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<br />' San Luis PtojeM Phase n Rtiae 1 Ezpaneion -Final Construction Report <br />' On August 23, 1993 BMRI received written approval for construction of the fast 10 ft of <br />' embankment fill. Fill placement commenced on September 3, 1993. Initial construction involving <br />the fast 10 ft of fill was completed on September 11, 1993. On September 7, 1993 settlement <br />mazkers were installed in the fill beneath the crest of the embankment raise following placement of <br />the initial 3 ft lift of fill and daily readings were initiated. During this construction period and a <br />subsequent three week waiting period required by the Division, settlement mazkers showed a <br />maximum settlement of 0.5 ft. Review of the settlement monitoring data indicated that the <br />settlement occurred during construction with no significant differential settlement. <br />1 Placement of fill in the embankment raise resumed on October 4, 1993, but was halted on October <br />' 8 after completion of one three foot lift of fill and partial placement of a second three foot lift. <br />Construction was resumed on November 17, 1993 and continued until completion on December 11, <br />1993. No signs of excessive settlement of the tailings along the upstream toe of the raise, such <br />' as heaving or cracking, was observed at any point during construction. The settlement mazkers <br />were surveyed daily throughout construction. The daily surveys continued after construction until <br />t there was no movement (within instrumentation limitation) for three consecutive days and thereafter <br />were monitored weekly throughout January and eazly February until no movement was recorded for <br />four consecutive weeks. Settlement marker monitoring is being continued on a monthly basis. <br />' Settlement mazker locations and monitoring data are presented in Appendix A. <br />Five standpipe piezometers were installed beneath the crest of the main embankment starting <br />September 23, 1993 and completed on September 29, 1993. These piezometers were installed <br />beneath the crest of the main embankment to approximately 10 ft above the liner. The piezometers <br />have been monitored monthly since their installation and no water has been observed in the <br />piezometers to date, indicating a low or non-existent phreatic surface within the main embankment. <br />The Division will be notified if any water is detected. Details of the piezometer installations aze <br />contained in Appendix B. <br />' Subgrade preparation, secondary clay liner placement and acceptance, and synthetic liner placement <br />' to the ultimate limits of the facility were completed during this construction campaign. This <br />amounted to an azea of 57 acres for the expansion. The limits of the facility expansion are depicted <br />' on Drawing 14719-102. It should be noted that BMRI elected to complete the liner construction to <br />the ultimate limits of the facility as will be discussed in Section 4.2. <br />' <br /> aY 4 JeM o. __ <br />1 <br />