2015-08-12_INSPECTION - M1980244

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PERMIT #: M-1980-244 INSPECTOR’S INITIALS: AME INSPECTION DATE: August 12, 2015 Page 5 of 15 obtained during this inspection is enclosed as Attachment A, and the values are summarized below in the Transducer Readings (Table A). All recorded readings were well beneath their respective 80% capacity limits. It should be noted that a reading could not be obtained from pump #6 for Phase IV HVSCS, as the display screen was not functioning properly. Mr. Campbell was uncertain as to why the reading was not showing for pump #6. However, it may have something to do with the recent relocation of the computer where transducer readings are shown for Phase IV. In the past, the readings were recorded from displays near the pumps (Photo 7). Now, the readings are obtained from a new shed that was constructed adjacent to the pumps (Photo 8). During the last inspection (on 7/21/2015), the transducer readings appeared to be inaccurate for the Phase IV HVSCS, as they were all reading 100 feet. It appears that this malfunction has been corrected. Construction Activities in SGVLF: The inspector, accompanied by Mr. Campbell, stopped at the overlook above (southeast of) the new high grade mill to observe construction activities occurring in the SGVLF (Photo 9). Construction of the Squaw Gulch Adsorption Desorption and Recovery Plant (SGADR) continues. Soil Liner Fill (SLF) was being placed, compacted, and graded on portions of Phase I. Drain cover fill (DCF) was being placed on portions of Phase I where the 80 mil LLDPE geomembrane liner has been installed and approved. Previously placed DCF on Phase I PSSA slopes was eroded during recent rain events. During the inspection, evidence of this was seen in the northwestern corner of the PSSA where DCF material had washed out, exposing the 100 mil LLDPE liner (Photo 10). It was also noted during the inspection that meteoric water is collecting in the PSSA. According to the Weekly Construction Quality Assurance (CQA) Report submitted by the operator for the week ending on 07/04/2015, DCF is replaced on eroded areas after the geomembrane liner has been inspected and re-approved. In addition, the HVSCS piping layouts are re-established and connected to design plans. As Phase I construction continues, clearing for Phase II has begun. Scheduled Blasting in Main Cresson Mine: The inspector, accompanied by Mr. Campbell and Mr. Cash, observed a scheduled blasting event that took place in the Main Cresson Mine at 1:00 pm. The inspector observed this event from an overlook located northwest of the mine (Photo 11). The pit was cleared of all staff well beforehand. Blasting occurred in three groups on the pit floor at an elevation of 9,270 feet (Photos 12 and 13). The detonation of each group was preceded by an appropriate timing delay including a five second countdown, and then, the warning exclamation of “fire in the hole”. The inspector felt very minor vibrations from the top of the pit during blasting. Very minimal smoke was produced from each blasting group. This operation blasts a maximum of 1,100 holes per day between the hours of 11:00 am and 4:00 pm, on Mondays through Thursdays. Blasting can occur on Fridays as needed. According to information provided by the operator in Amendment 10 (Revision No. AM-10, approved 09/12/2012), explosive agents are detonated by trained and qualified CC&V personnel. The materials, charges, pattern or spacing, and timing of blasting is dictated by the type of rock, the size requirements of the ore, the mining equipment, the geology and rock mechanics, characteristics of the mine layout, issued air permits, and the need to control the offsite vibration effect of each production blast. The operator’s evaluations of their blasting methods indicate that in order to maintain a peak particle velocity below the approved standard of 0.5 inches per second for sensitive historic structures, the recommended scaled distance is 43.5 for the North Cresson Mine area, 34.2 for the Main Cresson Mine area, 34 for the East Cresson Mine area, and 47.7 for the South Cresson portion of the Main Cresson Mine area. These evaluations have confirmed that the monitoring plan is sufficient and ongoing monitoring has confirmed that no structural damage to surrounding structures should occur from blasting activities at the mine. Monitoring has verified blasting projections, and that operations under the Mine Life Extension 2 (Revision No. AM-10) will not negatively impact neighboring communities. As of AM-10, the operator had two existing blast monitors in the City of Victor and one in the unincorporated area of Goldfield. An additional permanent monitor will be installed near the City of Cripple Creek when mining activities commence in the North Cresson