Flaming Gorge Power Plant

Noise levels in many areas of the Flaming Gorge Hydroelectric Power Plant in Dutch John, UT were above the target noise levels of 85 dB(A) set by the Bureau of Reclamation. This high noise environment not only creates a potential noise induced hearing loss hazard but also creates a safety hazard, causing loss of concentration. A series of engineering controls was installed in the Flaming Gorge Power Plant in order to reduce noise levels below 85 dB(A). These controls included the following:

  • High transmission loss/absorption acoustical blankets on railing on top of generator housing
  • Acoustic absorption material on plant walls
  • Acoustic absorption material in turbine pits and turbine pit galleries
  • High transmission loss acoustic strip curtains in draft tube opening in penstock gallery
  • Absorption in the Unit 2 draft tube corridor
  • Acoustic blankets around bearing cooling water supply valves in unwatering and pipe gallery
  • High transmission loss acoustic strips in scroll case opening in unwatering and pipe gallery

The installed controls were successful in reducing noise levels on the main and turbine pit floor to below 85 dB(A). On the turbine pit floor, noise levels inside the pits were significantly reduced (14-15 dB) after the installation of absorption panels. The levels just outside the turbine pit accesses, in the electrical gallery, were reduced by 5-6 dB. In the unwatering gallery, noise levels at all locations were reduced by 3 dB and are now just under the 85 dB(A) targets. Noise levels in the draft tube corridor that was treated with absorption was lowered by more than 15 dB as compared to the draft tube corridors that were not treated. In addition, the acoustic strip curtains at the entrance to the draft tube corridors provided 7-9 dB of attenuation.