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• <br /> Ali r& a C. <br /> LARRY E.O'BRIAN 7985 VANCE DRIVE,SUITE 205A <br /> FOUNDER ARVADA,COLORADO 80003 <br /> STEVAN L.O'BRIAN 303-423-7297 <br /> PRESIDENT FAX 303423-7599 <br /> January 16, 2019 <br /> —>Mr. Jared Ebert RECEIVED <br /> Division of Reclamation, Mining & Safety JAN 2 <br /> 1313 Sherman St., Suite 215 3 2019 <br /> Denver, CO 80215 DIVISION OF RECLAIWA77ON <br /> MINING AND SAFETY <br /> Dear Jared; <br /> RE: Albert Frei and Sons, Inc. - Hatchery Pit - M-2014-043 <br /> Technical Revision 01 Adequacy Response 02 <br /> On behalf of my client Albert Frei and Sons, Inc., I am responding to your second <br /> adequacy review letter dated January 15, 2019. I have included your review points that <br /> need to be addressed in the order presented so The questions and answers wiii be in The <br /> same document for easy reference. I included a copy of the revised Ground Water <br /> Mitigation Plan since changes were made to it as discussed in the following text. <br /> 1.) The applicant proposes a trigger elevation maximum for MW01 as 5080.0 feet, however <br /> two feet above the highest water level recorded during the first seven monitoring periods <br /> was 5,076.62 feet. Given this, the trigger elevation maximum for MWO1 should be <br /> 5078.62. Please revise. <br /> I used the bottom of the french drain elevation in that area instead of the highest <br /> groundwater elevation because using the highest groundwater elevation places the MWO1 <br /> trigger point 7.4 inches above the base of the french drain pipe. I'm not sure that really <br /> is a valid elevation since the top of the groundwater will not have completely eclipsed the <br /> french drian. The 5080.0 feet elevation places the trigger point approximately 10.0 <br /> inches above the top of the french drain pipe and 18 inches below the top of the liner. I <br /> believe it is better to have the trigger point above the top of the pipe but below the top <br /> of the liner and request that the 5080.0 feet remain as the upper trigger point. I also <br /> found a mistake the column for MWO1 in Table Gm-1 so have corrected that too. <br /> 2.) The applicant proposes to reduce the water monitoring frequency to annually two years <br /> after the clay liner has been installed. The Division agrees that two years after liner <br /> installation, it may be appropriate to reduce the water monitoring frequency as proposed. <br />