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<br />blue <br />~~on <br />• company <br />iii iiiiiiiiiiiuiii <br />blue ribbon coal company <br />I~PR ~ 01989 P.o. box 1352 <br />palisade, Colorado 81526 <br />(303)464-7951 <br />.L'. 1..~v ~_'~,'.,i <br />flrCl /Ai'!~-i IQ?1 17~VIcf01~' <br />April 18, 1989 <br />Matthew S. Hayes <br />Mined Land Reclamation Division <br />215 Centennial Building <br />1313 Sherman Street <br />Denver, Colorado 80203-2273 <br />Re: Quarterly Bench Stability Monitoring <br />Permit No. C-81-047 <br />Dear Mr. Hayes: <br />The first quarter 1989 bench stability survey was performed March <br />22, 1989. Vertical angles were measured with a 20 second <br />theodolite and elevations were calculated using predetermined <br />horizontal distances. A summary of this survey, the last two <br />surveys and the 11-20-85 base line survey is as follows: <br /> 11-20-85 09-20-88 12-02-88 03-22-89 <br />S-1 6400.90 6400.70 6400.68 6400.68 <br />S-2 6396.06 6395.93 6395.92 6395.89 <br />S-3 6385.77 6385.61 6385.60 6385.57 <br />S-5 6479.92 6479.58 6479.59 6479.57 <br />S-6 6480.51 6479.93 6479.89 6479.81 <br />S-7 6479.31 6479.08 6479.05 6478.98 <br />S-8 6479.92 6479.57 6479.56 6479.50 <br />Let me know if there are any questions <br />Also attached is a compilation of the <br />data from September 1986 to date. <br />Sincerely, <br />.,, nG`lov~~ <br />Jim Stover, P.E. <br />Chief Engineer <br />concerning this data. <br />quarterly bench monitoring <br />