4

35

154

1,540

13.5

-

329

2.6

135

1,190

10.5

~

«

279

3.0

148

1,400

12.2

-

~

308

3.0

152

1,450

12.4

-

«

313

12324200-CLARK FORK AT DEER LODGE. MONT.

Period of record for biological data: 1986-87, 1990-95

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Hvdroo

15

15

15

15

15

15

15

15

svchf cockercUi

23

32

136

3340

18.2

1,030

2.4

391

.8

.4

54.7

490

4.3

499

3

132

1.4

1.6

95.9

1,170

9.1

708

1.2

188

1.3

1.9

98.2

1,040

8.9

688

1.1

184

HvJroosvehf oeeutentulis

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

15

15

15

15

15

15

15

15

2.7

23

134

1,580

13.4

2,840

12.9

299

.8

.6

49

557

6.3

1,130

1.1

1%

1.4

1.8

103

1,310

10.3

1,810

2.3

239

1.3

2.0

109

1,350

9.9

1,730

1.6

228

100 Water-quality, bad-sadimant, and biological data (Octobar 1994 through Saptambar 1995) and statistical summarias of data for straams 

in tha Uppar Clark Fork Basin, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Number of MaxiConstltuent composite Minimum 

mum 

samples

Mean Median

12324200-CLARK FORK AT DEER LODGE MONT -Continued

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc 

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc 

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc 

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

Period of record for biological data: 1986-87, 1990-95

Hvdrnosvchf son.

3 2.0 1.2

0

1.6

3 222 103 145 

3 2,220 1,110 1,520

3 15.0 5.6

0 

0

8.8

3 203 185 195 

12324590-LnTLE BLACKFOOT RIVER NEAR GARRISON. MONT.

Period of record for biological data: 1987, 1994 

Arctonsvfhf wtUldis

9 .4 .2

9 .8 .6

9 14.0 9.1 

9 325 177

9 13 .5

9 596 318 

9 .6 .4

9 179 113 

C'laasvfnia \ahuloso

4 3 .1

4 .8 .7

4 34.0 20.0 

4 200 98

4 <.7 <.4

4 62.1 46.7 

4 .7 .5

4 233 191 

ttvdfoosvctif cockffttli

1

1

1 

1

1

1 _ 

1

1

3

.7

11.5 

242

.8

471 

.5

146 

.2

.8

27.9 

138

<.6

53.4 

.6

206 

.6

1.6

28.4 

478

3.6

399 

1.2

123

1.6

~

111 

1,240

5.7

197 

3

.8

11.8 

230

.8

492 

.5

145 

.2

.8

28.8 

127

<.6

51.3 

.5

201

TABLE 27 101
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Number of 

Constituent composite 

samples

MsjclMinimum 

mum

Mean Median

12324S90--LITTLE BLACKFOOT RIVER NEAR GARRTSONr M ONT.-.Cnntiniied

Period of record for biological data: 1987, 1994

Hvdropsvche oceidentalis

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

1

1

1

1

1

1

1

1

~

__

~

-

~

-

--

-

<.7

1.3

15.1

426

<3.7

434

.8

110

-

~

~

--

12324680--CLARK FORK AT GOLDCREEK. MONT.

Period of record for biological data: 1992-95

Arctopsvche grandis

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

5

5

5

5

5

5

5

5

Tfofm

7

7

7

7

7

7

7

7

6.6

23

39.9

476

3.8

1,100

1.0

309

'eniu sohuloso

2.1

1.6

66.6

230

1.6

179

.7

296

1.4

.8

28.8

339

2.3

592

.2

175

.6

.3

33.0

63.0

.8

65.1

.2

166

2.8

1.2

32.5

412

2.8

907

.5

218

1.1

.8

52.8

155

1.1

111

.3

237

2.0

1.0

31.5

387

2.9

1,030

.6

195

.9

.8

50.6

171

1.0

90.3

.3

257

Hvdropsvche coekereUi

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

6

6

6

6

6

6

6

6

2.1

42

67.1

655

6.9

713

1.5

201

.6

.7

33.5

589

4.5

538

.6

137

1.6

2.0

54.5

617

5.4

607

1.1

171

1.8

1.8

58.0

617

5.1

596

1.2

172

102 Watw-quality, btd-stdimant, and biological data (Octobar 1994 through Saptamoar 1995) and statistical summaries of data for straams 

In the Upper Clark Fork Basin, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Number of

MaxlConstltuent composite Minimum

mum

samples

Mean Median

12324680--CLARK FORK AT GOLDCREEK. MONT.-Continued

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for bfotogkal data: 1992-95

Hvdroosvche morosa group

4 1.7 1.1

4 1.4 1.3

4 72.9 43.8

4 1,320 612

4 6.9 2.4

4 1,030 538

4 1.4 .9

4 190 137

Hvdropsvche occidentalis

7 1.7 .7

7 1.7 .4

7 55.5 26.4

7 1,180 466

7 6.0 2.9

7 1,800 530

7 1.2 .8

7 207 97

1.4

1.4

60.5

1,050

4.6

804

1.2

167

1.2

1.0

41.6

750

5.0

1,140

1.0

167

1.4

1.4

62.7

1,130

4.6

822

1.2

170

1.2

1.0

45.0

751

5.4

959

1.0

170

12331500--FIJNT CREEK NEAR DRUMMOND. MONT.

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biologkal data: 1986, 1992-95

Arctopsvche prandis

22 .6 .2

22 4.7 .6

22 19.7 9.8

22 2,460 606

22 17.5 3.7

22 2,480 848

22 23 .6

22 275 151

Hvdropsvche cockeretti

4 .4 .2

4 1.2 1.0

4 283 9.5

4 1,500 996

4 11.1 3.1

4 1,440 401

4 22 .9

4 193 85

.4

2.0

15.0

1,320

9.0

1,570

13

199

.3

1.0

18.3

1,220

6.8

955

1.6

132

.4

1.8

15.0

1,300

7.6

1,340

1.2

186

.4

1.0

17.8

1,180

6.4

992

1.5

126

TABLE 27 103
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Constituent

Number of Maxtcompostte Minimum

mum 

samples

Mean Median

12331500.-FI JNT CREEK NEAR DRUMMOND. MONT .-Continued

Period of record for biological data: 1986, 1992-95

ffvdropsvche oecidfntotts

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium 

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

4

4

4

4

4

4

4

4

2 

2

2

2

2

2

2

2

1.0

17.6

26.4

2,550

29.2

2,690

6.9

243

103

16.0

1320

153

1,400

3.1

139

.2

.7

15.1

912

5.8

1,400

.8

128

.6

5.4

729

5.0

1,180

.5

107

.6

6.0

20.2

1,770

16.6

1,820

3.7

180

5.4

10.7

1,020

10.2

1,290

1.8

123

.6

2.8

17.2

1,810

15.7

1,600

3.6

175

5.4

10.7

1,020

10.2

1,290

1.8

123

12331800-CLARK FORK NEAR DRUMMOND. MONT.

Period of record for biological data:

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium 

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

13

13

13

13

13

13

13

13

20 

20

20

20

20

20

20

20

Arctopsvche frandts

1.8

1.0

443

931

11.8

2,010

1.9

308

22 

33

130

290

22

270

1.1

469

1986, 1991-95

.7

.2

18.2

240

2.1

462

.2

142

3 

3

18

76.0

.2

45.9

.1

140

1.2

.8

26.0

497

4.5

923

.6

193

1.1 

.9

60.2

139

.9

132

.4

266

1.1

.8

23.7

443

3.8

643

.4

189

1.0 

.6

50.0

108

.7

144

.3

235

104 Water-quality, bed-sediment, and biological data (Octobar 1994 through September 1995) and statistic*! summaries of data for streams 

In the Upper Clark Fork Basin, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Number of 

Constituent composite 

samples

MaxlMlnlmum 

mum

Mean Median

12331800--CLARK FORK NEAR DRUMMOND. MONT.-Contlnued

Period of record for biological data: 1986, 1991-95

Hvdropsvche eockeretti

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

8

8

8 

8

8

8 

8

8

1.7 .7

1.8 .4

67.2 37.9 

1,060 506

9.0 5.1

901 549 

1.2 .5

195 164

1.2

1.2

50.6 

730

6.3

706 

.8

175

1.4

1.4

49.2 

737

5.9

697 

.8

169

Hvdropsvche morosa group

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

6

6

6 

6

6

6 

6

6

13 1.1

2.8 1.9

57.4 50.2 

1,730 1,380

10.8 7.0

1,940 1,260 

1.7 1.3

250 227

1.2

2.3

55.2 

1,570

8.9

1,610 

1.5

239

12

2.2

55.8 

1,600

9.0

1,620 

1.5

240

Hvdropsvche occidenlatis

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

8

8

8 

8

8

8 

8

8

1.5 .7

8.1 .4

57.2 13.3 

1,800 424

12.5 2.9

2,920 619 

2.4 .5

283 164

1.1

2.5

46.5 

1,080

8.1

1,670 

1.5

226

1.1

2.0

49.3 

865

7.3

1,210 

1.7

222

Hvdropsvche spp.

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

1

0

1 

1

1

0 

0

1

__

._

--

..

2.6

85.0 

940

9.1

260

TABLE 27 105
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Constituent

Number of 

composite 

samples

Maximum

Minimum Mean Median

122US10..ROCK CREEK NEAR CLINTON. MONT.

Period of record for biological data: 1987, 1991-95

Arctopsvche frandis

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

22

22

22 

22

22

22 

22

22

CJaassi

11

11

11 

11

11

11 

11

11

3

2.9

123 

770

1.0

328 

1.6

189

tnia sabulosa 

3

1.8

40.7 

115

1.0

43.2 

.9

242

.1

6

4.7 

191

.1

113 

.2

84

.1

.5

18.1 

49.8

.1

15.7 

.1

164

.2

1.1

8.0 

418

.4

207 

.7

122

.2

.9

29.5 

81.3

.4

28.5 

.3

201

.1

1.0

7.5 

398

3

214

120

.1

.6

28.5 

813

3

29.0 

3

211

Hvdropsvche cockerelli

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

3

3

3 

3

3

3 

3

3

<.2

1.0

13.1 

609

<1.1

258 

.9

99

<.2

.9

6.0 

485

<1.1

192 

.4

82

-1

.9

8.6 

530

-1

219 

.6

89

<.2

.9

6.6 

497

<1.1

208 

.4

86

Hvdropsvche occidentals

Cadmium

Chromium

Copper 

Iron

Lead

Manganese 

Nickel

Zinc

4

4

4 

4

4

4 

4

4

<1.0

2.4

17.6 

752

6.0

268 

1.7

144

<3

.9

9.6 

520

1.2

169 

.6

99

-1

1.6

12.0 

642

3.0

228 

1.2

121

<3

.9

10.2 

648

1.2

215 

.9

117

106 Water-quality, bad-aadlmant, and biological data (Octobar 1994 through Saptambar 1995) and statiatical summarlaa of data for atraama 

In the Uppar Clark Fork Baain, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium 

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Number of MaxiConstituent composite 

mum 

samples

123:U55A~rLARK FORK AT TURAH BRIDGE

Period of record for biological data:

Arctoosvche ffondill

IS 1.9

15 2.1

15 33.8

15 960

15 3.9

15 825

15 .9

15 240

f'lgasstnin ""^iifowi

14 1.7

14 2.0

14 76.5

14 181

14 1.0

14 117

14 .6

14 268

12 1.4 

12 8.0

12 48.6

12 1,100

12 5.7

12 788

12 2.6

12 224

Minimum Mean Median

. NEAR BONNER. MONT.

1986, 1991-95

.6

.6

20.1

420

2.1

351

.4

152

.3

.4

43.0

58.6

.2

42.0

.1

144

[

.6 

1.0

26.4

688

2.2

426

.6

148

.9

1.3

25.2

616

2.9

537

.7

180

.8

.9

56.5

97.4

.6

73.8

.2

210

.8 

2.0

36.7

934

3.7

544

1.1

177

.8

1.2

25.2

592

2.8

505

.6

167

.7

.8

55.6

94.1

.6

65.9

.2

208

.7 

1.5

35.7

949

3.7

533

1.0

175

Hvdropsvche morosa group

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

1 

1 

1 

1 

1 

1 ~

1 

1

--

~

--

~

1.1

4.6

26.8

986

6.6

U20

1.7

231

-

-

TABLE 27 107
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Constituent

Number of

composite

samples

Maximum

Minimum Mean Median

12334SSO-CLARK FORK AT TURAH BRIDGE. NEAR BQNNER. MONT Continued

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

Period of record for biological data: 1986,1991-95

Hvdroosvche offidtntnlis

9

9

9

9

9

9

9

9

.9

2.4

42.5

1,130

8.2

1,510

1.1

231

.3

.6

34.1

472

3.0

454

.6

145

.7

1.6

37.6

859

5.0

795

.8

185

.7

1.5

38.1

868

4.6

666

.8

179

12340000-BLACKFOOT RIVER NEAR BONNER. MONT. 

Period of record for biological data: 1986-87,1991,1993

Arctopsvche vrandis

6

0

6

6

6

0

0

6

9

0

9

9

9

0

0

9

<.4

17.9

483

<2.1

366

ClfifissentQ sobuloso

.6

~

51.0

199

<.9

~

233

<.l

~

12.1

108

<.6

~

~

123

.1

32.0

68.0

<.3

~

184

<.3

14.3

327

<1.1

223

.4

43.0

116

<.5

~

203

<3

13.1

431

<1.5

136

£

44.0

113

<.5

-

-

197

ffvdroDsvcht occidfntfilis

7

7

7

7

7

7

7

7

22

2.1

20.6

1,530

1.9

474

1.7

150

.8

1.2

13.2

1,060

1.1

414

.9

130

1.2

1.7

15.4

1,300

1.5

447

1.2

142

1.0

1.6

14.7

1,300

1.6

452

1.2

145

108 Water-quality, bed-sediment, and biological data (Octobar 1994 through September 1995) and statistical summarias of data for straams 

in the Upper Clark Fork Basin, Montana
Table 27. Statistical summary of biological data for the upper Clark Fork basin, Montana, August 1986 through 

August 1995 (Continued)

Constituent

Number of 

composite 

samples

Maximum

Minimum Mean Median

12353000-CLARK FORK BfiLQW MJSSOULA- MONT.2

Period of record for biological data: 1986, 1990-95

Aretoosvfhf muulis

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

6

6

6

6

6

6

6

6

.9

2.7

22.0

525

1.9

1,090

1.0

169

.3

.5

9.4

343

1.0

511

.4

106

.5

1.1

15.8

435

1.4

773

.7

139

.4

1.0

16.7

432

1.3

712

.7

140

Cloosscnio sabulosa

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

22

22

22

22

22

22

22

22

.7

1.2

57.8

127

13

168

3

286

.2

.05

31.1

66.6

.1

48.9

.1

146

.4

.6

44.8

86.7

.4

95.7

.2

200

3

5

44.9

81.3

3

91.8

,2

195

Hvdropsvche eoekerettt

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

18

18

18

18

18

18

18

18

.7

3.4

393

1,590

3.6

1,180

1.5

172

.2

.8

12.4

645

1.2

353

.5

77.4

.5

2.0

28.0

1,140

2.1

728

1.2

145

.6

1.9

29.5

1,170

1.9

663

1.3

163

Hvdropsvche off ftff fffgfiJT

Cadmium

Chromium

Copper

Iron

Lead

Manganese

Nickel

Zinc

8

8

8

8

8

8

8

8

.9

3.5

30.5

1,420

3.5

1,460

2.2

193

.2

.2

18.9

482

.7

667

.5

116

.4

1.4

23.4

806

1.8

949

1.0

141

.2

1.2

20.7

731

1.8

956

.8

131

'Values determined by arbitrarily substituting one-half of the detection level for censored (<) values, when both 

uncensored and censored values are used in determining the mean. When all data are below the detection level, the 

median is determined by ranking the censored values in order of detection level. No mean is reported when all values 

are below the detection level.

2Samples collected about 30 miles downstream of water-quality station to conform to previous sampling location.

 U.S. COVEHMHEBT PUNTING OFFICE: 1996-777-000/45074 TABLE 27 109