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1 <br /> <br /> <br />1 <br />1 <br />1 <br /> <br />Draft; March 2~J, 1999 • ~ Page 6 <br />2.2 Multiple-Completion Monitoring Wells (to be constructed) <br />Three multiple-completion monitoring wells are proposed. The well designated 21-3 will <br />be located down-gradient of the first-phase mine panel and will have four completion zones. <br />Another well, designated 29-4, will be located up-gradient of the first-phase mine panel and will <br />have three completion zones. There will not be a Dissolution Surface completion in 29-4 because <br />it is adjacent to 29-2, which is completed at the Dissolution Surface. The third multiple-completion <br />monitoring well, designated 21-4, will be located inside the northeast boundary of the first-phase <br />mine panel which isdown-gradient of the assumed flow directions. Monitoring well 21-4 will have <br />four completion zones, as detailed in Section 1. This layout provides for up-gradient, down-gradient, <br />and cross-gradient groundwater monitoring, according to all published and site-specific data. <br />The multiple-completion monitoring wells will be constructed in large-diameter boreholes <br />1 <br /> <br /> <br /> <br /> <br />LJ <br /> <br /> <br />1 <br /> <br /> <br />to allow a grout mixture to flow freely and fully seal the borehole between the completion zones. <br />All well construction materials (sand, bentonite, and grout) will be placed from the bottom of the <br />borehole by the tremmie method. Each completion will be constructed of 2-inch-diameter, <br />Schedule 80, flush-threaded, O-ring sealed, solid PVC, and machine-slotted PVC well screen of <br />equal specifications. Atypical multiple-completion monitoring well is shown on Figure 3. <br />2.3 Existing Monitoring Wells <br />Groundwater monitoring wells have been constructed at the Yankee Gulch Project site to <br />monitor the experimental test mine phase in preparation for monitoring of commercial operations. <br />These wells will be incorporated into the proposed groundwater monitoring plan. The existing wel Is <br />are all single completions. Of the ten existing wells, two aze completed at the Dissolution Surface, <br />two are completed in or near the B Groove, two aze completed in or near the A Groove, and three <br />are completed in the Uinta Formation. Monitoring of the water supply well 20-8 for water quality <br />provides monitoring of changing conditions resulting from operation of the test facility. <br />29-2 is an up-gradient well, and monitoring well 20-1 is adown-gradient well. <br />The existing Dissolution Surface monitoring wells include 29-2 and 20-1. Monitoring well <br />The existing B Groove monitoring wells include 20-4 and 20-9. Monitoring well 20-4 is a <br />cross-gradient well, and monitoring well 20-9 is adown-gradient well. <br />Agapito Associates, Inc. <br />1 <br />