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neatment facilities. The building was approximately 760 leer in the south easterly direction <br />from the shot. This out building consisted of a simple open sided pole shed with a fiber~~lass <br />paneled roof. Dimensions of the building are approximately 8'w x 15'I x 7'h. The purpose <br />of this building was to protect some electric flow chart recorders from the weather that <br />serviced the sewer plant facilities. Dollar damage to this structure and instruments are not <br />known at this time but a few hundred dollazs are anticipated. Most of the dollars will he in <br />replacing the damaged instruments. Further examination showed scattered fragments offly- <br />rock, both on and off the mine property. Fly rock off the property qualifies as a blasting <br />violation w7th the Colorado Division of Minerals and Geology regulatory group. No other <br />major property damage was noted. Minor damage of a few strands of barbed wire fencing <br />broken along 5th street right-of -way was also noted. Fly-rock was suspected as being the <br />culprit. Cost of fixing the damaged fence will be approximately two hours of labor. Lance <br />left the site to call a representative of the Nucla Sewer District to notify them of the damage. <br />I discussed what happened with Iohn King and the blasting crew. After much discussion, <br />eve concluded that none of us could have predicted the extend of the fly-rock or the damage <br />it had caused. We also concluded that what we did was the only safe thing to do and could <br />not thinl: of a thing we would have done differently, if we knew what we know now. After <br />this discussion, l lefr the site and informed our Colorado Division of Minerals and Geology <br />represenitive of what had happened. He informed me that most likely, there would he a <br />blasting related violation written to WFC for this incident. He predicted a financial fine <br />would be assessed but due to our clean record and good blasting practices. he ~~ttessed the <br />dollar amount to be low. <br />Conclusion: It is my professional opinion that the rock fall on the south east corner of the shot after <br />the bore hole in question was loaded was the cause of the accident. The portion of the comer that fell <br />off had been ]eft to stabilize for more than 24 hours. It is vary rare that such a large portion of <br />unstable rock would stay in place for more than 24 hours with out falling. There were a few cracks <br />running through that block of rock ,but it was believed that it was so massive and intact that it <br />"arranted to be blasted again to be sure the rock was fragmented sufficently for the truck-shovel <br />fleet. I1 the rock slab had fallen off before °that" bore hole was loaded, then we would not have <br />loaded it. The rock fall came three hours too soon. We all recognized the seriousness of the <br />situation and took all safe and prudent measures to guard against and minimize the damage from this <br />potential dangerous hole. The safety consequences of not detonating the borehole in question out <br />weighted the consequences of detonating it. No way could we I}ave predicted the extend of lire fly <br />rock before detonation. The rest of the 63 holes in the pattern performed as was planned. The <br />weather, the drill pattern design, the q~pe and amount of explosives, the loading and stemming <br />procedure and the detonating sequences were not a factor in this accident. <br />knss I.. Ciu a, I'. E. <br />C'hicf L= ~meer <br />C.ulata~wpd.na\rlg\blast412.doc <br />