SALT LAKE CITY (AP) -- A landslide expected to cut production by half inside a major U.S. copper mine this year will set back the Utah economy, an expert said Wednesday.
The effects already are being felt at one of Kennecott Utah Copper's outside contractors. Cementation USA Inc. said it laid off more than 40 workers who were tunneling into the pit to assess ore quality. Two tunnels were buried by the landslide.
"We've been left in the dark, so to speak, because we were working underground and don't know what comes next," Cementation human-resources chief Willie Finch said Wednesday.
Kennecott Utah Copper has asked 2,100 of its own employees to take vacation or unpaid leave, although few are doing so, company spokesman Kyle Bennett said Wednesday. Workers are being reassigned, and the company is working off a stockpile. A copper smelter is operating at reduced levels.
Kennecott has informed investors it will take 100,000 fewer tons of ore from the open pit in 2013.
Bennett said two crucial pieces of equipment — a rock crusher and conveyer belt — were left undamaged inside the pit, making a faster recovery possible. Kennecott planned to offer a timeline Thursday for ramping up operations.
"We would have been in serious trouble if it buried the crusher and conveyer system," said Wayne Holland of United Steel Workers, which represents Kennecott workers. "Nobody has been laid off yet."
The company faces "major challenges" getting back into full operation, Bennett said. "There's no question about that. One of the positive things is 90 percent of our equipment is operable."
The April 10 landslide was a major setback, said economists at the University of Utah. Kennecott adds $1.2 billion a year to the Utah economy, employs 2,810 workers on salaries and wages of $270 million and supports 14,971 other jobs, according to the school's Bureau of Economic and Business Research.
"These are good-paying jobs with a supply chain of contractors," said Pamela S. Perlich, a senior research economist at the University of Utah. "There will be ripple effects, but our economy is big and diversified enough to absorb the blow."
Mining experts are calling it one of the largest landslides in open mining pit, inside one of the world's biggest pits. Kennecott has said the slide unleashed 165 million tons of rock and dirt into the bottom of the pit.
That's enough material to pile rock and dirt 100 feet high across a square mile of land, and the landslide registered as a magnitude-2.4 seismic event, University of Utah mining engineering professor Kim McCarter said.
"This is a staggering amount," he said Thursday. "We'd have to find something pretty big to compare it with."
Nobody was hurt, and Kennecott said the company had instruments in place to anticipate the landslide. It buried or damaged three giant electric-powered shovels, 14 haul trucks and bulldozers, graders and drilling equipment, the company said.
Kennecott said federal regulators have been slow to allow limited access to the pit. Amy Louviere, a spokeswoman for the U.S. Mine Safety and Health Administration, said the agency has no information to release.
The landslide danger has passed, McCarter said.
"It's pretty much spent," he said. "It's not going to cause them any more grief — other than getting that loose material out of the pit." The debris is considered waste rock with no value as ore.