Geology topics

Michael Schoenberg

Publications and source records attributed to Michael Schoenberg.

4 recordsLinked to original sources

USGS1998

Hydrogeology and sources of recharge to the Buffalo and Wahpeton aquifers in the southern part of the Red River of the North drainage basin, west-central Minnesota and southeastern North Dakota

Declining hydraulic heads in the Buffalo and Wahpeton aquifers are of concern to the Minnesota Department of Natural Resources and local water managers because of limited groundwater resources in the southern part of the Red River of the North drainage basin. The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources and Moorhead Public Service, investigated the hydrogeology of and sources of recharge to the Buffalo and Wahpeton aquifers. The Buffalo aquifer is a complex, heterogeneous outwash deposit composed of medium to coarse sand and gravel. Part of the Buffalo aquifer is unconfined and part is confined. The direction of ground water flow in the Buffalo aquifer is from east to west. Water-level declines in observation wells near the Moorhead Public Service North Well Field extend beyond the eastern and western boundaries of the Buffalo aquifer. Transmissivity and storativity calculated from the drawdown part of an aquifer test ranged from 20,870 to 23,852 feet squared per day and from 3.0 x 10 -5 to 3.2 x 10 -2 , respectively. Transmissivity and hydraulic conductivity values of 29,090 and 28,450 feet squared per day and 272 and 266 feet per day were calculated from the recovery-phase data. Potential recharge from the Buffalo River and its tributaries to the Buffalo aquifer ranged from 5 to 14 cubic feet per second. Recharge from precipitation where the Buffalo aquifer is unconfined was about 1.49 x 10 5 cubic feet per day. Recharge per unit length of the Buffalo aquifer during an aquifer test near the Moorhead Public Service North Well Field ranged from 3.9 x 10 -4 to 2.0 x 10 -2 cubic feet per day. The Wahpeton Shallow Sand, the Wahpeton Sand Plain, and the Wahpeton Buried Valley aquifers comprise the Wahpeton aquifers in order of increasing depth. All the aquifers are composed of fine- to coarse-grained sand mixed with gravel. Confining units are interleaved with the Wahpeton aquifers. Ground-water-flow directions in the Wahpeton aquifers were changed by ground-water development. Before development, ground water flowed from the Wahpeton Buried Valley aquifer upward to the Wahpeton Sand Plain aquifer and the Wahpeton Shallow Sand aquifer. After development, ground water flowed from the Wahpeton Shallow Sand aquifer to the Wahpeton Sand Plain and the Wahpeton Buried Valley aquifers. The potential sources of recharge to the Wahpeton aquifers investigated were the Red River of the North, and adjacent hydro geologic units. The volume of ground water pumped from the Wahpeton aquifers provides an estimate of the upper limit for the volume of recharge to the aquifer. Based on pumpage from all of the Wapheton aquifers from 1990 to 1993, the upper limit is about 580 million gallons per year (2.4 x 10 5 cubic feet per day).

Minnesota, North Dakota↗

USGS1990

Effects of present and projected ground-water withdrawals on the Twin Cities aquifer system, Minnesota

The Twin Cities aquifer system in Minnesota contains 5 aquifers and 4 confining units composed of 14 stratigraphic units. Bedrock aquifers consist of friable sandstones and highly fractured carbonate rocks; aquifers in the glacial drift consist of outwash and alluvium. From 1880 to 1980, groundwater withdrawals had caused long-term declines of water levels of as much as 90 feet in the Prairie du Chien-Jordan aquifer and 240 feet in the deeper Mount Simon-Hinckley aquifer--the two major sources of ground-water supplies in the area. A steady-state model of ground-water flow was used successfully to simulate the potentiometric surfaces of the aquifers during the 1970's. assuming a withdrawal rate of about 190 million gallons per day from the entire system. Projected changes in population and industrial development suggest that future ground-water withdrawals may increase from those for the 1970's. Steady-state model results indicate that the potentiometric surface of the Mount Simon-Hinckley aquifer would be lowered as much as 400 feet if pumpage from that aquifer were increased by 125 percent above 1980 ground-water withdrawal rates of about 200 million gallons per day. The potentiometric surface of the Prairie du Chien-Jordan aquifer also would be lowered as much as 400 feet if pumpage from that aquifer were increased by 200 percent above 1980 ground-water withdrawals of 160 million gallons per day. Given the projected distribution of future ground-water development, and the limitations inherent in simulating ground-water flow, the model results indicate that an approximate limit of ground-water availability in the Twin Cities Metropolitan Area, Minnesota, is from about 500 to 800 million gallons per day.

Minnesota↗

USGS1984

Water levels and water-level changes in the Prairie du Chien-Jordan and Mount Simon-Hinckley aquifers, Twin Cities metropolitan area, Minnesota, 1971-80

The ground-water system in the Twin Cities Metropolitan Area includes five aquifers; two of these aquifers the Prairie du Chien-Jordan and the Mount Simon-Hinckley supply about 80 percent and 10 percent, respectively, of the ground water pumped for public supply. Water levels and changes in water levels in these two aquifers differ greatly in the Twin Cities Metropolitan Area. The Mississippi, Minnesota, and St. Croix Rivers are in hydraulic connection with and influence the pattern of flow in the upper aquifer, the Prairie du Chien-Jordan. Water generally flows toward these streams from water-level highs northeast, northwest, and south of Minneapolis and St. Paul. Consequently, heavy pumping has caused only localized cones of depression in the potentiometric surface of this aquifer. In contrast, the Mount Simon-Hinckley, which has only a slight hydraulic connection to the streams, is greatly influenced by pumping. Pumping in the urban centers of Minneapolis and St. Paul has caused a large cone of depression in the Mount Simon-Hinckley potentiometric surface. During 1971, the measurable cone was centered in eastcentral Hennepin County, was about 25 miles in diameter, and was as much as 150 feet deep at its center. Between 1971 and 1980, average water levels in the Prairie du Chien-Jordan aquifer changed less than 5 feet in most of the study area, but rose or declined as much as 25 feet locally in response to pumpage and recharge. During this period, seasonal declines of water levels from winter to summer lessened, and the area where these declines exceeded 10 feet decreased. In contrast, between 1971 and 1980, average water levels in the Mount Simon-Hinckley aquifer rose as much as 60 feet in the center of the cone of depression in response to decreased pumping. Also, the measurable cone of depression contracted from about 25 miles to about 15 miles in diameter. However, because of increased summer pumping due to below-average precipitation during 1980, seasonal water levels declined much more and over a wider area during 1980 than in 1971. Water-level data suggest that (1) little variation in annual pumpage between 1971 and 1980 from the Prairie du Chien-Jordan aquifer produced generally stable water levels in that aquifer, (2) decreased annual pumpage from the Mount Simon-Hinckley aquifer from 1971 to 1980 caused water levels in that aquifer to rise, and (3) a greater seasonal component of pumpage from the Mount Simon-Hinckley aquifer than from the Prairie du Chien-Jordan produced larger and more widespread seasonal water-level declines in the Mount Simon-Hinckley than in the Prairie du Chien-Jordan, particularly during dry years.

Minnesota↗

USGS1981

Preliminary evaluation of ground-water contamination by coal-tar derivatives, St. Louis Park area, Minnesota

Operation of a coal-tar distillation and wood preserving plant for 1918-72 in St. Louis Park, Minnesota, resulted in ground-water contamination. This report presents the results of the first year (1979) of an ongoing study. By 1932, water in the Prairie du Chien-Jordan aquifer, the region 's major source of ground water, was contaminated 3,500 feet from the plant. The hydraulic characteristics of the Prairie du Chien-Jordan aquifer , its long contamination history, and fluctuating pumpage combine to creat a complex distribution of coal-tar derivatives observed in the aquifer. The Prairie du Chien-Jordan aquifer underlies the area at depths of 250 to 500 feet and is overlain by two bedrock aquifers (Platteville and St. Peter), two confining beds (Glenwood and basal part of St. Peter), and 70 to 100 feet of glacial drift. Multiaquifer wells in the area have permitted contaminated water from near-surface aquifers to flow downward into the Prairie du Chien-Jordan aquifer. Flow rates of 20 to 150 gallons per minute from the shallower aquifers into the Prairie du Chien-Jordan aquifer were observed in five wells. In the drift, a hydrocarbon fluid phase is moving vertically downward relative to the aqueous phase. Dissolved constituents in the drift and Platteville aquifer, the uppermost bedrock unit over most of the area, have moved at least 4,000 feet. Low-molecular-weight compounds are moving preferentially through the drift and Platteville aquifer system. (USGS)

Minnesota↗