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at Well A4 to 12.96 feet at Well A!l, Mean saturated thicknesses in those portions of the •
<br />Sage Creek alluvial aquifer system monitored ra rige from 4.32 feet at Well A7 to 40.57 feet
<br />at Well A5. It is assumed that Bill the USGS alluvial wells completely penetrated the
<br />alluvium at each location.
<br />The Sage Creek alluvial wells exhibit mea su rablc~ seasonal water level changes. The spring
<br />appears to be the dominant period 1'or recharge to the Sage Creek alluvial system. Of the
<br />13 USGS alluvial wells, 11 showed the shallowest mean water levels in the spring. The
<br />spring mean water levels ranged frcm 1.13 feet at Well A10 to 12.01 feet at Well A9, Two
<br />of the alluvial wells, AB and A11, showed the shallowest mean water levels in the summer,
<br />thus indicating that rainfall recharge is also important. The deepest water levels rve re
<br />observed in the fall and winter months. Eight alluvial wells showed the deepest mean
<br />water levels in the winter and five showed the deepest levels in the fall. Mean fall and
<br />winter water levels ranged from 1.35 feet to 13,76 feet. At individual wells, the water
<br />level fluctuations are significant. Fluctuations range from 3.31 feet at Well A7 to 9.53
<br />feet at Well A2,
<br />Wadge Overburden Water Levels. Thirteen monitor wells (CW-52W-tOV, -20V, -30V, -40V1, •
<br />-40V2, -SOV, -110V, -120V, -140V, -150V, -160V, -170V, and -180V) have been completed as
<br />of October 1, 1989 to monitor water levels in the overburden aquifer at Seneca I I-W.
<br />Exhibits 7-1 and 7-2 show the overburden monitor well locations and the potentiometric
<br />surface for the overburden aquifer, respectively.
<br />Water level data for Wells GW-52W-~IOV, -20V, -30V, -40V1, -40V2, and -SOV was collected
<br />from February and May of 1980 through 1986, 1985, 1988, 1986, 1986, and 1986,
<br />respectively. Water level monitoring at Wells 110V and 120V began in August, 1982 and at
<br />Wells 140V, 150V, 160V, 170V, and 180V in October, 1987. Monthly water level data for the
<br />overburden wells, including hydrograph s, are presented in Appendix 7-2. Table 7-2
<br />summarizes the well completion information for the nested overburden wells.
<br />Wells IOV, 20V, 30V, 40V1, 40V2, and SOV were nested in the same boring as coal and
<br />underburden wells (refer to Appendix 7-1), Based on field notes and observations, several
<br />of the nested wells yielded suspect water level data because of leaks in the annular seals
<br />separating the different aquifer units, except 30V. Monitoring was discontinued at all
<br />sites except 30V in 1986, Monitoring was eventually discontinued at Site 30V in 1988 •
<br />because the well was completed too shallow and thus, always dry. Table 7-4 is presented
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