BINGHAM CANYON — Federal regulators were not granting Kennecott Utah Copper access Friday into its Bingham Canyon Mine to assess the impact of a massive landslide and figure out how to resume work.
The Mine Safety and Health Administration has issued an order suspending operations at the open-pit copper mine and dispatched personnel to the site, according to MSHA spokeswoman Amy Louviere.
Kennecott is waiting for clearance from MSHA to send its experts into the pit to assess the damage, said Kyle Bennett, spokesman for Rio Tinto's Utah Kennecott Copper.
"The size of the slide was significant," Bennett said. "We don't have information yet regarding the magnitude or impact. We do know that the flow into the pit extended beyond the scenarios we forecasted, having a greater impact on equipment."
Bennett said the company is no longer in emergency response mode, but a time frame for resuming work in the mine hasn't been determined. The closure of the mine means about 900 people won't have work until access is granted and cleanup begins.
The slide occurred about 9:30 p.m. Wednesday in the northeast section of the southwestern Salt Lake County mine. No employees were injured, but roads, buildings and vehicles inside the pit were damaged.
Kennecott was aware of the impending slide and warned residents near the mine that a slide was possible any day. Kennecott engineers detected ground movement as far back as February.
Ted Himebaugh, Kennecott's general manager of operation readiness, estimated about two-thirds of the bottom of the pit was buried.
"They figured it was going to be 250 million tons. They think it's probably double that," said Dell Garner, heavy haul truck driver at the mine.
Garner called the volume of the slide shocking.
"We expected it to come down to the bottom and stop there, and not come clear through the entire bottom," he said.
Kennecott officials think it might take as long a two years to dig out, Garner said.
"All of that is waste materials," he said. "It's not ore."
Bennett said any estimates about the size of the slide or a timelines for cleanup are speculation and unconfirmed.
There's constantly little slips falling. It's just a common thing that happens. But this is a huge, probably the largest of anything that's happened in the mine.
–Dell Garner, haul trucker driver
Slides are just a condition of the mine, Garner said.
"We're always looking for trickling of rocks. There's constantly little slips falling. It's just a common thing that happens. But this is a huge, probably the largest of anything that's happened in the mine," he said.
The Utah Division of Oil, Gas and Mining issues a permit to Kennecott for it operations. Division spokesman Jim Springer said the slide occurred in the permitted area.
"They do a good job of watching for that sort of thing," he said.
Springer said the division won't be doing anything special as a result of the slide, such as sending inspectors in to assess the situation.
Kennecott is the second largest copper producer in the United States, supplying about a quarter of the country's copper, according to the company's website. Bingham Canyon Mine is the largest man-made excavation on Earth.
Contributing: Geoff Liesik