English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The U.S. Geological Survey has analyzed hundreds of aquifer tests that were conducted from June 1942 through May 1988 in 75 of the 82 counties in Mississippi. This report briefly describes the occurrence, types, and methods of analysis of aquifer tests in the State and tabulates and summarizes the results of 574 tests. Most of these tests were conducted by water-well drillers upon completion of the wells, although U.S. Geological Survey personnel conducted or helped conduct many of the tests. The Theis nonequilibrium method and modifications were used to analyze aquifer-test data. About 20 percent of the aquifer tests are multiple-well tests and 80 percent are single-well tests. Generally, the aquifers in younger rocks have larger transmissivity and hydraulic conductivity values than the aquifers in older rocks. Transmissivity ranged from 5 to 84,000 feet squared per day; the median transmissivity was 4,500 feet squared per day. The median transmissivity exceeded 1,000 feet squared per day for 12 of the 14 principal aquifers in the State. Hydraulic conductivity ranged from 0.3 to 400 feet per day; the median hydraulic conductivity was 57 feet per day. The median hydraulic conductivity exceeded 10 feet per day for 13 of the 14 principal aquifers. INTRODUCTION Ground water is a valuable resource in Mississippi; it is the source of water for about 92 percent of the State's population (2.6 million people). About 68 percent or 1,580 Mgal/d (million gallons per day) of the total freshwater withdrawals for all offstream water-use categories in the State (Solley and others, 1988) is from groundwater supplies. Wells capable of yielding 200 gal/min (gallons per minute) of water with quality suitable for most uses can be obtained nearly anywhere in the State (Bednar, 1988). For State agencies to manage and receive maximum benefit from its ground-water resource, it is essential that hydrologists, water-well contractors, water users, and water-resource planners and managers have information that describes hydraulic characteristics of the principal aquifers in the State. Such information commonly is obtained from aquifer tests. Purpose and Scope The U.S. Geological Survey (USGS) has analyzed hundreds of aquifer tests that were conducted from June 1942 through May 1988 in 75 of the 82 counties in Mississippi. This report briefly describes the occurrence, types, and methods of analysis of aquifer tests in the State and tabulates and summarizes the results of 574 tests. The results of the aquifer tests are for the specific geologic units or zones in geologic units in which wells tested are completed and represent point sources of data representative of the unit tested. Consequently, the summaries of the aquifertest data should be considered qualitative or, at best, semi-quantitative indications of the properties of the geologic units or principal aquifers as a whole. General Hydrogeologic Setting Mississippi is almost entirely in the East Gulf Coastal Plain (Fenneman, 1946) and is underlain by deposits of clay, sand, gravel, chalk, marl, and limestone. Rocks of Paleozoic age crop out in a few valleys in Tishomingo County in extreme northeastern Mississippi (fig.l). Aquifers in strata of Cretaceous age, which occur in the northern part of the State, dip and thicken westward and southwestward. Aquifers in strata of Eocene? age generally dip westward in the northern part of the State and southward in the central and southern parts. Principal Aquifers Most wells in Mississippi yield water from 1 or more of 14 principal aquifers. The aquifer names used in this report have been used traditionally in the State of Mississippi and by the U.S. Geological the names do not conform to the Survej Survej Laney 's current guidelines, as specified by and Davidson (1986), for phasing out time-stratigraphic names for aquifers. Except for the Paleozoic aquifer, the principal aquifers in Mississippi are irregular in thickness and physical character and exhibit extreme variation in their capacity to store and transmit water (Wasson, 1986). The lithology, confining conditions, water quality, and water use of the principal aquifers were described by Bos well (1985); similarly, water quality and related topics (such as effects of land use on water quality and potential for water-quality changes) for the principal aquifers were described by Bednar (1988). More detailed information on the principal aquifers in the State was published by Gandl (1982) and Wasson (1986), The following descriptions of principal aquifers in the State are based largely on the reports by Gandl (1982), Boswell (1985), and \Yasson (1986); the water-use data are from Callahan and Barber (1990). The numbers in brackets are the aquifer numbers used ih this report and correspond to those used by Bednar (1988). The geographic distribution of the principal aquifers is shown in figure 1. [1] The Mississippi River alluvial aquifer (taile 1; Boswell, 1985) consists of alluvium primarily clay, silt, sand, and graVel of Quaternary age. The aquifer is semiconfined. The Mississippi River alluvial aquifer underlies a 7,000-squaremile area in the northwestern part of the State commonly referred to as the "Delta." In 1985, more than 75 percent (1,190 Mgal/d) of all ground water used in the State was withdrawn from wells completed in this aquifer (Callahan and Barber, 1990). [2] The Citronelle aquifers consist primarily of clay, silt, sand, and gravel in Pliocene deposits (table 1; Bos well, 1985). The Citronelle aquifers generally are unconfined. In 1985, about 0.4 percent (6.7 Mgal/d) of ground water used in the State was withdrawn from these aquifers (Callahan and Barber, 1990). [3] The Miocene aquifer system (table 1; Boswell, 1985; Wasson, 1986), includes aquifers in the Graham Ferry, Pascagoula, and Hattiesburg Formations and Catahoula Sandstone and consists primarily of clay, silt, sand, gravel, and sandstone. Aquifers of the Miocene system generally are confined throughout most of their area of use. In 1985, about 7.8 percent (124 Mgal/d) of the ground water used in the State was withdrawn from this aquifer system. [4]-The Oligocene aquifer system (table 1; Boswell, 1985) includes the Waynesboro Sand lentil of the Bucatunna Formation, the Byram, Glendon, Marianna, Mint Spring, and Forest Hill Formations, and consists primarily of clay, silt, sand, marl, and limestone. Aquifers of the Oligocene system generally are confined throughout most of their area of use. In 1985, less than 0.3 percent (4 Mgal/d) of the ground water used in the State was withdrawn from this aquifer system. Aquifers in the Eocene system (table 1; Boswell, 1985) include the Cockfield, Sparta, Winona-Tallahatta, Meridianupper Wilcox, and lower Wilcox. In 1985, about 11 percent (174 Mgal/d) of ground water used in Mississippi was withdrawn from this aquifer system. [5]--The Cockfield aquifer (table 1; Gandl, 1982; Boswell, 1985) consists primarily of clay, silt, sand, marl, and lignite. Generally, the Cockfield is confined throughout most of its area of use. [6]~The Sparta aquifer (table 1; Boswell, 1985) consists primarily of clay, silt, sand, and lignite. Generally, the Sparta aquifer is confined throughout most of its area of use. [7]-The Winona-Tallahatta aquifer (table 1; Boswell, 1985) consists primarily of clay and glauconitic sand. Generally, this aquifer is confined throughout most of its area of use. [8] The Meridian-upper Wilcox aquifer (table 1; Boswell, 1985) consists primarily of clay, silt, sand, and lignite. Generally, this aquifer is confined throughout most of its area of use. [9]-The lower Wilcox aquifer (table 1; Boswell, 1985) consists primarily of clay, silt, sand, and lignite. Generally, this aquifer is confined throughout most of its area of use. The Cretaceous aquifer system (table 1; Boswell, 1985) includes the Ripley aquifers, the Coffee Sand aquifer, the Eutaw-McShan aquifer, and the Tuscaloosa aquifer system. In 1985, about 4.9 percent (78 Mgal/d) of ground water used in the State was withdrawn from this aquifer system. [10]--The Ripley aquifers (table 1; Boswell, 1985) consist primarily of clay, sand, sandstone, and limestone. Generally, these aquifers are confined throughout most of their area of use. [111-The Coffee Sand aquifer (table 1; Boswell, 1985) consists primarily of clay, sand, and sandstone. Generally, this aquifer is confined throughout most of its area of use. [12]-The Eutaw-McShan aquifer (table 1; Boswell, 1985) consists primarily of clay and sand. Generally, this aquifer is confined throughout most of its area of use. [13]-The Tuscaloosa aquifer system (table 1; Boswell, 1985) consists primarily of clay, silt, and sand. These aquifers generally are confined throughout most of their area of use. [14] The Paleozoic aquifer (table 1; Boswell, 1985) consists primarily of clay, chert, and limestone. Generally, this aquifer is confined throughout most of its area of use. In 1985, about 0.3 percent (4.4 Mgal/d) of ground water used in the State was withdrawn from this aquifer. AVAILABILITY AND ANALYSIS OF AQUIFER TESTS In cooperation with State, local, and other Federal agencies, the USGS has been gathering and analyzing aquifer-test data in Mississippi since the 1940's. Although the USGS conducted some aquifer tests, much of the available aquifer-test data have been provided by water-well drillers, State and local agencies, and other Federal agencies. Data analyzed by the USGS as of June 1963 were published by Harvey (1963); data analyzed as of June 1971 were published by Newcome (1971). This report includes all data analyzed by June 1990 and includes results of tests conducted from June 1942 through May 1988. The earliest reported aquifer test in Mississippi was completed in June 1942 at Hattiesburg in Forrest County. In December 1942 and early 1943, three aquifer tests were completed at Camp McCain in Grenada County (Brown and Adams, 1943). Three aquifer tests were conducted i

Summary of aquifer tests in Mississippi, June 1942 through May 1988