Tunnel company ready to go at Lake Mead, waiting on OSHA
Eight days after an accident that killed a worker at the third intake construction site, the project's general contractor is ready to resume work on the tunnel under Lake Mead.
A spokesman for the Southern Nevada Water Authority, which is paying for the $800 million water intake, said Vegas Tunnel Constructors is awaiting clearance from the Nevada Occupational Safety and Health Administration.
"As far as VTC is concerned, they are ready to go again. They have not gotten the green light, and they will not go until they get it," water authority spokesman Scott Huntley said.
A message left for Steve Coffield, chief administrative officer with Nevada OSHA, was not returned.
In a statement released the day after the accident, Coffield said construction activities would not be allowed to resume until the cause was identified and corrected and the safety of the tunnel was verified.
He also said the circumstances of the accident would not be released by Nevada OSHA until the investigation is complete.
Inquiries made to the state OSHA office in the days since have been met with the same written response from Coffield: "We do not have any additional information to provide at this time."
Work has been shut down at the tunnel 600 feet underground since 44-year-old Thomas Albert Turner was killed there on June 11. The accident occurred as a crew was assembling one of 2,500 rings of concrete pipe that will line the finished three-mile tunnel.
Huntley said the preliminary investigation indicates a section of pipe ring "slipped," creating a 2-foot-by-4-inch gap that allowed a pressurized grout mixture to shoot through. Turner was struck by the mixture and killed.
A funeral for the married father of two was held Friday.
There were initial reports that another man was injured in the accident, but the water authority reports that other workers at the site were checked out and that no one needed medical attention.
The grout being used in the tunnel is made from a combination of cement, sand, water and ash, but Huntley said the stream of material that hit Turner also contained mud and rocks as big as a fist.
The mixture is used to fill the space between the rock walls of the 23-foot-tall tunnel and the 20-foot-diameter pipe that will line it.
For the grout to work, it has to be pressurized to about 200 pounds per square inch, roughly five times the force produced by a garden hose running full blast, Huntley said.
The accident is the the latest setback for a project considered the most complicated and expensive job ever undertaken by the water authority.
When finished, the 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.
The water authority board approved a rate increase this year to help cover the last $360 million of the intake project, which was running about 20 months behind schedule before the June 11 accident.
The delay was caused by a series of floods in the work area in 2010 and 2011 that forced Vegas Tunnel Constructors, which also designed the intake, to abandon its first tunnel and excavate a new one in a different direction.
Contact reporter Henry Brean at hbrean@review
journal.com or 702-383-0350.
