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Concentrations and annual fluxes for selected water-quality constituents from the USGS National Stream Water Quality Accounting Network (NASQAN)

By Valerie J. Kelly, Richard P. Hooper, Brent T. Aulenbach, and Mary Janet

Summary Statistics--Mississippi Basin, Water Years 1997-2000

Missouri River near Culbertson, Montana (06185500)

Daily Mean Streamflow

Units                               N             Min     5th       25th     Median    75th      95th      Max

Cubic feet per second             1,827         4,550     5,710     9,270    10,606    14,000    20,500    26,600
Cubic meters per second           1,827           129       162       262       300       396       580       753

Field Parameters, Turbidity, and Suspended Sediment

Units in milligrams per liter, except where noted

Parameter                             N               Min      5th     25th    Median     75th     95th     Max

00010 Temperature (C)                35                 0.0     3.0      7.5      12.5     17.0     20.0     22.0
00076 Turbidity (NTU)                35                 2.9     3.3     18.0      28.0     44.0    288.0    300.0
00095 Conductance (uS/cm)            35               372.0   442.0    581.0     591.0    634.0    714.0    856.0
00300 Dissolved oxygen               35                 7.5     7.7      8.4       9.1     10.4     12.1     13.2
00400 pH (standard units)            35                 7.9     7.9      8.2       8.4      8.5      8.6      8.6
00452 CO3 (filtered)                 35                 0.0     0.0      0.0       4.0      5.0      8.0      9.0
00453 HCO3 (filtered)                35               110.0   134.0    175.0     186.0    190.0    211.0    239.0
39086 Alk (filtered, as CaCO3)       35                90.0   110.0    152.0     155.0    163.0    174.0    210.0
70331 % finer than 62 microns        35                21.3    28.0     40.0      46.0     57.0     76.0     77.0
80154 Suspended sediment             35                35.0   127.0    160.0     264.0    411.0    980.0   1930.0

Nutrients and Organic Carbon, dissolved (filtered at 0.45 microns) and whole-water (unfiltered)

Units in milligrams per liter

Note: because of changes in reporting levels (RL), all censored data in this summary are converted to the highest RL reported for this station

                                          Percent
Parameter                       RL  N    Detections    Min      5th      25th    Median    75th     95th     Max

00608 NH3-N                   .020  35       66      < 0.020  < 0.020  < 0.020    0.015    0.026    0.078    0.102
00613 NO2-N                   .010  35       46      < 0.010  < 0.010  < 0.010  < 0.010    0.010    0.015    0.030
00623 Org+NH3-N (filtered)    .200  35       83      < 0.200  < 0.200    0.147    0.193    0.225    0.469    1.161
00625 Org+NH3-N (whole-water) .200  35       97      < 0.200    0.205    0.271    0.316    0.460    1.414    1.666
00631 NO2+NO3-N               .050  35       51      < 0.050  < 0.050  < 0.050    0.050    0.062    0.195    0.315
00665 Total P (whole-water)   .010  35       97      < 0.010    0.028    0.059    0.106    0.202    0.550    0.761
00666 Total P (filtered)      .050  35       54      < 0.050  < 0.050  < 0.050    0.010    0.017    0.050    0.050
00671 PO4-P                   .010  34      100        0.003    0.003    0.006    0.008    0.010    0.018    0.020
00681 DOC                     .300  33      100        2.463    2.556    2.700    2.900    3.400    6.500    6.800
00689 SOC                     .200  32      100        0.200    0.300    0.577    0.800    1.350    4.700    4.900

Major Ions, dissolved (filtered at 0.45 microns)

Units in milligrams per liter, except where noted

                                          Percent
Parameter                       RL  N    Detections    Min      5th      25th    Median    75th     95th     Max

00915 Calcium                 .020  35      100        22.76    30.50    48.56    49.64    51.11    53.13    53.86
00925 Magnesium               .010  35      100        10.24    13.18    19.30    20.13    20.86    22.25    26.99
00930 Sodium                  .200  35      100        35.62    37.68    41.51    43.23    50.17    76.42    89.34
00935 Potassium               .010  35      100        3.340    3.400    3.540    3.730    4.290    5.950    7.320
00940 Chloride                .010  35      100        3.690    5.465    8.030    8.430    8.872    9.400    11.16
00945 Sulfate                 .010  35      100        81.28    95.93    125.7    135.9    150.0    187.1    215.5
00950 Fluoride                .100  35      100        0.280    0.353    0.633    0.689    0.726    0.895    0.908
00955 Silica                  .010  35      100        5.279    5.475    6.002    6.674    6.886    7.601    7.668

Trace Elements, dissolved (filtered at 0.45 microns)

Units in micrograms per liter

Note: because of changes in reporting levels (RL), all censored data in this summary are converted to the highest RL reported for this station

                                          Percent
Parameter                       RL  N    Detections    Min      5th      25th    Median    75th     95th     Max

01000 Arsenic                  1.0  35      100          1.3      1.3      2.0      2.3      2.7      3.0      3.0
01005 Barium                   1.0  24      100         23.5     30.1     36.4     38.7     39.7     42.6     47.0
01010 Beryllium                1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01020 Boron                   16.0  35      100         72.9     78.9     86.3     91.3     99.1    140.8    167.3
01025 Cadmium                  1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01030 Chromium                 1.0  24       79      <   1.0  <   1.0      1.2      1.9      2.6      4.0      4.3
01035 Cobalt                   1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01040 Copper                   1.0  24      100          1.5      1.7      2.0      2.3      2.8      3.0      4.3
01046 Iron                    10.0  34       12      <  10.0  <  10.0  <  10.0  <  10.0  <  10.0     12.9     17.6
01049 Lead                     1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01056 Manganese                1.0  24       58      <   1.0  <   1.0  <   1.0      1.1      1.7      6.1      7.2
01060 Molybdenum               1.0  24      100          1.9      2.0      2.7      2.8      2.9      3.0      3.2
01065 Nickel                   1.0  24      100          1.1      1.2      1.5      1.7      2.1      3.0      3.3
01075 Silver                   1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01080 Strontium                0.5  35      100        225.2    285.3    439.6    459.5    480.0    504.5    507.5
01085 Vanadium                10.0  35        0      <  10.0  <  10.0  <  10.0  <  10.0  <  10.0  <  10.0  <  10.0
01090 Zinc                     1.0  24       33      <   1.0  <   1.0  <   1.0  <   1.0      1.2      1.5      2.7
01095 Antimony                 1.0  24        0      <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0  <   1.0
01106 Aluminum                 1.0  24       88      <   1.0  <   1.0      1.2      1.4      2.0      5.0      5.8
01130 Lithium                  4.0  35      100         25.8     32.8     48.5     50.6     52.8     57.5     69.2
01145 Selenium                 2.4  35       11      <   2.4  <   2.4  <   2.4  <   2.4  <   2.4      2.4      2.4
22703 Uranium                  1.0  24      100          1.4      1.7      2.5      2.7      2.8      3.0      3.5

Pesticides, dissolved (filtered at 0.7 microns)

Units in micrograms per liter, except where noted

Note: concentrations sometimes are estimated below the reporting level (RL); in this summary, all censored and estimated concentrations are converted to highest RL reported for this station; the percent detections described in the table include estimated concentrations, when appropriate

                                          Percent
Parameter                       RL  N    Detections    Min      5th      25th    Median    75th     95th     Max

04024 Propachlor              .007  35        0      < 0.007  < 0.007  < 0.007  < 0.007  < 0.007  < 0.007  < 0.007
04028 Butylate                .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
04035 Simazine                .005  35        0      < 0.005  < 0.005  < 0.005  < 0.005  < 0.005  < 0.005  < 0.005
04037 Prometon                .018  35       11      < 0.018  < 0.018  < 0.018  < 0.018  < 0.018    0.018    0.018
04040 Desethyl atrazine       .003  35        6      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003    0.003    0.003
04041 Cyanazine               .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
04095 Fonofos                 .003  35        0      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003
34253 alpha-HCH               .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
34653 p,p DDE                 .006  35        6      < 0.006  < 0.006  < 0.006  < 0.006  < 0.006    0.006    0.006
38933 Chlorpyrifos            .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
39341 gamma-HCH               .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
39381 Dieldrin                .001  35        0      < 0.001  < 0.001  < 0.001  < 0.001  < 0.001  < 0.001  < 0.001
39415 Metolachlor             .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
39532 Malathion               .005  35        9      < 0.005  < 0.005  < 0.005  < 0.005  < 0.005    0.005    0.008
39542 Parathion               .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
39572 Diazinon                .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
39632 Atrazine                .004  35       34      < 0.004  < 0.004  < 0.004  < 0.004    0.003    0.005    0.007
46342 Alachlor                .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
49260 Acetochlor              .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
82630 Metribuzin              .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82660 Diethylanaline          .003  35        0      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003
82661 Trifluralin             .002  35        3      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002    0.002
82663 Ethalfluralin           .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82664 Phorate                 .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
82665 Terbacil                .007  35        0      < 0.007  < 0.007  < 0.007  < 0.007  < 0.007  < 0.007  < 0.007
82666 Linuron                 .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
82667 Methyl parathion        .006  35        0      < 0.006  < 0.006  < 0.006  < 0.006  < 0.006  < 0.006  < 0.006
82668 EPTC                    .050  35        0      < 0.050  < 0.050  < 0.050  < 0.050  < 0.050  < 0.050  < 0.050
82669 Pebulate                .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82670 Tebuthiuron             .010  35        0      < 0.010  < 0.010  < 0.010  < 0.010  < 0.010  < 0.010  < 0.010
82671 Molinate                .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82672 Ethoprop                .003  35        0      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003
82673 Benfluralin             .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
82674 Carbofuran              .003  35        3      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003    0.010
82675 Terbufos                .013  35        0      < 0.013  < 0.013  < 0.013  < 0.013  < 0.013  < 0.013  < 0.013
82676 Pronamide               .003  35        6      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003    0.015    0.029
82677 Disulfoton              .017  35        0      < 0.017  < 0.017  < 0.017  < 0.017  < 0.017  < 0.017  < 0.017
82678 Triallate               .001  35       31      < 0.001  < 0.001  < 0.001  < 0.001    0.002    0.029    0.032
82679 Propanil                .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82680 Carbaryl                .003  35        0      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003
82681 Thiobencarb             .002  35        0      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002
82682 Dachthal (DCPA)         .002  35        3      < 0.002  < 0.002  < 0.002  < 0.002  < 0.002  < 0.002    0.002
82683 Pendimethalin           .004  35        0      < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004  < 0.004
82684 Napropamide             .003  35        0      < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003  < 0.003
82685 Propargite              .690  33        0      < 0.690  < 0.690  < 0.690  < 0.690  < 0.690  < 0.690  < 0.690
82686 Azinphos methyl         .001  35        0      < 0.001  < 0.001  < 0.001  < 0.001  < 0.001  < 0.001  < 0.001
82687 Permethrin              .005  35        0      < 0.005  < 0.005  < 0.005  < 0.005  < 0.005  < 0.005  < 0.005
91063 Diazinon-d10 (%)        .100  35      100        83.91    86.28    95.45    107.5    112.7    121.2    137.6
91064 Terbuthylazin (%)       .100  22      100        95.45    101.9    109.5    115.7    122.6    128.9    129.8
91065 HCH alpha-D6 (%)        .100  35      100        74.74    83.76    90.76    99.07    104.0    114.7    120.8

Suspended Sediment Chemistry

Units in parts per million (ppm) or parts per hundred (%)

Values censored higher than the reporting level (RL) indicate samples with insufficient sediment mass to quantify concentration above the RL

                                          Percent
Parameter                    RL       N  Detections    Min      5th      25th    Median    75th     95th     Max

29816 Antimony (ppm)        0.10     24     100       0.80     0.90     1.00     1.85      2.75     4.00      9.20
29818 Arsenic (ppm)         0.10     24     100      13.30    13.30    13.80    14.40     15.00    16.70     17.30
29820 Barium (ppm)          1.00     24     100      180.0    310.0    550.0    780.0     860.0    990.0      1100
29822 Beryllium (ppm)       0.10     24     100       1.00     1.10     1.20     1.30      1.40     1.70      1.70
29826 Cadmium (ppm)         0.10     24      96    <  0.10     0.10     0.10     0.20      0.30     0.40      0.60
29829 Chromium (ppm)        1.00     24     100      48.00    48.00    60.50    67.00     70.50    77.00     78.00
29832 Copper (ppm)          1.00     24     100       9.00    12.00    14.50    16.00     21.50    23.00     23.00
29836 Lead (ppm)            1.00     24     100       8.00    11.00    13.00    15.00     16.00    18.00     18.00
29839 Manganese (ppm)       10.0     24     100      290.0    300.0    320.0    340.0     375.0    480.0     580.0
29841 Mercury (ppm)         0.01     24      83    <  0.01  <  0.01     0.01     0.02      0.03     0.04      0.04
29843 Molybdenum (ppm)      5.00     24       8    <  2.00  <  5.00  <  5.00  <  5.00   <  5.00     5.00      6.00
29845 Nickel (ppm)          1.00     24     100      25.00    31.00    34.00    36.00     40.00    45.00     46.00
29847 Selenium (ppm)        0.10     24     100       0.20     0.30     0.40     0.40      0.50     0.60      0.60
29850 Silver (ppm)          0.50     24       8    <  0.50  <  0.50  <  0.50  <  0.50   <  0.50     0.50      0.50
29853 Vanadium (ppm)        1.00     24     100      55.00    65.00    75.00    81.00     105.0    140.0     170.0
29855 Zinc (ppm)            1.00     24     100      50.00    60.00    70.00    80.00     90.00    110.0     120.0
30221 Aluminum (%)          0.10     24     100       4.80     4.90     5.05     5.35      5.95     6.70      6.70
30244 Total carbon (%)      0.10     24     100       0.90     1.10     1.20     1.45      1.60     1.90      3.40
30269 Iron (%)              0.10     24     100       1.80     2.00     2.20     2.30      2.70     3.40      3.50
30292 Phosphorus (%)        0.01     24     100       0.05     0.05     0.06     0.06      0.07     0.07      0.07
30308 Sulfur (%)            0.10     21      95    <  0.10     0.20     0.30     0.50      0.70     0.90      1.00
30317 Titanium (%)          0.01     24     100       0.18     0.19     0.20     0.23      0.30     0.31      0.33
35031 Cobalt (ppm)          1.00     24     100       8.00     9.00    10.00    10.00     11.00    12.00     12.00
35040 Strontium (ppm)       0.01     24     100      190.0    190.0    240.0    265.0     280.0    300.0     300.0
35046 Uranium (ppm)         50.0     24       0    < 50.00  < 50.00  < 50.00  < 50.00   < 50.00  < 50.00   < 50.00
35050 Lithium (ppm)         1.00     24     100      23.00    26.00    29.50    34.00     37.00    45.00     47.00
49955 Thallium (ppm)        50.0     24       0    < 50.00  < 50.00  < 50.00  < 50.00   < 50.00  < 50.00   < 50.00
50279 Sediment (mg/L)       1.00     24     100      149.0    150.0    215.5    332.0     421.5     1033      1703
50465 Organic carbon (%)    0.10     24     100       0.40     0.60     0.70     0.80      0.90     1.00      1.20

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