The chemical character of the ground water in the alluvium of that part of the Neosho river valley here considered is shown by the analyses of samples of water collected from six of the test holes and the partial analyses of samples from test holes 26 and 11 given in table 6. The analyses were made by Howard Stoltenberg in the Water and Sewage Laboratory of the Kansas State Board of Health. The constituents were determined by the methods used by the U. S. Geologicial Survey.
Table 6--Analyses of water front test holes in Neosho river valley, Labette county, Kansas. (Analyzed by Howard Stoltenberg. Dissolved constituents given in parts per million1; reacting values are given in italics2)
|Test hole no.
(Na + K)
|T. 31 S., R. 21 E.|
|4||NW corner NE NE sec. 27||Jan. 22||55||12||45|
|11||SW corner SE sec. 27||Jan. 19||55||36||540||800||448||352|
|26||NW corner sec. 34||Jan. 18||54||12||27||384||385 5||0|
|T. 32 S., R. 21 E.|
|36||NE SE SW sec. 4||Jan. 24||55||20||100|
|36||NE SE SW sec. 4 4||Feb. 9||59||18||97|
|35||SE NW SE sec. 4||Jan. 25||56||28||97|
|38||SW SE SE sec. 4||Jan. 24||55||18||84|
|41||NE NW sec. 9||Jan. 23||55||8.4||100|
|40||SW NW sec. 9||Jan. 23||55||19||85|
|1. One part per million is equivalent to 1 pound of substance per million pounds of water, or 8.33 pounds per million gallons of water.
2. Equivalents per million.
4. Collected after 19.5 hours pumping.
5. Total alkalinity, 422 parts per million; excess alkalinity, 38 parts per million.
6. Total alkalinity, 318 parts per million; excess alkalinity, 10 parts per million.
7. Total alkalinity, 315 parts per million; excess alkalinity, 7 parts per million.
8. Total alkalinity, 298 parts per million; excess alkalinity, 28 parts per million.
Chemical Constituents in Relation to Use
The following discussion of the chemical constituents of ground water has been adapted from publications of the U. S. Geological Survey.
Total dissolved solids--The residue left after a natural water has evaporated consists of rock materials, with which may be included some organic material and a small amount of water of crystallization. Water containing less than 500 parts per million of dissolved solids generally is entirely satisfactory for domestic use except for the difficulties resulting from its hardness and, in some areas, because of excessive corrosiveness. Water having more than 1,000 parts per million of dissolved solids is likely to contain enough of certain constituents to produce a noticeable taste or to make the water unsuitable in some other respects.
The content of total dissolved solids in the samples collected from the alluvium ranges from 365 to 801 parts per million, the average being about 500. Water of this concentration is suitable for most ordinary purposes.
Hardness--The hardness of water, which is the property that generally receives the most attention, is commonly recognized by its effects when soap is used with the water in washing. Calcium and magnesium cause almost all the hardness of ordinary waters. These constituents 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.
In addition to the total hardness, the table of analyses shows the carbonate hardness and the noncarbonate hardness. The carbonate hardness is that due to the presence of calcium and magnesium bicarbonates. The noncarbonate hardness is due to the presence of sulphates or chlorides of calcium and magnesium. 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 removal of hardness under ordinary circumstances is not necessary. Hardness between 50 and 150 parts per million does not seriously interfere with the use of water for most purposes. It does slightly increase the consumption of soap, and its removal by a softening process is profitable for laundries and other industries using large quantities of soap. Waters in the upper part of this range of hardness will cause considerable scale in steam boilers. Hardness exceeding 150 parts per million can be noticed by anyone, and if the hardness is 200 or 300 parts per million it is common practice to soften water for household use or to install a cistern to collect soft rain water. Where municipal water supplies are softened, an attempt is generally made to reduce the hardness to 60 or 80 parts per million.
The samples of water from the Neosho river valley ranged in hardness from 146 to 800 parts per million. Most of the hardness, however, is in the form of carbonate hardness, and only two of the samples had appreciable amounts of noncarbonate hardness.
Iron--Next to hardness, iron is the constituent of natural waters that generally receives the most attention. The quantity of iron in ground waters may differ greatly from place to place, even though the waters are from the same formation. If a water contains much more than 0.2 or 0.3 part per million of iron the excess may separate out 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 water by simple aeration and filtration, but a few waters require the addition of lime or some other substance.
As indicated in the table, all of the waters contained iron in amounts sufficient to produce a reddish sediment on exposure to air, the range being from 8.4 to 36 parts per million.
Chloride--Chloride (Cl) is an abundant constituent of sea water and is dissolved in small quantities from rock materials or in some localities comes from sewage. However, there are many sources of chloride and therefore its presence in large quantities cannot be taken as a definite indication of pollution. Chloride has little effect on the suitability of water for ordinary use unless there is enough to impart a salty taste. Waters high in chloride may be corrosive if used in steam boilers.
All the samples had a low content of chloride except the one collected from test hole 11. The chloride content of that sample is much higher than the others and is difficult to explain. Mr. Fulkman, of the architect-engineers, suggested that the slow flowing stream passing close to test hole 11 may have carried water high in chloride derived from some cinder dumps. There is no known abandoned oil well nearby. The chloride content is believed not to result from contamination.
Because of its hardness and high content of iron, ground water in this part of the Neosho river valley would require treatment for municipal use and for industrial purposes. Because most of the hardness is of the carbonate type, however, the treatment required for reduction of hardness and removal of iron would be relatively simple. The chloride content is generally low, and the one known occurrence of water containing considerable chloride is believed to be of only local extent.
Test drilling indicated that the water-bearing material in the Neosho river valley near Parsons, Kansas, has a considerable range in thickness and physical character. In general, it is about 35 feet thick. The most permeable beds of gravel are in the basal part of the alluvium and range from a few inches to 15 feet in thickness. These gravels are sinuous in areal extent and are thickest in old channels once occupied by Neosho river.
The ground water in the alluvium moves toward Neosho river. The water table was as much as 18 feet above normal river level during the period of this investigation, and in some places in the valley it intersected the land surface, causing small ponds and swamps. The depth to the water table was less than 10 feet below land surface in most parts of the valley in 1942. During the same period the gradient of the water table ranged from about 10 to 20 feet per mile. In 1941 the precipitation was 132 percent of normal and in 1942 it was 111 percent. Owing to this fact the water table probably was at a higher stage in 1942 than in years of normal precipitation. No direct evidence is available concerning the stage of the water table in years of drought, but the observation-well program begun in June, 1943, and continuing at present indicates that considerable fluctuation in water level may be expected, especially during the summer. Farm wells in the alluvium in this area are reported not to have failed during the droughts that occurred between 1930 and 1940. There are in the area many live cottonwood trees as large as 3 feet in diameter whose root systems probably tap the saturated part of the alluvium. The fact that they are still alive seems to indicate that the alluvium was not completely unwatered during earlier years of drought.
Data obtained from the pumping test indicate that, in the vicinity of the pumped well, the coefficient of permeability of the saturated part of the aquifer is approximately 420 and the specific yield is about 20 percent. The specific capacity of the test well was about 3.9 gallons a minute per foot of draw-down.
Recharge to the ground-water reservoir comes largely from precipitation, but some recharge occurs from seasonal flood waters. The amount of recharge from precipitation was not determined but is probably at least 5 percent of the average annual precipitation, or about 35,000,000 gallons to the square mile annually.
Pumping from wells will result in a decrease in the amount of water discharged naturally into Neosho river and its tributaries and through evaporation and the transpiration by plants, and, at least temporarily, a decrease in the amount of water stored in the underground reservoir. Pumping may result also in increased recharge in parts of the valley where the water table is very close to or intersects the land surface. In some years or seasons potential recharge may be rejected under natural conditions, whereas it might be admitted to the zone of saturation if the water table were lowered by pumping.
The quantity of water passing a line 1 mile long at right angles to the slope of the water table, as computed above, is approximately 135,000 gallons a day. Although the slope of the water table and the thickness of the more permeable parts of the aquifer are variable, this quantity of water is probably a close approximation of the underflow across comparable reference lines in most parts of the valley.
The average amount of free ground water in storage in each square mile was about 680,000,000 gallons at the time of this investigation. Part of this water would be available to wells in seasons of low precipitation and would be replenished in seasons of above-normal precipitation.
The quantity of water that can be recovered by wells depends in part upon the area over which it is practicable to spread the wells. The above computations and assumptions indicate that during years of normal precipitation and temperature about 200,000 gallons of water daily could be obtained from several wells properly distributed within an area of not less than 1 square mile in a part of the valley in which the total saturated thickness of the alluvium and the thickness of the basal gravel are near average. There is no direct evidence concerning the quantity of water available to wells in years of drought, but the available quantity of water probably would be less. Observation of water levels in 1943 indicates that considerable decline may be expected in dry periods. There is indirect evidence that the alluvium has not been completely unwatered in recent dry years, but such complete unwatering could conceivably occur if severe drought conditions were sufficiently prolonged.
The permeability of the aquifer and the shape of the cone of depression developed during the pumping test (fig. 6) indicate that wells should be spaced 1,000 to 2,000 feet apart in order to avoid serious mutual interference. Development of a water supply from an aquifer of this type should be preceded by test drilling to determine the proper location of the wells.
The quality of the ground water occurring in the alluvium is indicated by the analyses given in table 6. The carbonate hardness and the iron content are high and the removal of iron and reduction of hardness would be necessary for municipal and most industrial uses. Such treatment, however, would not be difficult.
Kansas Geological Survey, Geology
Placed on web Aug. 11, 2008; originally published March 1944.
Comments to firstname.lastname@example.org
The URL for this page is http://www.kgs.ku.edu/Publications/Bulletins/52_2/05_concl.html