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geomembrane layer. Without the implementation of improved equipment control <br />methodology to offset the increased risk of damage, it is not appropriate for the Division <br />to approve decreasing the drain cover fill thickness. CC&VG should propose control <br />methodology to offset the increased risk due to closer equipment /liner proximity." <br />Based on the bold type in which this summary statement was presented, it is CC&V's belief that <br />the quotation from the OMLR's referenced letter is the summation of this section of their letter, <br />including a summation of the detailed calculations of loading of the Drain Cover Fill. Based on <br />this belief, if CC&V can respond to the OMLR in an acceptable manner to this summary <br />statement, the concerns of the OMLR that remain regarding placement of the two-foot thickness <br />will be satisfied. Based on this highlighted summary, CC&V directed its contractors to expedite <br />and finalize the search for additional monitoring procedures. <br />CC&V has been investigating, since the issue was raised by the OMLR in its February 2, 1996 <br />memorandum, methods of "electronically" surveying the depth of the Drain Cover Fill. CC&V <br />has investigated satellite-assisted positioning to find the accuracy and rapidity of response to be <br />inappropriate. Similarly, laser-assisted surveying has been found to be inappropriate for the <br />terrain involved. While investigating these methods, CC&V identified sonic monitoring to as <br />having some possibility. However, no manufacturer of the sonic equipment was able to show <br />us an operation that could allay our concerns about exactly how the sensor would be located and <br />operated to provide consistently reliable signals. <br />Lately, we thought that some experience with a seismic monitor in the coal mining industry <br />would have some promise, but subsequent information on the lack of rapid and reliable response <br />required us to discount this method. Ground-penetrating radar was considered, but the <br />equipment could only be used to measure after placement because of the position required for <br />the antenna, the fragile and sensitive nature of the antenna, and the potential that desired <br />accuracy might not be rapidly obtained. <br />Upon receipt of the information on the current position of the OMLR in early April, CC&V <br />emphasized the need to resolve the monitoring issue to its contractors and surveyors. As a <br />result, CC&V has developed an additional monitoring procedure for consideration by the OMLR <br />which we believe should meet with the OMLR's approval. This survey procedure will only be <br />used if it, and the "visual" monitoring previously specified, make the two-foot thickness of the <br />Drain Cover Fill acceptable to the OMLR. <br />The survey procedure that was found available, described in some detail below, makes use, <br />during the monitoring phase, of land-based and satellite-based positioning equipment. The <br />objective is to obtain elevations on top of placed Drain Cover Fill that correspond to elevations <br />at the same location on the synthetic liner. In using this procedure, placement of the Drain <br />Cover Fill at the two-foot thickness using dozers is restricted to periods of time when the <br />satellite positioning system is operating. The actual satellite availability has been studied to <br />determine the period of time, at present, that there will be adequate satellite coverage. It <br />appears adequate, for example, for this week. In the event of a "national crisis" that requires <br />5 <br />