State denies any cover-up over Kennecott tailings pond

A 1997 Kennecott Utah Copper document suggests that the state and Kennecott were part of a conspiracy to cover up evidence about potential seismic weakness in a now-retired tailings pond.

The document focuses on the potential problems that could be caused by a major earthquake, especially with the southeast corner that is known as the Magna Corner, as identified in a 1988 study. It also raises concerns about the apparent intentions to keep secret the risks for residents of nearby neighborhoods.

But David Marble, an assistant state engineer over dam safety in Utah, said Thursday before a meeting with residents in Magna that he isn't convinced there was a cover-up in the sense that officials with Kennecott and the state were actively trying to keep information about the tailings pond risk from others. Marble suggested that if anyone along the way had asked the right questions about the seismic instability, the state or Kennecott would have answered them.

"I really don't think there was any kind of cover-up at all," Marble said. "I believe people involved had the public interest at heart."

Marble has been state director over dam safety since 2004, but he was in the dam design, construction and safety business in the early 1990s when Kennecott's south impoundment was being upgraded, and he knew people working on the project. The state's job then, as it is now, is as a technical review and regulation agency.

"I don't set their public policy," he said about Kennecott and its relationship to state inspectors. "I don't accept their liability. I am the regulatory oversight ... we do safety inspections."

He said Kennecott identified the problem, came up with a solution and fixed the Magna Corner, a portion of which could still liquefy and send tailings flowing across the road. He said it isn't now — nor was it in the early '90s — his office's job to tell nearby residents what could happen to the Magna Corner in the event of a big earthquake.

There is an inherent risk with any dam, he said, a word he noted multiple times should no longer be applied to the Magna Corner and the embankment that comprises the south impoundment. But if a 7.0 magnitude earthquake did hit the Salt Lake area, the risk of failure would be significantly less today.

"I have absolutely nothing to hide," Marble said. "I think the public and state officials and everyone will be comfortable with where the dam safety program is and what's being done."

The south impoundment still contains mine tailings, and does get inspected, according to both state and Kennecott officials. But the state's focus is on the newer north impoundment, which holds mining waste and water.