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<br />TABLE 14-1 <br />AI1tBLAST LIMITS <br />Lower-Frequenry Limit of Measuring <br />System, in Hz (± 3dB) Maximum Level <br />In dB <br />0.1 Hz of lower -Flat response 134 peak <br />2 Hz ox lower -Flat response 133 peak <br />6 Hz or lower -Flat response 129 peak <br />C -Weighted, Slow response 105 C <br />SCC will conduct continuous air blast monitoring at the Brian Valora and Gaty Valora residences to <br />ensure compliance with air blast limitations. Monitoring at the Gary Valora residence will be <br />conducted, particularly during overburden shots in the northern half of the piL Monitoring will also <br />be conducted at the closest residence (Brian Valora), particularly during overburden shots in the <br />southern half of the pit. The measuring systems used shall have anupper-end flat-frequency of at least <br />200 Hz. <br />SCC has conducted continuous air blast monitoring at the Brian Valora and Gary Valora <br />• residences since 2002 when blasting was conducted in the close vicinity of the residences. <br />The area referred to as the Scraper Pit has been completely bacldlled as of September 1, 2005, <br />no future blasting will be conducted in this area. Now that mining/blasting has ceased in <br />the areas adjacent to these residences, air blast monitoring is no longer necessary. The <br />nearest future blasting to the Brian Valora residence will be approximately 3,600 feet to the <br />east and behind an intervening ridge. The nearest future blasting to the Gary Valora <br />residence will be approximately 4,500 feet to the southeast and pardaily behind an intervening <br />ridge. SCC will cease air blast monitoring upon approval of MR-24. <br />Ground Vibration. In the past Seneca has utilized the scale-distance equation W=(D/Ds)z to <br />determine the allowable charge weight (VU) of explosives to be detonated in any 8-millisecond period. <br />The scaled distance factors (Ds) for distance (D) to structures of 0 to 300 feet, 301 to 5,000 feet, and <br />5,001 feet and beyond aze 5Q 55, and 65, respectively. These aze the default scale distances used by <br />CDMG if no supporting studies aze available (Rrr/e 4.OB.4(10)). Thus seismic monitoring may be for <br />the purpose of complying with the maximum one-inch per second ground vibration limitation. The <br />equation will be applied to comply with vibration limitations at the location of any dwelling, public <br />building, school, church, or community of institutional building outside the permit area. Computation <br />• of the formula or seismographic information and results will be recorded on the blasting record form <br />(Attachment 141) for each blast. <br />MR-24 3 Revised 9/05 <br />