Laserfiche WebLink
Jul 15 13 11:08a Elk Creek Sand & Gravel <br />f <br />l <br />440�014�\ Matheson <br />4V11 Mining <br />Cconsultaants, Inc. <br />October 2, 2012 <br />303 -816 -7147 p,1 <br />Pftm .� <br />2801 Youngfeld �-S6d f>C41 <br />Golden, Co 8MI -2266 <br />303- 456-5638 <br />Toll Free 868- 456 -5638 <br />Fax 303 - 456,5639 <br />w w w. math es onmining. coin <br />MMr. Jim Knoll <br />Yenter Companies <br />M20300 Highway 72 <br />Arvada, CO 80007 <br />Re: Elk Creek Sand & Gravel Quarry, Jefferson County, CO, October 2, 2012 <br />e <br />i <br />Dear Mr. Knoll, <br />On October 2, 2012, Matheson Mining Consultants Inc. (MMC) monitored one production blast at <br />the Elk Creek Sand & Gravel Quarry looted @ CO HWY285ftuth Elk Creek Rd. (near °Shaffer's <br />Crossing ") in Jefferson County, Colorado Portable seismographs were deployed at four separate <br />locations; one adjacent to the equipment maintenance building/well, on the Elk Creek Sand & <br />Gravel Quany property (Loc. 1), one at the Elk Creek Sand & Gravel office trallerrtruck scale (Loc. <br />2), one at the resdence of Rodger & Juliet Moores (Loc. 3), & one at Cliff Eden's shop building, <br />directly across the street from the quarry (Loc. 4). Below is a table lisfing the location #/instrument <br />serial number, distance & direction from the blast, peak particle velocity, and peak air overpressure <br />measurements. <br />Ground Vibration Summary <br />. Location ( #) /Inst. <br />Serial Number <br />Distance (yards) <br />& Direction <br />I Peak Particle Ve/0667 <br />inches/sec <br />Peak Air Overpressure <br />dB (L) <br />1 IBA10328 <br />-105 - NW <br />1.03 127.6 <br />2 /BA10185 <br />-140-NNW <br />0.64 1262 <br />3 /BA5738 <br />-280 - SE <br />0.26 117.5 <br />4 /BA6752 <br />-255 - West <br />0.23 127.8 <br />The highest reading measured was at the closest distance, adjacent to the Elk Creek Sand & <br />Gravel equipment maintenance building (where the well is locateo). <br />Aff four instruments recorded vibrations that are significantly less Man the United States Bureau of <br />Mines Report of Investigations 8507 and the Office of Surface Mining Reclamation and <br />Enforcement non- damage standards for drywall in framed houses. <br />RECEIVED <br />,11 tl t 5 2013 <br />Division of Reclamation, <br />Minna & Safety <br />