Mitigation measures to avoid or reduce acoustical impacts (noise) from an energy transmission project.
The following are examples of mitigation measures that could be applied to reduce noise impacts of a project depending on site- and project-specific conditions. Noise impacts are related to the source of the noise (e.g., vehicles, construction equipment, workers, explosives, and project facility components) and the proximity to the noise receptor (e.g., humans and wildlife). Many impacts can be reduced or avoided when considered during the siting and design of a project during the site evaluation phase.
Develop a final set of mitigation measures for any project in consultation with the appropriate federal resource management agencies and stakeholders. Conduct these consultations in the project development process and preferably prior to final project siting and design.
Siting and Design Mitigation Measures
Siting and design considerations that mitigate impacts include:
To the extent practicable, site the right-of-way (ROW) to avoid residential areas and important wildlife habitat areas (e.g., rookeries, raptor nesting areas, calving areas).
Consider noise impact early in the design process for compressor or pump house facilities.
Locate all stationary equipment (i.e., compressors and generators) as far as practicable from nearby residences.
General Mitigation Measures
General mitigation practices and principles that could apply to any or all phases of an energy transmission project include:
All equipment should have sound-control devices no less effective than those provided on the original equipment. Motorized equipment used should be adequately muffled and maintained.
Project Phase-Specific Mitigation Measures
Mitigation measures specific to a particular phase of an energy transmission project include:
Site Evaluation
Proponents of an energy transmission project should take measurements to assess the existing background noise levels at a given site and compare them with the anticipated noise levels associated with the proposed project.
Construction
Limit noisy construction activities (including blasting) to the least noise-sensitive times of day (weekdays only between 7 a.m. and 10 p.m.).
Whenever feasible, schedule different noisy activities (e.g., blasting and earthmoving) to occur at the same time, since additional sources of noise generally do not add a significant amount of noise. That is, less-frequent noisy activities would be less annoying than frequent less-noisy activities..
Notify nearby residents in advance if blasting or other noisy activities are required during the construction period.
Operation and Maintenance
Use exhaust silencers, quieter cooling fans, and optimized acoustical pipe lagging (acoustical wrapping) to minimize compressor noise.
Decommissioning/Site Reclamation
Repeat mitigation measures used to minimize noise impacts during construction during the decommissioning/site reclamation phase.
