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Pawnee Valley

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Chemical Character of Ground Water

The general chemical character of the ground waters in Pawnee Valley is indicated by the analyses of water from 70 wells distributed as uniformly as practicable within the area and among the principal water-bearing formations (Table 20). Table 20 includes the analyses of 13 water samples from wells in the Dakota formation, 21 water samples from wells in the Greenhorn limestone, 9 water samples from wells in terrace deposits, 26 water samples from wells in alluvium, and 1 water sample from a well in the Permian rocks. The samples of water were analyzed by Howard A. Stoltenberg, chemist, in the Water and Sewage Laboratory of the Kansas State Board of Health.

Chemical Constituents in Relation to Use

Dissolved solids

When water is evaporated the residue that is left consists mainly of the mineral constituents listed in Table 20 and generally includes a small quantity of organic material and a little water of crystallization. Water containing less than 500 parts per million of dissolved solids generally is entirely satisfactory for domestic use, except for difficulties resulting from the hardness or an excessive content of iron. Water containing more than 1,000 parts per million is likely to include enough of certain constituents to produce a noticeable taste or to make the water unsuitable in some other respects.

The amount of dissolved solids in the samples of ground water collected in Pawnee Valley is indicated in Table 21. Of the 35 samples of water collected from wells in the alluvium and terraces the dissolved solids in 20 samples ranged between 300 and 400 parts per million. Only two samples from wells in the alluvium (wells 21-16-33cd and 22-16-4ca) contained more than 1,000 parts per million of dissolved solids.

Hardness

The hardness of a water is commonly recognized by the increased amount of soap needed to produce a lather and by the curdy precipitate that forms before a permanent lather is obtained. Calcium and magnesium compounds cause practically all the hardness of ordinary water, and they are also the active agents in the formation of the greater part of all the scale formed in steam boilers and in other vessels in which water is heated or evaporated.

Table 20--Analyses of water from typical wells in Pawnee Valley, Kansas. Analyzed by H. A. Stoltenberg. Dissolved constituents given in parts per million,a and in equivalents per millionb (in italics)

Well
Designation
(c)		 Depth
(feet)		 Geologic
source		 Date of
collection		 Temp.
(°) F		 Dissolved
solids		 Silica
(SiO2)		 Iron
(Fe)		 Calcium
(Ca)		 Magnesium
(Mg)		 Sodium and
potassium
(Na+K)		 Bicarbonate
(HCO3)		 Sulfate
(SO4)		 Chloride
(Cl)		 Fluoride
(F)		 Nitrate
(NO3)		 Hardness as CaCO3
Total
 Carbonate Noncarbonate
20-19-26cc 160 Greenhorn 8-24-1944 60 354   4.3 49
2.44		 20
1.64		 57
2.46		 284
4.66		 58
1.21		 21
.59		 1
.05		 2.1
.03		 204 204 0
20-19-29dd 44.7 Greenhorn 8-24-1944 59 409   4.7 116
5.79		 11
.90		 14
.62		 340
5.58		 14
.29		 13
.37		 .2
.01		 66
1.06		 334 279 55
20-20-32cd 110 Dakota 10-11-1944 59 972   5.8 45
2.25		 28
2.80		 267
11.60		 379
6.22		 322
6.70		 107
3.02		 2.4
.13		 5.3
.08		 228 228 0
20-21-31ad 37 Alluvium 6-10-1947 59 326 12 1.8 90
4.49		 12
.99		 13
.55		 300
4.92		 14
.29		 16
.45		 .5
.03		 21
.34		 274 246 28
20-22-9bb 43.6 Greenhorn 6-10-1947 58 652 5.8 14 156
7.78		 20
1.64		 37
1.59		 290
4.76		 218
4.53		 42
1.18		 1.4
.07		 29
.47		 471 238 233
20-22-9dd 27.3 Greenhorn 6-10-1947 58 396 18 .08 109
5.44		 8.6
.71		 12
.51		 279
4.58		 15
.31		 16
.45		 .6
.03		 80
1.29		 308 229 79
20-22-20ca 48.4 Alluvium 7-6-1946 58 386 31 .06 89
4.44		 12
.99		 28
1.23		 301
4.94		 54
1.12		 16
.45		 .4
.02		 8
.13		 272 247 25
20-22-24de 38.8 Terrace deposits 8-12-1946 58 324 22 .03 86
4.29		 9.2
.76		 16
.72		 289
4.74		 22
.46		 11
.81		 .3
.02		 15
.24		 252 237 15
20-22-27bb 28.5 Alluvium 6-10-1947 57 365 20 .84 92
4.59		 13
1.07		 22
.96		 315
5.17		 40
.83		 19
.54		 .6
.03		 3
.05		 283 258 25
20-23-14aa 28.9 Greenhorn 6-10-1947 57 564 9.6 .68 125
6.24		 15
1.23		 45
1.97		 312
5.12		 80
1.66		 38
1.07		 .6
.03		 97
1.56		 374 256 118
20-23-20ad 21.7 Greenhorn 6-10-1947 55 48 15 9.7 136
6.79		 84
.69		 14
.61		 322
5.28		 27
.56		 16
.45		 .2
.01		 111
1.79		 374 264 110
2 0-23-22dc 34.6 Greenhorn 8-12-1946 57 385 15 .05 108
5.39		 7.4
.61		 14
.61		 295
4.84		 17
.85		 12
.34		 .3
.02		 66
1.06		 300 4  
20-23-25db 57.6 Alluvium 7-5-1946 58 359 33 .08 86
4.29		 13
1.07		 21
.90		 310
5.08		 33
.69		 14
.39		 .3
.02		 5.3
.08		 268 254 14
20-23-32ca 69.6 Alluvium 8- 3-1946 58 324 30 .11 80
3.99		 10
.82		 20
.85		 288
4.72		 24
.50		 12
.34		 .3
.02		 5.3
.08		 240 236 4
20-23-36bb 42 Greenhorn 6-10-1947 59 341 16 .05 92
4.59		 8.8
.72		 17
.76		 287
4.71		 26
.54		 13
.37		 .4
.02		 27
.43		 266 236 30
21-16-7dd 38.8 Terrace deposits 10- 7-1944 58 551   2.7 89
4.44		 14
1.15		 102
4.44		 299
4.90		 27
.56		 155
4.37		 .3
.02		 11
.18		 280 245 35
21-16-33cd 70 Alluvium 8-11-1945   1,480   0 178
8.88		 54
4.44		 201
8.73		 254
4.17		 726
15.10		 94
2.65		 0
.00		 4.9
.08		 666 208 458
21-17-18dd 42.5 Terrace deposits 10-10-1944 58 295   2.5 76
3.79		 9.8
.81		 25
1.10		 311
5.10		 7.4
.15		 10
.28		 .5
.03		 8.4
.14		 230 230 0
21-18-5ad 100 Terrace deposits 10-13-1944 59 287   13 75
3.74		 11
.90		 19
.83		 317
5.20		 0
.00		 6
.17		 .9
.05		 3.2
.05		 232 232 0
21-18-17cc 120 Alluvium 6-21-1945   272   10 74
3.69		 14
1.15		 13
.56		 288
4.72		 11
.23		 12
.34		 .5
.03		 5.3
.08		 242 236 6
21-18-29bb 110 Alluvium 6-21-1945   276   9.4 76
8.79		 14
1.15		 13
.57		 300
4.92		 8.2
.17		 11
.31		 .5
.03		 5.3
.08		 247 246 1
21-18-32bb1 418 Permian redbeds 6-22-1945   8,830   6.1 628
31.34		 284
28.34		 2,049
89.10		 116
1.90		 2,990
62.21		 2,820
79.52		 1.8
.09		 3.5
.06		 2,730 95 2,640
21-18-32bb2 306 Dakota (?) 6-13-1945   423   17 56
2.79		 17
1.40		 86
3.73		 293
4.80		 37
.77		 80
2.26		 1.1
.06		 2
.03		 210 210 0
21-18-32cc 120 Alluvium 9-25-1944   370   .08 74
3.69		 15
1.23		 49
2.13		 324
5.31		 32
.66		 36
1.02		 .8
.04		 1.4
.02		 246 246 0
21-19-27cb 42 Alluvium 8-24-1944 59 319   .52 80
3.99		 14
1.15		 26
1.15		 340
5.58		 13
.27		 13
.37		 .7
.04		 2
.03		 257 257 0
21-20-15da 45 Alluvium 9-25-1944 58 403   24 122
6.09		 14
.15		 11
.49		 405
6.64		 19
.40		 11
.31		 .2
.01		 23
.37		 362 332 30
21-20-20ba1 55 Alluvium 9-21-1944 60 331   .05 80
3.99		 113
1.07		 28
1.21		 299
4.90		 38
.79		 17
.48		 .6
.03		 4.4
.07		 253 245 8
21-20-28ed 126 Dakota 8-24-1944 60 369   1.6 74
3.69		 25
2.06		 30
1.31		 327
5.36		 56
1.16		 16
.45		 1.1
.06		 2.1
.03		 288 268 20
21-21-9ed 58.7 Terrace deposits 6-10-1947 58 356 11 3.3 72
3.59		 11
.90		 46
1.98		 298
4.89		 42
.87		 20
.56		 1
.05		 6.2
.10		 224 224 0d
21-21-18aa 54.6 Alluvium 8-3-1946 58 414 26 .15 97
4.84		 15
1.23		 31
1.35		 356
5.84		 52
1.08		 16
.45		 .4
.02		 2
.03		 304 292 12
21-21-22da 51.5 Alluvium 6-10-1947 58 407 21 .30 92
4.59		 14
1.15		 37
1.62		 357
5,85		 50
1.04		 15
.42		 .5
.03		 1.4
.02		 287 287 0e
21-21-36ab 93.5 Alluvium 8-2-1946 58 395 25 .23 71
3.54		 13
1.07		 55
2.41		 332
5.44		 42
.87		 23
.65		 .8
.04		 1.1
.02		 230 230 0f
21-22-3ab 62.7 Alluvium 7-1-1946 58 379 31 .48 94
4.69		 11
.90		 24
1.04		 321
5.26		 40
.83		 16
.45		 .3
.02		 4.3
.07		 280 263 17
21-22-4dd 30.7 Greenhorn 6-10-1947 57 380 17 11 99
4.94		 13
1.07		 25
1.09		 359
5,89		 18
.37		 27
.76		 .3
.02		 4
.06		 300 294 6
21-22-8bb 35.7 Greenhorn 6-10-1947 57 329 11 27 78
3.89		 8.9
.73		 27
1.17		 259
4.25		 27
.56		 13
.37		 .5
.03		 36
.58		 231 212 19
21-22-15ac 35.2 Greenhorn 6-10-1947 57 397 16 .11 124
6.19		 8
.66		 9.2
.40		 372
6.10		 18
.37		 12
.34		 .2
.01		 27
.43		 342 305 37
21-22-27cb 285 Dakota 8-12-1946 61 622 8 .32 50
2.50		 16
1.82		 156
6.80		 309
5.07		 170
3.54		 67
1.89		 2
.10		 1.5
.02		 191 191 0g
22-16-4ca 12 Alluvium 10-6-1944 59 1,020   .46 188
9.28		 40
3.29		 90
3.90		 295
4.84		 501
10.42		 37
1.04		 1
.05		 14
.22		 634 242 392
22-17-5ca   Alluvium 10-10-1944 59 795   7 128
6.39		 28
2.30		 128
5.58		 418
6,86		 118
2.45		 171
4.82		 .5
.02		 5.3
.08		 434 343 91
22-17-11dd 20 Alluvium 8-23-1944 58 981   .72 169
8.43		 34
2.79		 102
4.44		 239
3.92		 492
10.23		 38
1.07		 .7
.04		 25
1.40		 561 196 365
22-17-19cb 215 Dakota 8-23-1944 60 1,480   .58 42
2.10		 26
2.14		 491
21.36		 337
5.53		 129
2.68		 610
17.20		 2
.10		 5.8
.09		 212 212 0
22-18-9ce 26 Alluvium 10-11-1944 58 316   .16 88
4.39		 12
.99		 18
.77		 331
5.43		 7
.15		 12
.34		 .3
.02		 13
.21		 269 269 0
22-18-28cc 82.5 Terrace deposits 10-10-1944 59 391   6.7 103
5.14		 17
1.40		 16
.69		 300
4.92		 12
.25		 54
1.52		 .3
.02		 32
.52		 327 246 81
22-18-35dd 56.5 Terrace deposits 10-7-1944 59 455   20 116
5.79		 18
1.48		 29
1.27		 454
7.44		 15
.31		 25
.70		 .4
.02		 4.2
.07		 364 364 0
22-19-8dd 40.5 Terrace deposits 10-9-1944 60 314   .30 66
3.29		 13
1.07		 38
1.66		 290
4.76		 18
.37		 26
.73		 1
.05		 7.1
.11		 218 218 0
22-19-29cc 100 Dakota 10-11-1944 59 527   34 42
2.10		 22
1.81		 118
5.13		 351
5.76		 76
1.58		 54
1.52		 2.6
.14		 2.5
.04		 196 196 0
22-20-4bb 210 Dakota 10-9-1944 60 361   5.5 64
3.19		 27
2.22		 32
1.40		 310
5.08		 63
1.31		 11
.31		 1.4
.07		 2.3
.04		 270 254 16
22-20-29ba 28.2 Terrace deposits 10-9-1944 58 348   .12 102
5.09		 7.2
.59		 15
.67		 300
4.92		 14
.29		 15
.42		 44
.71		 .2
.01		 284 246 38
22-21-9cc 67.4 Alluvium 8-2-1946 58 343 21 0 85
4.24		 13
1.07		 21
.92		 300
4.92		 30
.62		 22
.62		 .5
.03		 2.7
.04		 266 246 20
22-21-10cb 100 Alluvium 6-11-1947 58 315 4.6 6.9 96
4.79		 9.4
.77		 12
.51		 303
4.97		 19
.40		 23
.65		 .3
.02		 2.1
.03		 278 248 30
22-21-12ab 70.4 Terrace deposits 8-11-1946 59 343 7 .27 85
4.24		 22
1.81		 14
.61		 327
5.36		 33
.69		 18
.51		 1.1
.06		 2.2
.04		 302 268 34
22-21-14aa 67.2 Dakota 6-11-1947 58 240 5.6 6.3 60
2.99		 10
.82		 16
.68		 227
3.72		 4.1
.08		 12
.34		 .5
.03		 20
.32		 190 186 4
22-21-25aa 126.3 Dakota 6-11-1947 59 111 2.4 18 5.6
.28		 3.8
.31		 33
1.44		 72
1.18		 9
.19		 16
.45		 .8
.04		 .70
.01		 30 30 0h
22-22-13cb2 75.5 Alluvium 7-23-1946 58 363 31 .29 86
4.29		 12
.99		 26
1.12		 321
5.26		 26
.54		 16
.45		 .3
.02		 8
.18		 264 263 1
22-22-27ca 106 Alluvium 8-3-1946 58 460 29 .25 87
4.34		 13
1.07		 59
2.58		 327
5.36		 67
1.39		 42
1.18		 .8
.04		 1.3
.02		 270 268 2
22-22-31dc 59.4 Alluvium 7-9-1946 57 503 32 .05 106
5.29		 15
1.23		 51
2.20		 366
6.00		 75
1.56		 36
1.02		 .6
.03		 7.1
.11		 326 300 26
23-21-2bb 207.4 Dakota 6-11-1947 59 337 6.4 5.2 47
2.34		 27
2.22		 44
1.90		 303
4.97		 44
.92		 17
.48		 1.4
.07		 1.2
.02		 228 228 0i
23-22-11cc 98.1 Dakota 8-13-1946 58 409 30 .32 74
3.69		 14
1.15		 56
2.44		 337
5.53		 26
.54		 40
1.13		 1
.05		 1.8
.03		 242 242 0j
23-22-29dd 248 Dakota 8-12-1946 61 1,610 5.4 .36 40
2.00		 25
2.06		 549
23.89		 346
5.67		 126
2.62		 690
19.46		 3
.16		 2.2
.04		 203 203 0k
23-23-15cd 128.1 Dakota 8-12-1946 60 362 17 5.4 86
4.29		 14
1.15		 26
1.11		 300
4.92		 52
1.08		 17
.48		 .9
.05		 1.1
.02		 272 246 26
  1. One part per million is equivalent to one pound of substance per million pounds of water or 8.33 pounds per million gallons of water.
  2. An equivalent per million is a unit chemical equivalent weight of solute per million unit weights of solution. Concentration in equivalents per million is calculated by dividing the concentration in parts per million by the chemical combining weight of the substance or ion.
  3. When the number is preceded by T, the sample was collected from a test hole.
  4. Excess alkalinity, 20 parts per million.
  5. Excess alkalinity, 5 parts per million.
  6. Excess alkalinity, 42 parts per million.
  7. Excess alkalinity, 63 parts per million.
  8. Excess alkalinity, 37 parts per million.
  9. Excess alkalinity, 20 parts per million.
  10. Excess alkalinity, 34 parts per million.
  11. Excess alkalinity, 81 parts per million.

Table 21--Summary of the chemical characteristics of the samples of water collected from wells in Pawnee Valley, Kansas

Range in parts per million Number of samples
Dakota Greenhorn Terraces Alluvium
Dissolved solids
Less than 200 1      
201-300 1   2 2
301-400 4 7 5 15
401-500 2 2 1 4
501-1,000 3 2 1 3
More than 1,000 2     2
Hardness
Less than 200 4      
201-300 9 3 6 19
301-400   7 3 3
401-500   1   1
More than 500       3
Iron
Less than 0.1   2   8
0.1-1.0 4 3 6 13
1.1-5.0 1 2 0 1
5.1-10.0 5 1 1 4
More than 10.0 3 3 2  
Chloride
Less than 10     1  
11-20 6 6 4 16
21-50 1 5 2 8
51-100 3   1 1
101-500 1   1 1
More than 500 2      

In addition to the total hardness, the table of analyses shows the carbonate hardness and the noncarbonate hardness. The carbonate hardness is that caused by calcium and magnesium bicarbonates and can be almost entirely removed by boiling. This type of hardness is often called "temporary hardness." The noncarbonate hardness is due to calcium and magnesium sulfates or chlorides and cannot be removed by boiling. It is sometimes referred to as "permanent hardness." With reference to use with soaps, there is no difference between the carbonate and noncarbonate hardness. In general, the noncarbonate hardness forms harder scale in steam boilers.

Water having a hardness of less than 50 parts per million is generally rated as soft, and its treatment for the removal of hardness is rarely justified. Hardness between 50 and 150 parts per million does not seriously interfere with the use of water for most purposes, but it does increase slightly the consumption of soap; removal of the hardness by a softening process is profitable for laundries or other industries that use large quantities of soap. Treatment for the prevention of scale is necessary for the successful operation of steam boilers using water in the upper part of this range of hardness. Hardness of more than 150 parts per million can be noticed by anyone, and where the hardness is 200 or 300 parts per million it is common practice to soften water for household use or to install cisterns to collect soft rain water.

The hardness of 59 of the samples of water that were analyzed is indicated in Table 20; distribution by ranges of hardness are indicated in Table 21.

Iron

Next to hardness, iron is the constituent of natural waters that in general receives the most attention. The quantity of iron in ground waters may differ greatly from place to place, even in waters from the same formation. If a water contains much more than 0.1 part per million of iron, the excess may separate out after exposure to the air and settle as a reddish sediment. Iron, which may be present in sufficient quantity to give a disagreeable taste and to stain cooking utensils, may be removed from most waters by simple aeration and filtration, but a few waters require the addition of lime or some other substance. For the samples analyzed, 50 of the total of 60 contained more than 0.1 part per million of iron.

The iron content of the samples of ground water that were analyzed is shown in Table 21.

Water for irrigation

The suitability of water for use in irrigation is commonly believed to depend mainly on the quantity of soluble salts and on the ratio of the quantity of sodium to the total quantity of sodium, calcium, and magnesium. The quantity of chloride may be large enough to affect the use of the water, and in some areas there may be other constituents, such as boron, in sufficient quantity to cause difficulty. Magistad and Christiansen (1944, pp. 8-9) makes the following statement concerning irrigation waters:

Plants in saline soils are adversely affected by high concentrations of salts in the soil solution and by poor physical condition of the soil. Both conditions are greatly affected by the type of irrigation water used. An irrigation water having a high sodium percentage will, after a time, give rise to a soil having a large proportion of replaceable sodium in the colloid, often designated as black alkali soil. Even on sandy soils with good drainage waters of 85 percent sodium or higher will give rise to impermeable soils after prolonged use. With higher total salt content there is a flocculating action that tends to counterbalance the poor physical condition caused by a high sodium concentration in the water. On a heavy soil already high in replaceable sodium, the poorest water that one could use would be one low in total salts but having a high sodium percentage.

Magistad and Christiansen proposed standards for irrigation waters which are helpful in appraising or evaluating supplies. A class I water which is considered as excellent to good should contain not more than 700 parts per million of salt and not more than 60 percent sodium. A class 2 water which is classed as good to injurious contains from 700 to 2,000 parts per million of salt and a sodium percentage between 60 and 75. A class 2 water is probably harmful to the more sensitive crops. A class 3 water which is generally unsatisfactory contains more than 2,000 parts per million salts and more than 75 percent sodium.

It is recognized that the harmfulness of irrigation water is so dependent upon the type of land and crops, on the manner of use, and on the drainage that no specific limits can be adopted. Most of the water in the alluvium and terrace deposits of Pawnee Valley can be used safely for irrigation. Two samples contained more than 1,000 parts per million dissolved solids (wells 21-16-33cd and 22-16-4ca). The wells from which these samples were collected are in the Arkansas Valley near the mouth of Pawnee River.

Quality in Relation to Water-bearing Formations

The quality of water from the alluvium, Dakota formation, and Greenhorn limestone is indicated by the analyses in Table 20, is summarized in Table 21, and is shown graphically in Figure 12. The quality of water in these formations and in the Permian redbeds is discussed below.

Figure 12--Analyses of waters from the principal water-bearing formations in Pawnee Valley.

Bar charts for Dakota fm., Greenhorn ls., Terrace deposits, and alluvium showing water quality.

Permian redbeds

The undifferentiated redbeds of Permian age yield little or no water to wells in this area, but the quality of the water from these beds is important because of the danger of pollution of the overlying beds that contain fresh water. Several deep wells and test holes in this area have encountered salt water under artesian pressure in these deposits. Therefore, such wells and test holes must be effectively sealed to prevent contamination of water.

The analysis of one sample of water from the Permian redbeds is given in Table 20 (21-18-32bb1). This sample contained 8,834 parts per million dissolved solids, 2,991 parts per million of sulfate, and 2,820 parts per million of chloride.

Dakota formation

Thirteen samples of water were collected from wells penetrating the Dakota formation. Seven of these samples contained more than 400 parts per million of dissolved solids, two of which had a dissolved solids content over 1,000 ppm. Water from the Dakota formation is moderately hard to hard. The 13 samples had an average hardness of 212. The maximum hardness was 288 and the minimum was 30 (well 22-21-25aa).

Greenhorn limestone

Eleven samples of water were collected from wells penetrating the Greenhorn limestone. Seven of these samples contained between 300 and 400 parts per million of dissolved solids, two contained between 400 and 500 parts per million, and two contained between 500 and 1,000 parts per million. Seven of the samples had a hardness between 300 and 400. The chloride content of all samples was less than 50 parts per million.

Terrace deposits

The dissolved solids in five of nine samples ranged from 300 to 400 parts per million. The hardness of six of the samples ranged from 200 to 300 parts per million. The other three samples had a hardness ranging from 300 to 400 parts. Seven samples had a chloride content of less than 50 parts per million, one had 54 parts per million, and one had 155 parts per million.

Alluvium

Twenty-six samples of water from the alluvium were analyzed. A few of the samples were from wells in the Arkansas Valley near the mouth of Pawnee River. The water in the alluvium of Pawnee Valley is generally of good quality, but the water in Arkansas Valley may contain a fairly high amount of dissolved solids. The dissolved solids in the 26 samples ranged from 272 to 1,480. Nineteen samples had a hardness between 200 and 300 parts per million and 7 samples had a hardness of more than 300 parts.

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Kansas Geological Survey, Geohydrology
Placed on web May 31, 2012; originally published April 1952.
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