Search USGS⌕ Search

Geology topics

B. E. Wasson

Publications and source records attributed to B. E. Wasson.

16 recordsLinked to original sources
USGS1987

Geohydrology and simulated effects of withdrawals on the Miocene aquifer system in the Mississippi Gulf Coast area

Intense development of the Miocene aquifer system for water supplies along the Mississippi Gulf Coast has resulted in large water level declines that have altered the groundwater flow pattern in the area. Water levels in some Miocene aquifers have declined about 2 ft/year since 1940; declines exceed 100 ft (80 ft sea level) in large areas along the coast. Water levels in the surficial aquifer system, generally less than 20 ft below land surface, have not declined. The Miocene and younger interbedded and lenticular sands and clays crop out in southern Mississippi and dip to the south and southwest. These sediments have large vertical variations in head and locally respond to stresses as separate aquifers. Freshwater recharge to the Miocene aquifer system primarily is from rainfall on the surficial aquifers. The water generally moves to the south and southeast along the bedding planes toward the Mississippi Gulf Coast where the water is either withdrawn by wells, discharges to the ocean, or gradually percolates upward into overlying aquifers. Drawdowns caused by large groundwater withdrawals along the coast probably have resulted in the gradual movement of the saltwater toward the pumping centers. In parts of the Miocene aquifer system commonly used for water supplies, the water generally is a sodium bicarbonate type. Increasing chloride concentrations in a few wells indicate that saline water is migrating into parts of all layers in the Pascagoula area. A quasi three-dimensional numerical model of the groundwater flow system was constructed and calibrated on the basis of the both pre- and post-development conditions. The effects of an expected 1.5% annual increase in groundwater withdrawals during the period 1985-2005 were evaluated by the flow model. Additional water level declines expected by the year 2005 in response to estimated pumpage are as follows: Gulfport, 135 ft in layer 4; Biloxi-Gulfport area, 100 ft in layer 5 and 50 ft in layer 3; Pascagoula area, 40 ft in layer 6 and 30 ft in layer 4. The most serious threats of saltwater encroachment occur in layers 4, 5, and 6 (the 800-, 600- and 400-ft sands) in the Pascagoula area where contamination of the southern edges of the production areas is expected to occur in less than 10 years. (Author 's abstract)

Water-Resources Investigations Report↗
USGS1984

Summary of results of an investigation to define the geohydrology and simulate the effects of large ground-water withdrawals on the Mississippi River alluvial aquifer in northwestern Mississippi

The 7,000 square-mile Mississippi River alluvial plain in north-western Mississippi (the Delta) is underlain by the prolific Mississippi River alluvial aquifer that currently (1983) yields about 1,100 Mgal/d of water to irrigation wells. Commonly, about 20 feet of clay underlying the Delta land surface is underlain by about 80 to 180 feet of sand and gravel that forms the aquifer. The Mississippi River is in good hydraulic connection with the alluvial aquifer. Generally smaller streams are less likely to have good hydraulic connection with the aquifer. Direct vertical recharge to the alluvial aquifer is small. A two-dimensional finite-difference computer model of the alluvial aquifer was constructed, calibrated, and verified using water levels observed for five dates within the period April 1981 to September 1983. The model shows that the aquifer had a net loss in storage of about 360 Mgal/d for the 2-year period April 1981 to April 1983, when pumpage was about 1,100 Mgal/d. The net inflows from the sources of recharge were: Mississippi River, 390 Mgal/d; recharge along east edge of the Delta, 170 Mgal/d; streams within the Delta, 81 Mgal/d; and areal recharge from infiltration, 180 Mgal/d. The effects of several levels of pumpage by wells were projected 20 years into the future. In 2003, the result of continued pumpage at the 1,100 Mgal/d pumping rate would be lowered ground-water levels of more than 20 feet in a large area in the central part of the Delta, and ground-water levels would continue to decline. (USGS)

Water-Resources Investigations Report↗
USGS1981

Potentiometric map of the Cockfield Aquifer in Mississippi, fall, 1980

This potentiometric map of the Cockfield aquifer is the eleventh in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources , Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Cockfield quifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by large ground-water withdrawals in the Jackson and Greenville areas. Historically, water levels in or near the outcrop of the Cockfield aquifer have shown little or no long-term changes, but in much of the confined part of the aquifer during the past 20 years, water levels have declined from 1 to 2 feet per year.

Mississippi↗
USGS1980

Potentiometric map of the Eutaw-McShan Aquifer in northeastern Mississippi, September, October, and November 1978

This potentiometric map of the Eutaw-McShan aquifer in northeastern Mississippi is the third in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. From its outcrop area the Eutaw-McShan aquifer dips about 30 feet per mile to the west and southwest. Thickness of the aquifer commonly is between 200 and 300 feet in most of the area, and commonly about one-half this thickness consists of sand. In the outcrop area the potentiometric surface is strongly affected by recharge from precipitation, topography, and drainage of the aquifer by streams. The potentiometric surface of the aquifer slopes generally to the west away from the area of outcrop and it is strongly affected by large ground-water withdrawals at or near Tupelo, Aberdeen, and West Point. Historically, water levels in or near the outcrop of the Eutaw-McShan aquifer have shown little or no long-term changes. Withdrawals of water by wells from the downdip area have caused long-term water-level declines of 1 to 2 feet per year in much of the confined part of the aquifer. Water-level declines during recent years in several observation wells in Lee County ranged from 2 to 9 feet per year. One hydrograph in Clay County that is near the center of the depression in the potentiometric surface at West Point shows about 5 feet per year of water-level decline since 1972. (USGS)

Open-File Report↗
USGS1980

Potentiometric map of the Ripley Aquifer in northeastern Mississippi, October and November 1978

This potentiometric map of the Ripley aquifer in northeastern Mississippi is the fifth in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Ripley aquifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes generally to the west away from the area of outcrop and is mildly affected by pumpage from wells and by discharge of flowing wells in the valleys. Historically, water levels in or near the outcrop have shown little or no long-term changes. (USGS)

Open-File Report↗
USGS1980

Potentiometric map of the Coffee Sand Aquifer in northeastern Mississippi, October and November 1978

This potentiometric map of the Coffee Sand aquifer in northeastern Mississippi is the fourth in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop areas the potentiometric surface is strongly affected by recharge from precipitation, topography, and drainage of the aquifer by streams. The potentiometric surface slopes generally to the west away from the area of outcrop and is mildly affected by moderate ground-water withdrawals by wells in Tippah and Union County. Historically, water levels in or near the outcrop of the Coffee Sand have shown little or no long-term changes as shown by a hydrograph of one well in Alcorn County. In the downdip part of the aquifer water-level declines of 2 feet per year are common. (USGS)

Open-File Report↗
USGS1980

Potentiometric map of the Meridian-Upper Wilcox Aquifer in Mississippi, fall 1979

The potentiometric map of the Meridian-upper Wilcox aquifer is one of a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Meridian-upper Wilcox aquifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by large groundwater withdrawals in the Greenwood, Indianola, Marks, Grenada, and Memphis areas. Historically, water levels in or near the outcrop of the Meridian-upper Wilcox have shown little or no long-term changes, but during the past 20 years water levels have declined from 1 to 2 feet per year in much of the confined part of the aquifer. (USGS)

Open-File Report↗
USGS1980

Potentiometric map of the Lower Wilcox Aquifer in Mississippi, fall 1979

The potentiometric map of the lower Wilcox aquifer is one of a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources , delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the lower Wilcox aquifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop but is strongly affected by pumpage from public and industrial wells in several areas in northwestern Mississippi. This pumpage has caused a large shallow depression in the potentiometric surface in the Marks-Batesville-Charleston-Tunica area. (USGS)

Open-File Report↗
USGS1980

Potentiometric map of the Winona-Tallahatta aquifer in northwestern Mississippi, fall 1979

The potentiometric map of the Winona-Tallahatta aquifer is one of a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources , Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. In the outcrop area of the Winona-Tallahatta aquifer the potentiometric surface is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by recharge from precipitation, by topography, and by drainage of the aquifer by streams. The potentiometric surface slopes downward generally to the west away from the area of outcrop and is strongly affected by pumpage from wells in Leflore, Sunflower , and Bolivar Counties, Historically, water levels in or near the outcrop of the Winona-Tallahatta have shown little or no long-term changes, but the heavy withdrawals in the confined part of the aquifer have caused long-term water-level declines of 1 to 2 feet per year. (USGS)

Mississippi↗
USGS1979

Potentiometric map of the Gordo Aquifer in northeastern Mississippi, September, October, and November 1978

This potentiometric map of the Gordo aquifer in northeastern Mississippi is the second in a series of maps, prepared by the U.S. Geological Survey in cooperation with the Mississippi Department of Natural Resources, Bureau of Land and Water Resources, delineating the potentiometric surfaces of the major aquifers in Mississippi. The potentiometric surface of the Gordo aquifer slopes generally to the west away from the outcrop area and it is depressed generally by large ground-water withdrawals in the Tupelo and Columbus areas. Historically, water levels in or near the outcrop of the Gordo aquifer have shown little or no long-term changes. Heavy withdrawals from the downdip area have caused long-term water-level declines of 1 to 2 feet per year in much of the confined part of the aquifer. Water-level decline in one observation well in Tupelo has averaged about 5 feet per year since 1966. (USGS)

Open-File Report↗
USGS1979

Potentiometric map of the Paleozoic aquifer in northeastern Mississippi, October and November 1978

The Paleozoic rocks that outcrop in Tishomingo County, Mississippi, supply water to public, industrial, and domestic wells in two counties in the northeastern part of the State. Paleozoic rocks in the area consist mostly of beds of sandstone, shale, and limestone which dip about 30 feet per mile to the southwest. The potentiometric surface of the Paleozoic aquifer slopes generally to the west away from the area of outcrop and is strongly influenced by large ground-water withdrawals at Corinth. The water level at Corinth has declined about 140 feet since 1954. Pumping at Corinth has affected water levels in wells more than 10 miles from the center of pumping. (Woodard-USGS).

Mississippi↗
USGS1971

Water resources of the Big Black River basin, Mississippi

Abundant supplies of water of good quality are available in the Big Black River basin from either ground-water or surface-water sources. For 90 percent of the time flow in the lower part of the Big Black River below Pickens is not less than 85 cfs (cubic feet per second), and low flows of more than 5 cfs are available in five of the eastern tributary streams in the upper half of the basin. Chemical quality of water in the streams is excellent, except for impairment caused by pollution at several places. The Big Black River basin is underlain by several thousand feet of clay, silt, sand, gravel, and limestone. This sedimentary material is mostly loose to semiconsolidated and is stratified. The beds dip to the southwest at the rate of 20 to 50 feet per mile. The Big Black River flows southwestward but at a lower gradient; therefore, any specific formation is at a greater depth below the river the farther one goes down stream. The formations crop out in northwest-southeast trending belts. Most of the available ground water is contained in six geologic units; thickness of these individual units ranges from 100 to 1,000 feet. The aquifers overlap to the extent that a well drilled to the base of fresh water will, in most places, penetrate two or more aquifers. Well depths range from less than 10 to 2,400 feet. Water suitable for most needs can be obtained from the aquifers available at most localities. Dissolved-solids content of water within an aquifer increases down the dip. Also, generally the deeper a well is the higher will be the dissolved-solids content of the water. Shallow ground water (less than 200 ft deep) in the basin usually contains about 100 mg/l (milligrams per liter) of dissolved solids. Most water in the basin from more than 2,500 feet below land surface contains m ore than 1,000 mg/l of dissolved solids. In several areas fresh water is deeper than 2,500 feet, but near the mouth of the Big Black River brackish water is only about 300 feet below land surface. Practically all water pumped for man's use in the basin is from the ground (about 11 million gallons per day); however, a small amount of surface water is used for supplemental irrigation of row crops. Wells producing 500 to 1,000 gpm (gallons per minute) are not unusual in the basin. Most of the area is underlain by one or more aquifers from which a properly constructed well could produce as much as 2,000 gpm. All the towns in the area have sufficient ground water available to at least double or triple their ground-water pumpage.

Water Supply Paper↗