Source: http://www.rockproducts.com/key-issues/safety/13654-300-ft-highwall-not-controlled-miners-risked-injury-from-rock-falls.html
Timestamp: 2019-04-22 02:03:59+00:00

Document:
A company was found to have used unsafe mining methods where miners worked around a 230-to-300-ft. highwall, despite the use of spotters and frequent inspections to look for potentially dangerous conditions, according to a recent Commission decision.
The decision upholds ALJ Margaret Miller’s September 2011 findings that Connolly-Pacific Co., located on Catalina Island, Calif., violated §56.3130, §56.3131 and §56.3200 (33 FMSHRC 2270). In addition, the Commission agreed that the conditions cited by MSHA constituted an imminent danger.
Since the 1950s, Connolly-Pacific Co. has owned and operated the Pebbly Beach quarry. The company would blast the highwall, which measured as high as 300 ft., and gather rock along the talus pile created below. “Rainfall and gravity” would also bring down the rock.
The company maintained that the 300-ft. quarry walls could not be scaled and it was undisputed that the company has never used benches. For safety, it used a system of spotters, photographs and management inspections to observe any changes and predict the fall of material. No worker had ever been injured by a rock fall. Although inspected by MSHA since at least 1992, the quarry had never been cited for using this type of mining technique, until a May 2011 inspection.
The first citation issued by MSHA inspector Chad Hilde alleged a violation of §56.3130 where a loader operator was working under the highwall. The inspector said the highwall had loose and unconsolidated materials, and a 70-ft. tall pile of rock at the base of the highwall. MSHA said that Connolly Pacific had not taken any action to determine or maintain the stability of the highwall. ALJ Margaret Miller upheld the violation and increased MSHA’s proposed penalty of $555 to $1,000.
The second violation of §56.3131 involved an area 230 ft. in height above the talus pile, with loose and unconsolidated material that had not been sloped to the angle of repose. The operator was also cited for failing to correct fall-of-materials hazards. In this instance, the judge upheld MSHA’s penalty of $555.
In the third violation, the company was cited for failing to post warning signs or barricading an unsafe area to restrict access – a violation of §56.3200. The company said at the time of the citation that it had intended to barricade the area. Judge Miller increased MSHA’s proposed penalty of $555 to $1,000 for this violation.
After finding the conditions, MSHA issued an imminent danger order directing the company to cease all mining operations in two areas of the quarry. The company maintained before the Commission that the highwall was stable. They noted that bench construction or scaling was impossible, but they could safely mine. Because it had been using these unconventional mining methods for years, and took precautions, it claimed in it argument before the Commission that Judge Miller erred in how she applied the standards. The company also argued it was deprived of fair notice and due process.
In agreeing with Judge Miller’s findings and MSHA’s citations, the Commission said that Connolly’s mining methods do not comply with the plain language of the three regulations.
Allowing rock to slide down a highwall does not maintain wall stability where miners work and travel; creates a fall-of-material hazard at or near the quarry perimeter; and, does not comply with the language that requires hazardous ground conditions to be taken down or supported before miners work or travel in the area, the commissioners said.
The company’s reliance on a spotter does not prevent a fall of materials, and the Commission questioned whether a spotter could even warn an equipment operator in time to move away from a rock fall.
On the day of the citations and imminent danger order, photographs showed the highwall was hazardous with a potential of sliding or toppling rocks, and it was reasonable for the inspector to issue the imminent danger order. Witnesses agreed about the conditions, but had differing opinions as to the danger that existed. The Commission found no reasons to overturn Judge Miller’s credibility determinations or evident that the inspector did not abuse his discretion – especially given the extraordinary height of the highwall.
The company also questioned Judge Miller’s reliance on an MSHA/NIOSH publication on highwall stability, which noted that 100 ft. was the outer limit of an acceptable highwall height. However, Connolly did not question the ALJ’s reliance on the document during the hearing, and the company had an opportunity to respond to the document during the hearing before Judge Miller, but failed to do so.
All five commissioners agreed that Connolly did not comply with the three standards in question; did not correct the hazardous conditions before permitting miners to work under the highwall; and, that the conditions photographed and described by MSHA presented an imminent danger.
Wall, bank, and slope stability.
Mining methods shall be used that will maintain wall, bank and slope stability in places where persons work or travel in performing their assigned tasks. When benching is necessary, the width and height shall be based on the type of equipment used for cleaning of benches or for scaling of walls, banks, and slopes.
Pit or quarry wall perimeter.
In places where persons work or travel in performing their assigned tasks, loose or unconsolidated material shall be sloped to the angle of repose or stripped back for at least 10 ft. from the top of the pit or quarry wall. Other conditions at or near the perimeter of the pit or quarry wall which create a fall-of-material hazard to persons shall be corrected.
Ground conditions that create a hazard to persons shall be taken down or supported before other work or travel is permitted in the affected area. Until corrective work is completed, the area shall be posted with a warning against entry and, when left unattended, a barrier shall be installed to impede unauthorized entry.

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