The number of wells completed in each of the sandstone aquifers is difficult to determine for various reasons. Many wells are completed in several aquifers, including both unconsolidated deposits and consolidated rocks. Classifying these wells as to principal aquifer is difficult if the screened interval of the well or a lithologic description of the well bore is not available. The total number of applications to appropriate ground water by large-capacity wells (yields of more than 100 gal/min) from sandstone aquifers also is difficult to determine. According to the Division of Water Resources, Kansas State Board of Agriculture, early applications for water rights were not reported or granted on the basis of any particular sandstone aquifer.
A partial listing of selected wells drilled into the sandstone aquifers is given in a table of wells in Kume and Spinazola (1982). The table lists about 374 wells in 20 counties in southwestern Kansas; which is an average density of approximately 19 wells per county. Eighty percent of these wells were completed in aquifers in the Dakota Formation, and every county has wells in these aquifers. The water from sandstone aquifers is used primarily for domestic and stock purposes, with 54% of the wells in this list in that category. A secondary use is for irrigation, with 23% of the wells in that category. Generally, the sandstone aquifers are underdeveloped.
Aquifers in the Dakota Formation
The aquifers in the Dakota Formation are the most widely used sandstone aquifers for ground water in the study area. Irrigation-well construction in the Dakota aquifers has occurred in two main areas shown in fig. 20--1) northeastern Ford County in the vicinity of Spearville and Ford (about 46 irrigation wells) and 2) central Hodgeman County in the vicinity of Jetmore (about 19 irrigation wells).
Other well construction in Ford and Hodgeman counties has been for public supplies for Jetmore and Spearville, industrial supplies for several cattle feedlots and a beef-packing plant near Dodge City, and numerous stock and domestic supplies. The annual withdrawal of water from the aquifers in the Dakota Formation during 1973 was estimated to range from 7,700 to 15,000 acre-ft/yr in Hodgeman and northern Ford counties (Lobmeyer and Weakly, 1979).
Other areas of large-capacity well construction in the Dakota aquifers include: 1) Edwards County--15 irrigation and public-supply wells, 2) Finney County--irrigation supplies and industrial supplies at a coal-fired electric-generation plant near Holcomb, 3) Kearny County--irrigation supplies and public supplies at Lakin, 4) western Stanton County near Manter--irrigation supplies, 5) Wichita County--irrigation supplies, and 6) Grant and Ness counties--irrigation supplies.
Aquifers in rocks of Late Jurassic age
The aquifers in rocks of Late Jurassic age are the second most widely used source of ground water from sandstone aquifers in the study area. However, the aquifers occur only in the western one-fourth of the study area, and the aquifer thicknesses are quite limited in some areas. Most of the well development has occurred where the aquifers are less than 550 ft deep. The aquifers are developed extensively in Stanton and Grant counties, southern Hamilton and Kearny counties, and northern Morton and Stevens counties. These are important areas of groundwater use for irrigation, domestic, and stock supplies. However, the wells are completed not only in the aquifers in rocks of Late Jurassic age but in aquifers in the rocks of Early Cretaceous age and in Tertiary and Pleistocene deposits as well.
Other sandstone aquifers
Other sandstone aquifers occur in rocks of Permian age, the Cheyenne Sandstone, the Kiowa Formation, and the Codell Sandstone Member of the Carlile Shale. They are the least-used sources of ground water from sandstone aquifers in the study area. Only minor stock- and domestic-well use occurs in these aquifers. Very little well construction has occurred in the aquifers in rocks of Permian age because they may contain very poor quality water and are generally deeper than the other sandstone aquifers. The aquifers in the Cheyenne Sandstone are used in Hamilton, Grant, and Stanton counties. In Stanton County, these aquifers are hydraulically connected with the aquifers in rocks of Late Jurassic age, and both aquifers are screened together for irrigation supplies. Just east of the study area in Russell County, Swineford and Williams (1945) reported that the Cheyenne Sandstone was used as a legal shallow-disposal zone for oil-field brine and that the water in the sandstone is not potable. In some areas, the "poor-quality" water in these aquifers has curtailed well construction. Very little well construction has occurred in the aquifers in the Kiowa Formation because the sandstone in this formation is very localized. The aquifers in the Codell Sandstone Member are used in Trego, Ellis, and Gove counties.
Additional studies are needed to provide the detailed data for a better understanding of the geohydrology and chemical quality of water in sandstone aquifers. Suggestions include
- Additional test drilling is required, especially in the deep-aquifer areas. The study area needs test-hole data; where data are sparse, units from the land surface down to the Permian need describing.
- Borehole geophysical logs need to be run in each test hole drilled. The lithology and hydraulic characteristics of the well bore also need to be described.
- Construction of test wells is necessary. Steel-cased (inside diameter, 5 inches) and screened wells capable of being pumped need to be constructed. A pump and power plant also need to be installed in each test well to check yield and to facilitate collection of water samples.
- Aquifer tests are essential. Water discharge and drawdown data need to be collected. Water-velocity surveys inside the well casing could be run along the well screen during discharge tests.
- Collection of samples need to be made for chemical analysis from selected privately owned wells in the significant sandstone beds in aquifers in rocks of Jurassic age, the Cheyenne Sandstone, and the Kiowa Formation throughout the study area.
- Piezometers need to be established in each aquifer throughout the study area in test holes or privately owned wells.
- Water levels in observation wells need to be monitored quarterly or at least annually in January.
- Annual water-level maps for each aquifer need to be made from the project measurements and from January mass measurements in western Kansas.
- Maps of formation thickness and depth, structural contours, and sandstone-bed thicknesses need to be updated as new data become available.
- Interpretation of geophysical logs from oil and gas wells needs to be continued. New logs are continually available as more wells are drilled. Geologic sections need to be updated as new data are available.
- The current status of water-well construction in sandstone aquifers is needed. All unlisted sandstone-aquifer wells need to be entered into the computer data base. Previously listed wells need to be updated if new data are available.
- Measurements of well discharge and time-of-pump operation need to be made to determine the water use from sandstone aquifers for each year.
- Digital computer models of ground-water-flow systems in the sandstone aquifers need to be prepared.
Sandstone aquifers occur in Upper Permian, Upper Jurassic, and Lower and Upper Cretaceous rocks in southwestern Kansas. Information regarding sandstone aquifers compiled in this report included extent of formations, lithologies, altitude of formation surface, depth below land surface, formation thickness, thickness of sandstone beds, altitude of potentiometric surface, aquifer properties, water types, suitability for irrigation, chemical characteristics, and use of water during 1980.
Rocks of Permian age crop out in Meade County and are present in the subsurface throughout the study area. These rocks are characterized by sandstones, siltstones, shales, evaporites, limestones, and dolomites. The altitude of the top of the Permian surface increases southwestwardly from below 1,300 ft in northwestern Rush County to approximately 3,400 ft in Morton County. Depths below land surface to the top of the Permian increase northwestwardly from 0 at the outcrop to 2,100 ft in Wallace County. Altitude of the potentiometric surface during 1975-79 ranged from approximately 2,500 ft in the west to 2,100 ft in the east along the eastern edge of the study area.
Water from aquifers in rocks of Permian age was generally saline to briny. The water was of the sodium chloride or calcium sulfate types, but calcium bicarbonate type also was present. Dissolved-solids concentrations in samples ranged from 89 to 51,000 mg/L. The results of chemical analysis showed a low to very high sodium hazard and a low to very high salinity hazard. Specific conductance ranged from 115 to 60,000 µmho/cm at 25°C. Water from rocks of Permian age generally was not suitable for irrigation but may be used in isolated areas because of local recharge. Water from Permian sandstone aquifers is used for stock and domestic supplies.
Rocks of Late Jurassic age crop out in Morton County and occur in the subsurface of the western half of the study area. Rocks of Late Jurassic age overlie rocks of Permian age in the study area and underlie rocks of Early Cretaceous age in most of the study area. Rocks of Late Jurassic age underlie Tertiary deposits south of the limit of rocks of Cretaceous age in Grant, Haskell, Morton, Seward, and Stevens counties. Rocks of Late Jurassic age consist of varicolored shales and red sandstones. The altitude of the top of Upper Jurassic rocks decreases from approximately 3,500 ft in Morton County to just over 1,400 ft in Logan County. Depth below land surface ranges from 0 at the outcrop to about 2,000 ft in Wallace County. The thickness of the rocks ranges from 0 along the eastern limit to about 250 ft in northwestern Scott County and averages 103 ft. Sandstone beds range in thickness from 0 to about 50 ft and average 24 ft but exhibit little regional continuity.
Rocks of Late Jurassic age and the Cheyenne Sandstone comprise a single hydrologic unit in parts of Grant, Stanton, and neighboring counties in southwestern Kansas. The potentiometric surface in this hydrologic unit ranged from 3,500 ft in the west to about 2,850 ft in the east. Hydrographs show an approximate 25-ft decline in water levels between 1959 and 1979. Water samples from the unit were classified as fresh. Dissolved-solids concentrations ranged from 296 mg/L to 517 mg/L. Calcium or sodium bicarbonate were the most common chemical types. Water exclusively from rocks of Late Jurassic age was suitable for irrigation at the one well for which a chemical analysis was made. The water at this site had a low sodium hazard and a medium salinity hazard. Specific conductance was 660 µmho/cm at 25°C. Water from rocks of Late Jurassic age is used for irrigation, stock, and domestic supplies in the study area.
Geophysical logs were used to differentiate rocks of Early Cretaceous age into the Cheyenne Sandstone, Kiowa Formation, and Dakota Formation in most of the study area. In parts of Finney, Grant, Gray, Haskell, Hodgeman, Kearny, Scott, Stanton, and Wichita counties, the three formations comprising the Lower Cretaceous Series in the study area were not differentiated. Facies changes within each formation make the correlation of formation tops impractical in some areas, using available information. Rocks of Early Cretaceous age crop out in Ford, Hamilton, Hodgeman, Kearny, Pawnee, and Stanton counties.
The Cheyenne Sandstone consists of light-colored, fine-grained sandstone, gray and sandy shale, shale, siltstone, and clay in the study area. The altitude of the top of the Cheyenne Sandstone decreases northward from approximately 3,400 ft in Stanton and Morton counties to just over 1,400 ft in Gove County. Depth below land surface to the top of the Cheyenne Sandstone increases northward from 150 ft in Morton County to about 1,950 ft in Wallace County. The thickness of the formation ranges from about 20 ft in Pawnee County to 245 ft in Ford County and averages 91 ft. Thickness of sandstone beds ranges from 0 in southeastern Wallace County and northeastern Finney County to 190 ft in southwestern Hodgeman County and averages 37 ft. Sandstone beds tend to be local and discontinuous. The potentiometric surface in the Cheyenne decreased easterly from about 3,200 ft in Hamilton County to about 2,100 ft in Pawnee and Rush counties during 1975-1981. Vertical movement of water between rocks of Permian age and the Cheyenne Sandstone occurs through a hydraulic connection in Pawnee County where the hydraulic head is about 5 ft greater in the rocks of Permian age than in the Cheyenne rocks.
Water from the Cheyenne is generally saline to briny. Water with lower dissolved-solids concentrations may be available where the Cheyenne is hydraulically connected with rocks of Late Jurassic age or near outcrop areas. Dissolved-solids concentrations in samples ranged from 192 to 51,000 mg/L. Sodium sulfate or sodium chloride were the common water types. The suitability of water for irrigation from the Cheyenne is variable. Samples had a low sodium hazard and a medium to high salinity hazard. Specific conductance ranged from 325 to 60,000 µmho/cm at 25°C. In Grant, Hamilton, and Stanton counties, water from the Cheyenne Sandstone is used for irrigation.
The Kiowa Formation consists of light-gray to black illitic shale. Limestone beds and sandstone lenses occur locally. The altitude of the top of the Kiowa ranges from approximately 3,500 ft in Morton County to approximately 1,600 ft in the counties along the northern boundary of the study area. The Kiowa generally is considered to be a confining layer in the study area, but sandstone lenses found mainly in the northeast part of the study area yield minor amounts of water for domestic and stock uses.
The Dakota Formation is composed of varicolored claystone, mudstone, shale, siltstone, and sandstone. The altitude of the top of the Dakota decreases northward from approximately 3,600 ft in Stanton County to just less than 1,800 ft in Trego County. Depth below land surface to the top of the Dakota ranges from 0 at the outcrop to about 1,650 ft in Wallace County. Thickness of the formation ranges from about 60 ft to about 460 ft and averages 218 ft. Thickness of sandstone beds ranges from 0 to 150 ft and averages 58 ft. Large variations in formation and sandstone thicknesses are apparent within short distances in the study area. Transmissivity values in aquifers in the Dakota Formation range from 940 to 7,100 ft2/d, and storage coefficients range from 0.0004 to 0.07. Well yields range from a few gallons per minute to 2,200 gal/min. The maximum decline of water levels in wells in the Dakota for the period between 1969 and 1979 averaged 60 ft. The potentiometric surface in the Dakota Formation ranged from about 3,300 ft in the west to about 1,900 ft in the east during 1975-1981. Higher hydraulic heads in the Ogallala and Pleistocene aquifers in Finney, Grant, Hamilton, Haskell, and Stanton counties induce downward flow of water to the stratigraphically adjacent Dakota Formation through a hydraulic connection in these areas.
Water from the Dakota Formation was fresh to moderately saline. Dissolved-solids concentrations in samples ranged from 201 to 3,660 mg/L. Sodium bicarbonate was the predominant water type among calcium bicarbonate, sodium chloride, sodium sulfate, and calcium sulfate types. Sodium chloride type water found in Ellis and Russell counties probably migrated upwards from underlying Permian rocks. The suitability of water from the Dakota Formation for irrigation is variable. Samples ranged from a medium to very high salinity hazard and from a low to very high sodium hazard. Specific conductance ranged from 470 to 6,740 µmho/cm at 25°C. Water from the Dakota is used for stock, domestic, irrigation, and municipal supplies in the study area.
The Codell Sandstone Member of the Carlile Shale in the Upper Cretaceous Series occurs in Ellis, Gove, Ness, Rush, and Trego counties and crops out in Rush County. The Codell is a fine- to very fine grained sandstone that occurs in the upper part of the Carlile Shale. The Codell reaches a maximum thickness of about 25 ft in Ellis County and thins to 0 in the northeast and south. Water from the Codell Sandstone Member is fresh. Calcium bicarbonate and calcium sulfate were the most common chemical types of water. Dissolved-solids concentrations ranged from 264 to 564 mg/L. The water was suitable for irrigation with a low sodium hazard and a medium to high salinity hazard. Specific conductance ranged from 465 to 915 µmho/cm at 25°C. The Codell Sandstone Member is used in Trego, Ellis, and Gove counties as a source of irrigation, stock, and domestic water.
Kansas Geological Survey, Geohydrology
Placed on web June 14, 2013; originally published 1985.
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