OSHA clears work to resume on Lake Mead tunnel

State safety regulators have cleared workers to start mining again at the scene of a deadly accident 600 feet below Lake Mead.

Construction activity was halted in the Southern Nevada Water Authority's new intake tunnel after 44-year-old Thomas Albert Turner was killed there on June 11.

The Nevada Occupational Safety and Health Administration gave the green light Tuesday afternoon for work to resume after reviewing engineering documents and revised procedures provided by the project's general contractor, Vegas Tunnel Constructors.

Water authority spokesman Scott Huntley said the contractor plans to begin prep work immediately and may start mining again "within the next few days."

"They are going to proceed very deliberately," he said.

The two-week shutdown at the site is not expected to delay completion of the $800 million project, which is slated to be finished in the summer of 2014.

In an email, Steve Coffield, chief administrative officer with Nevada OSHA, said the contractor was cleared to resume normal work activities after its "proposed corrective actions" were approved by safety regulators.

He did not specify what corrective actions would be taken.

Turner was part of a crew assembling rings of concrete pipe that line the water intake tunnel underneath the lake.

According to the authority, he was killed when a section of pipe ring shifted, creating a gap that allowed pressurized grout, mud and rocks to shoot through.

Authority spokesman J.C. Davis said the contractor's new procedures involve "more and stronger restraints" for the concrete rings to keep them from slipping during assembly.

OSHA is still investigating Turner's death. The results of the probe are confidential until the investigation is complete, Coffield said.

Vegas Tunnel Constructors has excavated roughly 1,000 feet of 23-foot-tall tunnel that will stretch for three miles beneath the bed of Lake Mead.

When finished, the so-called third intake is expected to keep water flowing to Las Vegas even if the lake shrinks enough to force one of the two existing straws to shut down.

The valley depends on the Colorado River's largest reservoir for about 90 percent of its drinking water.

In April, the water authority began charging customers a controversial new infrastructure surcharge to help cover the last $360 million of the intake project.

The job is running about 20 months behind schedule because of a series of floods in the work area in 2010 and 2011 that forced Vegas Tunnel Constructors to abandon its first tunnel and excavate a new one in a different direction.

That setback added $39.5 million to what already was the single largest construction contract the agency ever issued. The change order, approved by the board in February 2011, also extended the timeline for the project by 593 days.

Water authority board members received a short report on the June 11 accident at their monthly meeting Thursday.

North Las Vegas Mayor Shari Buck, who serves as chairwoman for the board, said, "Certainly our condolences and our sympathies go out to the family of that young man."

"It was very tragic," she said. "As we go forward, we hope to never have another accident like that."

Contact reporter Henry Brean at hbrean@reviewjournal.com or 702-383-0350.