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Bohling, Geoffrey C. / A ground penetrating radar study of water table elevation in a portion of Wisconsin's central sand plain
[DNR-050] (1988)

II. Geology and hydrogeology of the study area,   pp. 10-18 PDF (1.9 MB)


Page 16

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elevation of the bottom of the outwash. The water table slopes from an
elevation of about 1060 feet in the southern part of the study area to
about 1040 feet near the river bluff. The saturated thickness of the
aquifer ranges from about 70 feet in the southern part of the study area to
about 40 feet near the river bluff (Kraft, in preparation). The saturated
thickness and the hydraulic conductivity of the sediments determine the
ability of the aquifer to transmit water laterally.
A pump test in the central part of the study area (Figure 2) yielded
a hydraulic conductivity for the outwash of 320 ft/day, or 0.11 cm/s
(Weeks, 1969; Weeks and Stangland, 1971, p. 24). This is somewhat high
compared to other pump test results in the sand plain area, apparently
because the sediment is somewhat coarser in the study area than it is else-
where in the sand plain (Weeks and Stangland, 1971, p. 25). The pump
test results were also used to calculate a ratio of horizontal to vertical
hydraulic conductivity of 7. Results of slug tests in and near observation
well number 1 (Figure 2) give an average hydraulic conductivity of 0.048
cm/s (Kraft, in preparation). Slug tests typically give a lower hydraulic
conductivity than do pump tests (e.g., see Muldoon, 1987), presumably
because pump tests sample a larger portion of the aquifer material and
therefore incorporate the effects of coarser lenses or beds. Therefore, this
discrepancy in results is not too surprising.


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