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Site Reclamation Activity <br />April 2001 - March 2002 <br />Page 9 <br />4) Mine Pool <br />The mine pool water is no longer accessible for monitoring <br />with the final closure of the Terry Tunnel and placement of <br />the American Tunnel #2 Bulkhead. Monitoring at the #2 bulkhead <br />reflects water quality between the American Tunnel bulkheads <br />and remained within bulkhead design parameters. <br />MONITORING - Settling, phreatic water levels and bulkhead <br />inspections <br />Included in Appendix A are settlement monitoring data for Tailings <br />Pond No.4, phreatic water level monitoring for Tailings Pond No.4 <br />and American tunnel pressure gage readings indicating final depth <br />of mine pool and pressure rise on the American Tunnel #2 Bulkhead. <br />Tailings Pond No.4 settling and phreatic level monitoring does not <br />reveal any adverse trends. The phreatic level remained low since <br />pond reduction occurred. <br />Monitoring of the bulkhead pressure gage in the American Tunnel #1 <br />Bulkhead ended with final pipe and valve grouting. As of May 14, <br />2001, the pressure was 438 psi which reflects a pool surface <br />elevation of 11,661 feet MSL. With some annual variation, this <br />level reflects mine pool physical equilibrium. <br />The American Tunnel Bulkhead #2 pressure has been monitored since <br />valve closure on August 31, 2001. Pressure has continued to rise <br />throughout the report year although it is well below design <br />pressure. PH and sulfate levels have also remained below design <br />criteria for the bulkhead. <br />• <br />