View Full Table | Close Full ViewTable 1.

Discharge name, the year the mine opened, coal seam mined, size of mine, and acidity values for each discharge.

 
Discharge Year opened Coal seam Size Acidity
1968 1980 2000 2006
ha mg L−1 as CaCO3
Bull 1 1955 UF† 21 2805 1401 780
Bull 2 1957 UF 923 1905 756 540
Bull 3 1957 UF 923 640 214 78
Bull 4 1955 UF 86 250 360 530 478
Bull 5 1955 UF 58 1370 336 334
Fickey 1 1945 UF 28 3270 961 486
Fickey 5‡ 1950 UF 38 515 460 697 461
Fickey 6 1950 UF 75 1300 425 118 94
Fickey 7 1950 UF 60 1670 1086 490
Fickey 8 1952 UF 78 1505 625 390 420
Fickey 9 1945 UF 47 1920 498 636
Glade 1 1955 UF 26 1705 151 90
Glade 2 1950 UF 52 390 179 31
Glade 3 1950 UF 69 675 412 266
Glade 4 1950 UF 156 1660 1250 230 450
Glade 5 1950 UF 156 1765 1330 283 239
Greens 1 1945 UF 33 945 455 702 188
Greens 2§ 1945 UF 42 8 4 6
Greens 3‡ 1950 UF 88 1504 830 1732 1214
Martin 2 1955 UF 11 2315 545 135 110
Martin 3 1955 UF 11 490 253 35
Middle 1 1952 UF 310 917 515 291 290
Muddy 2 1940 UF 72 687 410 86 198
Muddy 3 1935 UF 278 170 110 45 72
Muddy 5 1950 UF 148 20 30 71
Muddy 6 1945 UF 98 4400 492 192
Muddy 7 1945 UF 86 520 57 27
Muddy 9 1952 UF 78 1515 1225 1050 800
Muddy 10 1940 UF 121 1440 487 414
Muddy 11 1943 UF 35 2140 634 550 444
Cheat PA 1 1935 P 63 2457 563 424
Cheat 2 1935 P 112 1061 1033 1048
Cheat 5 1935 P 55 1825 210 104 446
Cheat 6 1952 P 311 1450 488 214
Lynn 1 1943 P 34 1368 605 102 170
Lynn 2 1935 P 448 4690 3800 434 360
Lynn 3 1935 P 448 4988 1930 537 810
P, Pittsburgh; UF, Upper Freeport.
Not included in analyses because of surface disturbance.
§ Not included in analyses because of low acidity.



View Full Table | Close Full ViewTable 2.

Mean acidity, summary statistics, percent decrease, and annual percent decrease for Upper Freeport and Pittsburgh coal seam underground mines in 1968, 1980, 2000, 2006, and overall.

 
Coal seam Year(s) n Mean SD Min. Median Max. Decrease Annual decrease
mg L−1 % % yr−1
UF† 1968 27 1422 1003 20 1440 4400
1980 12 657 394 110 530 1330 54‡ 4.5‡
2000 27 434 357 30 336 1401 34‡ 1.7‡
2006 27 306 228 27 266 800 30‡ 4.9‡
overall 93 712 20 486 4400 78§ 2.1§
P 1968 7 2548 1627 1061 1825 4988
1980 4 1636 1619 210 1268 3800 36‡ 3.0‡
2000 7 466 316 102 487 1033 72‡ 3.6‡
2006 7 496 320 170 424 1048 −6.5‡ −1.1‡
overall 25 1245 102 605 4988 80§ 2.1§
UF, Upper Freeport; P, Pittsburgh.
From previous data collection time.
§ From 1968 to 2006.



View Full Table | Close Full ViewTable 3.

Prediction errors for first-order decay models.

 
Subset regression (k = 2.73 × 10−2 yr−1) Mean CD† = 0 (k = 3.95 × 10−2 yr−1)
CD % Error CD % Error
mg L−1 % mg L−1 %
Mean 174 151 0 58
Median 159 138 −13 50
Min. 86 73 −80 9
Max. 296 224 77 104
CD, cumulative difference.



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Prediction errors for simple linear decline models.

 
Subset regression (b 1 = −1.81 × 10−2 yr−1) Mean CD† = 0 (b 1 = 2.04 × 10−2 yr−1)
CD % Error CD % Error
mg L−1 % mg L−1 %
Mean 115 119 0 58
Median 95 107 −13 50
Min. 29 51 −79 9
Max. 221 183 77 104
CD, cumulative difference.