Identify Primary Noise Sources in the Powerplant and Implement Noise Engineering Controls to Reduce Exposures to Employees

Project ID: 6433
Principal Investigator: Theresa Gallagher
Research Topic: Public and Employee Safety
Priority Area Assignments: 2014 (Renewable Energy and Energy Conservation)
Funded Fiscal Years: 2012, 2013 and 2014
Keywords: None

Research Question

Where do we focus our engineering efforts and resources to gain the greatest improvement on employee safety and health in the powerplants with regard to preventing hearing loss?

What are the most cost effective engineering solutions that can be implemented to eliminate or reduce the noise levels below the industrial standard for hazardous noise of 85 decibels A weighted?

Need and Benefit

Hearing loss is the number one workers compensation issue in Reclamation. Over the last 10 years, Reclamation has paid approximately 5.24 million dollars in hearing loss claims. Reclamation and its partners in this proposal encounter this issue on a daily basis. Reducing continuous noise in the powerplants will hopefully eliminate these claims in the future.

Noise is often overlooked as a hazard because there are no obvious indicators of acute or chronic exposure. However, noise induced hearing loss (NIHL) is one of the highest workers compensation expenses agencies have for non-traumatic injuries. NIHL is preventable by reducing the noise at the source, providing effective hearing protectors, and/or by limiting frequency and duration of exposure. Most of the existing powerplants are over 40 years old and were constructed before many modern noise control technologies were developed. It is paramount to determine the source and type (frequency and level) of noise in the powerplants prior to evaluating potential mitigation measures. The Occupational Safety and Health Administration requires elimination/reduction of a hazard through engineering controls prior to implementing administrative and personal protective equipment strategies.

Contributing Partners


Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Engineering Controls for Hydroelectric Powerplant Noise Reduction (final, PDF, 671KB)
By Theresa Gallagher and Mr. Jeffrey Komrower
Report completed on March 30, 2015

This project significantly reduced overall noise levels in all three powerplants (Green Springs, Roza, and Chandler). Noise reductions ranged from 3 to 16 dBA except for directly inside the turbine pits. The project successfully decreased noise levels below 85dBA where controls were installed and thus deleted the requirement to wear hearing protection. Single protection hearing protection resulted for the turbine pits instead of the required double hearing protection.
Keywords: noise engineering controls

Last Updated: June 29, 2015