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Ground-water Resources, continued
Availability of Ground Water
Unconsolidated Rock Aquifers
Alluvium and Wisconsinan Terrace Deposits
Marais Des Cygnes River Valley
Moderate quantities of ground water are available from Recent alluvium and terrace deposits in the Marais des Cygnes River valley. The extent of these deposits is shown on Plate 1. Logs of test holes indicate that these deposits have a maximum thickness of about 55 feet. The thickness of saturated water-bearing material ranges from 0 to about 46 feet.
The permeabilities of saturated alluvial and terrace deposits are probably relatively low, and only locally are there lenses of more permeable material. Specific capacities (yield in gpm per foot of drawdown) of wells drilled into this material are low to moderate. Movement of ground water through the unconsolidated deposits is probably slow, the hydraulic gradient being about 2 to 4 feet per mile. The water table in these deposits is relatively constant and does not fluctuate rapidly, as does the water table in the consolidated rocks. The storage coefficient of the unconsolidated deposits is much higher than that of the consolidated rocks, and, where a sufficiently saturated section is present, relatively dependable domestic supplies can be developed. [Storage Coefficient: In non-artesian aquifers this is the approximate ratio of the volume of water a rock will yield by gravity to its own volume.] Yields of most of the wells in these deposits are 1 to 5 gpm, but one well has been reported to yield as much as 45 gpm. In general the water from these aquifers can be characterized as very hard calcium bicarbonate water with a high iron content. Chemical analyses of water from two wells in the terrace deposits of the Marais des Cygnes River are shown in Table 2.
Other Stream Valleys
Tributaries of the Marais des Cygnes River contain alluvium and local terrace deposits, but these deposits are thin and yield only small water supplies to wells. The alluvium in these tributary valleys is composed of silty and clayey deposits ranging in thickness from 10 to 30 feet. The quality of ground water in these smaller valleys is reported to be generally satisfactory except for excessive hardness and iron content.
Consolidated Rock Aquifers
Limestone and Shale Aquifers
Limestone and shale units are widespread over the county at or near the surface. Individual stratigraphic units are relatively uniform in thickness and composition and are laterally continuous. The unweathered limestones and shales are relatively impermeable and generally will not yield enough water to wells to provide an adequate water supply. At or near the land surface weathering processes tend to increase or enlarge the open spaces within the rocks, especially along joints, fractures, and bedding planes, so that locally the rocks may yield 1 to 3 gpm of ground water to shallow wells.
The permeability of the weathered zone in limestone and shale differs greatly from place to place. Factors such as type and thickness of soil, vegetative cover, slope, and topographic position, as well as thickness and extent of the weathered zone have a marked influence on the amount of ground-water recharge and discharge in limestone and shale aquifers.
Probably all the limestones and shales between the base of the Kansas City Group and the top of the Weston Shale Member of the Stranger Formation yield water locally in variable amounts to wells in Miami County. Local differences in permeability, degree of weathering, distance from points of recharge, and structural attitude of the rocks govern the amount of water, if any, that will be discharged to wells.
The quality of water from the weathered limestone and shale aquifers is generally satisfactory for domestic use except for excessive hardness and iron content. The sanitary quality of ground water from such wells may be poor if the wells are not properly constructed or are located near sources of pollution.
Black fissile, carbonaceous shale occurs in the Swope and Dennis limestones, in the Cherryvale Shale, in the Stanton Limestone, and locally in the Iola Limestone. These black shales yield some water to wells and locally may be the principal aquifers for small domestic supplies. Wells 18-23-12ab and 19-23-15ab obtain water from black shales in the Dennis and Swope limestones, respectively, and are representative of wells obtaining water from black shales. The black shale facies of the Muncie Creek Shale Member of the Iola Limestone is only a few inches thick and is not an important source of water for wells.
Unconfirmed reports indicate that water in some of the pre-Pennsylvanian rocks is of better quality than the water obtained from lower Pennsylvanian rocks. The Hunton limestone of Silurian and Devonian ages is known to contain water of usable quality in parts of Brown and Doniphan counties in northeastern Kansas(3), and the Arbuckle Group, of Cambrian and Ordovician ages, yields municipal water supplies in southeastern Kansas. No analyses of ground water from beds of pre-Kansas City age were obtained during this investigation. [Water analyses on file in offices of U.S. Geological Survey, Ground-Water Branch, Lawrence, Kansas, and Kansas State Department of Health, Topeka, Kansas.]
Sandstone Aquifers
Several of the shale units in Miami County contain relatively thin intraformational sandstones, which locally yield 1 to 2 gpm of ground water to domestic wells. The sandstones have similar lithologic and hydrologic properties—chiefly very fine- to fine-grained micaceous, quartzose sandstone, with angular to subangular phenoclasts. Wells 17-23-24bbb and 18-22-12acc obtain water from sandstone in the Chanute Shale and are representative of wells obtaining water from sandstone aquifers (Table 5).
A small area of sec. 23, T. 15 S., R. 21 E., in the extreme northwestern part of the county, is underlain by about 20 feet of sandstone in the Lawrence Formation. This sandstone is similar in lithology and water-hearing characteristics to channel sandstones reported in Douglas County (O'Connor, 1960). No data as to quantity or quality of water from this aquifer in Miami County are available; however, in Douglas County wells in similar sandstone yield as much as 45 gpm and have permeabilities ranging from 18 to 343 gpd/sq. ft.
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Kansas Geological Survey, Miami County Geohydrology
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Web version June 2002. Original publication date June 1966.
URL=http://www.kgs.ku.edu/General/Geology/Miami/08_gw4.html