Intake structure and dam are stable; no structural problems detected
Safety and operations at PPL Montana’s Hebgen Dam and the Madison River downstream of the dam are not affected by work delays at the intake structure at the dam.
“Work at Hebgen Dam has been on hold since early August, when instrumentation installed in the temporary cofferdam detected higher than anticipated stresses, but a thorough engineering inspection found that no part of the structure had failed,” said David Hoffman, director of external affairs for PPL Montana.
Work resumed on the intake structure with the completion of dewatering wells that reduced the stresses on the cofferdam.
“PPL Montana is working on plans for additional stabilization and reinforcement of the cofferdam and, as always, safety of the public is our number one priority,” Hoffman said.
Completed in 2010, the cofferdam retains the water in the lake and gives workers access to normally submerged portions of the intake structure, allowing work on the permanent repairs. The goal of the project is to anchor and reinforce the intake structure and gates to meet seismic structural design requirements.
“PPL Montana operates the dam safely to balance the interests of all those who care about and depend on Hebgen Lake and the Madison River,” Hoffman said.
PPL has 500 employees in Montana who generate and sell electricity. PPL Montana operates coal-fired power plants at Colstrip and Billings, as well as 11 hydroelectric power plants along Rosebud Creek and the Missouri, Madison, Clark Fork and Flathead rivers. It has a combined generating capacity of about 1,200 megawatts and has offices in Billings, Butte and Helena. PPL EnergyPlus operates a trading floor in Butte that markets and sells power in the wholesale and retail energy market. PPL Montana and PPL EnergyPlus are subsidiaries of PPL Corporation (NYSE: PPL). More information about PPL Montana is available at www.pplmontana.com.