Ground-water regions in Osage County are determined primarily by the underlying rock materials, the structure of the area, and the climate. The quality of water in the principal aquifers is also a factor considered. On this basis the county is divided into several regions in which ground water occurs under similar conditions. The region boundaries are necessarily generalized and within each region the discussion is not applicable to some wells.
Region A (Pl. 3) includes the valley areas underlain by clay, silt, sand, and gravel of the alluvium and low terrace deposits (chiefly Illinoian or younger). In the Marais des Cygnes River Valley and parts of Salt Creek, Dragoon Creek, and One Hundred and Ten Mile Creek Valleys, wells having yields of 10 to 50 gallons a minute can be developed. Water is obtained from sand and gravel in the basal parts of the deposits. The thickness of the fluvial deposits ranges from a maximum of about 40 feet in the Marais des Cygnes River Valley to about 5 feet in small tributary valleys.
In parts of the county where other ground-water resources are available, wells in alluvial deposits are preferred because of their greater reliability during drought periods, larger yields, and better chemical quality of the water. Excellent stock and domestic wells and, locally, small municipal supplies can be developed in most of this region.
Areas in which rocks of the Admire and Wabaunsee groups of early Permian and late Pennsylvanian age are the chief source of well water are included in Region B (Pl. 3). Because of differences in depths and yields of wells and quality of water, this region is divided into two parts for purposes of discussion.
Area B1--In Area B1 of Region B the principal water-bearing beds are the thin sandstones and sandy zones in the shales. The sandstones are composed chiefly of very fine to medium sand grains generally containing enough silt and clay to make them low in permeability. Sandy zones occur locally in nearly all the shale formations, but the zones are not individually extensive or thick. Locally, some of the limestone beds have enough porosity and permeability to yield small supplies of water to shallow wells for domestic or stock use. In other places they yield little or no water to wells.
Throughout most of this area an adequate and dependable supply of water of good quality is difficult to obtain. Most wells are 30 feet or less in depth, although a few are as deep as 60 feet. Ground water obtained from depths greater than 30 to 60 feet generally contains enough of certain dissolved mineral constituents to make it unsatisfactory for domestic use, and in some places water at depths of less than 30 feet is unsatisfactory.
Large-diameter shallow dug wells are the predominant type of well in this area. Yields are generally small and the storage space provided by large-diameter wells is desirable. During dry seasons many wells are inadequate or go dry. Some of the farms in this area have no wells but depend on large cisterns for domestic water supplies and ponds or creeks for stock-water supplies. Ponds and cisterns are important supplements to ground-water supplies in this area.
Area B2--In Area B2 of Region B many farms have drilled wells which range in depth from about 60 to 240 feet. These wells derive water chiefly from beds of sandstone in the White Cloud shale and the Severy shale. (Some of the wells have been reported to penetrate as much as 40 feet of sandstone.) Yields of drilled wells in this area are reported to range from half a gallon a minute to as much as 20 gallons a minute. Most wells probably yield 2 to 5 gallons a minute. The quality of water from these wells is generally good (well 15-15-6ab, Table 4). Along the western margin of this area chloride generally increases and may limit the usefulness of the water.
Shallow wells comparable in quality of water, depth, and yield to those of Area B1 are also found in the remainder of Area B2.
Region C (Pl. 3) includes the area in which wells obtain ground water chiefly from Pennsylvanian rocks of the Shawnee group.
Dug wells, generally 15 to 60 feet deep, obtain small supplies of water from fractures in the limestones and shales. Beds of sandstone, especially in the Calhoun and Kanwaka shales, are the principal source of water for both dug and drilled wells in some localities. Drilled wells obtain water suitable for domestic and stock use at depths ranging from 40 feet to 150 feet. Because the sandstones occur as erratic channel deposits or lenticular beds that grade laterally into shale, wells drilled into these beds are not always successful (14-17-16ab, Table 6).
Water obtained from the sandstones of the Shawnee group is generally a sodium bicarbonate water moderately high in dissolved solids. Chloride is generally the constituent that determines the usefulness of the water. Shallow wells constructed in the weathered limestones and shales generally yield a much harder calcium bicarbonate water.
Wells in this region yield from only a few gallons a day to a maximum of 10 gallons a minute. During years of normal precipitation the average well in this region would probably yield 1 gallon a minute.
Many farms use cisterns to supplement the domestic ground-water supplies and for soft water and have ponds for stock-water supplies.
Water from deeper aquifers in this region is too mineralized for stock or domestic use.
Pennsylvanian rocks of the Douglas group are the principal aquifers in Region D (Pl. 3). The Ireland sandstone member of the Lawrence shale is extensive in this region, attaining a maximum thickness of 60 to 80 feet. Nearly all the wells in Osage County that tap the Ireland sandstone member are drilled wells that range in depth from about 80 to 350 feet. Yields of these wells range from 1 to 40 gallons a minute.
Local residents report that in a small area in the southeast corner of the county wells drilled to the depth that should penetrate the Ireland sandstone member are not successful because the sand is "dry" or because no sandstone is present. This area includes parts or all of secs. 21, 22, 27, 28, 33, and 34, T. 18 S., R. 17 E. Two Kansas Emergency Relief Committee (KERC) wells in sec. 10, T. 18 S., R. 17 E., drilled into the Ireland sandstone member during the drought years of the l930s, were reported as dry also.
The water obtained from the Ireland sandstone member ranges from a soft sodium bicarbonate water to a somewhat harder calcium bicarbonate water. As in other parts of Osage County where wells obtain water from sandstone, the fluoride content has a wide range of concentration and in many places is more than the recommended maximum of 1.5 parts per million (Table 4). The amount of chloride in some of the wells in the Ireland sandstone member is enough to give a salty taste to the water.
Records were obtained for one well and one test hole drilled into the Tonganoxie sandstone member of the Stranger formation in Osage County (14-16-19ad and 17-17-9dd). The water in each instance was highly mineralized and not suitable for domestic or stock use.
From the data available in Osage County and adjacent counties, it is known that the quality of water in both the Ireland sandstone member and Tonganoxie sandstone member changes from usable to unusable within short distances.
The west boundary of Region D (Pl. 3) depicts as accurately as possible from the data available, the area in which water of suitable quality for domestic or stock use can be obtained from the Ireland sandstone member. Where wells penetrating the Ireland are sparse, the boundary may be in error by one-half to 2 miles.
Kansas Geological Survey, Geology
Web version April 2002. Original publication date May 1955.
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