Archives - Page 6
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Chemical Quality Series 4: Chemical Quality of Irrigation Waters in Hamilton, Kearny, Finney, and Northern Gray Counties
The utilization of irrigation waters in Kansas has increased dramatically since the drought period of the 1950's. With this development has come the need for information which can be used in the determination of compatibility of groundwaters with soils and crops and in the management of the groundwater systems tapped for agricultural purposes. An important component of this information is the chemical character of the waters under consideration.
The chemical quality data contained in this report show that groundwater presently in use from the Arkansas River valley in Kearny, Hamilton, and Finney counties and a band north of the river in Finney County is of sufficiently poor quality that it could produce adverse effects upon soils and crop yields with uncontrolled long-term usage. In most cases, poorer quality groundwater is associated with the presence of saline soils and shallow water tables.
Further efforts in this study are being directed toward correlating the chemistry of the groundwaters with natural variables such as soil association, bedrock types, depth to water, and surface and bedrock topography, and using these correlations to produce areal presentations of the chemical quality data. With these correlations and more complete coverage of western Kansas, positive policy recommendations concerning the conservation and proper use of the groundwater supplies of the state will be possible. This series of studies was begun on a limited scale in 1974 with that goal in mind. Greeley, Wichita, Scott, Lane, and southern Wallace counties were covered in that year; the results were reported in Kansas Geological Survey Chemical Quality Series 2. This report covers work done in 1975. In 1976, the rest of the southwest portion of the state was sampled; a report on that area is in preparation. This summer the Great Bend Prairie area will be sampled.
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Chemical Quality Series 5: Ground Water from Lower Cretaceous Rocks in Kansas
Continuing declines in the water table in western Kansas due to the heavy demands of irrigation and municipalities have led to a search for additional supplies of water. Lower Cretaceous rocks (primarily the Cheyenne Sandstone and Dakota Formation) have long supplied water for irrigation and stock.
This survey of the available data on the quantity and quality of ground water available from Lower Cretaceous rocks indicates that an estimated 70-80 million acre-feet of fresh water containing less than 1,000 mg/l (milligrams per liter) dissolved solids and 10-15 million acre-feet of slightly saline water containing 1,000-3,000 mg/l dissolved solids could be obtained. The Kansas Department of Health and Environment recommends less than 500 mg/l dissolved solids for drinking water and will accept up to 1,000 mg/l. Thus, much of the available water could be used as is and even more would be available after desalinization. Water quality tends to be good to the south and the east along the Lower Cretaceous outcrop belt and to gradually decline towards the north and west.
The Lower Cretaceous rocks outcrop in a band from the southwest in a northeasterly direction across the center of the State and are present in the subsurface to the north and west. Their depth increases to 2,600 feet below land surface in the extreme northwest. The thickness of sandstone in the Lower Cretaceous rocks is less than 200 feet in most of Kansas, but is as much as 400 feet in Lane County. The movement of water in Lower Cretaceous sandstones is generally in an easterly or northeasterly direction. The rocks are directly overlain and hydraulically connected with Pliocene and Pleistocene aquifers in parts of southwestern Kansas. Although ground water from the Lower Cretaceous rocks has seen only moderate use to date, there are indications that, locally, pumpage already exceeds recharge.
The ground-water resources in the Lower Cretaceous rocks of western Kansas represent a significant resource for present and future. Additional studies are needed of the regional relationships of the Lower Cretaceous aquifers to overlying Pliocene and Pleistocene aquifers and underlying Jurassic and Permian aquifers with respect to head changes and water-quality changes that may result from water-level declines in the overlying aquifers and pumpage from large numbers of multi-aquifer irrigation wells. Careful planning could result in an extended lifetime for the aquifers.
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Chemical Quality Series 12: A survey of organic carbon and trihalomethane formation potential
Drinking-water standards promulgated by the U.S. Environmental Protection Agency (EPA) underscore the importance of detailed water-quality data for sources used in conjunction with public water supplies. It has been recognized that reaction of the chlorine (used as a disinfectant) with organic matter present in surface waters can lead to formation of trihalomethanes (THMs) in concentrations which may exceed the 100 µg/L maximum contaminant level (MCL) established by the EPA. However, relatively little consideration has been given to ground-water sources with regard to the organic carbon content of the waters, the potential for THM formation, or the presence of ammonium ion (NH4+), which both consumes chlorine and serves to reduce THM formation. The successful operation of water-treatment plants for public supplies is dependent upon many factors, such as operator skill and the condition of the equipment, but of similar importance is a detailed knowledge of water quality for the sources being employed.
A survey of Kansas ground waters to determine their concentrations of total organic carbon (TOC) and trihalomethane-formation potential (TFP) was conducted in the spring of 1986. Wells were carefully selected, based on well logs made during construction, to represent particular geologic intervals. Thirty-four samples were collected from public water supply wells and 16 samples were collected from private water wells. Samples from 11 alluvial aquifers, four unconsolidated aquifers in Quaternary and Tertiary formations, and four consolidated aquifers in Cretaceous, Permian, Pennsylvanian, and Cambrian-Ordovician rocks were taken.
The mean and median TOC concentrations were 1.03 ± 0.76 and 0.84 mg/L, while the mean and median TFP concentrations were 46.7 ± 39.5 and 30.6 µg/L, respectively. The mean TFP yield was 0.242 ± 0.07 µmol per mg of TOC, and the TFP concentration in micromoles per liter was very strongly correlated (r = 0.953) with TOC. Only 8% of the samples had a TFP concentration exceeding the present MCL for THMs of 100 µg/L, but 56% exceeded 25 µg/L and 90% exceeded 10 µg/L, suggesting that many Kansas water-supply systems using ground water might have difficulty meeting a substantially lower THM standard.
The average instantaneous THM (ITHM) concentration was only 6.95 µg/L, while the average terminal (TTHM) concentration was 35.6 µg/L. Hence, only a small fraction of the THM concentration to which consumers might be exposed is formed prior to distribution. For the 21 TTHM samples having a free chlorine residual at the end of the incubation period, TTHM was strongly correlated with both TOC (r = 0.819) and TFP (r = 0.926), suggesting that either of these might be a good surrogate measure for TTHM.
TOC (and TFP) appeared to be unrelated to aquifer (well screen) depth, but both were clearly much higher in the alluvial aquifers, all of which were located at relatively shallow depths. TOC also appeared to be unrelated to the inorganic constituents present in the samples, with the exception of a subset of samples from alluvial aquifers having high concentrations of NH4+ (>0.1 mg/L) and Fe + Mn (>1.0 mg/L). For these samples, TOC was strongly correlated with both NH4+ (r = 0.676) and Fe + Mn (r = 0.991). These relationships merit further investigation, since all of the constituents involved pose problems for water-treatment plants.
In Kansas, efforts to control THMs in public water supplies from groundwater sources should focus primarily on alluvial aquifers, especially those having high concentrations of TOC, NH4+, Fe, and Mn. TOC and TFP may be useful surrogates for TTHM and could be used as a basis for exemptions from monitoring requirements. Use of combined chlorine appears to be the simplest and most effective means of limiting THM formation, but the necessary precautions must be taken to ensure that the microbial quality of the drinking-water supply is not compromised.
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Bulletin 231: Lexicon of Geologic Names of Kansas (through 1995)
The purpose of this lexicon is to make available a compilation of the myriad names that are used and have been used in the past by geologists working in the state. Names recognized as valid nomenclature (shown in boldface) by the Kansas Geological Survey are distinguished from improper and informal terms; names are defined briefly as to lithology, thickness, age, underlying and overlying units, and type locality and/or reference section. Because many of the names have been redefined and variously modified, a nomenclatural history has been compiled for each name in the style of the various lexicons published by the U.S. Geological Survey, particularly that of Bulletin 896 by Wilmarth (1938).
This lexicon is the result of a group effort by the most knowledgeable stratigraphers on the staff of the Kansas Geological Survey. D. L. Baars served as organizer and chairman of the committee, and was responsible for the chronostratigraphic terms. Christopher G. Maples took over general compilation and provided complete and comprehensive information on many of the names included through the entire lexicon.
Names of Precambrian sedimentary rocks were the responsibility of Pieter Berendsen; those of the Cambrian-Ordovician Arbuckle Group were handled by P. Allen Macfarlane; the Simpson through Devonian units by K. David Newell; the Chattanooga Shale by Michael W. Lambert; Mississippian names by Christopher G. Maples; formations of the Pennsylvanian Morrow, Atoka, and Cherokee by Lawrence L. Brady; Marmaton and Kansas City units by W. Lynn Watney; Frank W. Wilson was responsible for the Lansing through Shawnee Groups; Howard R. Feldman was responsible for the Douglas Group; Wabaunsee through Council Grove Groups were the responsibility of Christopher G. Maples and Ronald R. West; Frank W. Wilson did the Chase Group; colloquial names for Lower Permian units were prepared by David A. Grisafe; rocks of the Leonardian and Guadalupian Series were compiled by D. L. Baars; Triassic and Jurassic names were the responsibility of John H. Doveton; Howard R. Feldman, P. Allen Macfarlane, and Christopher G. Maples compiled the Cretaceous and Tertiary terms; Pleistocene deposits and Cretaceous intrusive igneous bodies were compiled by Christopher G. Maples. David Collins and Janice Sorensen reviewed previous versions of the manuscript and provided valuable information in making the publication more inclusive. Valuable general contributions were made by Lee C. Gerhard and Rex Buchanan. Technical editing was by Marla Adkins-Heljeson; cover design by Jennifer Sims. Completion and verification of many sources throughout the lexicon were completed by Marla Adkins-Heljeson, Janice Sorensen, David Collins, and Rex Buchanan. Secretarial assistance by Lea Ann Davidson and Esther Price was much appreciated.
This compilation is as exhaustive of all terms in use or previously used in Kansas as time and patience would allow. However, we do not claim perfection. It would be appreciated if corrections or additions to this list discovered by the reader would be brought to the attention of the Kansas Geological Survey.
Formal names recognized and used by the Kansas Geological Survey are shown in boldface type; informal names and those not recognized by the Survey are in regular type. The first letters of all formal stratigraphic names have been capitalized in accordance with the stratigraphic code of the North American Commission on Stratigraphic Nomenclature (1983). In the interest of brevity, a semi-telegraphic style of writing has been used in the summary material, as is used in the U. S. Geological Survey lexicons.
