Table 1–1. Summary information relating to quality-control samples (equipment blank and replicate samples) collected at sites in the Boulder River and Tenmile Creek 

watersheds, Montana, based on data collected during water years 1997–2013.

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. LRL, laboratory reporting level; RPD, relative percent difference; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; NA, not applicable; mg/L, micrograms per liter; mg/L, milligrams per liter]

Constituent or property, 

units of measurement

Summary information relating to field blank samples Summary information relating to field replicate 

samples

Number of 

field blank 

samples

Number of field 

blank samples 

with detected 

concentrations 

greater than the 

LRL at the time 

of analysis

Percent of field 

blank samples 

with detected 

concentrations 

greater than the 

LRL at the time 

of analysis

Median 

detected 

concentration 

for field blank 

samples

Maximum 

detected 

concentration 

for field blank 

samples

Number 

of field 

replicate 

pairs

10th 

percentile 

RPD1

Median 

RPD

90th 

percentile 

RPD1

Specific conductance, mS/cm at 25 °C NA NA NA NA NA 26 0.0 0.0 0.0

Cadmium, filtered, mg/L 30 0 0 no detections no detections 34 -4.3 0.0 4.2

Cadmium, unfiltered-recoverable, mg/L 30 0 0 no detections no detections 34 -3.3 -0.1 5.5

Copper, filtered, mg/L 30 8 27 0.242 0.526 34 -4.3 0.0 8.3

Copper, unfiltered-recoverable, mg/L 30 3 10 0.46 1.03 34 -11 -1.1 11

Lead, filtered, mg/L 30 1 3 0.048 0.048 34 -11 0.0 13

Lead, unfiltered-recoverable, mg/L 30 4 13 0.04 0.12 34 -3.7 0.2 10

Zinc, filtered, mg/L 30 13 43 0.43 2.40 34 -2.1 -0.2 3.2

Zinc, unfiltered-recoverable, mg/L 30 6 20 1.19 5.84 34 -2.7 -0.2 4.2

Arsenic, filtered, mg/L 30 1 3 0.03 0.03 34 -2.0 0.2 4.6

Arsenic, unfiltered-recoverable, mg/L 30 2 7 0.09 0.12 34 -8.2 2.1 15

Suspended sediment, mg/L NA NA NA NA NA 21 -62 0.0 89

1

Relative percent difference (RPD) for each primary and replicate sample pair is calculated by using the following equation:

RPD

X Y

X Y = −

[ ] +

100

2  ( ) /

where

RPD is the relative percent difference,

X is the value of the primary sample, and

Y is the value of the replicate sample.
Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data]

Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Boulder River above Kleinsmith Gulch (site 1, fig. 1, table 1)

5/2012–8/2013 Streamflow, instantaneous, ft3

/s 7(0) 9.5 ND3 23 97 ND3 237 NA

pH, standard units 7(0) 7.4 ND3 7.6 7.8 ND3 8.4 NA

Specific conductance, μS/cm at 25 °C 7(0) 56 ND3 141 114 ND3 157 NA

Hardness, mg/L as CaCO3 7(0) 21.2 ND3 47.1 42.5 ND3 59.2 NA

Calcium, filtered, mg/L 7(0) 6.37 ND3 14.1 12.8 ND3 17.9 NA

Magnesium, filtered, mg/L 7(0) 1.29 ND3 2.91 2.57 ND3 3.53 NA

Cadmium, filtered, μg/L 7 (6) 0.017 ND4 ND4 ND4 ND4 ND4 NA

Cadmium, unfiltered-recoverable, μg/L 7 (3) 0.019 ND3 0.019 0.020 ND3 0.028

Copper, filtered, μg/L 7 (0) 0.90 ND3 1.90 1.74 ND3 2.30

106

Copper, unfiltered-recoverable, μg/L 7 (0) 1.00 ND3 1.80 1.86 ND3 3.30

Lead, filtered, μg/L 7 (0) 0.032 ND3 0.084 0.095 ND3 0.170

56

Lead, unfiltered-recoverable, μg/L 7 (0) 0.10 ND3 0.15 0.39 ND3 1.09

Zinc, filtered, μg/L 7 (2) 1.50 ND3 1.50 2.20 ND3 6.20

47

Zinc, unfiltered-recoverable, μg/L 7 (3) 3.20 ND3 3.20 3.25 ND3 5.30

Arsenic, filtered, μg/L 7 (0) 2.50 ND3 3.00 3.17 ND3 4.00

86

Arsenic, unfiltered-recoverable, μg/L 7 (0) 3.00 ND3 3.50 3.43 ND3 4.10

Suspended sediment, mg/L 7(0) 1 ND3 3 10 ND3 29 NA

Suspended sediment, percent fines5 7(0) 35 ND3 88 76 ND3 98 NA

Bullion Mine adit (site 2, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 14(0) 0.01 0.01 0.01 0.01 0.01 0.03 NA

pH, standard units 18(0) 2.5 2.8 3.0 3.0 3.3 3.4 NA

Specific conductance, μS/cm at 25 °C 18(0) 1,070 1,370 1,580 1,770 2,080 3,100 NA
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Bullion Mine adit (site 2, fig. 1, table 1)—Continued

Hardness, mg/L as CaCO3 18(0) 234 277 290 302 324 398 NA

Calcium, filtered, mg/L 18(0) 57.6 68.1 72.0 73.7 80.1 92.6 NA

Magnesium, filtered, mg/L 18(0) 21.9 25.9 27.0 28.5 29.8 40.5 NA

Cadmium, filtered, μg/L 18 (0) 214 278 344 431 480 1,070

110

Cadmium, unfiltered-recoverable, μg/L 18 (0) 193 266 314 402 404 1,100

Copper, filtered, μg/L 18 (0) 1,220 3,130 4,920 7,330 9,020 22,500

98

Copper, unfiltered-recoverable, μg/L 18 (0) 1,330 3,450 5,020 7,340 9,460 23,100

Lead, filtered, μg/L 18 (0) 196 284 355 358 408 666

92

Lead, unfiltered-recoverable, μg/L 18 (0) 266 362 384 412 446 664

Zinc, filtered, μg/L 18 (0) 22,100 28,300 35,200 48,400 53,100 141,000

111

Zinc, unfiltered-recoverable, μg/L 18 (0) 20,800 29,300 31,800 45,400 46,800 132,000

Arsenic, filtered, μg/L 18 (0) 513 968 1,530 2,350 3,040 10,100

63

Arsenic, unfiltered-recoverable, μg/L 18 (0) 904 1,420 2,420 2,870 3,390 9,700

Suspended sediment, mg/L 0(0) -- -- -- -- -- -- NA

Suspended sediment, percent fines5 0(0) -- -- -- -- -- -- NA

Bullion Mine tributary at mouth (site 3, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 20(0) 0.07 0.22 0.61 2.2 3.8 8.5 NA

pH, standard units 20(0) 5.5 6.7 6.8 6.9 7.2 7.7 NA

Specific conductance, μS/cm at 25 °C 20(0) 49 57 115 114 152 226 NA

Hardness, mg/L as CaCO3 20(0) 17.6 21.0 39.4 41.8 57.4 80.9 NA

Calcium, filtered, mg/L 20(0) 5.1 6.1 11.3 11.9 16.3 22.6 NA

Magnesium, filtered, mg/L 20(0) 1.19 1.38 2.82 2.95 4.03 5.93 NA

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Bullion Mine tributary at mouth (site 3, fig. 1, table 1)—Continued

Cadmium, filtered, μg/L 20 (0) 2.07 3.50 13.9 12.5 17.0 38.6

93

Cadmium, unfiltered-recoverable, μg/L 20 (0) 2.29 3.84 15.0 12.3 17.0 31.9

Copper, filtered, μg/L 20 (0) 16.1 35.6 52.8 87.2 79.2 416

43

Copper, unfiltered-recoverable, μg/L 20 (0) 41.6 72.6 122 161 244 436

Lead, filtered, μg/L 20 (3) 0.101 0.248 0.696 0.838 1.11 3.47

14

Lead, unfiltered-recoverable, μg/L 20 (0) 2.02 3.98 5.16 5.88 7.46 11.6

Zinc, filtered, μg/L 20 (0) 252 430 1,700 1,470 2,050 4,550

92

Zinc, unfiltered-recoverable, μg/L 20 (0) 280 452 1,840 1,490 1,990 4,080

Arsenic, filtered, μg/L 20 (0) 0.8 1.5 3.5 4.8 5.3 17.9

18

Arsenic, unfiltered-recoverable, μg/L 20 (0) 6.1 12.6 19.1 20.7 26.2 47.9

Suspended sediment, mg/L 19(0) 1 5 7 7 10 17 NA

Suspended sediment, percent fines5 20(0) 13 49 88 72 97 99 NA

Jack Creek at mouth (site 4, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 20(0) 1.0 1.8 5.2 15 25 52 NA

pH, standard units 20(0) 7.0 7.3 7.4 7.4 7.5 8.0 NA

Specific conductance, μS/cm at 25 °C 20(0) 42 49 78 73 90 101 NA

Hardness, mg/L as CaCO3 20(0) 16.2 19.2 29.2 28.0 34.8 38.4 NA

Calcium, filtered, mg/L 20(0) 4.66 5.53 8.35 7.97 9.90 10.9 NA

Magnesium, filtered, mg/L 20(0) 1.11 1.34 2.04 1.97 2.46 2.73 NA

Cadmium, filtered, μg/L 20 (0) 0.544 0.720 1.27 1.31 1.86 2.24

89

Cadmium, unfiltered-recoverable, μg/L 20 (0) 0.543 0.878 1.43 1.52 2.01 3.98

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Jack Creek at mouth (site 4, fig. 1, table 1)—Continued

Copper, filtered, μg/L 20 (0) 5.40 8.75 11.6 13.8 18.8 26.5

67

Copper, unfiltered-recoverable, μg/L 20 (0) 7.90 12.3 17.4 24.6 26.6 137

Lead, filtered, μg/L 20 (0) 0.119 0.178 0.286 0.332 0.468 0.617

29

Lead, unfiltered-recoverable, μg/L 20 (0) 0.31 0.60 0.99 2.78 2.48 20.1

Zinc, filtered, μg/L 20 (0) 73.6 104 169 181 262 318

85

Zinc, unfiltered-recoverable, μg/L 20 (0) 74.5 106 198 191 271 359

Arsenic, filtered, μg/L 20 (0) 2.9 4.0 4.2 4.6 5.1 7.7

54

Arsenic, unfiltered-recoverable, μg/L 20 (0) 4.8 5.7 7.9 10.2 10.6 46.8

Suspended sediment, mg/L 20(0) 1 1 1 10 11 57 NA

Suspended sediment, percent fines5 20(0) 3 43 81 67 86 93 NA

Basin Creek at Basin (site 5, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 20(0) 2.9 4.8 18 76 98 414 NA

pH, standard units 20(0) 7.0 7.3 7.6 7.5 7.8 8.1 NA

Specific conductance, μS/cm at 25 °C 20(0) 34 45 76 72 93 118 NA

Hardness, mg/L as CaCO3 20(0) 12.4 16.3 29.1 28.0 37.1 46.3 NA

Calcium, filtered, mg/L 20(0) 3.62 4.73 8.30 8.04 10.63 13.2 NA

Magnesium, filtered, mg/L 20(0) 0.82 1.10 2.03 1.93 2.56 3.22 NA

Cadmium, filtered, μg/L 20 (0) 0.158 0.209 0.245 0.252 0.284 0.419

81

Cadmium, unfiltered-recoverable, μg/L 20 (0) 0.177 0.226 0.302 0.332 0.365 0.726

Copper, filtered, μg/L 20 (0) 3.00 4.05 5.50 5.49 6.20 9.30

72

Copper, unfiltered-recoverable, μg/L 19 (0) 3.20 4.00 7.60 7.72 10.6 19.4

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Basin Creek at Basin (site 5, fig. 1, table 1)—Continued

Lead, filtered, μg/L 20 (0) 0.085 0.165 0.274 0.336 0.520 0.689

42

Lead, unfiltered-recoverable, μg/L 20 (0) 0.31 0.45 0.65 2.50 3.63 12.8

Zinc, filtered, μg/L 20 (0) 24.8 32.1 41.9 43.2 53.1 68.4

86

Zinc, unfiltered-recoverable, μg/L 20 (0) 26.1 35.2 48.9 48.6 56.3 87.2

Arsenic, filtered, μg/L 20 (0) 3.2 4.0 4.7 4.7 5.6 6.1

74

Arsenic, unfiltered-recoverable, μg/L 20 (0) 3.6 5.3 6.3 7.9 8.1 27.9

Suspended sediment, mg/L 20(0) 1 1 2 17 13 128 NA

Suspended sediment, percent fines5 20(0) 16 38 77 62 83 91 NA

Crystal Mine adit (site 6, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 18(0) 0.02 0.04 0.05 0.06 0.07 0.20 NA

pH, standard units 18(0) 2.1 3.8 4.7 4.5 5.4 5.7 NA

Specific conductance, μS/cm at 25 °C 17(0) 478 610 695 695 788 961 NA

Hardness, mg/L as CaCO3 18(0) 144 168 203 192 211 218 NA

Calcium, filtered, mg/L 18(0) 39.1 45.4 53.9 52.0 57.5 59.8 NA

Magnesium, filtered, mg/L 18(0) 11.4 14.0 15.7 15.1 16.4 16.9 NA

Cadmium, filtered, μg/L 18 (0) 331 431 536 512 555 718

103

Cadmium, unfiltered-recoverable, μg/L 18 (0) 342 416 521 498 574 638

Copper, filtered, μg/L 18 (0) 2,610 4,140 7,165 6,931 8,230 15,000

97

Copper, unfiltered-recoverable, μg/L 18 (0) 3,160 4,320 7,370 7,068 8,810 15,600

Lead, filtered, μg/L 18 (0) 8.11 14.8 63.5 82 134 266

78

Lead, unfiltered-recoverable, μg/L 18 (0) 24.6 27.7 81.3 121 206 297

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Crystal Mine adit (site 6, fig. 1, table 1)—Continued

Zinc, filtered, μg/L 18 (0) 24,500 36,700 44,000 41,994 47,200 57,200

106

Zinc, unfiltered-recoverable, μg/L 18 (0) 26,700 31,800 41,500 38,578 44,100 50,600

Arsenic, filtered, μg/L 18 (0) 18.4 77.0 121 157 206 715

32

Arsenic, unfiltered-recoverable, μg/L 18 (0) 86 150 372 704 1,160 2,450

Suspended sediment, mg/L 0(0) -- -- -- -- -- -- NA

Suspended sediment, percent fines5 0(0) -- -- -- -- -- -- NA

Cataract Creek above Uncle Sam Gulch (site 7, fig. 1, table 1)

3/20110–8/2010 Streamflow, instantaneous, ft3

/s 12(0) 1.6 2.8 5.9 35 34 220 NA

pH, standard units 11(0) 7.0 7.4 7.6 7.5 7.8 7.9 NA

Specific conductance, μS/cm at 25 °C 12(0) 40 54 101 88 115 124 NA

Hardness, mg/L as CaCO3 12(0) 16.7 22.9 43.6 38.7 51.7 54.3 NA

Calcium, filtered, mg/L 12(0) 5.06 6.98 13.45 11.88 16.00 16.8 NA

Magnesium, filtered, mg/L 12(0) 0.99 1.33 2.44 2.19 2.89 3.05 NA

Cadmium, filtered, μg/L 12 (0) 0.118 0.137 0.147 0.171 0.211 0.287

86

Cadmium, unfiltered-recoverable, μg/L 12 (0) 0.121 0.133 0.171 0.188 0.220 0.373

Copper, filtered, μg/L 12 (0) 2.40 3.05 3.55 4.13 5.60 6.90

91

Copper, unfiltered-recoverable, μg/L 12 (0) 2.60 3.00 3.90 4.74 5.80 10.0

Lead, filtered, μg/L 12 (0) 0.080 0.100 0.142 0.208 0.272 0.540

31

Lead, unfiltered-recoverable, μg/L 12 (0) 0.14 0.22 0.46 1.30 0.70 9.41

Zinc, filtered, μg/L 12 (0) 25.0 31.3 37.2 40.9 51.1 62.2

96

Zinc, unfiltered-recoverable, μg/L 12 (0) 26.1 31.4 38.8 41.6 52.2 62.2

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Cataract Creek above Uncle Sam Gulch (site 7, fig. 1, table 1)—Continued

Arsenic, filtered, μg/L 12 (0) 1.8 2.3 2.5 2.5 2.7 3.7

91

Arsenic, unfiltered-recoverable, μg/L 12 (0) 1.9 2.5 2.8 3.1 3.4 6.7

Suspended sediment, mg/L 12(0) 1 1 1 7 4 58 NA

Suspended sediment, percent fines5 12(0) 13 71 80 74 85 99 NA

Cataract Creek at Basin (site 8, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 20(0) 2.8 6.1 15 48 72 228 NA

pH, standard units 20(0) 7.3 7.4 7.7 7.7 7.9 8.1 NA

Specific conductance, μS/cm at 25 °C 19(0) 44 54 108 99 133 175 NA

Hardness, mg/L as CaCO3 20(0) 18.4 21.7 45.5 43.4 61.1 74.2 NA

Calcium, filtered, mg/L 20(0) 5.56 6.52 14.0 13.2 18.7 22.5 NA

Magnesium, filtered, mg/L 20(0) 1.11 1.31 2.64 2.56 3.49 4.37 NA

Cadmium, filtered, μg/L 20 (0) 0.499 0.660 1.02 0.961 1.23 1.37

98

Cadmium, unfiltered-recoverable, μg/L 20 (0) 0.611 0.938 1.04 1.08 1.26 1.93

Copper, filtered, μg/L 20 (0) 4.00 6.05 9.50 10.1 13.1 23.2

90

Copper, unfiltered-recoverable, μg/L 20 (0) 4.80 7.75 10.6 14.5 20.8 35.7

Lead, filtered, μg/L 20 (0) 0.125 0.174 0.281 0.371 0.542 0.828

20

Lead, unfiltered-recoverable, μg/L 20 (0) 0.42 0.87 1.38 3.71 6.49 13.6

Zinc, filtered, μg/L 20 (0) 65.6 81.4 101 108 123 182

98

Zinc, unfiltered-recoverable, μg/L 20 (0) 73.5 88.9 103 112 130 192

Arsenic, filtered, μg/L 20 (0) 2.9 3.4 3.9 4.4 5.1 8.2

64

Arsenic, unfiltered-recoverable, μg/L 20 (0) 4.1 4.8 6.1 7.7 11.4 16.9

Suspended sediment, mg/L 20(0) 1 1 2 9 10 50 NA

Suspended sediment, percent fines5 20(0) 22 44 69 64 83 92 NA

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

High Ore Creek near Basin (site 9, fig. 1, table 1)

3/2011–8/2013 Streamflow, instantaneous, ft3

/s 12(0) 0.36 0.75 1.6 3.5 2.2 24 NA

pH, standard units 12(0) 7.6 7.9 8.1 8.1 8.2 8.4 NA

Specific conductance, μS/cm at 25 °C 12(0) 126 190 277 244 288 306 NA

Hardness, mg/L as CaCO3 12(0) 52.4 87.2 133 115 142 154 NA

Calcium, filtered, mg/L 12(0) 14.7 24.3 36.6 31.6 38.6 42.3 NA

Magnesium, filtered, mg/L 12(0) 3.78 6.47 10.1 8.82 11.1 11.7 NA

Cadmium, filtered, μg/L 12 (0) 0.684 1.02 1.57 1.51 1.93 2.35

80

Cadmium, unfiltered-recoverable, μg/L 12 (0) 1.270 1.56 1.96 2.47 2.48 8.50

Copper, filtered, μg/L 12 (1) 1.50 1.91 2.15 2.48 2.65 6.00

61

Copper, unfiltered-recoverable, μg/L 12 (0) 2.50 3.10 3.50 11.7 4.85 91.1

Lead, filtered, μg/L 12 (0) 0.146 0.232 0.299 0.552 0.491 2.96

4

Lead, unfiltered-recoverable, μg/L 12 (0) 1.84 3.02 6.77 45.2 11.1 438

Zinc, filtered, μg/L 12 (0) 228 271 427 458 612 844

92

Zinc, unfiltered-recoverable, μg/L 12 (0) 313 382 462 612 773 1,510

Arsenic, filtered, μg/L 12 (0) 15.3 16.3 23.8 23.4 29.7 32.2

79

Arsenic, unfiltered-recoverable, μg/L 12 (0) 20.2 23.5 30.0 65.7 32.0 458

Suspended sediment, mg/L 12(0) 1 3 8 37 12 255 NA

Suspended sediment, percent fines5 12(0) 25 70 78 73 83 94 NA

Boulder River below Little Galena Gulch (site 10, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 20(0) 18 40 101 414 505 2,880 NA

pH, standard units 20(0) 7.3 7.9 8.0 8.0 8.3 8.6 NA

Specific conductance, μS/cm at 25 °C 20(0) 49 69 124 114 158 170 NA

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Boulder River below Little Galena Gulch (site 10, fig. 1, table 1)—Continued

Hardness, mg/L as CaCO3 20(0) 19.3 25.1 46.1 44.2 62.3 70.7 NA

Calcium, filtered, mg/L 20(0) 5.76 7.42 13.8 13.1 18.5 20.8 NA

Magnesium, filtered, mg/L 20(0) 1.20 1.60 2.88 2.80 3.90 4.55 NA

Cadmium, filtered, μg/L 20 (0) 0.135 0.174 0.226 0.226 0.251 0.382

80

Cadmium, unfiltered-recoverable, μg/L 20 (0) 0.183 0.240 0.281 0.658 0.348 7.43

Copper, filtered, μg/L 20 (0) 4.20 5.30 5.95 6.64 6.65 19.4

86

Copper, unfiltered-recoverable, μg/L 20 (0) 5.20 6.20 6.95 22.9 9.45 304

Lead, filtered, μg/L 20 (0) 0.074 0.136 0.171 0.360 0.333 1.860

19

Lead, unfiltered-recoverable, μg/L 20 (0) 0.32 0.55 0.89 15.9 3.20 280

Zinc, filtered, μg/L 20 (0) 15.5 28.6 31.2 37.1 41.6 69.7

75

Zinc, unfiltered-recoverable, μg/L 20 (0) 24.7 35.9 41.6 79.2 62.9 716

Arsenic, filtered, μg/L 20 (0) 3.3 4.0 4.8 5.3 6.4 9.50

75

Arsenic, unfiltered-recoverable, μg/L 20 (0) 3.8 5.7 6.4 18.7 7.6 245

Suspended sediment, mg/L 20(0) 1 2 3 65 17 969 NA

Suspended sediment, percent fines5 20(0) 30 50 76 69 87 90 NA

Tenmile Creek above City Diversion (site 11, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 16(0) 0.86 3.0 6.6 27 35 123 NA

pH, standard units 17(0) 6.6 7.0 7.2 7.2 7.5 7.8 NA

Specific conductance, μS/cm at 25 °C 18(0) 29 34 55 52 62 107 NA

Hardness, mg/L as CaCO3 18(0) 10.7 12.3 20.2 19.1 21.9 42.6 NA

Calcium, filtered, mg/L 18(0) 3.20 3.64 5.92 5.61 6.38 12.6 NA

Magnesium, filtered, mg/L 18(0) 0.672 0.776 1.32 1.24 1.46 2.73 NA

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Tenmile Creek above City Diversion (site 11, fig. 1, table 1)—Continued

Cadmium, filtered, μg/L 18 (0) 0.255 0.356 0.682 0.760 1.03 2.18

90

Cadmium, unfiltered-recoverable, μg/L 18 (0) 0.282 0.476 0.754 0.833 1.10 2.00

Copper, filtered, μg/L 18 (0) 2.00 2.40 3.25 3.36 4.10 9.10

89

Copper, unfiltered-recoverable, μg/L 18 (0) 2.30 2.80 3.65 4.13 4.80 40.0

Lead, filtered, μg/L 18 (0) 0.329 0.753 0.800 0.913 0.994 3.97

46

Lead, unfiltered-recoverable, μg/L 18 (0) 0.91 1.61 1.75 3.75 3.85 18.8

Zinc, filtered, μg/L 18 (0) 49.0 63.8 179 180 243 542

107

Zinc, unfiltered-recoverable, μg/L 18 (0) 46.4 70.1 167 177 219 530

Arsenic, filtered, μg/L 18 (0) 2.2 3.5 4.4 4.7 5.8 9.6

70

Arsenic, unfiltered-recoverable, μg/L 18 (0) 2.8 5.3 6.3 6.8 7.9 12.6

Suspended sediment, mg/L 18(0) 1 2 3 21 7 195 NA

Suspended sediment, percent fines5 18(0) 22 41 72 65 90 96 NA

Minnehaha Creek near Rimini (site 12, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 18(0) 0.38 1.1 2.8 14 10 72 NA

pH, standard units 17(0) 6.7 7.2 7.3 7.3 7.5 7.8 NA

Specific conductance, μS/cm at 25 °C 18(0) 36 46 62 58 65 83 NA

Hardness, mg/L as CaCO3 18(0) 11.5 15.1 21.2 19.4 23.0 29.1 NA

Calcium, filtered, mg/L 18(0) 3.27 4.40 6.06 5.59 6.57 8.24 NA

Magnesium, filtered, mg/L 18(0) 0.799 0.998 1.43 1.33 1.57 2.06 NA

Cadmium, filtered, μg/L 18 (0) 0.479 0.732 0.824 0.819 0.927 1.06

89

Cadmium, unfiltered-recoverable, μg/L 18 (0) 0.774 0.824 0.927 0.997 1.12 1.55

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Minnehaha Creek near Rimini (site 12, fig. 1, table 1)—Continued

Copper, filtered, μg/L 18 (0) 3.10 3.80 5.70 5.88 7.20 11.9

79

Copper, unfiltered-recoverable, μg/L 18 (0) 2.80 5.70 7.25 8.90 9.6 27.4

Lead, filtered, μg/L 18 (0) 0.097 0.120 0.252 0.702 0.686 4.77

24

Lead, unfiltered-recoverable, μg/L 18 (0) 0.23 0.46 1.04 4.35 2.39 44.9

Zinc, filtered, μg/L 18 (0) 79.0 130 145 146 162 193

98

Zinc, unfiltered-recoverable, μg/L 18 (0) 115 130 148 151 172 196

Arsenic, filtered, μg/L 18 (0) 1.7 2.4 2.6 2.8 3.0 5.2

84

Arsenic, unfiltered-recoverable, μg/L 18 (0) 1.9 2.7 3.1 4.7 3.3 26.4

Suspended sediment, mg/L 18(0) 1 2 4 14 10 98 NA

Suspended sediment, percent fines5 18(0) 15 42 57 57 80 91 NA

Tenmile Creek near Rimini (site 13, fig. 1, table 1)

4/2009–8/2013 Streamflow, instantaneous, ft3

/s 17(0) 1.0 4.0 14 93 76 536 NA

pH, standard units 17(0) 6.9 7.1 7.3 7.3 7.5 7.6 NA

Specific conductance, μS/cm at 25 °C 18(0) 38 44 88 88 122 159 NA

Hardness, mg/L as CaCO3 18(0) 14.5 15.9 30.9 33.3 47.0 60.9 NA

Calcium, filtered, mg/L 18(0) 4.25 4.62 8.74 9.48 13.3 17.4 NA

Magnesium, filtered, mg/L 18(0) 0.940 1.06 2.19 2.33 3.34 4.26 NA

Cadmium, filtered, μg/L 18 (0) 0.459 0.572 1.23 1.38 1.49 4.30

93

Cadmium, unfiltered-recoverable, μg/L 18 (0) 0.466 1.16 1.32 1.60 1.81 5.05

Copper, filtered, μg/L 18 (0) 2.00 3.70 4.80 5.87 8.20 13.2

79

Copper, unfiltered-recoverable, μg/L 18 (0) 2.00 4.50 6.05 10.2 12.2 35.7

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Period of waterquality sampling 

during 

water years 

2009–13

Constituent or property, 

units of measurement

Statistical summaries of water-quality data1 Ratio of 

median filtered 

to median 

unfilteredrecoverable 

concentrations 

for trace 

elements, 

percent

Number of 

samples 

(values in 

parentheses 

indicate 

number of 

censored 

values)

Minimum 

uncensored 

value2

25th 

percentile Median Mean 75th percentile Maximum

Tenmile Creek near Rimini (site 13, fig. 1, table 1)—Continued

Lead, filtered, μg/L 18 (0) 0.104 0.527 0.805 0.816 0.949 2.23

39

Lead, unfiltered-recoverable, μg/L 18 (0) 0.33 1.15 2.04 9.95 5.16 80.5

Zinc, filtered, μg/L 18 (0) 92.5 100 239 258 280 785

102

Zinc, unfiltered-recoverable, μg/L 18 (0) 92.4 167 234 267 311 699

Arsenic, filtered, μg/L 18 (0) 5.4 7.5 13.9 17.3 25.3 62.6

61

Arsenic, unfiltered-recoverable, μg/L 18 (0) 6.2 16.6 22.6 32.4 27.5 133

Suspended sediment, mg/L 17(0) 1 1 3 22 4 194 NA

Suspended sediment, percent fines5 17(0) 33 63 87 78 94 96 NA

1

Distributional parameters affected by censored observations (that is, concentrations reported as less than the laboratory reporting level) were estimated by using adjusted maximum likelihood estimation 

(Cohn, 1988).

2

Minimum uncensored value refers to the smallest concentration reported as detected above any of the various laboratory reporting levels applicable for a given constituent.

3

Not determined because of insufficient number of samples to statistically define distributional parameter.

4

Not determined because an excessive number of values were censored (that is, concentrations reported as less than the laboratory reporting level).

5

Percent fines refers to the percentage of suspended sediment smaller than 0.062-millimeter diameter.

Table 1–2. Summary information relating to water-quality constituents and properties in samples collected at sites in the Boulder River and Tenmile Creek watersheds, 

Montana, based on data collected during water years 2009–13.—Continued

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. ft3/s, cubic feet per second; ND, not determined; NA, not applicable; μS/cm at 25 °C, 

microsiemens per centimeter at 25 degrees Celsius; CaCO3, calcium carbonate; mg/L, milligrams per liter; μg/L, micrograms per liter; --, no data] 
Table 1–3. Aquatic life standards (based on median hardness for water years 2009–13) for sites in the Boulder River and Tenmile Creek watersheds, Montana.

[Water year is the 12-month period from October 1 through September 30 and is designated by the year in which it ends. CaCO3, calcium carbonate]

Site 

number 

(table 1, 

fig. 1)

Site name 

(table 1, fig. 1)

Median hardness 

for water 

years 2009–13, 

in milligrams 

per liter as CaCO3

Aquatic life standards (Montana Department of Environmental Quality, 2012a)

Cadmium Copper Lead Zinc

Acute Chronic Acute Chronic Acute Chronic Acute Chronic

1 Boulder River above Kleinsmith Gulch 47.1 0.99 0.15 6.9 4.9 31 1.2 63 63

2 Bullion Mine adit 290 6.3 0.59 38 23 320 12 290 290

3 Bullion Mine tributary at mouth 39.3 0.83 0.14 5.8 4.2 25 0.97 54 54

4 Jack Creek at mouth 29.2 0.61 0.11 4.4 3.3 17 0.66 42 42

5 Basin Creek at Basin 29.0 0.61 0.11 4.4 3.2 17 0.66 42 42

6 Crystal Mine adit 202 4.4 0.46 27 17 200 7.8 220 220

7 Cataract Creek above Uncle Sam Gulch 43.6 0.92 0.15 6.4 4.6 28 1.1 59 59

8 Cataract Creek at Basin 45.5 0.96 0.15 6.7 4.8 30 1.2 61 61

9 High Ore Creek near Basin 133 2.9 0.33 18 12 120 4.6 150 150

10 Boulder River below Little Galena Gulch 46.1 0.97 0.15 6.7 4.8 30 1.2 62 62

11 Tenmile Creek above City Diversion 20.2 0.42 0.083 3.1 2.4 11 0.42 31 31

12 Minnehaha Creek near Rimini 21.2 0.44 0.086 3.2 2.5 11 0.44 32 32

13 Tenmile Creek near Rimini 30.9 0.65 0.11 4.6 3.4 18 0.71 44 44