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LEEDSHILL•HERKENHOFF, INC. <br /> 2.4.1 Well Construction Details <br /> The three wells were constructed between 1948 and 1958 to total depths <br /> between 262 and 300 feet. LVMD wells #1 and #2 were each constructed <br /> with telescoping casings. Well #1 has an outer casing which is <br /> 14 inches in diameter and extends from the ground surface to a depth of <br /> ' approximately 102 feet. The smaller inner casing is 12 inches in diam- <br /> eter and extends from a depth of 40 feet to 200 feet. Well #2 has an <br /> outer casing which extends from the ground surface to a depth of 126 <br /> ' feet, and the inner casing extends from 124 to 256 feet. Well #6 was <br /> constructed using only a single, 14-inch-diameter casing. Per the <br /> available well log, the distance from the ground surface to the upper- <br /> most perforation is 160 feet for LVMD #1, 208 feet for LVMD #2, and <br /> 210 feet for LVMD #6. <br /> ' According to ' construction details available for LVMD #2 and #6, these <br /> wells do have a cement annular surface seal to a depth of 80 and <br /> ' 40 feet, respectively. The presence of an annular cement seal at <br /> LVMD #1 (prior to installation of the seal installed during rennovation <br /> activities conducted in the spring of 1985) could neither be confirmed <br /> ' nor denied. Discussions with representatives of SJCPW indicate that <br /> during the summer of 1984, LVMD #6 was "reworked." A PVC liner and <br /> filter pack were installed to reduce the quantities of very fine sand <br /> ' which were being produced by the well . The well logs and construction <br /> details for LVMD wells #1, #2, and #6 are presented in Appendix A. <br /> 2.4.2 Geologic Information <br /> ' Review of well logs from LVMD wells #1, #2, and #6 reveal a lithology <br /> under Lincoln Village Center composed of interbedded layers of clay, <br /> silt, and sand typical of stream and lake bed deposition. Generally, <br /> ' there appear to be both unconfined and partially confined water bearing <br /> zones beneath LVC. These two water bearing zones can be identified by <br /> their difference in static water levels. At the time of this investiga- <br /> tion, there was a difference of approximately 12 feet between the deeper <br /> municipal supply wells and the shallow monitoring wells. The municipal <br /> ' supply wells were constructed with deep perforations, to draw water <br /> primarily from the lower water bearing formations. The monitoring wells <br /> were installed to obtain water from the uppermost water bearing zone. <br /> ' 2-7 <br /> 1 <br />