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to show those time periods for each well that the water level data is interpreted to be • <br />representative of natural conditions. As can be seen, significant portions of the water <br />level records for Wells 10V, 20V, 40V2, and SOV are believed to be invalid. For the <br />following water level discussion, only that portion of the water level data believed valid <br />will be interpreted and used to supl~o rt any conclusions. <br />Ground water in the overburden aquifer occurs under unconfined conditions, except at Well <br />20V where flowing artesian conditions were encountered, and at Well 180V. At the time of <br />drilling, wet cuttings were noted in Well 180V at a depth of 317 feet. The mean water <br />level is approximately 200 feet. The wells penetrating the unconfined portions of the <br />overburden aquifer show mean water levels ranging from 27.7 feet to 310.2 feet. The high <br />degree of variability in the mean depths to water are primarily a function of boring <br />depth, downgradient distance from outcrops, and topography. Mean saturated thicknesses in <br />the unconfined portions of the overburden aquifer range from 5.3 feet at Well 120V to <br />155.3 feet at Well 10V. The two wells penetrating the confined portions of the overburden <br />aquifer show mean water levels ranging from +58.3 feet to 199.9 feet and mean saturated <br />thicknesses ranging from 152.1 feet to 321 feet. <br />Measurable seasonal water level changes have been monitored in the overburden aquifer (see <br />Table 7-3). There is no distinct trend concerning seasonal mean water levels. The <br />shallowest mean water levels mainly occur in the spring and summer (see Appendix 7-2), <br />suggesting that both spring and summer are significant recharge periods or that there is a <br />lag time before the effects of spring recharge are noticed at the monitor wells. The <br />deepest mean water levels appear mainly in the fall and winter. The two artesian wells <br />show the shallowest mean seasonal water levels in the fall, perhaps suggesting that there <br />is a longer lag time before the effects of spring recharge are noticed in the artesian <br />portion of the aquifer. The amount: of seasonal water level fluctuation is quite varied <br />and also shows no distinct trend. Both the least and greatest amount of seasonal water <br />level fluctuation occurs principally in the spring and fall with fluctuations ranging from <br />0.03 feet at Well 180V to 45 feet at Well 150V. It should be qualified that the <br />overburden well water levels are affected to some extent 6y drawdowns associated with <br />water quality sampling. Wells 140'J, 150V, 170V, and 180V all show some residual water <br />level effects from water quality sampling. Unfortunately, in low yielding aquifers, it is <br />difficult to monitor for both chemistry and water levels without introducing same noise <br />into the water level record. <br />~1 <br />L J <br />• <br />14 <br />