Geology topics

Research about Memphis, Tennessee

Source-linked reports with geographic coverage including Memphis, Tennessee.

25 records · Page 2Linked to original sources

USGS1982

Installation and sampling of observation wells and analyses of water from the shallow aquifer at selected waste-disposal sites in the Memphis area, Tennessee

Observation wells were installed and sampled at six abandoned waste-disposal sites in the Memphis area that have been identified as having received unknown quantities and types of industrial wastes. These sites are: (1) Bellevue Dump, (2) Brooks Road Dump, (3) Hollywood Dump, (4) Jackson Pit Dump, (5) Millington Dump-Landfill, and (6) Old Ordnance Dump. Ten wells were installed adjacent to and downgradient from these sites in the shallow water-table aquifer. This aquifer is made up chiefly of the alluvium and fluvial (terrace) deposits of Quaternary age, but locally may include sand in the uppermost part of the Jackson Formation and Claiborne Group of Tertiary age. Water samples were collected from these 10 wells and from two other wells in the shallow water-table aquifer at the Hollywood Dump. Most wells were sampled twice --initially in the early summer when water levels were high and again in the fall when water levels were low. Other wells were sampled only once in either summer or fall. The water was analyzed for common constituents, selected trace constituents, and selected organic compounds.

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USGS1981

Chemical character of ground water in the shallow water-table aquifer at selected localities in the Memphis area, Tennessee

The City of Memphis depends solely on ground water for its water supply. About 97 percent of inventoried pumpage in the Memphis area, which totaled about 194 Mgal/d in 1979, is from the Memphis Sand. This aquifer generally has been believed to be separated from the shallow water-table aquifer (alluvium and fluvial deposits) by a relatively thick and wide-spread confining bed consisting chiefly of clay. Studies by the Geological Survey in recent decades, however, have indicated that part of the recharge to the Memphis Sand probably is derived by vertical leakage from the shallow water-table aquifer through the confining bed and that locally "windows" of sand exist in the confining bed through which any contaminants in the shallow water-table aquifer could enter the Memphis Sand (See Criner and others, 1964, p. 30; Bell and Nyman, 1968, p. 7-8; Parks and Lounsbury, 1976, p. 26-27). More recently, additional evidence of vertical leakage being a component of recharge to the Memphis Sand was provided during the calibration of a digital computer model of the aquifers in the Memphis area. For this calibration a leakage factor, averaging about 20 percent over the Memphis area, had to be applied to the model in order to simulate known historic water levels in the Memphis Sand (J. V. Brahana, 1980, oral commun. ). This discovery has heightened concern about the possibility of contaminants being in the shallow water table aquifer, and thus, the potentiality for any contaminants to enter the Memphis Sand. Areas where the shallow water-table aquifer is most susceptible to contamination are those that have been or are being used for waste disposal. Historically, Memphis and Shelby County along with private concerns and industries have used dumps and landfills in two geologically and topographically different areas -- the flood plains of nearby streams and abandoned gravel pits in upland areas. These dumps and landfills have received a large variety of wastes including ashes, construction and demolition materials, garbage, rubbish, street refuse, and chemical and industrial wastes. Most of these dumps and landfills were closed in the early 1970's at the beginning of state regulation of waste disposal practices. Nevertheless, leachates from these waste disposal facilities presumably have been and are entering the shallow water-table aquifer.

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USGS1977

Preliminary evaluation of flood frequency relations in the urban areas of Memphis, Tennessee

A storm-runoff relation for streams in the urban areas of Memphis was determined by a statistical evaluation of 59 flood discharges from 19 gaging stations. These flood discharges were related to drainage area, percent imperviousness of the drainage basin, and rainfall occurring over 120-minute periods. The defined relation is Q = (158.3A^(0.777A^(-0.02)))*((IMP+1)^(0.227))*((I120)^((0.539*(I120))^0.40)) where Q is flood discharge in cfs, A is drainage area in square miles, IMP is percent imperviousness in the basin, and 1120 is rainfall in inches, over 120 minute time period. The defined relation was used to synthesize sets of annual flood peaks for drainage basins ranging from .05 square miles to 10 square miles and imperviousness ranging from 0 to 80 percent for the period of rainfall record at Memphis. From these series of flood peaks, frequency relations were defined and presented for 2, 5, 10, 25, 50 and 100 year recurrent intervals.

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USGS1976

Summary of some current and possible future environmental problems related to geology and hydrology at Memphis, Tennessee

Memphis, Tennessee, like many other cities in the Nation, has some problems related to local geology and hydrology. The city is in the Coastal Plain physiographic province and is underlain at shallow depths by sand, clay, silt, gravel, and lignite. These post-Midway strata (Wilcox and younger) make up geologic units belonging to the uppermost Paleocene, Eocene, and Pliocene (?) Series of the Tertiary System and to the Pleistocene and Holocene Series of the Quaternary System. Environmental problems of immediate or future concern are associated with six general topics: (1) aggregate resources, (2) foundation materials, (3) earthquake hazards, (4) flood hazards, (5) water resources, and (6) solid waste disposal. Consideration of these topics in one report should provide an overall insight into the close interrelation of the problems and the need for coordinated studies of the geology and hydrology at Memphis.

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USGS1976

Historic water-level changes and pumpage from the principal aquifers of the Memphis area, Tennessee: 1886-1975

The Memphis Sand ("500-foot" sand) supplies about 95 percent of the water used in the Memphis area for municipal and industrial purposes. In general, pumpage has increased at an irregular rate since the completion of the first well to this aquifer in 1886. These withdrawals are responsible for an almost continuous decline of water levels in wells throughout the Memphis area. Water-level data indicate that over the years a broad, regional cone of depression has developed in the potentiometric surface of the Memphis Sand and is centered near downtown Memphis. Areally smaller, subsidiary cones are superimposed upon this regional cone in areas heavily pumped by municipal and industrial wells. Pumpage from the Memphis Sand in Shelby County, Tenn., was 188 Mgal/d (million gallons per day) or 712 Ml/d (million litres per day) in 1975, although a maximum of 190 Mgal/d (719 Ml/d) was reached in 1974. Pumpage from the Fort Pillow Sand ("1,400-foot" sand) began in 1924 and increased at a yearly rate of about 0.6 Mgal/d (2.3 Ml/d) until 1942. From 1943 to 1962, pumpage averaged about 11.5 Mgal/d (43.5 Ml/d), then was reduced as MLGW (Memphis Light, Gas and Water Division) discontinued wells that became unserviceable. MLGW ceased pumping from the aquifer in 1974, and pumpage from the remaining industrial wells in Shelby County in 1975 was 4.4 Mgal/d (16.6 Ml/d). Water levels in the Fort Pillow Sand generally have risen since 1963. Water l evels in the aquifers in the Memphis area fluctuate inversely with changes in pumping. Analysis of observation-well and pumpage data indicates that local water levels can be altered by changing the pumping rates or by varying the areal distribution of pumping.

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USGS1973

Wolf River at Memphis, Tennessee: floodflow characteristics along proposed Interstate Highway 240, Shelby County

This report has been prepared by the U.S. Geological Survey at the request of Mr. Henry Derthick, Engineer of Structures of the Tennessee Department of Transportation, under the authority of a cooperative agreement between the two agencies. It supplements information contained in a report with the same title dated September 1966. The Department of Transportation proposes to construct a segment of Interstate Highway 240 and several bridges across the Wolf River on the northern side off Memphis, Shelby Count. Mt. Derthick has requested an analysis of the 50-year flood or the maximum flood of record to determine the possible effect of the proposed construction on flood profiles along the Wolf River.

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USGS1932

A preliminary report on the artesian water supply of Memphis, Tennessee

Memphis is located in the part of the Gulf Coastal Plain known as the Mississippi embayment. It is underlain by unconsolidated sand and clay formations of Tertiary and Cretaceous age. The Wilcox group, of Tertiary age, and the Ripley formation, of Cretaceous age, are excellent aquifers, and all the water consumed in Memphis is derived from them. The maximum pumpage from the Wilcox group was reached about 1920; in that year an estimated average of 37,575,000 gallons a day was pumped. In 1928 the average daily pumpage from the Wilcox group was about 33,984,000 gallons, and in addition to this the Memphis Artesian Water Department pumped an average of 4,616,000 gallons a day from the Ripley formation. The static level at Memphis varies with the pumpage and the stage of the Mississippi River. The original static level was about 235 feet above mean sea level. In 1928 the average static level at the Auction Avenue plant was 202 feet above mean sea level, which was about 33 feet lower than the original level. The yield is therefore about a million gallons a day for each foot of drawdown. The drawdown is not excessive, and additional pumpage can be developed without undue lowering of head. The water from both the Wilcox group and the Ripley formation is fairly soft and has a moderately low content of dissolved mineral matter. The iron content is sufficiently high to be objectionable, but the iron is easily removed by aeration followed by either settling or filtration for removal of sediment.

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