U.S. Geological Survey Open-File Report 09-0346
Trends in Precipitation Chemistry in the United States,
1983-1994: An Analysis of the Effects in 1995 of Phase I of the Clean Air Act Amendments of 1990, Title IV
Table A.4. Estimated changes in concentrations (µeq/L and percent) of individual ions
in preciptation from 1983 through 1994.
Hydrogen Ion Sulfate Nitrate Chloride
_________________ _________________ _________________ _________________
Change Percent Change Percent Change Percent Change Percent
Region Site (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change
---------------------------------------------------------------------------------------
NE il11 -7.686* -15.146 -7.399* -12.988 0.614 2.645 -0.304 -7.999
il18 -3.985 -11.841 -7.341 -14.694 2.502 10.677 -0.297 -8.372
il19 -9.866* -21.811 -11.533* -18.528 -2.841 -9.851 -0.662 -12.516
il35 2.767 7.652 -4.951 -11.514 -0.483 -2.725 -0.434 -9.467
il63 0.376 0.918 -6.282* -12.542 0.453 2.477 -0.417 -7.845
in20 -4.035 -8.281 -15.255* -24.788 -2.623 -9.024 -1.348* -30.916
in22 -0.512 -1.087 4.127 7.892 6.584* 38.812 -0.862 -15.839
in34 -10.301* -24.467 -7.957* -13.028 -0.582 -2.099 -0.548 -10.859
in41 -8.060* -16.298 -9.104* -15.201 -3.538 -12.701 -1.183* -26.376
ky03 -3.520 -8.022 -2.112 -4.687 0.300 1.643 -0.926 -21.075
ky22 -6.620* -16.509 -10.151* -24.279 -3.374* -17.747 -1.683* -42.701
ky35 -7.343 -15.074 -6.359 -12.972 -4.606 -20.336 -0.858* -23.836
ky38 -1.938 -5.723 -2.689 -7.176 1.371 8.766 -0.189 -4.259
ma01 5.106 16.724 -0.897 -2.464 4.663 32.617 0.014 0.018
ma08 -4.251 -9.625 -8.162 -20.377 -0.525 -2.401 -1.042 -14.949
ma13 -10.129* -19.810 -6.033 -12.854 1.974 11.324 -5.008* -26.769
md03 -0.578 -0.992 -2.749 -5.012 -0.361 -1.335 -2.241 -26.317
md13 -5.303 -10.354 -5.893 -11.846 -1.802 -7.533 -2.262 -17.265
me00 -4.764 -15.680 -4.307 -14.859 1.987 14.214 -0.962 -21.648
me02 1.368 4.221 -2.525 -8.417 3.982 30.197 -1.056 -17.766
me09 1.201 4.525 -1.749 -7.315 2.448 20.011 -0.592 -17.770
mi09 -6.432* -17.506 -8.165* -20.477 -0.722 -2.755 -0.412 -14.961
mi26 -8.570* -19.196 -13.327* -25.085 -2.917 -10.155 -0.675* -16.933
mi53 -8.420* -20.803 -6.702* -15.067 0.039 0.129 -0.624 -16.456
mi98 -10.775* -28.061 -10.626* -26.188 -2.387 -9.054 -0.621* -21.717
mi99 -2.909 -13.226 -5.725* -20.057 1.018 5.908 -0.680* -25.718
nh02 -2.791 -6.397 -4.967 -13.535 1.505 7.255 -0.572 -14.216
nj99 -3.318 -6.798 -0.765 -1.668 0.764 3.339 -1.511 -13.467
ny08 -9.416* -14.354 -7.970 -12.598 -2.883 -8.736 -0.914* -21.282
ny10 -10.530* -16.301 -17.690* -27.125 -1.567 -4.840 -1.610* -31.584
ny20 -1.749 -4.049 -5.130 -13.523 -0.957 -4.208 -0.898* -30.867
ny52 -10.207* -16.442 -10.778* -18.542 -3.510 -9.759 -1.441* -28.898
ny65 1.053 1.965 -2.843 -5.709 0.734 2.925 -0.321 -10.548
ny68 1.520 3.147 -2.342 -5.447 1.944 8.287 -0.204 -5.117
ny98 -9.057* -20.861 -10.998* -26.653 -2.680 -12.646 -0.421 -19.200
ny99 -5.387 -9.590 -7.092 -14.591 -3.960 -14.863 1.353 13.360
oh09 -6.053 -10.329 -6.832 -11.075 -1.333 -5.438 -0.248 -6.085
oh17 -0.969 -1.710 -2.545 -4.120 0.666 2.279 -0.176 -4.294
oh49 -0.756 -1.105 -2.783 -3.974 1.829 6.616 -0.372 -7.350
oh71 -4.392 -7.443 -4.850 -7.544 -1.437 -4.825 -0.507 -11.768
pa15 -14.989* -21.166 -12.499* -19.872 -6.720* -20.746 -1.129* -22.594
pa29 -9.636* -14.013 -7.594 -12.269 -1.536 -5.188 -0.607 -14.294
pa42 -8.500 -12.824 -10.300 -17.041 -4.143 -13.111 -0.582 -11.965
pa72 -9.461 -15.924 -10.793 -20.984 -3.281 -11.338 -1.407 -20.722
va00 -7.214 -13.640 -5.626 -11.670 -4.515 -17.906 -0.266 -4.484
va13 2.911 8.700 0.358 0.979 1.975 12.522 -0.637 -16.887
va28 -7.092* -20.044 -9.270* -25.231 -2.978 -19.344 -1.744* -40.299
vt01 8.432 20.283 2.704 6.920 5.932* 27.040 0.006 0.156
vt99 -1.224 -2.814 -1.919 -5.069 1.305 5.476 -0.285 -11.520
wi28 -11.771* -42.646 -15.264* -36.309 -3.314 -13.128 -1.065* -31.059
wi36 -4.346 -21.102 -7.405* -26.619 0.809 4.394 -0.490* -22.549
wi37 -3.601 -21.947 -8.438* -28.470 0.106 0.513 -0.708* -26.963
wi99 -4.221 -12.110 -10.748* -21.866 -0.767 -2.828 -1.298* -30.946
wv04 -9.779* -20.006 -14.136* -29.762 -2.738 -13.023 -1.051* -29.310
wv18 4.110 7.389 1.295 2.346 1.465 5.885 -0.526* -14.401
--------------------------------------------------------------------------------
SE al10 2.143 9.984 -5.903* -20.977 -1.290 -10.714 -2.055 -23.655
al99 -5.991 -18.741 -9.508 -24.084 0.653 5.054 -0.485 -8.509
fl03 1.497 6.931 -0.609 -2.593 2.710 28.850 -3.351 -19.705
fl11 0.237 2.634 -0.547 -3.498 1.821 29.430 4.736 14.864
fl14 -1.789 -9.171 -1.232 -6.621 0.994 12.287 -1.292 -10.509
fl41 2.449 16.627 -1.530 -7.376 1.457 14.562 -2.252 -11.308
ga20 -4.463 -19.522 -4.582 -18.508 0.851 8.333 -0.435 -4.228
ga41 -1.391 -5.184 -4.791 -15.644 -0.924 -7.665 -2.242* -28.732
ga50 2.191 13.005 -2.074 -10.257 1.138 12.498 -1.729 -17.618
ms10 -1.659 -8.801 -7.330* -28.084 -0.567 -4.808 -1.851 -22.186
ms30 -3.798 -17.237 -8.083* -32.691 -1.598 -13.303 -0.966 -14.970
nc03 -4.601 -14.697 -7.455* -21.790 -1.600 -10.566 -2.833 -19.753
nc25 -3.844 -13.803 -7.943* -25.356 -1.415 -12.123 -0.652 -13.166
nc34 -1.488 -3.952 -2.208 -5.265 -1.237 -6.805 -0.122 -1.796
nc36 8.063* 28.991 5.665 20.077 4.986* 39.317 0.604 6.240
nc41 -6.281 -20.078 -6.814 -19.045 -1.891 -11.698 -2.595 -24.568
sc06 -3.544 -12.182 -6.800 -20.781 1.662 15.666 -0.283 -2.198
tn00 -2.485 -5.240 -9.982* -19.532 -0.920 -5.246 -1.490* -25.053
tn11 -1.085 -3.348 -4.202 -12.141 -1.175 -7.904 -0.633 -18.836
tn14 2.792 12.875 1.594 6.843 3.049* 26.288 -1.220 -23.820
---------------------------------------------------------------------------------------
* Annual trend was significant (p<0.05).
---------------------------------------------------------------------------------------
Hydrogen Ion Sulfate Nitrate Chloride
_________________ _________________ _________________ _________________
Change Percent Change Percent Change Percent Change Percent
Region Site (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change
---------------------------------------------------------------------------------------
West ak03 -1.022 -14.915 -1.370 -30.398 1.123* 83.978 -0.214 -9.961
ar02 1.255 8.259 -3.770 -15.253 0.569 4.656 0.373 5.956
ar03 -2.009 -8.834 -3.448 -12.736 -0.792 -5.524 0.041 0.690
ar16 1.508 7.933 -2.019 -7.981 0.113 0.845 -0.837* -18.896
ar27 -2.622 -19.467 -6.637* -24.419 -1.073 -7.159 -0.596 -13.228
az03 -0.940 -13.464 -6.973* -38.732 0.922 6.923 -1.160 -26.798
az06 -0.495 -6.783 -5.676 -23.647 -2.856 -15.509 -1.780 -8.939
az99 -10.822* -53.165 -14.347* -45.606 -0.349 -2.847 -0.249 -6.200
ca42 -11.358* -53.773 -8.851* -37.800 -9.304 -27.569 -2.210 -16.163
ca45 -1.368* -26.118 -2.668* -39.510 1.276 34.085 -3.589 -31.664
ca75 -2.200* -45.562 -3.530 -27.754 4.507 31.240 -1.262 -29.208
ca88 -0.780* -41.635 -4.862* -24.974 0.496 2.289 -1.824 -19.206
ca98 -4.293 -40.056 -8.858* -52.688 -4.668 -24.167 -3.388* -50.924
ca99 -1.280 -16.603 -3.463 -30.993 1.267 8.220 -0.681 -16.069
co00 -1.490 -23.973 -5.813* -32.143 -1.567 -14.234 -1.304* -39.688
co01 -2.173* -46.153 -1.036 -5.717 -1.227 -6.269 -1.196 -31.578
co02 0.335 2.833 0.020 0.153 5.417* 50.805 -0.349 -14.023
co15 -0.334 -2.883 -3.255 -18.829 1.818 12.954 -0.849* -27.540
co19 -1.013 -9.279 -5.052* -30.500 3.841* 26.347 -0.335 -12.519
co21 0.273 1.959 -2.449 -15.214 2.670 14.997 -0.614* -24.087
co22 -3.206* -37.967 -5.681* -30.530 -1.897 -9.519 -0.910* -31.359
co97 1.221 8.901 4.472* 33.368 6.188* 89.920 0.331 20.233
co98 -1.888 -16.570 -4.954* -33.894 -0.101 -0.904 -0.733* -29.766
co99 -3.770 -23.072 -4.950* -20.925 0.772 5.251 -0.312 -11.563
ia08 2.591 19.465 -2.419 -6.566 4.958 23.033 -0.559 -18.285
ia23 -5.167 -29.378 -6.180 -18.327 5.239 30.921 -0.378 -12.636
id03 -0.252 -4.943 -3.098 -25.400 3.543 37.135 -1.609* -33.508
id11 -2.666* -44.656 0.068 0.781 5.569* 67.397 -0.566 -15.050
id15 -1.878 -28.189 -0.812 -13.771 2.013* 33.745 -0.196 -8.960
ks07 -2.295 -12.816 -5.060 -16.436 0.273 1.643 -1.342* -31.547
ks31 -2.643 -18.426 -1.482 -5.396 2.627 13.603 -0.479 -14.458
ks32 -1.086 -23.241 -1.124 -5.930 5.625* 35.999 -0.636 -22.278
la12 -0.949 -5.888 -4.621* -19.368 -0.716 -5.964 -3.431 -18.502
la30 1.570 9.314 -4.821* -19.437 -0.972 -7.885 -3.627* -25.201
mn16 -4.450 -29.933 -10.654* -42.126 -2.785 -14.456 -1.107* -42.338
mn18 -0.302 -2.212 -4.730* -24.123 -0.128 -0.849 -0.683* -33.065
mn23 -0.520 -5.654 -2.678 -13.208 2.781 16.302 -0.158 -8.031
mn27 -1.796 -24.658 -9.767* -31.578 -2.583 -10.399 -1.274* -38.745
mo03 -7.190* -26.516 -10.297* -27.416 -1.873 -9.394 -0.696* -18.475
mo05 -1.947 -6.750 -4.775 -13.682 -0.911 -5.108 -0.791 -16.930
mt00 -0.354 -4.459 -2.615 -17.484 1.717 16.942 -0.973* -35.923
mt05 -0.734 -8.229 -2.424* -26.097 0.579 9.978 -0.830* -39.579
mt07 0.034 0.399 -1.999 -19.297 1.351 20.739 -0.833* -35.492
mt13 -1.504 -19.481 -0.118 -0.583 2.579 21.649 -1.044* -35.820
nd07 -2.101 -22.814 -6.035* -28.930 -0.923 -6.725 -0.820* -33.175
nd08 -1.248 -19.054 -3.521 -18.105 0.287 1.664 -0.630 -24.361
nd11 -1.370 -26.814 -8.990* -32.615 -4.593 -17.776 -1.135* -35.893
ne15 -3.747* -45.079 -7.262* -20.967 1.375 6.472 -0.943* -30.323
nm07 -1.156 -9.489 -5.616* -29.176 -0.002 -0.016 -1.477* -45.922
nm08 -3.507* -38.893 -4.793 -23.604 1.336 14.364 -1.067 -31.244
nm09 -4.021* -27.596 -5.412* -28.396 -0.533 -4.051 -1.028* -32.435
nm12 -2.223 -25.067 2.855 23.329 10.544* 173.269 -0.970 -30.587
ok00 -1.164 -11.527 -4.835 -17.999 -0.117 -0.606 -3.205* -44.679
ok17 -1.348 -12.237 -6.101 -23.088 -0.509 -3.178 -1.881* -34.658
or02 -0.936 -16.976 -2.351* -28.856 1.114* 72.324 -10.162 -30.627
or09 -1.233 -14.897 -0.191 -3.497 3.604* 74.343 -2.107* -54.711
or10 -0.438 -6.924 -1.746* -31.201 1.315* 50.277 -2.088 -26.522
or18 -2.900* -31.972 -0.353 -7.570 2.003 43.798 -0.608* -28.563
or97 -1.660* -28.635 -2.293* -26.831 1.277* 34.775 -1.433 -9.597
or98 -1.266 -14.949 -1.718* -17.859 0.792 14.884 -1.298 -9.086
sd08 -1.409 -18.721 -4.149 -26.274 -0.207 -1.483 -0.704* -29.630
sd99 -4.137* -63.535 -6.430 -27.994 -0.973 -5.266 -0.508 -20.043
tx03 2.599 25.544 -0.924 -3.236 1.068 8.012 -2.955 -12.219
tx04 -0.453 -10.481 3.092 15.899 5.192* 60.543 -0.441 -12.040
tx10 2.363 17.542 -0.134 -0.619 1.858 16.316 -4.164 -22.374
tx16 -1.950 -25.040 2.236 10.662 2.542 25.366 0.927 16.333
tx21 -0.593 -2.552 -4.388 -13.416 -1.258 -8.857 -2.122 -22.090
tx22 -4.042* -46.559 -0.761 -3.237 5.074* 56.706 -0.019 -0.644
tx38 1.221 8.412 -4.675 -18.205 -0.266 -2.226 -3.939* -33.442
tx56 -0.330 -3.287 -5.151 -19.739 0.558 3.882 -2.310* -32.595
ut01 -1.703* -76.230 -2.355 -13.422 0.563 3.662 -4.906 -32.675
wa14 -0.773 -12.900 -0.869 -15.425 0.864* 77.984 -3.469 -16.795
wa19 -3.779* -29.212 -2.347 -25.188 1.733 35.108 -1.652 -25.456
wa21 -2.120 -14.526 -3.788 -25.376 1.028 18.366 -7.923* -57.686
wy02 -4.968* -42.674 -9.021* -51.257 -0.740 -7.125 -2.037* -58.345
wy06 1.099 12.152 -2.555 -17.916 3.794* 37.058 -1.066* -30.218
wy08 -2.397* -35.271 0.911 12.282 3.876* 69.203 -0.504 -18.702
wy99 -1.812 -20.584 -4.699* -26.039 0.157 1.137 -0.997* -37.450
---------------------------------------------------------------------------------------
* Annual trend was significant (p<0.05).
----------------------------------------------------------------------------------------------------------
Ammonium Calcium Magnesium Potassium Sodium
_________________ _________________ _________________ _________________ _________________
Change Percent Change Percent Change Percent Change Percent Change Percent
Region Site (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change
----------------------------------------------------------------------------------------------------------
NE il11 4.674* 27.414 -2.387* -23.531 -0.615* -26.888 -0.102 -21.469 0.118 5.102
il18 5.905 27.732 -3.194 -24.840 -1.302* -31.609 -0.043 -7.140 0.035 1.395
il19 0.158 0.699 -4.139 -26.478 -0.888 -16.701 -0.232* -31.375 -0.305 -8.764
il35 0.868 7.234 -2.127* -25.698 -0.638* -31.277 -0.149 -28.119 -0.566 -17.113
il63 -0.526 -3.614 -2.185* -25.717 -0.786* -37.004 -0.158 -24.569 -0.651 -17.027
in20 -3.023 -13.513 -4.268* -36.526 -1.961* -48.948 -0.325* -52.647 -1.252* -39.147
in22 8.674* 86.438 1.475 18.728 -0.104 -5.015 -0.003 -0.461 -0.987 -27.560
in34 0.628 3.019 1.669 9.177 -0.120 -2.106 -0.237* -36.766 -0.589 -18.913
in41 -1.937 -8.641 -3.754* -30.817 -1.271* -35.023 -0.257* -41.500 -0.524 -17.423
ky03 2.171 19.998 -2.503* -37.977 -0.549 -31.109 -0.012 -2.859 -0.652 -20.833
ky22 -0.145 -1.757 -6.784* -62.241 -1.524* -65.390 -0.243* -45.078 -0.769* -29.903
ky35 0.107 0.925 -2.850* -33.793 -1.096* -50.500 0.177 29.617 -0.553 -22.077
ky38 4.537* 56.345 -0.866 -15.671 -0.571* -32.758 0.050 9.981 -0.263 -7.185
ma01 1.570 27.261 -0.724 -13.167 -0.463 -3.007 -0.167 -10.258 0.778 1.220
ma08 2.241 27.662 -0.827* -28.464 -0.672* -34.050 -0.084 -23.411 -0.176 -3.654
ma13 1.870 28.328 -0.324 -8.912 -1.290* -32.103 -0.027 -5.170 -1.582 -11.652
md03 4.531* 37.156 -2.255* -35.655 -1.385* -49.046 -0.175 -29.797 -2.130* -35.515
md13 1.060 8.371 -1.610* -33.569 -1.304* -36.385 -0.114 -19.776 -1.453 -14.631
me00 1.230 19.663 -0.953 -21.259 -1.023* -58.634 -0.146* -36.784 -0.727 -19.867
me02 2.602 44.733 -0.492 -19.787 -0.850* -46.891 0.050 14.192 -1.447 -27.818
me09 0.607 10.463 -0.969* -36.060 -0.662* -50.336 -0.090* -27.650 -0.361 -13.328
mi09 -0.163 -0.959 -1.685 -18.689 -1.074* -36.394 -0.182* -31.617 -0.188 -10.148
mi26 0.150 0.712 -2.620* -25.696 -1.145* -34.168 -0.075 -15.713 -0.430 -16.865
mi53 4.231 22.535 -1.539 -13.873 -0.834 -20.695 -0.147* -27.070 -0.042 -1.843
mi98 1.861 10.658 -1.955 -23.807 -1.124* -40.958 -0.054 -13.227 -0.556 -25.885
mi99 1.991 15.330 -2.135* -26.778 -1.260* -48.488 -0.247* -41.220 -0.655* -27.325
nh02 0.939 11.658 -0.960* -31.642 -0.701* -46.503 -0.104* -29.191 -0.383 -12.299
nj99 3.177 31.440 -1.576* -32.497 -1.523* -41.783 -0.216* -40.173 -0.902 -10.602
ny08 0.314 1.722 -2.286* -31.958 -1.146* -48.192 -0.195* -47.981 -0.478 -21.063
ny10 -3.869* -20.248 -2.486* -32.200 -1.060* -44.090 -0.521* -67.629 -0.976* -34.137
ny20 0.376 3.781 -1.735* -37.876 -0.904* -56.959 -0.197* -52.294 -0.429 -23.195
ny52 -0.426 -2.240 -2.282* -28.817 -1.087* -42.022 -0.312* -47.026 -0.749* -25.443
ny65 1.129 9.464 -1.483* -30.536 -0.931* -53.182 -0.118* -38.293 -0.554* -27.270
ny68 2.864 32.375 -0.570 -17.146 -0.634* -39.878 0.007 2.126 0.096 3.858
ny98 -0.749 -7.017 -1.087* -27.734 -0.806* -53.095 -0.031 -8.635 -0.041 -3.057
ny99 1.161 12.369 -1.361* -30.306 -1.276* -40.175 0.011 2.300 -0.760 -11.064
oh09 2.857 21.114 -0.491 -7.099 -0.597 -26.799 0.183 47.570 -0.125 -4.848
oh17 2.936 16.070 -3.119* -31.490 -1.239* -37.316 -0.065 -11.273 -0.348 -12.305
oh49 0.304 2.140 -2.212* -24.180 -1.078* -37.099 -0.007 -1.022 -0.315 -12.103
oh71 -0.209 -0.981 -1.599 -17.660 -0.857* -30.188 -0.101 -21.977 -0.070 -2.909
pa15 -0.626 -4.647 -2.632* -40.102 -0.977* -48.572 -0.113 -24.685 -0.685* -27.393
pa29 -0.158 -1.145 -1.043 -18.155 -0.670* -37.015 -0.014 -3.392 -0.268 -12.984
pa42 -1.175 -7.733 -1.653* -27.257 -0.873* -42.297 -0.251* -39.487 -0.664* -25.405
pa72 0.779 7.871 -1.613* -35.395 -0.925* -41.267 -0.273* -46.665 -0.205 -4.627
va00 0.573 5.304 -1.398* -33.741 -0.807* -37.584 -0.324* -45.391 -0.027 -0.600
va13 1.894 21.329 -1.707* -26.732 -1.046* -45.720 -0.043 -4.394 -0.408 -13.750
va28 0.282 2.805 -1.249* -38.936 -0.869* -57.856 -0.092 -25.859 -1.111* -36.749
vt01 1.075 9.732 -0.288 -5.850 -0.794* -36.488 -0.148* -29.853 0.232 8.135
vt99 1.429 12.936 -0.876 -20.920 -0.806* -51.355 -0.033 -9.622 0.011 0.659
wi28 -1.147 -4.921 -4.743* -37.595 -1.638* -47.201 -0.379* -47.855 -0.690* -25.411
wi36 2.104 15.145 -3.025* -32.067 -1.266* -48.088 -0.213* -44.411 -0.516 -27.106
wi37 0.455 2.185 -2.364 -20.894 -1.275* -42.469 -0.372* -51.688 -0.603* -25.567
wi99 0.140 0.605 -3.916* -28.983 -1.438* -32.628 -0.185 -26.339 -0.693 -25.593
wv04 -1.344 -13.254 -2.690* -46.311 -1.058* -59.258 -0.344* -49.726 -0.849* -35.994
wv18 1.696 15.546 -1.013 -13.406 -0.782* -41.271 -0.144* -24.443 -0.322 -15.786
---------------------------------------------------------------------------------------------------
SE al10 -1.632 -21.745 -3.704* -55.514 -1.286* -47.803 -0.371* -42.285 -2.018* -26.042
al99 2.090 18.816 -1.580 -32.533 -0.679* -34.585 -0.136 -20.876 -0.018 -0.384
fl03 0.684 14.167 -1.780* -31.372 -1.299* -32.161 -0.414* -48.448 -2.126 -14.455
fl11 2.587* 73.907 -1.173 -17.180 0.402 5.714 0.328 23.489 3.528 12.892
fl14 -0.024 -0.555 -1.492* -38.360 -0.589 -19.598 -0.034 -5.985 1.255 14.342
fl41 1.652 33.927 -1.707 -25.730 -1.270 -25.854 -0.269 -30.368 -1.461 -8.555
ga20 0.913 12.524 -2.300* -45.920 -0.677 -23.146 0.114 12.246 0.690 8.631
ga41 0.899 12.120 -2.375* -52.124 -1.068* -45.527 -0.074 -9.528 -1.601* -24.916
ga50 0.889 15.527 -1.942* -42.928 -0.730 -25.636 0.010 0.948 -1.367 -16.216
ms10 1.898 23.161 -1.355 -28.909 -0.876* -35.528 -0.389* -42.162 -1.670 -22.396
ms30 0.605 8.169 -0.763 -18.502 -0.826* -40.308 -0.303 -38.026 -1.462 -26.526
nc03 1.166 13.630 -1.982* -46.498 -1.330* -34.836 -0.163 -21.583 -2.280 -18.918
nc25 -1.389 -16.315 -1.779* -47.294 -0.590* -38.738 -0.141 -24.792 -0.145 -3.706
nc34 -1.028 -7.306 -2.147* -44.188 -0.831* -34.526 -0.216 -21.255 0.565 10.819
nc36 3.495* 54.497 -0.621 -18.334 -0.471 -18.002 -0.116 -20.059 0.759 9.229
nc41 3.960 31.576 -1.718* -43.385 -1.069* -35.603 -0.039 -4.733 -1.612 -18.766
sc06 3.565* 89.764 -0.977 -19.852 0.145 4.836 0.990* 116.953 -0.299 -2.756
tn00 1.288 14.157 -3.676* -51.601 -1.420* -60.232 -0.272* -42.549 -0.928* -24.703
tn11 -1.671 -16.984 -2.294* -43.676 -1.090* -58.983 -0.634* -57.495 -0.303 -11.886
tn14 2.990* 42.675 -0.119 -3.206 -0.658* -37.558 -0.065 -12.828 -0.862 -19.201
----------------------------------------------------------------------------------------------------------
* Annual trend was significant (p<0.05).
----------------------------------------------------------------------------------------------------------
Ammonium Calcium Magnesium Potassium Sodium
_________________ _________________ _________________ _________________ _________________
Change Percent Change Percent Change Percent Change Percent Change Percent
Region Site (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change (µeq/L) Change
----------------------------------------------------------------------------------------------------------
West ak03 0.328 22.307 -0.652 -35.275 -0.402* -53.735 -0.110 -34.060 -0.272 -17.471
ar02 1.458 14.340 -2.144* -34.873 -0.419 -18.890 0.048 4.878 0.982 18.368
ar03 2.088 23.465 -0.856 -14.285 -0.336 -16.402 0.276* 45.148 0.347 6.398
ar16 -1.151 -10.280 -3.476* -43.385 -0.865* -42.478 -0.225 -26.454 -0.757 -18.101
ar27 -1.447 -9.132 -3.534* -35.058 -0.689* -33.995 -0.082 -10.954 -0.819 -18.803
az03 2.367 39.932 -6.629 -37.358 -2.424* -43.227 -0.218 -35.780 -1.309 -29.331
az06 -1.984 -12.857 -2.191 -16.500 -1.611 -25.943 -0.151 -13.495 -1.409 -8.329
az99 2.799 32.489 -0.314 -3.428 -1.092* -43.685 0.003 0.456 0.039 1.002
ca42 -1.528 -9.797 -3.529* -47.599 -2.101 -44.839 -0.363* -47.752 -1.059 -8.048
ca45 1.018 40.472 -1.392* -52.769 -1.434* -48.871 -0.254* -49.151 -2.521 -26.673
ca75 12.004 79.377 -1.243 -27.032 -0.952* -47.407 -0.377 -28.800 -0.807 -20.414
ca88 11.456* 30.744 -4.517* -52.938 -2.493* -46.582 -0.396 -30.909 -2.117 -25.024
ca98 0.589 6.373 -7.116* -67.043 -2.098* -71.489 -0.265 -30.565 -2.858 -46.962
ca99 3.388 28.336 -2.766 -39.983 -1.286* -48.316 -0.254 -32.975 -1.504 -33.318
co00 1.956 18.505 -6.674* -48.434 -1.810* -66.850 -0.400* -43.074 -2.083 -35.954
co01 10.121* 62.536 -3.479 -20.176 -1.329* -44.684 -0.656 -42.711 -0.675 -17.075
co02 4.691 88.297 -0.972 -12.748 -0.601 -32.111 -0.283 -37.214 -0.715 -23.569
co15 2.140 34.196 -5.059* -38.244 -1.829* -53.014 -0.270* -41.167 -1.193* -35.769
co19 3.975* 45.237 -2.310 -24.277 -1.300* -54.610 -0.160 -17.780 -0.978* -35.681
co21 4.395* 62.489 -2.726 -26.850 -1.507* -52.697 -0.520* -50.061 -0.568 -23.138
co22 2.022 10.012 -5.045* -43.863 -1.795* -65.640 -0.213 -31.164 -1.331* -43.660
co97 4.546* 162.938 0.719 13.715 -0.469 -29.992 0.066 17.290 0.506 33.869
co98 -0.176 -2.718 -4.188* -45.553 -1.306* -58.458 -0.224* -38.837 -0.577 -24.534
co99 1.084 19.604 -4.882 -26.272 -1.198* -35.450 -0.181* -32.469 -0.231 -8.508
ia08 10.961* 51.770 0.562 3.310 -0.182 -3.918 -0.158 -15.864 -0.258 -12.483
ia23 14.272* 91.988 -0.600 -4.208 -0.513 -21.663 -0.106 -15.481 -0.314 -13.410
id03 8.595* 110.849 -4.522 -39.011 -1.662* -57.385 -0.318* -45.363 -1.170 -29.323
id11 7.950* 112.733 -1.298 -13.703 -1.249* -46.534 -0.155 -17.302 1.140 23.453
id15 3.735* 101.459 0.539 13.784 -0.055 -5.476 0.128 31.874 0.365 13.609
ks07 4.372 34.134 -1.488 -12.421 -0.805* -37.164 -0.303 -39.414 -0.986 -26.294
ks31 5.264* 30.332 -0.593 -3.911 -0.739* -29.990 -0.157 -22.125 -0.622 -20.846
ks32 12.420* 62.339 -0.294 -2.182 -0.918 -37.936 -0.300 -25.542 -0.430 -17.641
la12 -0.211 -1.964 -0.941 -18.245 -1.070* -26.236 -0.239* -28.499 -3.070 -19.900
la30 -2.150 -18.954 -2.055* -41.947 -1.258* -35.659 -0.268* -35.708 -2.628 -21.228
mn16 -3.341 -18.045 -3.458* -34.738 -1.153* -42.180 -0.358* -43.055 -1.188* -46.631
mn18 -0.398 -3.237 -3.411* -43.475 -1.496* -62.400 -0.342* -58.788 -0.960* -47.633
mn23 8.736* 50.275 -1.483 -16.092 -0.730 -28.868 -0.201 -32.288 -0.271 -16.138
mn27 -0.829 -2.563 -5.957* -35.064 -2.434* -48.721 -0.477* -43.761 -0.922* -34.723
mo03 0.541 3.577 -2.969 -26.316 -0.683* -29.106 -0.295* -38.390 -0.602 -17.290
mo05 0.912 7.419 -2.791* -38.128 -1.039* -44.084 -0.227 -24.301 -0.716 -17.229
mt00 5.280* 94.964 -3.271 -32.278 -1.659* -54.788 -0.220 -32.171 -1.136 -37.600
mt05 0.715 19.846 -1.740* -37.099 -0.743* -51.972 -0.136 -20.378 -0.507 -23.756
mt07 1.354 32.445 -1.739 -26.931 -1.218* -64.684 -0.267* -46.368 -1.023* -44.767
mt13 7.190* 76.482 -7.390 -46.012 -3.477* -60.288 -0.482* -51.669 -0.758 -17.550
nd07 0.103 0.785 -4.454* -37.191 -1.392* -39.947 -0.200 -32.814 -0.687 -22.392
nd08 6.749 33.177 -4.528* -33.380 -1.214 -28.789 -0.180 -21.257 -0.758 -29.027
nd11 7.878 34.468 -7.261 -36.445 -4.357* -54.437 -1.068* -51.747 -2.284* -50.050
ne15 0.610 1.795 -2.399 -15.079 -1.037* -36.077 -0.233* -27.478 -0.791 -27.844
nm07 1.485 22.145 -5.494* -39.985 -1.412* -59.548 -0.580* -64.803 -1.780* -51.614
nm08 4.683* 88.198 -1.762 -10.553 -1.276* -45.323 -0.192 -34.113 -1.564 -39.808
nm09 1.992 32.916 -4.118* -38.062 -1.307* -57.385 -0.256* -44.626 -0.865* -28.643
nm12 10.147* 224.953 -0.199 -2.068 -1.145* -51.085 0.128 24.588 0.325 14.177
ok00 4.544 27.750 -6.887 -38.156 -1.875* -54.064 -0.146 -16.327 -3.262* -45.700
ok17 0.497 3.418 -2.082 -15.025 -0.552 -20.181 0.317 41.094 -0.550 -12.740
or02 0.417 28.398 -1.051* -36.163 -2.589* -37.916 -0.197 -24.536 -8.796 -31.331
or09 2.639* 113.339 -0.863 -25.149 -0.616* -46.120 -0.855* -71.537 -1.742* -46.888
or10 0.167 9.871 -1.001* -48.060 -0.893* -44.136 -0.140* -35.345 -1.477 -21.612
or18 2.296* 107.112 -1.364* -42.941 -0.549* -54.986 -0.122 -27.152 -0.546 -23.875
or97 3.260* 112.484 -1.356* -42.919 -1.216* -33.400 -0.110 -16.675 -0.526 -4.270
or98 2.381* 66.291 -0.538* -22.880 -0.769 -24.052 -0.048 -7.626 -0.782 -6.306
sd08 2.320 16.011 -2.963 -31.685 -1.124* -52.757 -0.338* -48.856 -0.389 -17.798
sd99 9.025 38.663 -2.069 -15.874 -0.921 -25.278 -0.203 -29.007 -0.119 -5.400
tx03 8.123 70.118 -4.154 -29.400 -1.107 -18.793 -0.026 -2.052 -1.649 -7.954
tx04 5.146 61.442 -3.723 -13.984 -1.231* -47.204 -0.174 -21.954 -0.184 -4.448
tx10 3.686 43.378 -3.257 -38.243 -1.472* -32.417 0.097 11.714 -2.828 -18.539
tx16 6.581* 74.111 4.647 33.808 -0.255 -10.896 0.076 11.633 0.832 14.546
tx21 -1.024 -10.358 -3.471* -39.886 -1.068* -34.480 -0.182 -19.349 -1.800 -20.602
tx22 6.660* 88.288 5.972 40.371 -0.148 -6.026 0.139 29.157 -0.065 -1.963
tx38 -1.244 -11.390 -3.752* -44.423 -1.685* -44.372 -0.867* -44.249 -3.553* -33.073
tx56 3.767 28.864 -7.207* -37.756 -1.391* -46.932 -0.300 -32.801 -2.791* -39.362
ut01 11.967 33.625 1.038 6.788 -0.805 -18.320 -0.163 -21.373 -1.301 -12.301
wa14 0.100 8.027 -0.685* -36.362 -1.015 -24.032 -0.091 -17.296 -0.295 -1.879
wa19 1.032* 57.147 -0.713* -41.248 -1.094* -52.413 -0.000 -0.065 -0.174 -3.945
wa21 1.445 58.465 -1.579* -57.388 -2.108* -65.664 -0.067 -14.033 -6.561* -55.343
wy02 0.927 16.481 -6.862* -54.802 -2.632* -72.074 -0.242* -50.588 -1.657* -51.023
wy06 3.034* 58.344 -3.709 -32.863 -1.872* -59.954 -0.284* -49.033 -1.229 -32.334
wy08 4.795* 113.937 0.745 9.152 -0.704 -33.909 -0.199 -28.406 0.471 24.535
wy99 2.861 31.035 -3.790 -25.688 -1.785* -55.638 -0.299* -42.363 -1.723* -52.391
* Annual trend was significant (p<0.05).
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Last Update: 1536 08JUL96 kjl